Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 9816 insertions, 0 deletions

diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
new file mode 100644
index 0000000000..149e3716e1
--- /dev/null
+++ b/widget/gtk/nsWindow.cpp
@@ -0,0 +1,9816 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:expandtab:shiftwidth=2:tabstop=2:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsWindow.h"
+
+#include <algorithm>
+#include <cstdint>
+#include <dlfcn.h>
+#include <gdk/gdkkeysyms.h>
+#include <wchar.h>
+
+#include "VsyncSource.h"
+#include "gfx2DGlue.h"
+#include "gfxContext.h"
+#include "gfxImageSurface.h"
+#include "gfxPlatformGtk.h"
+#include "gfxUtils.h"
+#include "GLContextProvider.h"
+#include "GLContext.h"
+#include "GtkCompositorWidget.h"
+#include "gtkdrawing.h"
+#include "imgIContainer.h"
+#include "InputData.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/Components.h"
+#include "mozilla/GRefPtr.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/WheelEventBinding.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/gfxVars.h"
+#include "mozilla/gfx/GPUProcessManager.h"
+#include "mozilla/gfx/HelpersCairo.h"
+#include "mozilla/layers/APZThreadUtils.h"
+#include "mozilla/layers/LayersTypes.h"
+#include "mozilla/layers/CompositorBridgeChild.h"
+#include "mozilla/layers/CompositorBridgeParent.h"
+#include "mozilla/layers/CompositorThread.h"
+#include "mozilla/layers/KnowsCompositor.h"
+#include "mozilla/layers/WebRenderBridgeChild.h"
+#include "mozilla/layers/WebRenderLayerManager.h"
+#include "mozilla/layers/APZInputBridge.h"
+#include "mozilla/layers/IAPZCTreeManager.h"
+#include "mozilla/Likely.h"
+#include "mozilla/MiscEvents.h"
+#include "mozilla/MouseEvents.h"
+#include "mozilla/NativeKeyBindingsType.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_apz.h"
+#include "mozilla/StaticPrefs_layout.h"
+#include "mozilla/StaticPrefs_mozilla.h"
+#include "mozilla/StaticPrefs_ui.h"
+#include "mozilla/StaticPrefs_widget.h"
+#include "mozilla/SwipeTracker.h"
+#include "mozilla/TextEventDispatcher.h"
+#include "mozilla/TextEvents.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/WidgetUtils.h"
+#include "mozilla/WritingModes.h"
+#ifdef MOZ_X11
+#  include "mozilla/X11Util.h"
+#endif
+#include "mozilla/XREAppData.h"
+#include "NativeKeyBindings.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsAppRunner.h"
+#include "nsDragService.h"
+#include "nsGTKToolkit.h"
+#include "nsGtkKeyUtils.h"
+#include "nsGtkCursors.h"
+#include "nsGfxCIID.h"
+#include "nsGtkUtils.h"
+#include "nsIFile.h"
+#include "nsIGSettingsService.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsImageToPixbuf.h"
+#include "nsINode.h"
+#include "nsIRollupListener.h"
+#include "nsIScreenManager.h"
+#include "nsIUserIdleServiceInternal.h"
+#include "nsIWidgetListener.h"
+#include "nsLayoutUtils.h"
+#include "nsMenuPopupFrame.h"
+#include "nsPresContext.h"
+#include "nsShmImage.h"
+#include "nsString.h"
+#include "nsWidgetsCID.h"
+#include "nsViewManager.h"
+#include "nsXPLookAndFeel.h"
+#include "prlink.h"
+#include "Screen.h"
+#include "ScreenHelperGTK.h"
+#include "SystemTimeConverter.h"
+#include "WidgetUtilsGtk.h"
+
+#ifdef ACCESSIBILITY
+#  include "mozilla/a11y/LocalAccessible.h"
+#  include "mozilla/a11y/Platform.h"
+#  include "nsAccessibilityService.h"
+#endif
+
+#ifdef MOZ_X11
+#  include <gdk/gdkkeysyms-compat.h>
+#  include <X11/Xatom.h>
+#  include <X11/extensions/XShm.h>
+#  include <X11/extensions/shape.h>
+#  include "gfxXlibSurface.h"
+#  include "GLContextGLX.h"  // for GLContextGLX::FindVisual()
+#  include "GLContextEGL.h"  // for GLContextEGL::FindVisual()
+#  include "WindowSurfaceX11Image.h"
+#  include "WindowSurfaceX11SHM.h"
+#endif
+#ifdef MOZ_WAYLAND
+#  include <gdk/gdkkeysyms-compat.h>
+#  include "nsIClipboard.h"
+#  include "nsView.h"
+#endif
+
+using namespace mozilla;
+using namespace mozilla::gfx;
+using namespace mozilla::layers;
+using namespace mozilla::widget;
+#ifdef MOZ_X11
+using mozilla::gl::GLContextEGL;
+using mozilla::gl::GLContextGLX;
+#endif
+
+// Don't put more than this many rects in the dirty region, just fluff
+// out to the bounding-box if there are more
+#define MAX_RECTS_IN_REGION 100
+
+#if !GTK_CHECK_VERSION(3, 18, 0)
+
+struct _GdkEventTouchpadPinch {
+  GdkEventType type;
+  GdkWindow* window;
+  gint8 send_event;
+  gint8 phase;
+  gint8 n_fingers;
+  guint32 time;
+  gdouble x;
+  gdouble y;
+  gdouble dx;
+  gdouble dy;
+  gdouble angle_delta;
+  gdouble scale;
+  gdouble x_root, y_root;
+  guint state;
+};
+
+typedef enum {
+  GDK_TOUCHPAD_GESTURE_PHASE_BEGIN,
+  GDK_TOUCHPAD_GESTURE_PHASE_UPDATE,
+  GDK_TOUCHPAD_GESTURE_PHASE_END,
+  GDK_TOUCHPAD_GESTURE_PHASE_CANCEL
+} GdkTouchpadGesturePhase;
+
+gint GDK_TOUCHPAD_GESTURE_MASK = 1 << 24;
+GdkEventType GDK_TOUCHPAD_PINCH = static_cast<GdkEventType>(42);
+
+#endif
+
+const gint kEvents = GDK_TOUCHPAD_GESTURE_MASK | GDK_EXPOSURE_MASK |
+                     GDK_STRUCTURE_MASK | GDK_VISIBILITY_NOTIFY_MASK |
+                     GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK |
+                     GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
+                     GDK_SMOOTH_SCROLL_MASK | GDK_TOUCH_MASK | GDK_SCROLL_MASK |
+                     GDK_POINTER_MOTION_MASK | GDK_PROPERTY_CHANGE_MASK;
+
+/* utility functions */
+static bool is_mouse_in_window(GdkWindow* aWindow, gdouble aMouseX,
+                               gdouble aMouseY);
+static nsWindow* get_window_for_gtk_widget(GtkWidget* widget);
+static nsWindow* get_window_for_gdk_window(GdkWindow* window);
+static GtkWidget* get_gtk_widget_for_gdk_window(GdkWindow* window);
+static GdkCursor* get_gtk_cursor(nsCursor aCursor);
+static GdkWindow* get_inner_gdk_window(GdkWindow* aWindow, gint x, gint y,
+                                       gint* retx, gint* rety);
+
+/* callbacks from widgets */
+static gboolean expose_event_cb(GtkWidget* widget, cairo_t* cr);
+static gboolean configure_event_cb(GtkWidget* widget, GdkEventConfigure* event);
+static void widget_map_cb(GtkWidget* widget);
+static void widget_unmap_cb(GtkWidget* widget);
+static void widget_unrealize_cb(GtkWidget* widget);
+static void size_allocate_cb(GtkWidget* widget, GtkAllocation* allocation);
+static void toplevel_window_size_allocate_cb(GtkWidget* widget,
+                                             GtkAllocation* allocation);
+static gboolean delete_event_cb(GtkWidget* widget, GdkEventAny* event);
+static gboolean enter_notify_event_cb(GtkWidget* widget,
+                                      GdkEventCrossing* event);
+static gboolean leave_notify_event_cb(GtkWidget* widget,
+                                      GdkEventCrossing* event);
+static gboolean motion_notify_event_cb(GtkWidget* widget,
+                                       GdkEventMotion* event);
+MOZ_CAN_RUN_SCRIPT static gboolean button_press_event_cb(GtkWidget* widget,
+                                                         GdkEventButton* event);
+static gboolean button_release_event_cb(GtkWidget* widget,
+                                        GdkEventButton* event);
+static gboolean focus_in_event_cb(GtkWidget* widget, GdkEventFocus* event);
+static gboolean focus_out_event_cb(GtkWidget* widget, GdkEventFocus* event);
+static gboolean key_press_event_cb(GtkWidget* widget, GdkEventKey* event);
+static gboolean key_release_event_cb(GtkWidget* widget, GdkEventKey* event);
+static gboolean property_notify_event_cb(GtkWidget* widget,
+                                         GdkEventProperty* event);
+static gboolean scroll_event_cb(GtkWidget* widget, GdkEventScroll* event);
+
+static void hierarchy_changed_cb(GtkWidget* widget,
+                                 GtkWidget* previous_toplevel);
+static gboolean window_state_event_cb(GtkWidget* widget,
+                                      GdkEventWindowState* event);
+static void settings_xft_dpi_changed_cb(GtkSettings* settings,
+                                        GParamSpec* pspec, nsWindow* data);
+static void check_resize_cb(GtkContainer* container, gpointer user_data);
+static void screen_composited_changed_cb(GdkScreen* screen, gpointer user_data);
+static void widget_composited_changed_cb(GtkWidget* widget, gpointer user_data);
+
+static void scale_changed_cb(GtkWidget* widget, GParamSpec* aPSpec,
+                             gpointer aPointer);
+static gboolean touch_event_cb(GtkWidget* aWidget, GdkEventTouch* aEvent);
+static gboolean generic_event_cb(GtkWidget* widget, GdkEvent* aEvent);
+
+static nsWindow* GetFirstNSWindowForGDKWindow(GdkWindow* aGdkWindow);
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+#ifdef MOZ_X11
+static GdkFilterReturn popup_take_focus_filter(GdkXEvent* gdk_xevent,
+                                               GdkEvent* event, gpointer data);
+#endif /* MOZ_X11 */
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+static gboolean drag_motion_event_cb(GtkWidget* aWidget,
+                                     GdkDragContext* aDragContext, gint aX,
+                                     gint aY, guint aTime, gpointer aData);
+static void drag_leave_event_cb(GtkWidget* aWidget,
+                                GdkDragContext* aDragContext, guint aTime,
+                                gpointer aData);
+static gboolean drag_drop_event_cb(GtkWidget* aWidget,
+                                   GdkDragContext* aDragContext, gint aX,
+                                   gint aY, guint aTime, gpointer aData);
+static void drag_data_received_event_cb(GtkWidget* aWidget,
+                                        GdkDragContext* aDragContext, gint aX,
+                                        gint aY,
+                                        GtkSelectionData* aSelectionData,
+                                        guint aInfo, guint32 aTime,
+                                        gpointer aData);
+
+/* initialization static functions */
+static nsresult initialize_prefs(void);
+
+static guint32 sLastUserInputTime = GDK_CURRENT_TIME;
+
+static SystemTimeConverter<guint32>& TimeConverter() {
+  static SystemTimeConverter<guint32> sTimeConverterSingleton;
+  return sTimeConverterSingleton;
+}
+
+bool nsWindow::sTransparentMainWindow = false;
+
+// forward declare from mozgtk
+extern "C" MOZ_EXPORT void mozgtk_linker_holder();
+
+namespace mozilla {
+
+#ifdef MOZ_X11
+class CurrentX11TimeGetter {
+ public:
+  explicit CurrentX11TimeGetter(GdkWindow* aWindow)
+      : mWindow(aWindow), mAsyncUpdateStart() {}
+
+  guint32 GetCurrentTime() const { return gdk_x11_get_server_time(mWindow); }
+
+  void GetTimeAsyncForPossibleBackwardsSkew(const TimeStamp& aNow) {
+    // Check for in-flight request
+    if (!mAsyncUpdateStart.IsNull()) {
+      return;
+    }
+    mAsyncUpdateStart = aNow;
+
+    Display* xDisplay = GDK_WINDOW_XDISPLAY(mWindow);
+    Window xWindow = GDK_WINDOW_XID(mWindow);
+    unsigned char c = 'a';
+    Atom timeStampPropAtom = TimeStampPropAtom();
+    XChangeProperty(xDisplay, xWindow, timeStampPropAtom, timeStampPropAtom, 8,
+                    PropModeReplace, &c, 1);
+    XFlush(xDisplay);
+  }
+
+  gboolean PropertyNotifyHandler(GtkWidget* aWidget, GdkEventProperty* aEvent) {
+    if (aEvent->atom != gdk_x11_xatom_to_atom(TimeStampPropAtom())) {
+      return FALSE;
+    }
+
+    guint32 eventTime = aEvent->time;
+    TimeStamp lowerBound = mAsyncUpdateStart;
+
+    TimeConverter().CompensateForBackwardsSkew(eventTime, lowerBound);
+    mAsyncUpdateStart = TimeStamp();
+    return TRUE;
+  }
+
+ private:
+  static Atom TimeStampPropAtom() {
+    return gdk_x11_get_xatom_by_name_for_display(gdk_display_get_default(),
+                                                 "GDK_TIMESTAMP_PROP");
+  }
+
+  // This is safe because this class is stored as a member of mWindow and
+  // won't outlive it.
+  GdkWindow* mWindow;
+  TimeStamp mAsyncUpdateStart;
+};
+#endif
+
+}  // namespace mozilla
+
+// The window from which the focus manager asks us to dispatch key events.
+static nsWindow* gFocusWindow = nullptr;
+static bool gBlockActivateEvent = false;
+static bool gGlobalsInitialized = false;
+static bool gUseAspectRatio = true;
+static uint32_t gLastTouchID = 0;
+// See Bug 1777269 for details. We don't know if the suspected leave notify
+// event is a correct one when we get it.
+// Store it and issue it later from enter notify event if it's correct,
+// throw it away otherwise.
+static GUniquePtr<GdkEventCrossing> sStoredLeaveNotifyEvent;
+
+#define NS_WINDOW_TITLE_MAX_LENGTH 4095
+
+// cursor cache
+static GdkCursor* gCursorCache[eCursorCount];
+
+// Sometimes this actually also includes the state of the modifier keys, but
+// only the button state bits are used.
+static guint gButtonState;
+
+static inline int32_t GetBitmapStride(int32_t width) {
+#if defined(MOZ_X11)
+  return (width + 7) / 8;
+#else
+  return cairo_format_stride_for_width(CAIRO_FORMAT_A1, width);
+#endif
+}
+
+static inline bool TimestampIsNewerThan(guint32 a, guint32 b) {
+  // Timestamps are just the least significant bits of a monotonically
+  // increasing function, and so the use of unsigned overflow arithmetic.
+  return a - b <= G_MAXUINT32 / 2;
+}
+
+static void UpdateLastInputEventTime(void* aGdkEvent) {
+  nsCOMPtr<nsIUserIdleServiceInternal> idleService =
+      do_GetService("@mozilla.org/widget/useridleservice;1");
+  if (idleService) {
+    idleService->ResetIdleTimeOut(0);
+  }
+
+  guint timestamp = gdk_event_get_time(static_cast<GdkEvent*>(aGdkEvent));
+  if (timestamp == GDK_CURRENT_TIME) return;
+
+  sLastUserInputTime = timestamp;
+}
+
+// Don't set parent (transient for) if nothing changes.
+// gtk_window_set_transient_for() blows up wl_subsurfaces used by aWindow
+// even if aParent is the same.
+static void GtkWindowSetTransientFor(GtkWindow* aWindow, GtkWindow* aParent) {
+  GtkWindow* parent = gtk_window_get_transient_for(aWindow);
+  if (parent != aParent) {
+    gtk_window_set_transient_for(aWindow, aParent);
+  }
+}
+
+#define gtk_window_set_transient_for(a, b)                         \
+  {                                                                \
+    MOZ_ASSERT_UNREACHABLE(                                        \
+        "gtk_window_set_transient_for() can't be used directly."); \
+  }
+
+nsWindow::nsWindow()
+    : mIsDestroyed(false),
+      mIsShown(false),
+      mNeedsShow(false),
+      mIsMapped(false),
+      mEnabled(true),
+      mCreated(false),
+      mHandleTouchEvent(false),
+      mIsDragPopup(false),
+      mWindowScaleFactorChanged(true),
+      mCompositedScreen(gdk_screen_is_composited(gdk_screen_get_default())),
+      mIsAccelerated(false),
+      mWindowShouldStartDragging(false),
+      mHasMappedToplevel(false),
+      mRetryPointerGrab(false),
+      mPanInProgress(false),
+      mDrawToContainer(false),
+      mTitlebarBackdropState(false),
+      mIsPIPWindow(false),
+      mIsWaylandPanelWindow(false),
+      mIsChildWindow(false),
+      mAlwaysOnTop(false),
+      mNoAutoHide(false),
+      mIsTransparent(false),
+      mHasReceivedSizeAllocate(false),
+      mWidgetCursorLocked(false),
+      mPopupTrackInHierarchy(false),
+      mPopupTrackInHierarchyConfigured(false),
+      mHiddenPopupPositioned(false),
+      mTransparencyBitmapForTitlebar(false),
+      mHasAlphaVisual(false),
+      mPopupAnchored(false),
+      mPopupContextMenu(false),
+      mPopupMatchesLayout(false),
+      mPopupChanged(false),
+      mPopupTemporaryHidden(false),
+      mPopupClosed(false),
+      mPopupUseMoveToRect(false),
+      mWaitingForMoveToRectCallback(false),
+      mMovedAfterMoveToRect(false),
+      mResizedAfterMoveToRect(false),
+      mConfiguredClearColor(false),
+      mGotNonBlankPaint(false),
+      mNeedsToRetryCapturingMouse(false) {
+  mWindowType = WindowType::Child;
+  mSizeConstraints.mMaxSize = GetSafeWindowSize(mSizeConstraints.mMaxSize);
+
+  if (!gGlobalsInitialized) {
+    gGlobalsInitialized = true;
+
+    // It's OK if either of these fail, but it may not be one day.
+    initialize_prefs();
+
+#ifdef MOZ_WAYLAND
+    // Wayland provides clipboard data to application on focus-in event
+    // so we need to init our clipboard hooks before we create window
+    // and get focus.
+    if (GdkIsWaylandDisplay()) {
+      nsCOMPtr<nsIClipboard> clipboard =
+          do_GetService("@mozilla.org/widget/clipboard;1");
+      NS_ASSERTION(clipboard, "Failed to init clipboard!");
+    }
+#endif
+  }
+  // Dummy call to mozgtk to prevent the linker from removing
+  // the dependency with --as-needed.
+  // see toolkit/library/moz.build for details.
+  mozgtk_linker_holder();
+}
+
+nsWindow::~nsWindow() {
+  LOG("nsWindow::~nsWindow()");
+  Destroy();
+}
+
+/* static */
+void nsWindow::ReleaseGlobals() {
+  for (auto& cursor : gCursorCache) {
+    if (cursor) {
+      g_object_unref(cursor);
+      cursor = nullptr;
+    }
+  }
+}
+
+void nsWindow::DispatchActivateEvent(void) {
+  NS_ASSERTION(mContainer || mIsDestroyed,
+               "DispatchActivateEvent only intended for container windows");
+
+#ifdef ACCESSIBILITY
+  DispatchActivateEventAccessible();
+#endif  // ACCESSIBILITY
+
+  if (mWidgetListener) mWidgetListener->WindowActivated();
+}
+
+void nsWindow::DispatchDeactivateEvent() {
+  if (mWidgetListener) {
+    mWidgetListener->WindowDeactivated();
+  }
+
+#ifdef ACCESSIBILITY
+  DispatchDeactivateEventAccessible();
+#endif  // ACCESSIBILITY
+}
+
+void nsWindow::DispatchResized() {
+  LOG("nsWindow::DispatchResized() size [%d, %d]", (int)(mBounds.width),
+      (int)(mBounds.height));
+
+  mNeedsDispatchSize = LayoutDeviceIntSize(-1, -1);
+  if (mWidgetListener) {
+    mWidgetListener->WindowResized(this, mBounds.width, mBounds.height);
+  }
+  if (mAttachedWidgetListener) {
+    mAttachedWidgetListener->WindowResized(this, mBounds.width, mBounds.height);
+  }
+}
+
+void nsWindow::MaybeDispatchResized() {
+  if (mNeedsDispatchSize != LayoutDeviceIntSize(-1, -1) && !mIsDestroyed) {
+    mBounds.SizeTo(mNeedsDispatchSize);
+    // Check mBounds size
+    if (mCompositorSession &&
+        !wr::WindowSizeSanityCheck(mBounds.width, mBounds.height)) {
+      gfxCriticalNoteOnce << "Invalid mBounds in MaybeDispatchResized "
+                          << mBounds << " size state " << mSizeMode;
+    }
+
+    if (mWindowType == WindowType::TopLevel) {
+      UpdateTopLevelOpaqueRegion();
+    }
+
+    // Notify the GtkCompositorWidget of a ClientSizeChange
+    if (mCompositorWidgetDelegate) {
+      mCompositorWidgetDelegate->NotifyClientSizeChanged(GetClientSize());
+    }
+
+    DispatchResized();
+  }
+}
+
+nsIWidgetListener* nsWindow::GetListener() {
+  return mAttachedWidgetListener ? mAttachedWidgetListener : mWidgetListener;
+}
+
+nsresult nsWindow::DispatchEvent(WidgetGUIEvent* aEvent,
+                                 nsEventStatus& aStatus) {
+#ifdef DEBUG
+  debug_DumpEvent(stdout, aEvent->mWidget, aEvent, "something", 0);
+#endif
+  aStatus = nsEventStatus_eIgnore;
+  nsIWidgetListener* listener = GetListener();
+  if (listener) {
+    aStatus = listener->HandleEvent(aEvent, mUseAttachedEvents);
+  }
+
+  return NS_OK;
+}
+
+void nsWindow::OnDestroy(void) {
+  if (mOnDestroyCalled) return;
+
+  mOnDestroyCalled = true;
+
+  // Prevent deletion.
+  nsCOMPtr<nsIWidget> kungFuDeathGrip = this;
+
+  // release references to children, device context, toolkit + app shell
+  nsBaseWidget::OnDestroy();
+
+  // Remove association between this object and its parent and siblings.
+  nsBaseWidget::Destroy();
+  mParent = nullptr;
+
+  NotifyWindowDestroyed();
+}
+
+bool nsWindow::AreBoundsSane() {
+  // Check requested size, as mBounds might not have been updated.
+  return !mLastSizeRequest.IsEmpty();
+}
+
+// Walk the list of child windows and call destroy on them.
+void nsWindow::DestroyChildWindows() {
+  LOG("nsWindow::DestroyChildWindows()");
+  if (!mGdkWindow) {
+    return;
+  }
+  while (GList* children = gdk_window_peek_children(mGdkWindow)) {
+    GdkWindow* child = GDK_WINDOW(children->data);
+    nsWindow* kid = get_window_for_gdk_window(child);
+    if (kid) {
+      kid->Destroy();
+    }
+  }
+}
+
+void nsWindow::Destroy() {
+  MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+
+  if (mIsDestroyed || !mCreated) {
+    return;
+  }
+
+  LOG("nsWindow::Destroy\n");
+
+  mIsDestroyed = true;
+  mCreated = false;
+
+  MozClearHandleID(mCompositorPauseTimeoutID, g_source_remove);
+
+  ClearTransparencyBitmap();
+
+#ifdef MOZ_WAYLAND
+  // Shut down our local vsync source
+  if (mWaylandVsyncSource) {
+    mWaylandVsyncSource->Shutdown();
+    mWaylandVsyncSource = nullptr;
+  }
+  mWaylandVsyncDispatcher = nullptr;
+#endif
+
+  /** Need to clean our LayerManager up while still alive */
+  DestroyLayerManager();
+
+  // Ensure any resources assigned to the window get cleaned up first
+  // to avoid double-freeing.
+  mSurfaceProvider.CleanupResources();
+
+  g_signal_handlers_disconnect_by_data(gtk_settings_get_default(), this);
+
+  nsIRollupListener* rollupListener = nsBaseWidget::GetActiveRollupListener();
+  if (rollupListener) {
+    nsCOMPtr<nsIWidget> rollupWidget = rollupListener->GetRollupWidget();
+    if (static_cast<nsIWidget*>(this) == rollupWidget) {
+      rollupListener->Rollup({});
+    }
+  }
+
+  // dragService will be null after shutdown of the service manager.
+  RefPtr<nsDragService> dragService = nsDragService::GetInstance();
+  if (dragService && this == dragService->GetMostRecentDestWindow()) {
+    dragService->ScheduleLeaveEvent();
+  }
+
+  NativeShow(false);
+
+  if (mIMContext) {
+    mIMContext->OnDestroyWindow(this);
+  }
+
+  // make sure that we remove ourself as the focus window
+  if (gFocusWindow == this) {
+    LOG("automatically losing focus...\n");
+    gFocusWindow = nullptr;
+  }
+
+  if (sStoredLeaveNotifyEvent) {
+    nsWindow* window =
+        get_window_for_gdk_window(sStoredLeaveNotifyEvent->window);
+    if (window == this) {
+      sStoredLeaveNotifyEvent = nullptr;
+    }
+  }
+
+  // We need to detach accessible object here because mContainer is a custom
+  // widget and doesn't call gtk_widget_real_destroy() from destroy handler
+  // as regular widgets.
+  if (AtkObject* ac = gtk_widget_get_accessible(GTK_WIDGET(mContainer))) {
+    gtk_accessible_set_widget(GTK_ACCESSIBLE(ac), nullptr);
+  }
+
+  gtk_widget_destroy(mShell);
+  mShell = nullptr;
+  mContainer = nullptr;
+
+  MOZ_ASSERT(!mGdkWindow,
+             "mGdkWindow should be NULL when mContainer is destroyed");
+
+#ifdef ACCESSIBILITY
+  if (mRootAccessible) {
+    mRootAccessible = nullptr;
+  }
+#endif
+
+  // Save until last because OnDestroy() may cause us to be deleted.
+  OnDestroy();
+}
+
+nsIWidget* nsWindow::GetParent() { return mParent; }
+
+float nsWindow::GetDPI() {
+  float dpi = 96.0f;
+  nsCOMPtr<nsIScreen> screen = GetWidgetScreen();
+  if (screen) {
+    screen->GetDpi(&dpi);
+  }
+  return dpi;
+}
+
+double nsWindow::GetDefaultScaleInternal() { return FractionalScaleFactor(); }
+
+DesktopToLayoutDeviceScale nsWindow::GetDesktopToDeviceScale() {
+#ifdef MOZ_WAYLAND
+  if (GdkIsWaylandDisplay()) {
+    return DesktopToLayoutDeviceScale(GdkCeiledScaleFactor());
+  }
+#endif
+
+  // In Gtk/X11, we manage windows using device pixels.
+  return DesktopToLayoutDeviceScale(1.0);
+}
+
+DesktopToLayoutDeviceScale nsWindow::GetDesktopToDeviceScaleByScreen() {
+#ifdef MOZ_WAYLAND
+  // In Wayland there's no way to get absolute position of the window and use it
+  // to determine the screen factor of the monitor on which the window is
+  // placed. The window is notified of the current scale factor but not at this
+  // point, so the GdkScaleFactor can return wrong value which can lead to wrong
+  // popup placement. We need to use parent's window scale factor for the new
+  // one.
+  if (GdkIsWaylandDisplay()) {
+    nsView* view = nsView::GetViewFor(this);
+    if (view) {
+      nsView* parentView = view->GetParent();
+      if (parentView) {
+        nsIWidget* parentWidget = parentView->GetNearestWidget(nullptr);
+        if (parentWidget) {
+          return DesktopToLayoutDeviceScale(
+              parentWidget->RoundsWidgetCoordinatesTo());
+        }
+        NS_WARNING("Widget has no parent");
+      }
+    } else {
+      NS_WARNING("Cannot find widget view");
+    }
+  }
+#endif
+  return nsBaseWidget::GetDesktopToDeviceScale();
+}
+
+// Reparent a child window to a new parent.
+void nsWindow::SetParent(nsIWidget* aNewParent) {
+  LOG("nsWindow::SetParent() new parent %p", aNewParent);
+  if (!mIsChildWindow) {
+    NS_WARNING("Used by child widgets only");
+    return;
+  }
+
+  nsCOMPtr<nsIWidget> kungFuDeathGrip = this;
+  if (mParent) {
+    mParent->RemoveChild(this);
+  }
+  mParent = aNewParent;
+
+  // We're already deleted, quit.
+  if (!mGdkWindow || mIsDestroyed || !aNewParent) {
+    return;
+  }
+  aNewParent->AddChild(this);
+
+  auto* newParent = static_cast<nsWindow*>(aNewParent);
+
+  // New parent is deleted, quit.
+  if (newParent->mIsDestroyed) {
+    Destroy();
+    return;
+  }
+
+  GdkWindow* window = GetToplevelGdkWindow();
+  GdkWindow* parentWindow = newParent->GetToplevelGdkWindow();
+  LOG("  child GdkWindow %p set parent GdkWindow %p", window, parentWindow);
+  gdk_window_reparent(window, parentWindow, 0, 0);
+  SetHasMappedToplevel(newParent && newParent->mHasMappedToplevel);
+}
+
+bool nsWindow::WidgetTypeSupportsAcceleration() {
+  if (mWindowType == WindowType::Invisible) {
+    return false;
+  }
+
+  if (IsSmallPopup()) {
+    return false;
+  }
+  // Workaround for Bug 1479135
+  // We draw transparent popups on non-compositing screens by SW as we don't
+  // implement X shape masks in WebRender.
+  if (mWindowType == WindowType::Popup) {
+    return HasRemoteContent() && mCompositedScreen;
+  }
+
+  return true;
+}
+
+void nsWindow::ReparentNativeWidget(nsIWidget* aNewParent) {
+  MOZ_ASSERT(aNewParent, "null widget");
+  MOZ_ASSERT(!mIsDestroyed, "");
+  MOZ_ASSERT(!static_cast<nsWindow*>(aNewParent)->mIsDestroyed, "");
+  MOZ_ASSERT(
+      !mParent,
+      "nsWindow::ReparentNativeWidget() works on toplevel windows only.");
+
+  auto* newParent = static_cast<nsWindow*>(aNewParent);
+  GtkWindow* newParentWidget = GTK_WINDOW(newParent->GetGtkWidget());
+
+  LOG("nsWindow::ReparentNativeWidget new parent %p\n", newParent);
+  GtkWindowSetTransientFor(GTK_WINDOW(mShell), newParentWidget);
+}
+
+void nsWindow::SetModal(bool aModal) {
+  LOG("nsWindow::SetModal %d\n", aModal);
+  if (mIsDestroyed) return;
+  gtk_window_set_modal(GTK_WINDOW(mShell), aModal ? TRUE : FALSE);
+}
+
+// nsIWidget method, which means IsShown.
+bool nsWindow::IsVisible() const { return mIsShown; }
+
+bool nsWindow::IsMapped() const {
+  // TODO: Enable for X11 when Mozilla testsuite is moved to new
+  // testing environment from Ubuntu 18.04 which is broken.
+  return GdkIsWaylandDisplay() ? mIsMapped : true;
+}
+
+void nsWindow::RegisterTouchWindow() {
+  mHandleTouchEvent = true;
+  mTouches.Clear();
+}
+
+LayoutDeviceIntPoint nsWindow::GetScreenEdgeSlop() {
+  if (DrawsToCSDTitlebar()) {
+    return GetClientOffset();
+  }
+  return {};
+}
+
+void nsWindow::ConstrainPosition(DesktopIntPoint& aPoint) {
+  if (!mShell || GdkIsWaylandDisplay()) {
+    return;
+  }
+
+  double dpiScale = GetDefaultScale().scale;
+
+  // we need to use the window size in logical screen pixels
+  int32_t logWidth = std::max(NSToIntRound(mBounds.width / dpiScale), 1);
+  int32_t logHeight = std::max(NSToIntRound(mBounds.height / dpiScale), 1);
+
+  /* get our playing field. use the current screen, or failing that
+    for any reason, use device caps for the default screen. */
+  nsCOMPtr<nsIScreenManager> screenmgr =
+      do_GetService("@mozilla.org/gfx/screenmanager;1");
+  if (!screenmgr) {
+    return;
+  }
+  nsCOMPtr<nsIScreen> screen;
+  screenmgr->ScreenForRect(aPoint.x, aPoint.y, logWidth, logHeight,
+                           getter_AddRefs(screen));
+  // We don't have any screen so leave the coordinates as is
+  if (!screen) {
+    return;
+  }
+
+  // For normalized windows, use the desktop work area.
+  // For full screen windows, use the desktop.
+  DesktopIntRect screenRect = mSizeMode == nsSizeMode_Fullscreen
+                                  ? screen->GetRectDisplayPix()
+                                  : screen->GetAvailRectDisplayPix();
+
+  // Expand for the decoration size if needed.
+  auto slop =
+      DesktopIntPoint::Round(GetScreenEdgeSlop() / GetDesktopToDeviceScale());
+  screenRect.Inflate(slop.x, slop.y);
+
+  if (aPoint.x < screenRect.x) {
+    aPoint.x = screenRect.x;
+  } else if (aPoint.x >= screenRect.XMost() - logWidth) {
+    aPoint.x = screenRect.XMost() - logWidth;
+  }
+
+  if (aPoint.y < screenRect.y) {
+    aPoint.y = screenRect.y;
+  } else if (aPoint.y >= screenRect.YMost() - logHeight) {
+    aPoint.y = screenRect.YMost() - logHeight;
+  }
+}
+
+void nsWindow::SetSizeConstraints(const SizeConstraints& aConstraints) {
+  mSizeConstraints.mMinSize = GetSafeWindowSize(aConstraints.mMinSize);
+  mSizeConstraints.mMaxSize = GetSafeWindowSize(aConstraints.mMaxSize);
+
+  ApplySizeConstraints();
+}
+
+bool nsWindow::DrawsToCSDTitlebar() const {
+  return mSizeMode == nsSizeMode_Normal &&
+         mGtkWindowDecoration == GTK_DECORATION_CLIENT && mDrawInTitlebar;
+}
+
+void nsWindow::AddCSDDecorationSize(int* aWidth, int* aHeight) {
+  if (!DrawsToCSDTitlebar()) {
+    return;
+  }
+  GtkBorder decorationSize = GetCSDDecorationSize(IsPopup());
+  *aWidth += decorationSize.left + decorationSize.right;
+  *aHeight += decorationSize.top + decorationSize.bottom;
+}
+
+#ifdef MOZ_WAYLAND
+bool nsWindow::GetCSDDecorationOffset(int* aDx, int* aDy) {
+  if (!DrawsToCSDTitlebar()) {
+    return false;
+  }
+  GtkBorder decorationSize = GetCSDDecorationSize(IsPopup());
+  *aDx = decorationSize.left;
+  *aDy = decorationSize.top;
+  return true;
+}
+#endif
+
+void nsWindow::ApplySizeConstraints() {
+  if (mShell) {
+    GdkGeometry geometry;
+    geometry.min_width =
+        DevicePixelsToGdkCoordRoundUp(mSizeConstraints.mMinSize.width);
+    geometry.min_height =
+        DevicePixelsToGdkCoordRoundUp(mSizeConstraints.mMinSize.height);
+    geometry.max_width =
+        DevicePixelsToGdkCoordRoundDown(mSizeConstraints.mMaxSize.width);
+    geometry.max_height =
+        DevicePixelsToGdkCoordRoundDown(mSizeConstraints.mMaxSize.height);
+
+    uint32_t hints = 0;
+    if (mSizeConstraints.mMinSize != LayoutDeviceIntSize()) {
+      if (GdkIsWaylandDisplay()) {
+        gtk_widget_set_size_request(GTK_WIDGET(mContainer), geometry.min_width,
+                                    geometry.min_height);
+      }
+      AddCSDDecorationSize(&geometry.min_width, &geometry.min_height);
+      hints |= GDK_HINT_MIN_SIZE;
+    }
+    if (mSizeConstraints.mMaxSize !=
+        LayoutDeviceIntSize(NS_MAXSIZE, NS_MAXSIZE)) {
+      AddCSDDecorationSize(&geometry.max_width, &geometry.max_height);
+      hints |= GDK_HINT_MAX_SIZE;
+    }
+
+    if (mAspectRatio != 0.0f) {
+      geometry.min_aspect = mAspectRatio;
+      geometry.max_aspect = mAspectRatio;
+      hints |= GDK_HINT_ASPECT;
+    }
+
+    gtk_window_set_geometry_hints(GTK_WINDOW(mShell), nullptr, &geometry,
+                                  GdkWindowHints(hints));
+  }
+}
+
+void nsWindow::Show(bool aState) {
+  if (aState == mIsShown) return;
+
+  mIsShown = aState;
+
+#ifdef MOZ_LOGGING
+  LOG("nsWindow::Show state %d frame %s\n", aState, GetFrameTag().get());
+  if (!aState && mSourceDragContext && GdkIsWaylandDisplay()) {
+    LOG("  closing Drag&Drop source window, D&D will be canceled!");
+  }
+#endif
+
+  // Ok, someone called show on a window that isn't sized to a sane
+  // value.  Mark this window as needing to have Show() called on it
+  // and return.
+  if ((aState && !AreBoundsSane()) || !mCreated) {
+    LOG("\tbounds are insane or window hasn't been created yet\n");
+    mNeedsShow = true;
+    return;
+  }
+
+  // If someone is hiding this widget, clear any needing show flag.
+  if (!aState) mNeedsShow = false;
+
+#ifdef ACCESSIBILITY
+  if (aState && a11y::ShouldA11yBeEnabled()) CreateRootAccessible();
+#endif
+
+  NativeShow(aState);
+}
+
+void nsWindow::ResizeInt(const Maybe<LayoutDeviceIntPoint>& aMove,
+                         LayoutDeviceIntSize aSize) {
+  LOG("nsWindow::ResizeInt w:%d h:%d\n", aSize.width, aSize.height);
+  const bool moved = aMove && *aMove != mBounds.TopLeft();
+  if (moved) {
+    mBounds.MoveTo(*aMove);
+    LOG("  with move to left:%d top:%d", aMove->x.value, aMove->y.value);
+  }
+
+  ConstrainSize(&aSize.width, &aSize.height);
+  LOG("  ConstrainSize: w:%d h;%d\n", aSize.width, aSize.height);
+
+  const bool resized = aSize != mLastSizeRequest || mBounds.Size() != aSize;
+#if MOZ_LOGGING
+  LOG("  resized %d aSize [%d, %d] mLastSizeRequest [%d, %d] mBounds [%d, %d]",
+      resized, aSize.width, aSize.height, mLastSizeRequest.width,
+      mLastSizeRequest.height, mBounds.width, mBounds.height);
+#endif
+
+  // For top-level windows, aSize should possibly be
+  // interpreted as frame bounds, but NativeMoveResize treats these as window
+  // bounds (Bug 581866).
+  mLastSizeRequest = aSize;
+  // Check size
+  if (mCompositorSession &&
+      !wr::WindowSizeSanityCheck(aSize.width, aSize.height)) {
+    gfxCriticalNoteOnce << "Invalid aSize in ResizeInt " << aSize
+                        << " size state " << mSizeMode;
+  }
+
+  // Recalculate aspect ratio when resized from DOM
+  if (mAspectRatio != 0.0) {
+    LockAspectRatio(true);
+  }
+
+  if (!mCreated) {
+    return;
+  }
+
+  if (!moved && !resized) {
+    LOG("  not moved or resized, quit");
+    return;
+  }
+
+  NativeMoveResize(moved, resized);
+
+  // We optimistically assume size changes immediately in two cases:
+  // 1. Override-redirect window: Size is controlled by only us.
+  // 2. Managed window that has not not yet received a size-allocate event:
+  //    Resize() Callers expect initial sizes to be applied synchronously.
+  //    If the size request is not honored, then we'll correct in
+  //    OnSizeAllocate().
+  //
+  // When a managed window has already received a size-allocate, we cannot
+  // assume we'll always get a notification if our request does not get
+  // honored: "If the configure request has not changed, we don't ever resend
+  // it, because it could mean fighting the user or window manager."
+  // https://gitlab.gnome.org/GNOME/gtk/-/blob/3.24.31/gtk/gtkwindow.c#L9782
+  // So we don't update mBounds until OnSizeAllocate() when we know the
+  // request is granted.
+  bool isOrWillBeVisible = mHasReceivedSizeAllocate || mNeedsShow || mIsShown;
+  if (!isOrWillBeVisible ||
+      gtk_window_get_window_type(GTK_WINDOW(mShell)) == GTK_WINDOW_POPUP) {
+    mBounds.SizeTo(aSize);
+    if (mCompositorWidgetDelegate) {
+      mCompositorWidgetDelegate->NotifyClientSizeChanged(aSize);
+    }
+    DispatchResized();
+  }
+}
+
+void nsWindow::Resize(double aWidth, double aHeight, bool aRepaint) {
+  LOG("nsWindow::Resize %f %f\n", aWidth, aHeight);
+
+  double scale =
+      BoundsUseDesktopPixels() ? GetDesktopToDeviceScale().scale : 1.0;
+  auto size = LayoutDeviceIntSize::Round(scale * aWidth, scale * aHeight);
+
+  ResizeInt(Nothing(), size);
+}
+
+void nsWindow::Resize(double aX, double aY, double aWidth, double aHeight,
+                      bool aRepaint) {
+  LOG("nsWindow::Resize [%f,%f] -> [%f x %f] repaint %d\n", aX, aY, aWidth,
+      aHeight, aRepaint);
+
+  double scale =
+      BoundsUseDesktopPixels() ? GetDesktopToDeviceScale().scale : 1.0;
+  auto size = LayoutDeviceIntSize::Round(scale * aWidth, scale * aHeight);
+  auto topLeft = LayoutDeviceIntPoint::Round(scale * aX, scale * aY);
+
+  ResizeInt(Some(topLeft), size);
+}
+
+void nsWindow::Enable(bool aState) { mEnabled = aState; }
+
+bool nsWindow::IsEnabled() const { return mEnabled; }
+
+void nsWindow::Move(double aX, double aY) {
+  double scale =
+      BoundsUseDesktopPixels() ? GetDesktopToDeviceScale().scale : 1.0;
+  int32_t x = NSToIntRound(aX * scale);
+  int32_t y = NSToIntRound(aY * scale);
+
+  LOG("nsWindow::Move to %d x %d\n", x, y);
+
+  if (mSizeMode != nsSizeMode_Normal && (mWindowType == WindowType::TopLevel ||
+                                         mWindowType == WindowType::Dialog)) {
+    LOG("  size state is not normal, bailing");
+    return;
+  }
+
+  // Since a popup window's x/y coordinates are in relation to to
+  // the parent, the parent might have moved so we always move a
+  // popup window.
+  LOG("  bounds %d x %d\n", mBounds.x, mBounds.y);
+  if (x == mBounds.x && y == mBounds.y && mWindowType != WindowType::Popup) {
+    LOG("  position is the same, return\n");
+    return;
+  }
+
+  // XXX Should we do some AreBoundsSane check here?
+
+  mBounds.x = x;
+  mBounds.y = y;
+
+  if (!mCreated) {
+    LOG("  is not created, return.\n");
+    return;
+  }
+
+  NativeMoveResize(/* move */ true, /* resize */ false);
+}
+
+bool nsWindow::IsPopup() const { return mWindowType == WindowType::Popup; }
+
+bool nsWindow::IsWaylandPopup() const {
+  return GdkIsWaylandDisplay() && IsPopup();
+}
+
+static nsMenuPopupFrame* GetMenuPopupFrame(nsIFrame* aFrame) {
+  return do_QueryFrame(aFrame);
+}
+
+void nsWindow::AppendPopupToHierarchyList(nsWindow* aToplevelWindow) {
+  mWaylandToplevel = aToplevelWindow;
+
+  nsWindow* popup = aToplevelWindow;
+  while (popup && popup->mWaylandPopupNext) {
+    popup = popup->mWaylandPopupNext;
+  }
+  popup->mWaylandPopupNext = this;
+
+  mWaylandPopupPrev = popup;
+  mWaylandPopupNext = nullptr;
+  mPopupChanged = true;
+  mPopupClosed = false;
+}
+
+void nsWindow::RemovePopupFromHierarchyList() {
+  // We're already removed from the popup hierarchy
+  if (!IsInPopupHierarchy()) {
+    return;
+  }
+  mWaylandPopupPrev->mWaylandPopupNext = mWaylandPopupNext;
+  if (mWaylandPopupNext) {
+    mWaylandPopupNext->mWaylandPopupPrev = mWaylandPopupPrev;
+    mWaylandPopupNext->mPopupChanged = true;
+  }
+  mWaylandPopupNext = mWaylandPopupPrev = nullptr;
+}
+
+// Gtk refuses to map popup window with x < 0 && y < 0 relative coordinates
+// see https://gitlab.gnome.org/GNOME/gtk/-/issues/4071
+// as a workaround just fool around and place the popup temporary to 0,0.
+bool nsWindow::WaylandPopupRemoveNegativePosition(int* aX, int* aY) {
+  // https://gitlab.gnome.org/GNOME/gtk/-/issues/4071 applies to temporary
+  // windows only
+  GdkWindow* window = gtk_widget_get_window(mShell);
+  if (!window || gdk_window_get_window_type(window) != GDK_WINDOW_TEMP) {
+    return false;
+  }
+
+  LOG("nsWindow::WaylandPopupRemoveNegativePosition()");
+
+  int x, y;
+  gtk_window_get_position(GTK_WINDOW(mShell), &x, &y);
+  bool moveBack = (x < 0 && y < 0);
+  if (moveBack) {
+    gtk_window_move(GTK_WINDOW(mShell), 0, 0);
+    if (aX) {
+      *aX = x;
+    }
+    if (aY) {
+      *aY = y;
+    }
+  }
+
+  gdk_window_get_geometry(window, &x, &y, nullptr, nullptr);
+  if (x < 0 && y < 0) {
+    gdk_window_move(window, 0, 0);
+  }
+
+  return moveBack;
+}
+
+void nsWindow::ShowWaylandPopupWindow() {
+  LOG("nsWindow::ShowWaylandPopupWindow. Expected to see visible.");
+  MOZ_ASSERT(IsWaylandPopup());
+
+  if (!mPopupTrackInHierarchy) {
+    LOG("  popup is not tracked in popup hierarchy, show it now");
+    gtk_widget_show(mShell);
+    return;
+  }
+
+  // Popup position was checked before gdk_window_move_to_rect() callback
+  // so just show it.
+  if (mPopupUseMoveToRect && mWaitingForMoveToRectCallback) {
+    LOG("  active move-to-rect callback, show it as is");
+    gtk_widget_show(mShell);
+    return;
+  }
+
+  if (gtk_widget_is_visible(mShell)) {
+    LOG("  is already visible, quit");
+    return;
+  }
+
+  int x, y;
+  bool moved = WaylandPopupRemoveNegativePosition(&x, &y);
+  gtk_widget_show(mShell);
+  if (moved) {
+    LOG("  move back to (%d, %d) and show", x, y);
+    gtk_window_move(GTK_WINDOW(mShell), x, y);
+  }
+}
+
+void nsWindow::WaylandPopupMarkAsClosed() {
+  LOG("nsWindow::WaylandPopupMarkAsClosed: [%p]\n", this);
+  mPopupClosed = true;
+  // If we have any child popup window notify it about
+  // parent switch.
+  if (mWaylandPopupNext) {
+    mWaylandPopupNext->mPopupChanged = true;
+  }
+}
+
+nsWindow* nsWindow::WaylandPopupFindLast(nsWindow* aPopup) {
+  while (aPopup && aPopup->mWaylandPopupNext) {
+    aPopup = aPopup->mWaylandPopupNext;
+  }
+  return aPopup;
+}
+
+// Hide and potentially removes popup from popup hierarchy.
+void nsWindow::HideWaylandPopupWindow(bool aTemporaryHide,
+                                      bool aRemoveFromPopupList) {
+  LOG("nsWindow::HideWaylandPopupWindow: remove from list %d\n",
+      aRemoveFromPopupList);
+  if (aRemoveFromPopupList) {
+    RemovePopupFromHierarchyList();
+  }
+
+  if (!mPopupClosed) {
+    mPopupClosed = !aTemporaryHide;
+  }
+
+  bool visible = gtk_widget_is_visible(mShell);
+  LOG("  gtk_widget_is_visible() = %d\n", visible);
+
+  // Restore only popups which are really visible
+  mPopupTemporaryHidden = aTemporaryHide && visible;
+
+  // Hide only visible popups or popups closed pernamently.
+  if (visible) {
+    gtk_widget_hide(mShell);
+
+    // If there's pending Move-To-Rect callback and we hide the popup
+    // the callback won't be called any more.
+    mWaitingForMoveToRectCallback = false;
+  }
+
+  if (mPopupClosed) {
+    LOG("  Clearing mMoveToRectPopupSize\n");
+    mMoveToRectPopupSize = {};
+#ifdef MOZ_WAYLAND
+    if (moz_container_wayland_is_waiting_to_show(mContainer)) {
+      // We need to clear rendering queue, see Bug 1782948.
+      LOG("  popup failed to show by Wayland compositor, clear rendering "
+          "queue.");
+      moz_container_wayland_clear_waiting_to_show_flag(mContainer);
+      ClearRenderingQueue();
+    }
+#endif
+  }
+}
+
+void nsWindow::HideWaylandToplevelWindow() {
+  LOG("nsWindow::HideWaylandToplevelWindow: [%p]\n", this);
+  if (mWaylandPopupNext) {
+    nsWindow* popup = WaylandPopupFindLast(mWaylandPopupNext);
+    while (popup->mWaylandToplevel != nullptr) {
+      nsWindow* prev = popup->mWaylandPopupPrev;
+      popup->HideWaylandPopupWindow(/* aTemporaryHide */ false,
+                                    /* aRemoveFromPopupList */ true);
+      popup = prev;
+    }
+  }
+  WaylandStopVsync();
+  gtk_widget_hide(mShell);
+}
+
+void nsWindow::ShowWaylandToplevelWindow() {
+  MOZ_ASSERT(!IsWaylandPopup());
+  LOG("nsWindow::ShowWaylandToplevelWindow");
+  gtk_widget_show(mShell);
+}
+
+void nsWindow::WaylandPopupRemoveClosedPopups() {
+  LOG("nsWindow::WaylandPopupRemoveClosedPopups()");
+  nsWindow* popup = this;
+  while (popup) {
+    nsWindow* next = popup->mWaylandPopupNext;
+    if (popup->mPopupClosed) {
+      popup->HideWaylandPopupWindow(/* aTemporaryHide */ false,
+                                    /* aRemoveFromPopupList */ true);
+    }
+    popup = next;
+  }
+}
+
+// Hide all tooltips except the latest one.
+void nsWindow::WaylandPopupHideTooltips() {
+  LOG("nsWindow::WaylandPopupHideTooltips");
+  MOZ_ASSERT(mWaylandToplevel == nullptr, "Should be called on toplevel only!");
+
+  nsWindow* popup = mWaylandPopupNext;
+  while (popup && popup->mWaylandPopupNext) {
+    if (popup->mPopupType == PopupType::Tooltip) {
+      LOG("  hidding tooltip [%p]", popup);
+      popup->WaylandPopupMarkAsClosed();
+    }
+    popup = popup->mWaylandPopupNext;
+  }
+}
+
+void nsWindow::WaylandPopupCloseOrphanedPopups() {
+#ifdef MOZ_WAYLAND
+  LOG("nsWindow::WaylandPopupCloseOrphanedPopups");
+  MOZ_ASSERT(mWaylandToplevel == nullptr, "Should be called on toplevel only!");
+
+  nsWindow* popup = mWaylandPopupNext;
+  bool dangling = false;
+  while (popup) {
+    if (!dangling &&
+        moz_container_wayland_is_waiting_to_show(popup->GetMozContainer())) {
+      LOG("  popup [%p] is waiting to show, close all child popups", popup);
+      dangling = true;
+    } else if (dangling) {
+      popup->WaylandPopupMarkAsClosed();
+    }
+    popup = popup->mWaylandPopupNext;
+  }
+#endif
+}
+
+// We can't show popups with remote content or overflow popups
+// on top of regular ones.
+// If there's any remote popup opened, close all parent popups of it.
+void nsWindow::CloseAllPopupsBeforeRemotePopup() {
+  LOG("nsWindow::CloseAllPopupsBeforeRemotePopup");
+  MOZ_ASSERT(mWaylandToplevel == nullptr, "Should be called on toplevel only!");
+
+  // Don't waste time when there's only one popup opened.
+  if (!mWaylandPopupNext || mWaylandPopupNext->mWaylandPopupNext == nullptr) {
+    return;
+  }
+
+  // Find the first opened remote content popup
+  nsWindow* remotePopup = mWaylandPopupNext;
+  while (remotePopup) {
+    if (remotePopup->HasRemoteContent() ||
+        remotePopup->IsWidgetOverflowWindow()) {
+      LOG("  remote popup [%p]", remotePopup);
+      break;
+    }
+    remotePopup = remotePopup->mWaylandPopupNext;
+  }
+
+  if (!remotePopup) {
+    return;
+  }
+
+  // ...hide opened popups before the remote one.
+  nsWindow* popup = mWaylandPopupNext;
+  while (popup && popup != remotePopup) {
+    LOG("  hidding popup [%p]", popup);
+    popup->WaylandPopupMarkAsClosed();
+    popup = popup->mWaylandPopupNext;
+  }
+}
+
+static void GetLayoutPopupWidgetChain(
+    nsTArray<nsIWidget*>* aLayoutWidgetHierarchy) {
+  nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
+  pm->GetSubmenuWidgetChain(aLayoutWidgetHierarchy);
+  aLayoutWidgetHierarchy->Reverse();
+}
+
+// Compare 'this' popup position in Wayland widget hierarchy
+// (mWaylandPopupPrev/mWaylandPopupNext) with
+// 'this' popup position in layout hierarchy.
+//
+// When aMustMatchParent is true we also request
+// 'this' parents match, i.e. 'this' has the same parent in
+// both layout and widget hierarchy.
+bool nsWindow::IsPopupInLayoutPopupChain(
+    nsTArray<nsIWidget*>* aLayoutWidgetHierarchy, bool aMustMatchParent) {
+  int len = (int)aLayoutWidgetHierarchy->Length();
+  for (int i = 0; i < len; i++) {
+    if (this == (*aLayoutWidgetHierarchy)[i]) {
+      if (!aMustMatchParent) {
+        return true;
+      }
+
+      // Find correct parent popup for 'this' according to widget
+      // hierarchy. That means we need to skip closed popups.
+      nsWindow* parentPopup = nullptr;
+      if (mWaylandPopupPrev != mWaylandToplevel) {
+        parentPopup = mWaylandPopupPrev;
+        while (parentPopup != mWaylandToplevel && parentPopup->mPopupClosed) {
+          parentPopup = parentPopup->mWaylandPopupPrev;
+        }
+      }
+
+      if (i == 0) {
+        // We found 'this' popups as a first popup in layout hierarchy.
+        // It matches layout hierarchy if it's first widget also in
+        // wayland widget hierarchy (i.e. parent is null).
+        return parentPopup == nullptr;
+      }
+
+      return parentPopup == (*aLayoutWidgetHierarchy)[i - 1];
+    }
+  }
+  return false;
+}
+
+// Hide popups which are not in popup chain.
+void nsWindow::WaylandPopupHierarchyHideByLayout(
+    nsTArray<nsIWidget*>* aLayoutWidgetHierarchy) {
+  LOG("nsWindow::WaylandPopupHierarchyHideByLayout");
+  MOZ_ASSERT(mWaylandToplevel == nullptr, "Should be called on toplevel only!");
+
+  // Hide all popups which are not in layout popup chain
+  nsWindow* popup = mWaylandPopupNext;
+  while (popup) {
+    // Don't check closed popups and drag source popups and tooltips.
+    if (!popup->mPopupClosed && popup->mPopupType != PopupType::Tooltip &&
+        !popup->mSourceDragContext) {
+      if (!popup->IsPopupInLayoutPopupChain(aLayoutWidgetHierarchy,
+                                            /* aMustMatchParent */ false)) {
+        LOG("  hidding popup [%p]", popup);
+        popup->WaylandPopupMarkAsClosed();
+      }
+    }
+    popup = popup->mWaylandPopupNext;
+  }
+}
+
+// Mark popups outside of layout hierarchy
+void nsWindow::WaylandPopupHierarchyValidateByLayout(
+    nsTArray<nsIWidget*>* aLayoutWidgetHierarchy) {
+  LOG("nsWindow::WaylandPopupHierarchyValidateByLayout");
+  nsWindow* popup = mWaylandPopupNext;
+  while (popup) {
+    if (popup->mPopupType == PopupType::Tooltip) {
+      popup->mPopupMatchesLayout = true;
+    } else if (!popup->mPopupClosed) {
+      popup->mPopupMatchesLayout = popup->IsPopupInLayoutPopupChain(
+          aLayoutWidgetHierarchy, /* aMustMatchParent */ true);
+      LOG("  popup [%p] parent window [%p] matches layout %d\n", (void*)popup,
+          (void*)popup->mWaylandPopupPrev, popup->mPopupMatchesLayout);
+    }
+    popup = popup->mWaylandPopupNext;
+  }
+}
+
+void nsWindow::WaylandPopupHierarchyHideTemporary() {
+  LOG("nsWindow::WaylandPopupHierarchyHideTemporary()");
+  nsWindow* popup = WaylandPopupFindLast(this);
+  while (popup && popup != this) {
+    LOG("  temporary hidding popup [%p]", popup);
+    nsWindow* prev = popup->mWaylandPopupPrev;
+    popup->HideWaylandPopupWindow(/* aTemporaryHide */ true,
+                                  /* aRemoveFromPopupList */ false);
+    popup = prev;
+  }
+}
+
+void nsWindow::WaylandPopupHierarchyShowTemporaryHidden() {
+  LOG("nsWindow::WaylandPopupHierarchyShowTemporaryHidden()");
+  nsWindow* popup = this;
+  while (popup) {
+    if (popup->mPopupTemporaryHidden) {
+      popup->mPopupTemporaryHidden = false;
+      LOG("  showing temporary hidden popup [%p]", popup);
+      popup->ShowWaylandPopupWindow();
+    }
+    popup = popup->mWaylandPopupNext;
+  }
+}
+
+void nsWindow::WaylandPopupHierarchyCalculatePositions() {
+  LOG("nsWindow::WaylandPopupHierarchyCalculatePositions()");
+
+  // Set widget hierarchy in Gtk
+  nsWindow* popup = mWaylandToplevel->mWaylandPopupNext;
+  while (popup) {
+    LOG("  popup [%p] set parent window [%p]", (void*)popup,
+        (void*)popup->mWaylandPopupPrev);
+    GtkWindowSetTransientFor(GTK_WINDOW(popup->mShell),
+                             GTK_WINDOW(popup->mWaylandPopupPrev->mShell));
+    popup = popup->mWaylandPopupNext;
+  }
+
+  popup = this;
+  while (popup) {
+    // Anchored window has mPopupPosition already calculated against
+    // its parent, no need to recalculate.
+    LOG("  popup [%p] bounds [%d, %d] -> [%d x %d]", popup,
+        (int)(popup->mBounds.x / FractionalScaleFactor()),
+        (int)(popup->mBounds.y / FractionalScaleFactor()),
+        (int)(popup->mBounds.width / FractionalScaleFactor()),
+        (int)(popup->mBounds.height / FractionalScaleFactor()));
+#ifdef MOZ_LOGGING
+    if (LOG_ENABLED()) {
+      if (nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame())) {
+        auto r = LayoutDeviceRect::FromAppUnitsRounded(
+            popupFrame->GetRect(),
+            popupFrame->PresContext()->AppUnitsPerDevPixel());
+        LOG("  popup [%p] layout [%d, %d] -> [%d x %d]", popup, r.x, r.y,
+            r.width, r.height);
+      }
+    }
+#endif
+    if (popup->WaylandPopupIsFirst()) {
+      LOG("  popup [%p] has toplevel as parent", popup);
+      popup->mRelativePopupPosition = popup->mPopupPosition;
+    } else {
+      if (popup->mPopupAnchored) {
+        LOG("  popup [%p] is anchored", popup);
+        if (!popup->mPopupMatchesLayout) {
+          NS_WARNING("Anchored popup does not match layout!");
+        }
+      }
+      GdkPoint parent = popup->WaylandGetParentPosition();
+
+      LOG("  popup [%p] uses transformed coordinates\n", popup);
+      LOG("    parent position [%d, %d]\n", parent.x, parent.y);
+      LOG("    popup position [%d, %d]\n", popup->mPopupPosition.x,
+          popup->mPopupPosition.y);
+
+      popup->mRelativePopupPosition.x = popup->mPopupPosition.x - parent.x;
+      popup->mRelativePopupPosition.y = popup->mPopupPosition.y - parent.y;
+    }
+    LOG("  popup [%p] transformed popup coordinates from [%d, %d] to [%d, %d]",
+        popup, popup->mPopupPosition.x, popup->mPopupPosition.y,
+        popup->mRelativePopupPosition.x, popup->mRelativePopupPosition.y);
+    popup = popup->mWaylandPopupNext;
+  }
+}
+
+// The MenuList popups are used as dropdown menus for example in WebRTC
+// microphone/camera chooser or autocomplete widgets.
+bool nsWindow::WaylandPopupIsMenu() {
+  nsMenuPopupFrame* menuPopupFrame = GetMenuPopupFrame(GetFrame());
+  if (menuPopupFrame) {
+    return mPopupType == PopupType::Menu && !menuPopupFrame->IsMenuList();
+  }
+  return false;
+}
+
+bool nsWindow::WaylandPopupIsContextMenu() {
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+  if (!popupFrame) {
+    return false;
+  }
+  return popupFrame->IsContextMenu();
+}
+
+bool nsWindow::WaylandPopupIsPermanent() {
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+  if (!popupFrame) {
+    // We can always hide popups without frames.
+    return false;
+  }
+  return popupFrame->IsNoAutoHide();
+}
+
+bool nsWindow::WaylandPopupIsAnchored() {
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+  if (!popupFrame) {
+    // We can always hide popups without frames.
+    return false;
+  }
+  return !!popupFrame->GetAnchor();
+}
+
+bool nsWindow::IsWidgetOverflowWindow() {
+  if (this->GetFrame() && this->GetFrame()->GetContent()->GetID()) {
+    nsCString nodeId;
+    this->GetFrame()->GetContent()->GetID()->ToUTF8String(nodeId);
+    return nodeId.Equals("widget-overflow");
+  }
+  return false;
+}
+
+bool nsWindow::WaylandPopupIsFirst() {
+  return !mWaylandPopupPrev || !mWaylandPopupPrev->mWaylandToplevel;
+}
+
+nsWindow* nsWindow::GetEffectiveParent() {
+  GtkWindow* parentGtkWindow = gtk_window_get_transient_for(GTK_WINDOW(mShell));
+  if (!parentGtkWindow || !GTK_IS_WIDGET(parentGtkWindow)) {
+    return nullptr;
+  }
+  return get_window_for_gtk_widget(GTK_WIDGET(parentGtkWindow));
+}
+
+GdkPoint nsWindow::WaylandGetParentPosition() {
+  GdkPoint topLeft = {0, 0};
+  nsWindow* window = GetEffectiveParent();
+  if (window->IsPopup()) {
+    topLeft = DevicePixelsToGdkPointRoundDown(window->mBounds.TopLeft());
+  }
+  LOG("nsWindow::WaylandGetParentPosition() [%d, %d]\n", topLeft.x, topLeft.y);
+  return topLeft;
+}
+
+#ifdef MOZ_LOGGING
+void nsWindow::LogPopupHierarchy() {
+  if (!LOG_ENABLED()) {
+    return;
+  }
+
+  LOG("Widget Popup Hierarchy:\n");
+  if (!mWaylandToplevel->mWaylandPopupNext) {
+    LOG("    Empty\n");
+  } else {
+    int indent = 4;
+    nsWindow* popup = mWaylandToplevel->mWaylandPopupNext;
+    while (popup) {
+      nsPrintfCString indentString("%*s", indent, " ");
+      LOG("%s %s %s nsWindow [%p] Menu %d Permanent %d ContextMenu %d "
+          "Anchored %d Visible %d MovedByRect %d\n",
+          indentString.get(), popup->GetFrameTag().get(),
+          popup->GetPopupTypeName().get(), popup, popup->WaylandPopupIsMenu(),
+          popup->WaylandPopupIsPermanent(), popup->mPopupContextMenu,
+          popup->mPopupAnchored, gtk_widget_is_visible(popup->mShell),
+          popup->mPopupUseMoveToRect);
+      indent += 4;
+      popup = popup->mWaylandPopupNext;
+    }
+  }
+
+  LOG("Layout Popup Hierarchy:\n");
+  AutoTArray<nsIWidget*, 5> widgetChain;
+  GetLayoutPopupWidgetChain(&widgetChain);
+  if (widgetChain.Length() == 0) {
+    LOG("    Empty\n");
+  } else {
+    for (unsigned long i = 0; i < widgetChain.Length(); i++) {
+      nsWindow* window = static_cast<nsWindow*>(widgetChain[i]);
+      nsPrintfCString indentString("%*s", (int)(i + 1) * 4, " ");
+      if (window) {
+        LOG("%s %s %s nsWindow [%p] Menu %d Permanent %d ContextMenu %d "
+            "Anchored %d Visible %d MovedByRect %d\n",
+            indentString.get(), window->GetFrameTag().get(),
+            window->GetPopupTypeName().get(), window,
+            window->WaylandPopupIsMenu(), window->WaylandPopupIsPermanent(),
+            window->mPopupContextMenu, window->mPopupAnchored,
+            gtk_widget_is_visible(window->mShell), window->mPopupUseMoveToRect);
+      } else {
+        LOG("%s null window\n", indentString.get());
+      }
+    }
+  }
+}
+#endif
+
+nsWindow* nsWindow::WaylandPopupGetTopmostWindow() {
+  nsView* view = nsView::GetViewFor(this);
+  if (view) {
+    nsView* parentView = view->GetParent();
+    if (parentView) {
+      nsIWidget* parentWidget = parentView->GetNearestWidget(nullptr);
+      if (parentWidget) {
+        nsWindow* parentnsWindow = static_cast<nsWindow*>(parentWidget);
+        LOG("  Topmost window: %p [nsWindow]\n", parentnsWindow);
+        return parentnsWindow;
+      }
+    }
+  }
+  return nullptr;
+}
+
+// Configure Wayland popup. If true is returned we need to track popup
+// in popup hierarchy. Otherwise we just show it as is.
+bool nsWindow::WaylandPopupConfigure() {
+  if (mIsDragPopup) {
+    return false;
+  }
+
+  // Don't track popups without frame
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+  if (!popupFrame) {
+    return false;
+  }
+
+  // Popup state can be changed, see Bug 1728952.
+  bool permanentStateMatches =
+      mPopupTrackInHierarchy == !WaylandPopupIsPermanent();
+
+  // Popup permanent state (noautohide attribute) can change during popup life.
+  if (mPopupTrackInHierarchyConfigured && permanentStateMatches) {
+    return mPopupTrackInHierarchy;
+  }
+
+  // Configure persistent popup params only once.
+  // WaylandPopupIsAnchored() can give it wrong value after
+  // nsMenuPopupFrame::MoveTo() call which we use in move-to-rect callback
+  // to position popup after wayland position change.
+  if (!mPopupTrackInHierarchyConfigured) {
+    mPopupAnchored = WaylandPopupIsAnchored();
+    mPopupContextMenu = WaylandPopupIsContextMenu();
+  }
+
+  LOG("nsWindow::WaylandPopupConfigure tracked %d anchored %d hint %d\n",
+      mPopupTrackInHierarchy, mPopupAnchored, int(mPopupHint));
+
+  // Permanent state changed and popup is mapped.
+  // We need to switch popup type but that's done when popup is mapped
+  // by Gtk so we need to unmap the popup here.
+  // It will be mapped again by gtk_widget_show().
+  if (!permanentStateMatches && mIsMapped) {
+    LOG("  permanent state change from %d to %d, unmapping",
+        mPopupTrackInHierarchy, !WaylandPopupIsPermanent());
+    gtk_widget_unmap(mShell);
+  }
+
+  mPopupTrackInHierarchy = !WaylandPopupIsPermanent();
+  LOG("  tracked in hierarchy %d\n", mPopupTrackInHierarchy);
+
+  // See gdkwindow-wayland.c and
+  // should_map_as_popup()/should_map_as_subsurface()
+  GdkWindowTypeHint gtkTypeHint;
+  switch (mPopupHint) {
+    case PopupType::Menu:
+      // GDK_WINDOW_TYPE_HINT_POPUP_MENU is mapped as xdg_popup by default.
+      // We use this type for all menu popups.
+      gtkTypeHint = GDK_WINDOW_TYPE_HINT_POPUP_MENU;
+      LOG("  popup type Menu");
+      break;
+    case PopupType::Tooltip:
+      gtkTypeHint = GDK_WINDOW_TYPE_HINT_TOOLTIP;
+      LOG("  popup type Tooltip");
+      break;
+    default:
+      gtkTypeHint = GDK_WINDOW_TYPE_HINT_UTILITY;
+      LOG("  popup type Utility");
+      break;
+  }
+
+  if (!mPopupTrackInHierarchy) {
+    // GDK_WINDOW_TYPE_HINT_UTILITY is mapped as wl_subsurface
+    // by default.
+    LOG("  not tracked in popup hierarchy, switch to Utility");
+    gtkTypeHint = GDK_WINDOW_TYPE_HINT_UTILITY;
+  }
+  gtk_window_set_type_hint(GTK_WINDOW(mShell), gtkTypeHint);
+
+  mPopupTrackInHierarchyConfigured = true;
+  return mPopupTrackInHierarchy;
+}
+
+bool nsWindow::IsInPopupHierarchy() {
+  return mPopupTrackInHierarchy && mWaylandToplevel && mWaylandPopupPrev;
+}
+
+void nsWindow::AddWindowToPopupHierarchy() {
+  LOG("nsWindow::AddWindowToPopupHierarchy\n");
+  if (!GetFrame()) {
+    LOG("  Window without frame cannot be added as popup!\n");
+    return;
+  }
+
+  // Check if we're already in the hierarchy
+  if (!IsInPopupHierarchy()) {
+    mWaylandToplevel = WaylandPopupGetTopmostWindow();
+    AppendPopupToHierarchyList(mWaylandToplevel);
+  }
+}
+
+// Wayland keeps strong popup window hierarchy. We need to track active
+// (visible) popup windows and make sure we hide popup on the same level
+// before we open another one on that level. It means that every open
+// popup needs to have an unique parent.
+void nsWindow::UpdateWaylandPopupHierarchy() {
+  LOG("nsWindow::UpdateWaylandPopupHierarchy\n");
+
+  // This popup hasn't been added to popup hierarchy yet so no need to
+  // do any configurations.
+  if (!IsInPopupHierarchy()) {
+    LOG("  popup isn't in hierarchy\n");
+    return;
+  }
+
+#ifdef MOZ_LOGGING
+  LogPopupHierarchy();
+  auto printPopupHierarchy = MakeScopeExit([&] { LogPopupHierarchy(); });
+#endif
+
+  // Hide all tooltips without the last one. Tooltip can't be popup parent.
+  mWaylandToplevel->WaylandPopupHideTooltips();
+
+  // See Bug 1709254 / https://gitlab.gnome.org/GNOME/gtk/-/issues/5092
+  // It's possible that Wayland compositor refuses to show
+  // a popup although Gtk claims it's visible.
+  // We don't know if the popup is shown or not.
+  // To avoid application crash refuse to create any child of such invisible
+  // popup and close any child of it now.
+  mWaylandToplevel->WaylandPopupCloseOrphanedPopups();
+
+  // Check if we have any remote content / overflow window in hierarchy.
+  // We can't attach such widget on top of other popup.
+  mWaylandToplevel->CloseAllPopupsBeforeRemotePopup();
+
+  // Check if your popup hierarchy matches layout hierarchy.
+  // For instance we should not connect hamburger menu on top
+  // of context menu.
+  // Close all popups from different layout chains if possible.
+  AutoTArray<nsIWidget*, 5> layoutPopupWidgetChain;
+  GetLayoutPopupWidgetChain(&layoutPopupWidgetChain);
+
+  mWaylandToplevel->WaylandPopupHierarchyHideByLayout(&layoutPopupWidgetChain);
+  mWaylandToplevel->WaylandPopupHierarchyValidateByLayout(
+      &layoutPopupWidgetChain);
+
+  // Now we have Popup hierarchy complete.
+  // Find first unchanged (and still open) popup to start with hierarchy
+  // changes.
+  nsWindow* changedPopup = mWaylandToplevel->mWaylandPopupNext;
+  while (changedPopup) {
+    // Stop when parent of this popup was changed and we need to recalc
+    // popup position.
+    if (changedPopup->mPopupChanged) {
+      break;
+    }
+    // Stop when this popup is closed.
+    if (changedPopup->mPopupClosed) {
+      break;
+    }
+    changedPopup = changedPopup->mWaylandPopupNext;
+  }
+
+  // We don't need to recompute popup positions, quit now.
+  if (!changedPopup) {
+    LOG("  changed Popup is null, quit.\n");
+    return;
+  }
+
+  LOG("  first changed popup [%p]\n", (void*)changedPopup);
+
+  // Hide parent popups if necessary (there are layout discontinuity)
+  // reposition the popup and show them again.
+  changedPopup->WaylandPopupHierarchyHideTemporary();
+
+  nsWindow* parentOfchangedPopup = nullptr;
+  if (changedPopup->mPopupClosed) {
+    parentOfchangedPopup = changedPopup->mWaylandPopupPrev;
+  }
+  changedPopup->WaylandPopupRemoveClosedPopups();
+
+  // It's possible that changedPopup was removed from widget hierarchy,
+  // in such case use child popup of the removed one if there's any.
+  if (!changedPopup->IsInPopupHierarchy()) {
+    if (!parentOfchangedPopup || !parentOfchangedPopup->mWaylandPopupNext) {
+      LOG("  last popup was removed, quit.\n");
+      return;
+    }
+    changedPopup = parentOfchangedPopup->mWaylandPopupNext;
+  }
+
+  GetLayoutPopupWidgetChain(&layoutPopupWidgetChain);
+  mWaylandToplevel->WaylandPopupHierarchyValidateByLayout(
+      &layoutPopupWidgetChain);
+
+  changedPopup->WaylandPopupHierarchyCalculatePositions();
+
+  nsWindow* popup = changedPopup;
+  while (popup) {
+    const bool useMoveToRect = [&] {
+      if (!StaticPrefs::widget_wayland_use_move_to_rect_AtStartup()) {
+        return false;  // Not available.
+      }
+      if (!popup->mPopupMatchesLayout) {
+        // We can use move_to_rect only when popups in popup hierarchy matches
+        // layout hierarchy as move_to_rect request that parent/child
+        // popups are adjacent.
+        return false;
+      }
+      if (popup->mPopupHint == PopupType::Panel &&
+          popup->WaylandPopupIsFirst() &&
+          popup->WaylandPopupFitsToplevelWindow(/* aMove */ true)) {
+        // Workaround for https://gitlab.gnome.org/GNOME/gtk/-/issues/1986
+        //
+        // PopupType::Panel types are used for extension popups which may be
+        // resized. If such popup uses move-to-rect, we need to hide it before
+        // resize and show it again. That leads to massive flickering
+        // so use plain move if possible to avoid it.
+        //
+        // Bug 1760276 - don't use move-to-rect when popup is inside main
+        // Firefox window.
+        //
+        // Use it for first popups only due to another mutter bug
+        // https://gitlab.gnome.org/GNOME/gtk/-/issues/5089
+        // https://bugzilla.mozilla.org/show_bug.cgi?id=1784873
+        return false;
+      }
+      if (!popup->WaylandPopupIsFirst() &&
+          !popup->mWaylandPopupPrev->WaylandPopupIsFirst() &&
+          !popup->mWaylandPopupPrev->mPopupUseMoveToRect) {
+        // We can't use move-to-rect if there are more parents of
+        // wl_subsurface popups types.
+        //
+        // It's because wl_subsurface is ignored by xgd_popup
+        // (created by move-to-rect) so our popup scenario:
+        //
+        // toplevel -> xgd_popup(1) -> wl_subsurface(2) -> xgd_popup(3)
+        //
+        // looks for Wayland compositor as:
+        //
+        // toplevel -> xgd_popup(1) -> xgd_popup(3)
+        //
+        // If xgd_popup(1) and xgd_popup(3) are not connected
+        // move-to-rect applied to xgd_popup(3) fails and we get missing popup.
+        return false;
+      }
+      return true;
+    }();
+
+    LOG("  popup [%p] matches layout [%d] anchored [%d] first popup [%d] use "
+        "move-to-rect %d\n",
+        popup, popup->mPopupMatchesLayout, popup->mPopupAnchored,
+        popup->WaylandPopupIsFirst(), useMoveToRect);
+
+    popup->mPopupUseMoveToRect = useMoveToRect;
+    popup->WaylandPopupMoveImpl();
+    popup->mPopupChanged = false;
+    popup = popup->mWaylandPopupNext;
+  }
+
+  changedPopup->WaylandPopupHierarchyShowTemporaryHidden();
+}
+
+static void NativeMoveResizeCallback(GdkWindow* window,
+                                     const GdkRectangle* flipped_rect,
+                                     const GdkRectangle* final_rect,
+                                     gboolean flipped_x, gboolean flipped_y,
+                                     void* aWindow) {
+  LOG_POPUP("[%p] NativeMoveResizeCallback flipped_x %d flipped_y %d\n",
+            aWindow, flipped_x, flipped_y);
+  LOG_POPUP("[%p]    new position [%d, %d] -> [%d x %d]", aWindow,
+            final_rect->x, final_rect->y, final_rect->width,
+            final_rect->height);
+  nsWindow* wnd = get_window_for_gdk_window(window);
+
+  wnd->NativeMoveResizeWaylandPopupCallback(final_rect, flipped_x, flipped_y);
+}
+
+// When popup is repositioned by widget code, we need to notify
+// layout about it. It's because we control popup placement
+// on widget on Wayland so layout may have old popup size/coordinates.
+void nsWindow::WaylandPopupPropagateChangesToLayout(bool aMove, bool aResize) {
+  LOG("nsWindow::WaylandPopupPropagateChangesToLayout()");
+
+  if (aResize) {
+    LOG("  needSizeUpdate\n");
+    if (nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame())) {
+      RefPtr<PresShell> presShell = popupFrame->PresShell();
+      presShell->FrameNeedsReflow(popupFrame, IntrinsicDirty::None,
+                                  NS_FRAME_IS_DIRTY);
+    }
+  }
+  if (aMove) {
+    LOG("  needPositionUpdate, bounds [%d, %d]", mBounds.x, mBounds.y);
+    NotifyWindowMoved(mBounds.x, mBounds.y, ByMoveToRect::Yes);
+  }
+}
+
+void nsWindow::NativeMoveResizeWaylandPopupCallback(
+    const GdkRectangle* aFinalSize, bool aFlippedX, bool aFlippedY) {
+  // We're getting move-to-rect callback without move-to-rect call.
+  // That indicates a compositor bug. It happens when a window is hidden and
+  // shown again before move-to-rect callback is fired.
+  // It may lead to incorrect popup placement as we may call
+  // gtk_window_move() between hide & show.
+  // See Bug 1777919, 1789581.
+#if MOZ_LOGGING
+  if (!mWaitingForMoveToRectCallback) {
+    LOG("  Bogus move-to-rect callback! Expect wrong popup coordinates.");
+  }
+#endif
+
+  mWaitingForMoveToRectCallback = false;
+
+  bool movedByLayout = mMovedAfterMoveToRect;
+  bool resizedByLayout = mResizedAfterMoveToRect;
+
+  // Popup was moved between move-to-rect call and move-to-rect callback
+  // and the coordinates from move-to-rect callback are outdated.
+  if (movedByLayout || resizedByLayout) {
+    LOG("  Another move/resize called during waiting for callback\n");
+    mMovedAfterMoveToRect = false;
+    mResizedAfterMoveToRect = false;
+    // Fire another round of move/resize to reflect latest request
+    // from layout.
+    NativeMoveResize(movedByLayout, resizedByLayout);
+    return;
+  }
+
+  LOG("  orig mBounds [%d, %d] -> [%d x %d]\n", mBounds.x, mBounds.y,
+      mBounds.width, mBounds.height);
+
+  LayoutDeviceIntRect newBounds = [&] {
+    GdkRectangle finalRect = *aFinalSize;
+    GdkPoint parent = WaylandGetParentPosition();
+    finalRect.x += parent.x;
+    finalRect.y += parent.y;
+    return GdkRectToDevicePixels(finalRect);
+  }();
+
+  LOG("  new mBounds [%d, %d] -> [%d x %d]", newBounds.x, newBounds.y,
+      newBounds.width, newBounds.height);
+
+  bool needsPositionUpdate = newBounds.TopLeft() != mBounds.TopLeft();
+  bool needsSizeUpdate = newBounds.Size() != mLastSizeRequest;
+
+  if (needsSizeUpdate) {
+    // Wayland compositor changed popup size request from layout.
+    // Set the constraints to use them in nsMenuPopupFrame::SetPopupPosition().
+    // Beware that gtk_window_resize() requests sizes asynchronously and so
+    // newBounds might not have the size from the most recent
+    // gtk_window_resize().
+    if (newBounds.width < mLastSizeRequest.width) {
+      mMoveToRectPopupSize.width = newBounds.width;
+    }
+    if (newBounds.height < mLastSizeRequest.height) {
+      mMoveToRectPopupSize.height = newBounds.height;
+    }
+    LOG("  mMoveToRectPopupSize set to [%d, %d]", mMoveToRectPopupSize.width,
+        mMoveToRectPopupSize.height);
+  }
+  mBounds = newBounds;
+  // Check mBounds size
+  if (mCompositorSession &&
+      !wr::WindowSizeSanityCheck(mBounds.width, mBounds.height)) {
+    gfxCriticalNoteOnce << "Invalid mBounds in PopupCallback " << mBounds
+                        << " size state " << mSizeMode;
+  }
+  WaylandPopupPropagateChangesToLayout(needsPositionUpdate, needsSizeUpdate);
+}
+
+static GdkGravity PopupAlignmentToGdkGravity(int8_t aAlignment) {
+  switch (aAlignment) {
+    case POPUPALIGNMENT_NONE:
+      return GDK_GRAVITY_NORTH_WEST;
+    case POPUPALIGNMENT_TOPLEFT:
+      return GDK_GRAVITY_NORTH_WEST;
+    case POPUPALIGNMENT_TOPRIGHT:
+      return GDK_GRAVITY_NORTH_EAST;
+    case POPUPALIGNMENT_BOTTOMLEFT:
+      return GDK_GRAVITY_SOUTH_WEST;
+    case POPUPALIGNMENT_BOTTOMRIGHT:
+      return GDK_GRAVITY_SOUTH_EAST;
+    case POPUPALIGNMENT_LEFTCENTER:
+      return GDK_GRAVITY_WEST;
+    case POPUPALIGNMENT_RIGHTCENTER:
+      return GDK_GRAVITY_EAST;
+    case POPUPALIGNMENT_TOPCENTER:
+      return GDK_GRAVITY_NORTH;
+    case POPUPALIGNMENT_BOTTOMCENTER:
+      return GDK_GRAVITY_SOUTH;
+  }
+  return GDK_GRAVITY_STATIC;
+}
+
+bool nsWindow::IsPopupDirectionRTL() {
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+  return popupFrame && popupFrame->IsDirectionRTL();
+}
+
+// Position the popup directly by gtk_window_move() and try to keep it
+// on screen by just moving it in scope of it's parent window.
+//
+// It's used when we position noautihode popup and we don't use xdg_positioner.
+// See Bug 1718867
+void nsWindow::WaylandPopupSetDirectPosition() {
+  GdkPoint topLeft = DevicePixelsToGdkPointRoundDown(mBounds.TopLeft());
+  GdkRectangle size = DevicePixelsToGdkSizeRoundUp(mLastSizeRequest);
+
+  LOG("nsWindow::WaylandPopupSetDirectPosition %d,%d -> %d x %d\n", topLeft.x,
+      topLeft.y, size.width, size.height);
+
+  mPopupPosition = {topLeft.x, topLeft.y};
+
+  if (mIsDragPopup) {
+    gtk_window_move(GTK_WINDOW(mShell), topLeft.x, topLeft.y);
+    gtk_window_resize(GTK_WINDOW(mShell), size.width, size.height);
+    // DND window is placed inside container so we need to make hard size
+    // request to ensure parent container is resized too.
+    gtk_widget_set_size_request(GTK_WIDGET(mShell), size.width, size.height);
+    return;
+  }
+
+  GtkWindow* parentGtkWindow = gtk_window_get_transient_for(GTK_WINDOW(mShell));
+  nsWindow* window = get_window_for_gtk_widget(GTK_WIDGET(parentGtkWindow));
+  if (!window) {
+    return;
+  }
+  GdkWindow* gdkWindow =
+      gtk_widget_get_window(GTK_WIDGET(window->GetMozContainer()));
+
+  int parentWidth = gdk_window_get_width(gdkWindow);
+  int popupWidth = size.width;
+
+  int x;
+  gdk_window_get_position(gdkWindow, &x, nullptr);
+
+  // If popup is bigger than main window just center it.
+  if (popupWidth > parentWidth) {
+    mPopupPosition.x = -(parentWidth - popupWidth) / 2 + x;
+  } else {
+    if (IsPopupDirectionRTL()) {
+      // Stick with right window edge
+      if (mPopupPosition.x < x) {
+        mPopupPosition.x = x;
+      }
+    } else {
+      // Stick with left window edge
+      if (mPopupPosition.x + popupWidth > parentWidth + x) {
+        mPopupPosition.x = parentWidth + x - popupWidth;
+      }
+    }
+  }
+
+  LOG("  set position [%d, %d]\n", mPopupPosition.x, mPopupPosition.y);
+  gtk_window_move(GTK_WINDOW(mShell), mPopupPosition.x, mPopupPosition.y);
+
+  LOG("  set size [%d, %d]\n", size.width, size.height);
+  gtk_window_resize(GTK_WINDOW(mShell), size.width, size.height);
+
+  if (mPopupPosition.x != topLeft.x) {
+    mBounds.MoveTo(GdkPointToDevicePixels(mPopupPosition));
+    LOG("  setting new bounds [%d, %d]\n", mBounds.x, mBounds.y);
+    WaylandPopupPropagateChangesToLayout(/* move */ true, /* resize */ false);
+  }
+}
+
+bool nsWindow::WaylandPopupFitsToplevelWindow(bool aMove) {
+  LOG("nsWindow::WaylandPopupFitsToplevelWindow() move %d", aMove);
+
+  GtkWindow* parent = gtk_window_get_transient_for(GTK_WINDOW(mShell));
+  GtkWindow* tmp = parent;
+  while ((tmp = gtk_window_get_transient_for(GTK_WINDOW(parent)))) {
+    parent = tmp;
+  }
+  GdkWindow* toplevelGdkWindow = gtk_widget_get_window(GTK_WIDGET(parent));
+
+  if (!toplevelGdkWindow) {
+    NS_WARNING("Toplevel widget without GdkWindow?");
+    return false;
+  }
+
+  int parentWidth = gdk_window_get_width(toplevelGdkWindow);
+  int parentHeight = gdk_window_get_height(toplevelGdkWindow);
+  LOG("  parent size %d x %d", parentWidth, parentHeight);
+
+  GdkPoint topLeft = aMove ? mPopupPosition
+                           : DevicePixelsToGdkPointRoundDown(mBounds.TopLeft());
+  GdkRectangle size = DevicePixelsToGdkSizeRoundUp(mLastSizeRequest);
+  LOG("  popup topleft %d, %d size %d x %d", topLeft.x, topLeft.y, size.width,
+      size.height);
+  int fits = topLeft.x >= 0 && topLeft.y >= 0 &&
+             topLeft.x + size.width <= parentWidth &&
+             topLeft.y + size.height <= parentHeight;
+
+  LOG("  fits %d", fits);
+  return fits;
+}
+
+void nsWindow::NativeMoveResizeWaylandPopup(bool aMove, bool aResize) {
+  GdkPoint topLeft = DevicePixelsToGdkPointRoundDown(mBounds.TopLeft());
+  GdkRectangle size = DevicePixelsToGdkSizeRoundUp(mLastSizeRequest);
+
+  LOG("nsWindow::NativeMoveResizeWaylandPopup Bounds %d,%d -> %d x %d move %d "
+      "resize %d\n",
+      topLeft.x, topLeft.y, size.width, size.height, aMove, aResize);
+
+  // Compositor may be confused by windows with width/height = 0
+  // and positioning such windows leads to Bug 1555866.
+  if (!AreBoundsSane()) {
+    LOG("  Bounds are not sane (width: %d height: %d)\n",
+        mLastSizeRequest.width, mLastSizeRequest.height);
+    return;
+  }
+
+  if (mWaitingForMoveToRectCallback) {
+    LOG("  waiting for move to rect, scheduling");
+    // mBounds position must not be overwritten before it is applied.
+    // OnConfigureEvent() will not set mBounds to an old position for
+    // GTK_WINDOW_POPUP.
+    MOZ_ASSERT(gtk_window_get_window_type(GTK_WINDOW(mShell)) ==
+               GTK_WINDOW_POPUP);
+    mMovedAfterMoveToRect = aMove;
+    mResizedAfterMoveToRect = aResize;
+    return;
+  }
+
+  mMovedAfterMoveToRect = false;
+  mResizedAfterMoveToRect = false;
+
+  bool trackedInHierarchy = WaylandPopupConfigure();
+
+  // Read popup position from layout if it was moved or newly created.
+  // This position is used by move-to-rect method as we need anchor and other
+  // info to place popup correctly.
+  // We need WaylandPopupConfigure() to be called before to have all needed
+  // popup info in place (mainly the anchored flag).
+  if (aMove) {
+    mPopupMoveToRectParams = WaylandPopupGetPositionFromLayout();
+  }
+
+  if (!trackedInHierarchy) {
+    WaylandPopupSetDirectPosition();
+    return;
+  }
+
+  if (aResize) {
+    LOG("  set size [%d, %d]\n", size.width, size.height);
+    gtk_window_resize(GTK_WINDOW(mShell), size.width, size.height);
+  }
+
+  if (!aMove && WaylandPopupFitsToplevelWindow(aMove)) {
+    // Popup position has not been changed and its position/size fits
+    // parent window so no need to reposition the window.
+    LOG("  fits parent window size, just resize\n");
+    return;
+  }
+
+  // Mark popup as changed as we're updating position/size.
+  mPopupChanged = true;
+
+  // Save popup position for former re-calculations when popup hierarchy
+  // is changed.
+  LOG("  popup position changed from [%d, %d] to [%d, %d]\n", mPopupPosition.x,
+      mPopupPosition.y, topLeft.x, topLeft.y);
+  mPopupPosition = {topLeft.x, topLeft.y};
+
+  UpdateWaylandPopupHierarchy();
+}
+
+struct PopupSides {
+  Maybe<Side> mVertical;
+  Maybe<Side> mHorizontal;
+};
+
+static PopupSides SidesForPopupAlignment(int8_t aAlignment) {
+  switch (aAlignment) {
+    case POPUPALIGNMENT_NONE:
+      break;
+    case POPUPALIGNMENT_TOPLEFT:
+      return {Some(eSideTop), Some(eSideLeft)};
+    case POPUPALIGNMENT_TOPRIGHT:
+      return {Some(eSideTop), Some(eSideRight)};
+    case POPUPALIGNMENT_BOTTOMLEFT:
+      return {Some(eSideBottom), Some(eSideLeft)};
+    case POPUPALIGNMENT_BOTTOMRIGHT:
+      return {Some(eSideBottom), Some(eSideRight)};
+    case POPUPALIGNMENT_LEFTCENTER:
+      return {Nothing(), Some(eSideLeft)};
+    case POPUPALIGNMENT_RIGHTCENTER:
+      return {Nothing(), Some(eSideRight)};
+    case POPUPALIGNMENT_TOPCENTER:
+      return {Some(eSideTop), Nothing()};
+    case POPUPALIGNMENT_BOTTOMCENTER:
+      return {Some(eSideBottom), Nothing()};
+  }
+  return {};
+}
+
+// We want to apply margins based on popup alignment (which would generally be
+// just an offset to apply to the popup). However, to deal with flipping
+// correctly, we apply the margin to the anchor when possible.
+struct ResolvedPopupMargin {
+  // A margin to be applied to the anchor.
+  nsMargin mAnchorMargin;
+  // An offset in app units to be applied to the popup for when we need to tell
+  // GTK to center inside the anchor precisely (so we can't really do better in
+  // presence of flips).
+  nsPoint mPopupOffset;
+};
+
+static ResolvedPopupMargin ResolveMargin(nsMenuPopupFrame* aFrame,
+                                         int8_t aPopupAlign,
+                                         int8_t aAnchorAlign,
+                                         bool aAnchoredToPoint,
+                                         bool aIsContextMenu) {
+  nsMargin margin = aFrame->GetMargin();
+  nsPoint offset;
+
+  if (aAnchoredToPoint) {
+    // Since GTK doesn't allow us to specify margins itself, when anchored to a
+    // point we can just assume we'll be aligned correctly... This is kind of
+    // annoying but alas.
+    //
+    // This calculation must match the relevant unanchored popup calculation in
+    // nsMenuPopupFrame::SetPopupPosition(), which should itself be the inverse
+    // inverse of nsMenuPopupFrame::MoveTo().
+    if (aIsContextMenu && aFrame->IsDirectionRTL()) {
+      offset.x = -margin.right;
+    } else {
+      offset.x = margin.left;
+    }
+    offset.y = margin.top;
+    return {nsMargin(), offset};
+  }
+
+  auto popupSides = SidesForPopupAlignment(aPopupAlign);
+  auto anchorSides = SidesForPopupAlignment(aAnchorAlign);
+  // Matched sides: Invert the margin, so that we pull in the right direction.
+  // Popup not aligned to any anchor side: We give up and use the offset,
+  // applying the margin from the popup side.
+  // Mismatched sides: We swap the margins so that we pull in the right
+  // direction, e.g. margin-left: -10px should shrink 10px the _right_ of the
+  // box, not the left of the box.
+  if (popupSides.mHorizontal == anchorSides.mHorizontal) {
+    margin.left = -margin.left;
+    margin.right = -margin.right;
+  } else if (!anchorSides.mHorizontal) {
+    auto popupSide = *popupSides.mHorizontal;
+    offset.x += popupSide == eSideRight ? -margin.Side(popupSide)
+                                        : margin.Side(popupSide);
+    margin.left = margin.right = 0;
+  } else {
+    std::swap(margin.left, margin.right);
+  }
+
+  // Same logic as above, but in the vertical direction.
+  if (popupSides.mVertical == anchorSides.mVertical) {
+    margin.top = -margin.top;
+    margin.bottom = -margin.bottom;
+  } else if (!anchorSides.mVertical) {
+    auto popupSide = *popupSides.mVertical;
+    offset.y += popupSide == eSideBottom ? -margin.Side(popupSide)
+                                         : margin.Side(popupSide);
+    margin.top = margin.bottom = 0;
+  } else {
+    std::swap(margin.top, margin.bottom);
+  }
+
+  return {margin, offset};
+}
+
+#ifdef MOZ_LOGGING
+void nsWindow::LogPopupAnchorHints(int aHints) {
+  static struct hints_ {
+    int hint;
+    char name[100];
+  } hints[] = {
+      {GDK_ANCHOR_FLIP_X, "GDK_ANCHOR_FLIP_X"},
+      {GDK_ANCHOR_FLIP_Y, "GDK_ANCHOR_FLIP_Y"},
+      {GDK_ANCHOR_SLIDE_X, "GDK_ANCHOR_SLIDE_X"},
+      {GDK_ANCHOR_SLIDE_Y, "GDK_ANCHOR_SLIDE_Y"},
+      {GDK_ANCHOR_RESIZE_X, "GDK_ANCHOR_RESIZE_X"},
+      {GDK_ANCHOR_RESIZE_Y, "GDK_ANCHOR_RESIZE_X"},
+  };
+
+  LOG("  PopupAnchorHints");
+  for (const auto& hint : hints) {
+    if (hint.hint & aHints) {
+      LOG("    %s", hint.name);
+    }
+  }
+}
+
+void nsWindow::LogPopupGravity(GdkGravity aGravity) {
+  static char gravity[][100]{"NONE",
+                             "GDK_GRAVITY_NORTH_WEST",
+                             "GDK_GRAVITY_NORTH",
+                             "GDK_GRAVITY_NORTH_EAST",
+                             "GDK_GRAVITY_WEST",
+                             "GDK_GRAVITY_CENTER",
+                             "GDK_GRAVITY_EAST",
+                             "GDK_GRAVITY_SOUTH_WEST",
+                             "GDK_GRAVITY_SOUTH",
+                             "GDK_GRAVITY_SOUTH_EAST",
+                             "GDK_GRAVITY_STATIC"};
+  LOG("    %s", gravity[aGravity]);
+}
+#endif
+
+const nsWindow::WaylandPopupMoveToRectParams
+nsWindow::WaylandPopupGetPositionFromLayout() {
+  LOG("nsWindow::WaylandPopupGetPositionFromLayout\n");
+
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+
+  const bool isTopContextMenu = mPopupContextMenu && !mPopupAnchored;
+  const bool isRTL = IsPopupDirectionRTL();
+  const bool anchored = popupFrame->IsAnchored();
+  int8_t popupAlign = POPUPALIGNMENT_TOPLEFT;
+  int8_t anchorAlign = POPUPALIGNMENT_BOTTOMRIGHT;
+  if (anchored) {
+    // See nsMenuPopupFrame::AdjustPositionForAnchorAlign.
+    popupAlign = popupFrame->GetPopupAlignment();
+    anchorAlign = popupFrame->GetPopupAnchor();
+  }
+  if (isRTL && (anchored || isTopContextMenu)) {
+    popupAlign = -popupAlign;
+    anchorAlign = -anchorAlign;
+  }
+
+  // Although we have mPopupPosition / mRelativePopupPosition here
+  // we can't use it. move-to-rect needs anchor rectangle to position a popup
+  // but we have only a point from Resize().
+  //
+  // So we need to extract popup position from nsMenuPopupFrame() and duplicate
+  // the layout work here.
+  LayoutDeviceIntRect anchorRect;
+  ResolvedPopupMargin popupMargin;
+  {
+    nsRect anchorRectAppUnits = popupFrame->GetUntransformedAnchorRect();
+    // This is a somewhat hacky way of applying the popup margin. We don't know
+    // if GTK will end up flipping the popup, in which case the offset we
+    // compute is just wrong / applied to the wrong side.
+    //
+    // Instead, we tell it to anchor us at a smaller or bigger rect depending on
+    // the margin, which achieves the same result if the popup is positioned
+    // correctly, but doesn't misposition the popup when flipped across the
+    // anchor.
+    popupMargin = ResolveMargin(popupFrame, popupAlign, anchorAlign,
+                                anchorRectAppUnits.IsEmpty(), isTopContextMenu);
+    LOG("  layout popup CSS anchor (%d, %d) %s, margin %s offset %s\n",
+        popupAlign, anchorAlign, ToString(anchorRectAppUnits).c_str(),
+        ToString(popupMargin.mAnchorMargin).c_str(),
+        ToString(popupMargin.mPopupOffset).c_str());
+    anchorRectAppUnits.Inflate(popupMargin.mAnchorMargin);
+    LOG("    after margins %s\n", ToString(anchorRectAppUnits).c_str());
+    nscoord auPerDev = popupFrame->PresContext()->AppUnitsPerDevPixel();
+    anchorRect = LayoutDeviceIntRect::FromAppUnitsToNearest(anchorRectAppUnits,
+                                                            auPerDev);
+    if (anchorRect.width < 0) {
+      auto w = -anchorRect.width;
+      anchorRect.width += w + 1;
+      anchorRect.x += w;
+    }
+    LOG("    final %s\n", ToString(anchorRect).c_str());
+  }
+
+  LOG("  relative popup rect position [%d, %d] -> [%d x %d]\n", anchorRect.x,
+      anchorRect.y, anchorRect.width, anchorRect.height);
+
+  // Get gravity and flip type
+  GdkGravity rectAnchor = PopupAlignmentToGdkGravity(anchorAlign);
+  GdkGravity menuAnchor = PopupAlignmentToGdkGravity(popupAlign);
+
+  LOG("  parentRect gravity: %d anchor gravity: %d\n", rectAnchor, menuAnchor);
+
+  // Gtk default is: GDK_ANCHOR_FLIP | GDK_ANCHOR_SLIDE | GDK_ANCHOR_RESIZE.
+  // We want to SLIDE_X menu on the dual monitor setup rather than resize it
+  // on the other monitor.
+  GdkAnchorHints hints =
+      GdkAnchorHints(GDK_ANCHOR_FLIP | GDK_ANCHOR_SLIDE_X | GDK_ANCHOR_RESIZE);
+
+  // slideHorizontal from nsMenuPopupFrame::SetPopupPosition
+  int8_t position = popupFrame->GetAlignmentPosition();
+  if (position >= POPUPPOSITION_BEFORESTART &&
+      position <= POPUPPOSITION_AFTEREND) {
+    hints = GdkAnchorHints(hints | GDK_ANCHOR_SLIDE_X);
+  }
+  // slideVertical from nsMenuPopupFrame::SetPopupPosition
+  if (position >= POPUPPOSITION_STARTBEFORE &&
+      position <= POPUPPOSITION_ENDAFTER) {
+    hints = GdkAnchorHints(hints | GDK_ANCHOR_SLIDE_Y);
+  }
+
+  FlipType flipType = popupFrame->GetFlipType();
+  if (rectAnchor == GDK_GRAVITY_CENTER && menuAnchor == GDK_GRAVITY_CENTER) {
+    // only slide
+    hints = GdkAnchorHints(hints | GDK_ANCHOR_SLIDE);
+  } else {
+    switch (flipType) {
+      case FlipType_Both:
+        hints = GdkAnchorHints(hints | GDK_ANCHOR_FLIP);
+        break;
+      case FlipType_Slide:
+        hints = GdkAnchorHints(hints | GDK_ANCHOR_SLIDE);
+        break;
+      case FlipType_Default:
+        hints = GdkAnchorHints(hints | GDK_ANCHOR_FLIP);
+        break;
+      default:
+        break;
+    }
+  }
+  if (!WaylandPopupIsMenu()) {
+    // we don't want to slide menus to fit the screen rather resize them
+    hints = GdkAnchorHints(hints | GDK_ANCHOR_SLIDE);
+  }
+
+  // We want tooltips to flip verticaly or slide only.
+  // See nsMenuPopupFrame::SetPopupPosition().
+  // https://searchfox.org/mozilla-central/rev/d0f5bc50aff3462c9d1546b88d60c5cb020eb15c/layout/xul/nsMenuPopupFrame.cpp#1603
+  if (mPopupType == PopupType::Tooltip) {
+    hints = GdkAnchorHints(GDK_ANCHOR_FLIP_Y | GDK_ANCHOR_SLIDE);
+  }
+
+  return {
+      anchorRect,
+      rectAnchor,
+      menuAnchor,
+      hints,
+      DevicePixelsToGdkPointRoundDown(LayoutDevicePoint::FromAppUnitsToNearest(
+          popupMargin.mPopupOffset,
+          popupFrame->PresContext()->AppUnitsPerDevPixel())),
+      true};
+}
+
+bool nsWindow::WaylandPopupAnchorAdjustForParentPopup(
+    GdkRectangle* aPopupAnchor, GdkPoint* aOffset) {
+  LOG("nsWindow::WaylandPopupAnchorAdjustForParentPopup");
+
+  GtkWindow* parentGtkWindow = gtk_window_get_transient_for(GTK_WINDOW(mShell));
+  if (!parentGtkWindow || !GTK_IS_WIDGET(parentGtkWindow)) {
+    NS_WARNING("Popup has no parent!");
+    return false;
+  }
+  GdkWindow* window = gtk_widget_get_window(GTK_WIDGET(parentGtkWindow));
+  if (!window) {
+    NS_WARNING("Popup parrent is not mapped!");
+    return false;
+  }
+
+  GdkRectangle parentWindowRect = {0, 0, gdk_window_get_width(window),
+                                   gdk_window_get_height(window)};
+  LOG("  parent window size %d x %d", parentWindowRect.width,
+      parentWindowRect.height);
+
+  // We can't have rectangle anchor with zero width/height.
+  if (!aPopupAnchor->width) {
+    aPopupAnchor->width = 1;
+  }
+  if (!aPopupAnchor->height) {
+    aPopupAnchor->height = 1;
+  }
+
+  GdkRectangle finalRect;
+  if (!gdk_rectangle_intersect(aPopupAnchor, &parentWindowRect, &finalRect)) {
+    return false;
+  }
+  *aPopupAnchor = finalRect;
+  LOG("  anchor is correct %d,%d -> %d x %d", finalRect.x, finalRect.y,
+      finalRect.width, finalRect.height);
+
+  *aOffset = mPopupMoveToRectParams.mOffset;
+  LOG("  anchor offset %d, %d", aOffset->x, aOffset->y);
+  return true;
+}
+
+bool nsWindow::WaylandPopupCheckAndGetAnchor(GdkRectangle* aPopupAnchor,
+                                             GdkPoint* aOffset) {
+  LOG("nsWindow::WaylandPopupCheckAndGetAnchor");
+
+  GdkWindow* gdkWindow = gtk_widget_get_window(GTK_WIDGET(mShell));
+  nsMenuPopupFrame* popupFrame = GetMenuPopupFrame(GetFrame());
+  if (!gdkWindow || !popupFrame) {
+    LOG("  can't use move-to-rect due missing gdkWindow or popupFrame");
+    return false;
+  }
+
+  if (popupFrame->IsFlippedByLayout()) {
+    LOG("  can't use move-to-rect, flipped / constrained by layout");
+    return false;
+  }
+
+  if (!mPopupMoveToRectParams.mAnchorSet) {
+    LOG("  can't use move-to-rect due missing anchor");
+    return false;
+  }
+  // Update popup layout coordinates from layout by recent popup hierarchy
+  // (calculate correct position according to parent window)
+  // and convert to Gtk coordinates.
+  LayoutDeviceIntRect anchorRect = mPopupMoveToRectParams.mAnchorRect;
+  if (!WaylandPopupIsFirst()) {
+    GdkPoint parent = WaylandGetParentPosition();
+    LOG("  subtract parent position from anchor [%d, %d]\n", parent.x,
+        parent.y);
+    anchorRect.MoveBy(-GdkPointToDevicePixels(parent));
+  }
+
+  *aPopupAnchor = DevicePixelsToGdkRectRoundOut(anchorRect);
+  LOG("  anchored to rectangle [%d, %d] -> [%d x %d]", aPopupAnchor->x,
+      aPopupAnchor->y, aPopupAnchor->width, aPopupAnchor->height);
+
+  if (!WaylandPopupAnchorAdjustForParentPopup(aPopupAnchor, aOffset)) {
+    LOG("  can't use move-to-rect, anchor is not placed inside of parent "
+        "window");
+    return false;
+  }
+
+  return true;
+}
+
+void nsWindow::WaylandPopupPrepareForMove() {
+  LOG("nsWindow::WaylandPopupPrepareForMove()");
+
+  if (mPopupHint == PopupType::Tooltip) {
+    // Don't fiddle with tooltips type, just hide it before move-to-rect
+    if (mPopupUseMoveToRect && gtk_widget_is_visible(mShell)) {
+      HideWaylandPopupWindow(/* aTemporaryHide */ true,
+                             /* aRemoveFromPopupList */ false);
+    }
+    LOG("  it's tooltip, quit");
+    return;
+  }
+
+  // See https://bugzilla.mozilla.org/show_bug.cgi?id=1785185#c8
+  // gtk_window_move() needs GDK_WINDOW_TYPE_HINT_UTILITY popup type.
+  // move-to-rect requires GDK_WINDOW_TYPE_HINT_POPUP_MENU popups type.
+  // We need to set it before map event when popup is hidden.
+  const GdkWindowTypeHint currentType =
+      gtk_window_get_type_hint(GTK_WINDOW(mShell));
+  const GdkWindowTypeHint requiredType = mPopupUseMoveToRect
+                                             ? GDK_WINDOW_TYPE_HINT_POPUP_MENU
+                                             : GDK_WINDOW_TYPE_HINT_UTILITY;
+
+  if (!mPopupUseMoveToRect && currentType == requiredType) {
+    LOG("  type matches and we're not forced to hide it, quit.");
+    return;
+  }
+
+  if (gtk_widget_is_visible(mShell)) {
+    HideWaylandPopupWindow(/* aTemporaryHide */ true,
+                           /* aRemoveFromPopupList */ false);
+  }
+
+  if (currentType != requiredType) {
+    LOG("  set type %s",
+        requiredType == GDK_WINDOW_TYPE_HINT_POPUP_MENU ? "MENU" : "UTILITY");
+    gtk_window_set_type_hint(GTK_WINDOW(mShell), requiredType);
+  }
+}
+
+// Plain popup move on Wayland - simply place popup on given location.
+// We can't just call gtk_window_move() as it's not effective on visible
+// popups.
+void nsWindow::WaylandPopupMovePlain(int aX, int aY) {
+  LOG("nsWindow::WaylandPopupMovePlain(%d, %d)", aX, aY);
+
+  // We can directly move only popups based on wl_subsurface type.
+  MOZ_DIAGNOSTIC_ASSERT(gtk_window_get_type_hint(GTK_WINDOW(mShell)) ==
+                            GDK_WINDOW_TYPE_HINT_UTILITY ||
+                        gtk_window_get_type_hint(GTK_WINDOW(mShell)) ==
+                            GDK_WINDOW_TYPE_HINT_TOOLTIP);
+
+  gtk_window_move(GTK_WINDOW(mShell), aX, aY);
+
+  // gtk_window_move() can trick us. When widget is hidden gtk_window_move()
+  // does not move the widget but sets new widget coordinates when widget
+  // is mapped again.
+  //
+  // If popup used move-to-rect before
+  // (GdkWindow has POSITION_METHOD_MOVE_TO_RECT set), popup will use
+  // move-to-rect again when it's mapped and we'll get bogus move-to-rect
+  // callback.
+  //
+  // gdk_window_move() sets position_method to POSITION_METHOD_MOVE_RESIZE
+  // so we'll use plain move when popup is shown.
+  if (!gtk_widget_get_mapped(mShell)) {
+    GdkWindow* window = gtk_widget_get_window(mShell);
+    if (window) {
+      gdk_window_move(window, aX, aY);
+    }
+  }
+}
+
+void nsWindow::WaylandPopupMoveImpl() {
+  // Available as of GTK 3.24+
+  static auto sGdkWindowMoveToRect = (void (*)(
+      GdkWindow*, const GdkRectangle*, GdkGravity, GdkGravity, GdkAnchorHints,
+      gint, gint))dlsym(RTLD_DEFAULT, "gdk_window_move_to_rect");
+
+  if (mPopupUseMoveToRect && !sGdkWindowMoveToRect) {
+    LOG("can't use move-to-rect due missing gdk_window_move_to_rect()");
+    mPopupUseMoveToRect = false;
+  }
+
+  GdkRectangle gtkAnchorRect;
+  GdkPoint offset;
+  if (mPopupUseMoveToRect) {
+    mPopupUseMoveToRect =
+        WaylandPopupCheckAndGetAnchor(&gtkAnchorRect, &offset);
+  }
+
+  LOG("nsWindow::WaylandPopupMove");
+  LOG("  original widget popup position [%d, %d]\n", mPopupPosition.x,
+      mPopupPosition.y);
+  LOG("  relative widget popup position [%d, %d]\n", mRelativePopupPosition.x,
+      mRelativePopupPosition.y);
+  LOG("  popup use move to rect %d", mPopupUseMoveToRect);
+
+  WaylandPopupPrepareForMove();
+
+  if (!mPopupUseMoveToRect) {
+    WaylandPopupMovePlain(mRelativePopupPosition.x, mRelativePopupPosition.y);
+    // Layout already should be aware of our bounds, since we didn't change it
+    // from the widget side for flipping or so.
+    return;
+  }
+
+  // Correct popup position now. It will be updated by gdk_window_move_to_rect()
+  // anyway but we need to set it now to avoid a race condition here.
+  WaylandPopupRemoveNegativePosition();
+
+  GdkWindow* gdkWindow = gtk_widget_get_window(GTK_WIDGET(mShell));
+  if (!g_signal_handler_find(gdkWindow, G_SIGNAL_MATCH_FUNC, 0, 0, nullptr,
+                             FuncToGpointer(NativeMoveResizeCallback), this)) {
+    g_signal_connect(gdkWindow, "moved-to-rect",
+                     G_CALLBACK(NativeMoveResizeCallback), this);
+  }
+  mWaitingForMoveToRectCallback = true;
+
+#ifdef MOZ_LOGGING
+  if (LOG_ENABLED()) {
+    LOG("  Call move-to-rect");
+    LOG("  Anchor rect [%d, %d] -> [%d x %d]", gtkAnchorRect.x, gtkAnchorRect.y,
+        gtkAnchorRect.width, gtkAnchorRect.height);
+    LOG("  Offset [%d, %d]", offset.x, offset.y);
+    LOG("  AnchorType");
+    LogPopupGravity(mPopupMoveToRectParams.mAnchorRectType);
+    LOG("  PopupAnchorType");
+    LogPopupGravity(mPopupMoveToRectParams.mPopupAnchorType);
+    LogPopupAnchorHints(mPopupMoveToRectParams.mHints);
+  }
+#endif
+
+  sGdkWindowMoveToRect(gdkWindow, &gtkAnchorRect,
+                       mPopupMoveToRectParams.mAnchorRectType,
+                       mPopupMoveToRectParams.mPopupAnchorType,
+                       mPopupMoveToRectParams.mHints, offset.x, offset.y);
+}
+
+void nsWindow::SetZIndex(int32_t aZIndex) {
+  nsIWidget* oldPrev = GetPrevSibling();
+
+  nsBaseWidget::SetZIndex(aZIndex);
+
+  if (GetPrevSibling() == oldPrev) {
+    return;
+  }
+
+  NS_ASSERTION(!mContainer, "Expected Mozilla child widget");
+
+  // We skip the nsWindows that don't have mGdkWindows.
+  // These are probably in the process of being destroyed.
+  if (!mGdkWindow) {
+    return;
+  }
+
+  if (!GetNextSibling()) {
+    // We're to be on top.
+    if (mGdkWindow) {
+      gdk_window_raise(mGdkWindow);
+    }
+  } else {
+    // All the siblings before us need to be below our widget.
+    for (nsWindow* w = this; w;
+         w = static_cast<nsWindow*>(w->GetPrevSibling())) {
+      if (w->mGdkWindow) {
+        gdk_window_lower(w->mGdkWindow);
+      }
+    }
+  }
+}
+
+void nsWindow::SetSizeMode(nsSizeMode aMode) {
+  LOG("nsWindow::SetSizeMode %d\n", aMode);
+
+  // Return if there's no shell or our current state is the same as the mode we
+  // were just set to.
+  if (!mShell) {
+    LOG("    no shell");
+    return;
+  }
+
+  if (mSizeMode == aMode && mLastSizeModeRequest == aMode) {
+    LOG("    already set");
+    return;
+  }
+
+  // It is tempting to try to optimize calls below based only on current
+  // mSizeMode, but that wouldn't work if there's a size-request in flight
+  // (specially before show). See bug 1789823.
+  const auto SizeModeMightBe = [&](nsSizeMode aModeToTest) {
+    if (mSizeMode != mLastSizeModeRequest) {
+      // Arbitrary size mode requests might be ongoing.
+      return true;
+    }
+    return mSizeMode == aModeToTest;
+  };
+
+  if (aMode != nsSizeMode_Fullscreen && aMode != nsSizeMode_Minimized) {
+    // Fullscreen and minimized are compatible.
+    if (SizeModeMightBe(nsSizeMode_Fullscreen)) {
+      MakeFullScreen(false);
+    }
+  }
+
+  switch (aMode) {
+    case nsSizeMode_Maximized:
+      LOG("    set maximized");
+      gtk_window_maximize(GTK_WINDOW(mShell));
+      break;
+    case nsSizeMode_Minimized:
+      LOG("    set minimized");
+      gtk_window_iconify(GTK_WINDOW(mShell));
+      break;
+    case nsSizeMode_Fullscreen:
+      LOG("    set fullscreen");
+      MakeFullScreen(true);
+      break;
+    default:
+      MOZ_FALLTHROUGH_ASSERT("Unknown size mode");
+    case nsSizeMode_Normal:
+      LOG("    set normal");
+      if (SizeModeMightBe(nsSizeMode_Maximized)) {
+        gtk_window_unmaximize(GTK_WINDOW(mShell));
+      }
+      if (SizeModeMightBe(nsSizeMode_Minimized)) {
+        gtk_window_deiconify(GTK_WINDOW(mShell));
+        // We need this for actual deiconification on mutter.
+        gtk_window_present(GTK_WINDOW(mShell));
+      }
+      break;
+  }
+  mLastSizeModeRequest = aMode;
+}
+
+#define kDesktopMutterSchema "org.gnome.mutter"_ns
+#define kDesktopDynamicWorkspacesKey "dynamic-workspaces"_ns
+
+static bool WorkspaceManagementDisabled(GdkScreen* screen) {
+  if (Preferences::GetBool("widget.disable-workspace-management", false)) {
+    return true;
+  }
+  if (Preferences::HasUserValue("widget.workspace-management")) {
+    return Preferences::GetBool("widget.workspace-management");
+  }
+
+  if (IsGnomeDesktopEnvironment()) {
+    // Gnome uses dynamic workspaces by default so disable workspace management
+    // in that case.
+    bool usesDynamicWorkspaces = true;
+    nsCOMPtr<nsIGSettingsService> gsettings =
+        do_GetService(NS_GSETTINGSSERVICE_CONTRACTID);
+    if (gsettings) {
+      nsCOMPtr<nsIGSettingsCollection> mutterSettings;
+      gsettings->GetCollectionForSchema(kDesktopMutterSchema,
+                                        getter_AddRefs(mutterSettings));
+      if (mutterSettings) {
+        mutterSettings->GetBoolean(kDesktopDynamicWorkspacesKey,
+                                   &usesDynamicWorkspaces);
+      }
+    }
+    return usesDynamicWorkspaces;
+  }
+
+  const auto& desktop = GetDesktopEnvironmentIdentifier();
+  return desktop.EqualsLiteral("bspwm") || desktop.EqualsLiteral("i3");
+}
+
+void nsWindow::GetWorkspaceID(nsAString& workspaceID) {
+  workspaceID.Truncate();
+
+  if (!GdkIsX11Display() || !mShell) {
+    return;
+  }
+
+#ifdef MOZ_X11
+  LOG("nsWindow::GetWorkspaceID()\n");
+
+  // Get the gdk window for this widget.
+  GdkWindow* gdk_window = gtk_widget_get_window(mShell);
+  if (!gdk_window) {
+    LOG("  missing Gdk window, quit.");
+    return;
+  }
+
+  if (WorkspaceManagementDisabled(gdk_window_get_screen(gdk_window))) {
+    LOG("  WorkspaceManagementDisabled, quit.");
+    return;
+  }
+
+  GdkAtom cardinal_atom = gdk_x11_xatom_to_atom(XA_CARDINAL);
+  GdkAtom type_returned;
+  int format_returned;
+  int length_returned;
+  long* wm_desktop;
+
+  if (!gdk_property_get(gdk_window, gdk_atom_intern("_NET_WM_DESKTOP", FALSE),
+                        cardinal_atom,
+                        0,          // offset
+                        INT32_MAX,  // length
+                        FALSE,      // delete
+                        &type_returned, &format_returned, &length_returned,
+                        (guchar**)&wm_desktop)) {
+    LOG("  gdk_property_get() failed, quit.");
+    return;
+  }
+
+  LOG("  got workspace ID %d", (int32_t)wm_desktop[0]);
+  workspaceID.AppendInt((int32_t)wm_desktop[0]);
+  g_free(wm_desktop);
+#endif
+}
+
+void nsWindow::MoveToWorkspace(const nsAString& workspaceIDStr) {
+  nsresult rv = NS_OK;
+  int32_t workspaceID = workspaceIDStr.ToInteger(&rv);
+
+  LOG("nsWindow::MoveToWorkspace() ID %d", workspaceID);
+  if (NS_FAILED(rv) || !workspaceID || !GdkIsX11Display() || !mShell) {
+    LOG("  MoveToWorkspace disabled, quit");
+    return;
+  }
+
+#ifdef MOZ_X11
+  // Get the gdk window for this widget.
+  GdkWindow* gdk_window = gtk_widget_get_window(mShell);
+  if (!gdk_window) {
+    LOG("  failed to get GdkWindow, quit.");
+    return;
+  }
+
+  // This code is inspired by some found in the 'gxtuner' project.
+  // https://github.com/brummer10/gxtuner/blob/792d453da0f3a599408008f0f1107823939d730d/deskpager.cpp#L50
+  XEvent xevent;
+  Display* xdisplay = gdk_x11_get_default_xdisplay();
+  GdkScreen* screen = gdk_window_get_screen(gdk_window);
+  Window root_win = GDK_WINDOW_XID(gdk_screen_get_root_window(screen));
+  GdkDisplay* display = gdk_window_get_display(gdk_window);
+  Atom type = gdk_x11_get_xatom_by_name_for_display(display, "_NET_WM_DESKTOP");
+
+  xevent.type = ClientMessage;
+  xevent.xclient.type = ClientMessage;
+  xevent.xclient.serial = 0;
+  xevent.xclient.send_event = TRUE;
+  xevent.xclient.display = xdisplay;
+  xevent.xclient.window = GDK_WINDOW_XID(gdk_window);
+  xevent.xclient.message_type = type;
+  xevent.xclient.format = 32;
+  xevent.xclient.data.l[0] = workspaceID;
+  xevent.xclient.data.l[1] = X11CurrentTime;
+  xevent.xclient.data.l[2] = 0;
+  xevent.xclient.data.l[3] = 0;
+  xevent.xclient.data.l[4] = 0;
+
+  XSendEvent(xdisplay, root_win, FALSE,
+             SubstructureNotifyMask | SubstructureRedirectMask, &xevent);
+
+  XFlush(xdisplay);
+  LOG("  moved to workspace");
+#endif
+}
+
+void nsWindow::SetUserTimeAndStartupTokenForActivatedWindow() {
+  nsGTKToolkit* toolkit = nsGTKToolkit::GetToolkit();
+  if (!toolkit || MOZ_UNLIKELY(mWindowType == WindowType::Invisible)) {
+    return;
+  }
+
+  mWindowActivationTokenFromEnv = toolkit->GetStartupToken();
+  if (!mWindowActivationTokenFromEnv.IsEmpty()) {
+    if (!GdkIsWaylandDisplay()) {
+      gtk_window_set_startup_id(GTK_WINDOW(mShell),
+                                mWindowActivationTokenFromEnv.get());
+      // In the case of X11, the above call is all we need. For wayland we need
+      // to keep the token around until we take it in
+      // TransferFocusToWaylandWindow.
+      mWindowActivationTokenFromEnv.Truncate();
+    }
+  } else if (uint32_t timestamp = toolkit->GetFocusTimestamp()) {
+    // We don't have the data we need. Fall back to an
+    // approximation ... using the timestamp of the remote command
+    // being received as a guess for the timestamp of the user event
+    // that triggered it.
+    gdk_window_focus(gtk_widget_get_window(mShell), timestamp);
+  }
+
+  // If we used the startup ID, that already contains the focus timestamp;
+  // we don't want to reuse the timestamp next time we raise the window
+  toolkit->SetFocusTimestamp(0);
+  toolkit->SetStartupToken(""_ns);
+}
+
+/* static */
+guint32 nsWindow::GetLastUserInputTime() {
+  // gdk_x11_display_get_user_time/gtk_get_current_event_time tracks
+  // button and key presses, DESKTOP_STARTUP_ID used to start the app,
+  // drop events from external drags,
+  // WM_DELETE_WINDOW delete events, but not usually mouse motion nor
+  // button and key releases.  Therefore use the most recent of
+  // gdk_x11_display_get_user_time and the last time that we have seen.
+#ifdef MOZ_X11
+  GdkDisplay* gdkDisplay = gdk_display_get_default();
+  guint32 timestamp = GdkIsX11Display(gdkDisplay)
+                          ? gdk_x11_display_get_user_time(gdkDisplay)
+                          : gtk_get_current_event_time();
+#else
+  guint32 timestamp = gtk_get_current_event_time();
+#endif
+
+  if (sLastUserInputTime != GDK_CURRENT_TIME &&
+      TimestampIsNewerThan(sLastUserInputTime, timestamp)) {
+    return sLastUserInputTime;
+  }
+
+  return timestamp;
+}
+
+#ifdef MOZ_WAYLAND
+void nsWindow::FocusWaylandWindow(const char* aTokenID) {
+  MOZ_DIAGNOSTIC_ASSERT(aTokenID);
+
+  LOG("nsWindow::FocusWaylandWindow(%s)", aTokenID);
+  if (IsDestroyed()) {
+    LOG("  already destroyed, quit.");
+    return;
+  }
+  wl_surface* surface =
+      mGdkWindow ? gdk_wayland_window_get_wl_surface(mGdkWindow) : nullptr;
+  if (!surface) {
+    LOG("  mGdkWindow is not visible, quit.");
+    return;
+  }
+
+  LOG("  requesting xdg-activation, surface ID %d",
+      wl_proxy_get_id((struct wl_proxy*)surface));
+  xdg_activation_v1* xdg_activation = WaylandDisplayGet()->GetXdgActivation();
+  if (!xdg_activation) {
+    return;
+  }
+  xdg_activation_v1_activate(xdg_activation, aTokenID, surface);
+}
+
+// Transfer focus from gFocusWindow to aWindow and use xdg_activation
+// protocol for it.
+void nsWindow::TransferFocusToWaylandWindow(nsWindow* aWindow) {
+  LOGW("nsWindow::TransferFocusToWaylandWindow(%p) gFocusWindow %p", aWindow,
+       gFocusWindow);
+  auto promise = mozilla::widget::RequestWaylandFocusPromise();
+  if (NS_WARN_IF(!promise)) {
+    LOGW("  quit, failed to create TransferFocusToWaylandWindow [%p]", aWindow);
+    return;
+  }
+  promise->Then(
+      GetMainThreadSerialEventTarget(), __func__,
+      /* resolve */
+      [window = RefPtr{aWindow}](nsCString token) {
+        window->FocusWaylandWindow(token.get());
+      },
+      /* reject */
+      [window = RefPtr{aWindow}](bool state) {
+        LOGW("TransferFocusToWaylandWindow [%p] failed", window.get());
+      });
+}
+#endif
+
+// Request activation of this window or give focus to this widget.
+// aRaise means whether we should request activation of this widget's
+// toplevel window.
+//
+// nsWindow::SetFocus(Raise::Yes) - Raise and give focus to toplevel window.
+// nsWindow::SetFocus(Raise::No) - Give focus to this window.
+void nsWindow::SetFocus(Raise aRaise, mozilla::dom::CallerType aCallerType) {
+  LOG("nsWindow::SetFocus Raise %d\n", aRaise == Raise::Yes);
+
+  // Raise the window if someone passed in true and the prefs are
+  // set properly.
+  GtkWidget* toplevelWidget = gtk_widget_get_toplevel(GTK_WIDGET(mContainer));
+
+  LOG("  gFocusWindow [%p]\n", gFocusWindow);
+  LOG("  mContainer [%p]\n", GTK_WIDGET(mContainer));
+  LOG("  Toplevel widget [%p]\n", toplevelWidget);
+
+  // Make sure that our owning widget has focus.  If it doesn't try to
+  // grab it.  Note that we don't set our focus flag in this case.
+  if (StaticPrefs::mozilla_widget_raise_on_setfocus_AtStartup() &&
+      aRaise == Raise::Yes && toplevelWidget &&
+      !gtk_widget_has_focus(toplevelWidget)) {
+    if (gtk_widget_get_visible(mShell)) {
+      LOG("  toplevel is not focused");
+      gdk_window_show_unraised(gtk_widget_get_window(mShell));
+      // Unset the urgency hint if possible.
+      SetUrgencyHint(mShell, false);
+    }
+  }
+
+  RefPtr<nsWindow> toplevelWindow = get_window_for_gtk_widget(toplevelWidget);
+  if (!toplevelWindow) {
+    LOG("  missing toplevel nsWindow, quit\n");
+    return;
+  }
+
+  if (aRaise == Raise::Yes) {
+    // means request toplevel activation.
+
+    // This is asynchronous. If and when the window manager accepts the request,
+    // then the focus widget will get a focus-in-event signal.
+    if (StaticPrefs::mozilla_widget_raise_on_setfocus_AtStartup() &&
+        toplevelWindow->mIsShown && toplevelWindow->mShell &&
+        !gtk_window_is_active(GTK_WINDOW(toplevelWindow->mShell))) {
+      LOG("  toplevel is visible but not active, requesting activation [%p]",
+          toplevelWindow.get());
+
+      // Take the time here explicitly for the call below.
+      const uint32_t timestamp = [&] {
+        if (nsGTKToolkit* toolkit = nsGTKToolkit::GetToolkit()) {
+          if (uint32_t t = toolkit->GetFocusTimestamp()) {
+            toolkit->SetFocusTimestamp(0);
+            return t;
+          }
+        }
+        return GetLastUserInputTime();
+      }();
+
+      toplevelWindow->SetUserTimeAndStartupTokenForActivatedWindow();
+      gtk_window_present_with_time(GTK_WINDOW(toplevelWindow->mShell),
+                                   timestamp);
+
+#ifdef MOZ_WAYLAND
+      if (GdkIsWaylandDisplay()) {
+        auto existingToken =
+            std::move(toplevelWindow->mWindowActivationTokenFromEnv);
+        if (!existingToken.IsEmpty()) {
+          LOG("  has existing activation token.");
+          toplevelWindow->FocusWaylandWindow(existingToken.get());
+        } else {
+          LOG("  missing activation token, try to transfer from focused "
+              "window");
+          TransferFocusToWaylandWindow(toplevelWindow);
+        }
+      }
+#endif
+    }
+    return;
+  }
+
+  // aRaise == No means that keyboard events should be dispatched from this
+  // widget.
+
+  // Ensure GTK_WIDGET(mContainer) is the focused GtkWidget within its toplevel
+  // window.
+  //
+  // For WindowType::Popup, this GtkWidget may not actually be the one that
+  // receives the key events as it may be the parent window that is active.
+  if (!gtk_widget_is_focus(GTK_WIDGET(mContainer))) {
+    // This is synchronous.  It takes focus from a plugin or from a widget
+    // in an embedder.  The focus manager already knows that this window
+    // is active so gBlockActivateEvent avoids another (unnecessary)
+    // activate notification.
+    gBlockActivateEvent = true;
+    gtk_widget_grab_focus(GTK_WIDGET(mContainer));
+    gBlockActivateEvent = false;
+  }
+
+  // If this is the widget that already has focus, return.
+  if (gFocusWindow == this) {
+    LOG("  already have focus");
+    return;
+  }
+
+  // Set this window to be the focused child window
+  gFocusWindow = this;
+
+  if (mIMContext) {
+    mIMContext->OnFocusWindow(this);
+  }
+
+  LOG("  widget now has focus in SetFocus()");
+}
+
+LayoutDeviceIntRect nsWindow::GetScreenBounds() {
+  const LayoutDeviceIntPoint origin = [&] {
+    // XXX Can't we use mGdkWindow here?
+    //
+    // Use the point including window decorations. Don't do this for popups,
+    // because we get wrong coordinates for gtk for override-redirect windows in
+    // HiDPI screens, and those don't have window decorations anyways.
+    //
+    // See https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/4820
+    if (mContainer && mWindowType != WindowType::Popup) {
+      gint x, y;
+      gdk_window_get_root_origin(gtk_widget_get_window(GTK_WIDGET(mContainer)),
+                                 &x, &y);
+      return GdkPointToDevicePixels({x, y});
+    }
+    return WidgetToScreenOffset();
+  }();
+
+  // mBounds.Size() is the window bounds, not the window-manager frame
+  // bounds (bug 581863).  gdk_window_get_frame_extents would give the
+  // frame bounds, but mBounds.Size() is returned here for consistency
+  // with Resize.
+  const LayoutDeviceIntRect rect(origin, mBounds.Size());
+#if MOZ_LOGGING
+  if (MOZ_LOG_TEST(IsPopup() ? gWidgetPopupLog : gWidgetLog,
+                   LogLevel::Verbose)) {
+    gint scale = GdkCeiledScaleFactor();
+    if (mLastLoggedScale != scale || !(mLastLoggedBoundSize == rect)) {
+      mLastLoggedScale = scale;
+      mLastLoggedBoundSize = rect;
+      LOG("GetScreenBounds %d,%d -> %d x %d, unscaled %d,%d -> %d x %d\n",
+          rect.x, rect.y, rect.width, rect.height, rect.x / scale,
+          rect.y / scale, rect.width / scale, rect.height / scale);
+    }
+  }
+#endif
+  return rect;
+}
+
+LayoutDeviceIntSize nsWindow::GetClientSize() {
+  return LayoutDeviceIntSize(mBounds.width, mBounds.height);
+}
+
+LayoutDeviceIntRect nsWindow::GetClientBounds() {
+  // GetBounds returns a rect whose top left represents the top left of the
+  // outer bounds, but whose width/height represent the size of the inner
+  // bounds (which is messed up).
+  LayoutDeviceIntRect rect = GetBounds();
+  rect.MoveBy(GetClientOffset());
+  return rect;
+}
+
+void nsWindow::RecomputeClientOffset(bool aNotify) {
+  if (mWindowType != WindowType::Dialog &&
+      mWindowType != WindowType::TopLevel) {
+    return;
+  }
+
+  auto oldOffset = mClientOffset;
+
+  mClientOffset = WidgetToScreenOffset() - mBounds.TopLeft();
+
+  if (aNotify && mClientOffset != oldOffset) {
+    // Send a WindowMoved notification. This ensures that BrowserParent picks up
+    // the new client offset and sends it to the child process if appropriate.
+    NotifyWindowMoved(mBounds.x, mBounds.y);
+  }
+}
+
+gboolean nsWindow::OnPropertyNotifyEvent(GtkWidget* aWidget,
+                                         GdkEventProperty* aEvent) {
+  if (aEvent->atom == gdk_atom_intern("_NET_FRAME_EXTENTS", FALSE)) {
+    RecomputeClientOffset(/* aNotify = */ true);
+    return FALSE;
+  }
+  if (!mGdkWindow) {
+    return FALSE;
+  }
+#ifdef MOZ_X11
+  if (GetCurrentTimeGetter()->PropertyNotifyHandler(aWidget, aEvent)) {
+    return TRUE;
+  }
+#endif
+  return FALSE;
+}
+
+static GdkCursor* GetCursorForImage(const nsIWidget::Cursor& aCursor,
+                                    int32_t aWidgetScaleFactor) {
+  if (!aCursor.IsCustom()) {
+    return nullptr;
+  }
+  nsIntSize size = nsIWidget::CustomCursorSize(aCursor);
+
+  // NOTE: GTK only allows integer scale factors, so we ceil to the larger scale
+  // factor and then tell gtk to scale it down. We ensure to scale at least to
+  // the GDK scale factor, so that cursors aren't downsized in HiDPI on wayland,
+  // see bug 1707533.
+  int32_t gtkScale = std::max(
+      aWidgetScaleFactor, int32_t(std::ceil(std::max(aCursor.mResolution.mX,
+                                                     aCursor.mResolution.mY))));
+
+  // Reject cursors greater than 128 pixels in some direction, to prevent
+  // spoofing.
+  // XXX ideally we should rescale. Also, we could modify the API to
+  // allow trusted content to set larger cursors.
+  //
+  // TODO(emilio, bug 1445844): Unify the solution for this with other
+  // platforms.
+  if (size.width > 128 || size.height > 128) {
+    return nullptr;
+  }
+
+  nsIntSize rasterSize = size * gtkScale;
+  RefPtr<GdkPixbuf> pixbuf =
+      nsImageToPixbuf::ImageToPixbuf(aCursor.mContainer, Some(rasterSize));
+  if (!pixbuf) {
+    return nullptr;
+  }
+
+  // Looks like all cursors need an alpha channel (tested on Gtk 2.4.4). This
+  // is of course not documented anywhere...
+  // So add one if there isn't one yet
+  if (!gdk_pixbuf_get_has_alpha(pixbuf)) {
+    RefPtr<GdkPixbuf> alphaBuf =
+        dont_AddRef(gdk_pixbuf_add_alpha(pixbuf, FALSE, 0, 0, 0));
+    pixbuf = std::move(alphaBuf);
+    if (!pixbuf) {
+      return nullptr;
+    }
+  }
+
+  cairo_surface_t* surface =
+      gdk_cairo_surface_create_from_pixbuf(pixbuf, gtkScale, nullptr);
+  if (!surface) {
+    return nullptr;
+  }
+
+  auto CleanupSurface =
+      MakeScopeExit([&]() { cairo_surface_destroy(surface); });
+
+  return gdk_cursor_new_from_surface(gdk_display_get_default(), surface,
+                                     aCursor.mHotspotX, aCursor.mHotspotY);
+}
+
+void nsWindow::SetCursor(const Cursor& aCursor) {
+  // if we're not the toplevel window pass up the cursor request to
+  // the toplevel window to handle it.
+  if (!mContainer && mGdkWindow) {
+    if (nsWindow* window = GetContainerWindow()) {
+      window->SetCursor(aCursor);
+    }
+    return;
+  }
+
+  if (mWidgetCursorLocked) {
+    return;
+  }
+
+  // Only change cursor if it's actually been changed
+  if (!mUpdateCursor && mCursor == aCursor) {
+    return;
+  }
+
+  mUpdateCursor = false;
+  mCursor = aCursor;
+
+  // Try to set the cursor image first, and fall back to the numeric cursor.
+  bool fromImage = true;
+  GdkCursor* newCursor = nullptr;
+  if (mCustomCursorAllowed) {
+    newCursor = GetCursorForImage(aCursor, GdkCeiledScaleFactor());
+  }
+  if (!newCursor) {
+    fromImage = false;
+    newCursor = get_gtk_cursor(aCursor.mDefaultCursor);
+  }
+
+  auto CleanupCursor = mozilla::MakeScopeExit([&]() {
+    // get_gtk_cursor returns a weak reference, which we shouldn't unref.
+    if (fromImage) {
+      g_object_unref(newCursor);
+    }
+  });
+
+  if (!newCursor || !mContainer) {
+    return;
+  }
+
+  gdk_window_set_cursor(gtk_widget_get_window(GTK_WIDGET(mContainer)),
+                        newCursor);
+}
+
+void nsWindow::Invalidate(const LayoutDeviceIntRect& aRect) {
+  if (!mGdkWindow) return;
+
+  GdkRectangle rect = DevicePixelsToGdkRectRoundOut(aRect);
+  gdk_window_invalidate_rect(mGdkWindow, &rect, FALSE);
+
+  LOG("Invalidate (rect): %d %d %d %d\n", rect.x, rect.y, rect.width,
+      rect.height);
+}
+
+void* nsWindow::GetNativeData(uint32_t aDataType) {
+  switch (aDataType) {
+    case NS_NATIVE_WINDOW:
+    case NS_NATIVE_WIDGET: {
+      return mGdkWindow;
+    }
+
+    case NS_NATIVE_SHELLWIDGET:
+      return GetToplevelWidget();
+
+    case NS_NATIVE_WINDOW_WEBRTC_DEVICE_ID:
+#ifdef MOZ_X11
+      if (GdkIsX11Display()) {
+        return (void*)GDK_WINDOW_XID(gdk_window_get_toplevel(mGdkWindow));
+      }
+#endif
+      NS_WARNING(
+          "nsWindow::GetNativeData(): NS_NATIVE_WINDOW_WEBRTC_DEVICE_ID is not "
+          "handled on Wayland!");
+      return nullptr;
+    case NS_RAW_NATIVE_IME_CONTEXT: {
+      void* pseudoIMEContext = GetPseudoIMEContext();
+      if (pseudoIMEContext) {
+        return pseudoIMEContext;
+      }
+      // If IME context isn't available on this widget, we should set |this|
+      // instead of nullptr.
+      if (!mIMContext) {
+        return this;
+      }
+      return mIMContext.get();
+    }
+    case NS_NATIVE_OPENGL_CONTEXT:
+      return nullptr;
+    case NS_NATIVE_EGL_WINDOW: {
+      void* eglWindow = nullptr;
+#ifdef MOZ_X11
+      if (GdkIsX11Display()) {
+        eglWindow = mGdkWindow ? (void*)GDK_WINDOW_XID(mGdkWindow) : nullptr;
+      }
+#endif
+#ifdef MOZ_WAYLAND
+      if (GdkIsWaylandDisplay()) {
+        if (mCompositorWidgetDelegate &&
+            mCompositorWidgetDelegate->AsGtkCompositorWidget() &&
+            mCompositorWidgetDelegate->AsGtkCompositorWidget()->IsHidden()) {
+          NS_WARNING("Getting OpenGL EGL window for hidden Gtk window!");
+          return nullptr;
+        }
+        eglWindow = moz_container_wayland_get_egl_window(
+            mContainer, FractionalScaleFactor());
+      }
+#endif
+      LOG("Get NS_NATIVE_EGL_WINDOW mGdkWindow %p returned eglWindow %p",
+          mGdkWindow, eglWindow);
+      return eglWindow;
+    }
+    default:
+      NS_WARNING("nsWindow::GetNativeData called with bad value");
+      return nullptr;
+  }
+}
+
+nsresult nsWindow::SetTitle(const nsAString& aTitle) {
+  if (!mShell) return NS_OK;
+
+    // convert the string into utf8 and set the title.
+#define UTF8_FOLLOWBYTE(ch) (((ch)&0xC0) == 0x80)
+  NS_ConvertUTF16toUTF8 titleUTF8(aTitle);
+  if (titleUTF8.Length() > NS_WINDOW_TITLE_MAX_LENGTH) {
+    // Truncate overlong titles (bug 167315). Make sure we chop after a
+    // complete sequence by making sure the next char isn't a follow-byte.
+    uint32_t len = NS_WINDOW_TITLE_MAX_LENGTH;
+    while (UTF8_FOLLOWBYTE(titleUTF8[len])) --len;
+    titleUTF8.Truncate(len);
+  }
+  gtk_window_set_title(GTK_WINDOW(mShell), (const char*)titleUTF8.get());
+
+  return NS_OK;
+}
+
+void nsWindow::SetIcon(const nsAString& aIconSpec) {
+  if (!mShell) return;
+
+  nsAutoCString iconName;
+
+  if (aIconSpec.EqualsLiteral("default")) {
+    nsAutoString brandName;
+    WidgetUtils::GetBrandShortName(brandName);
+    if (brandName.IsEmpty()) {
+      brandName.AssignLiteral(u"Mozilla");
+    }
+    AppendUTF16toUTF8(brandName, iconName);
+    ToLowerCase(iconName);
+  } else {
+    AppendUTF16toUTF8(aIconSpec, iconName);
+  }
+
+  nsCOMPtr<nsIFile> iconFile;
+  nsAutoCString path;
+
+  gint* iconSizes = gtk_icon_theme_get_icon_sizes(gtk_icon_theme_get_default(),
+                                                  iconName.get());
+  bool foundIcon = (iconSizes[0] != 0);
+  g_free(iconSizes);
+
+  if (!foundIcon) {
+    // Look for icons with the following suffixes appended to the base name
+    // The last two entries (for the old XPM format) will be ignored unless
+    // no icons are found using other suffixes. XPM icons are deprecated.
+
+    const char16_t extensions[9][8] = {u".png",    u"16.png", u"32.png",
+                                       u"48.png",  u"64.png", u"128.png",
+                                       u"256.png", u".xpm",   u"16.xpm"};
+
+    for (uint32_t i = 0; i < ArrayLength(extensions); i++) {
+      // Don't bother looking for XPM versions if we found a PNG.
+      if (i == ArrayLength(extensions) - 2 && foundIcon) break;
+
+      ResolveIconName(aIconSpec, nsDependentString(extensions[i]),
+                      getter_AddRefs(iconFile));
+      if (iconFile) {
+        iconFile->GetNativePath(path);
+        GdkPixbuf* icon = gdk_pixbuf_new_from_file(path.get(), nullptr);
+        if (icon) {
+          gtk_icon_theme_add_builtin_icon(iconName.get(),
+                                          gdk_pixbuf_get_height(icon), icon);
+          g_object_unref(icon);
+          foundIcon = true;
+        }
+      }
+    }
+  }
+
+  // leave the default icon intact if no matching icons were found
+  if (foundIcon) {
+    gtk_window_set_icon_name(GTK_WINDOW(mShell), iconName.get());
+  }
+}
+
+/* TODO(bug 1655924): gdk_window_get_origin is can block waiting for the X
+   server for a long time, we would like to use the implementation below
+   instead. However, removing the synchronous x server queries causes a race
+   condition to surface, causing issues such as bug 1652743 and bug 1653711.
+
+
+   This code can be used instead of gdk_window_get_origin() but it cuases
+   such issues:
+
+    *aX = 0;
+    *aY = 0;
+    if (!aWindow) {
+      return;
+    }
+
+    GdkWindow* current = aWindow;
+    while (GdkWindow* parent = gdk_window_get_parent(current)) {
+      if (parent == current) {
+        break;
+      }
+
+      int x = 0;
+      int y = 0;
+      gdk_window_get_position(current, &x, &y);
+      *aX += x;
+      *aY += y;
+
+      current = parent;
+    }
+*/
+LayoutDeviceIntPoint nsWindow::WidgetToScreenOffset() {
+  // Don't use gdk_window_get_origin() on wl_subsurface Wayland popups
+  // https://gitlab.gnome.org/GNOME/gtk/-/issues/5287
+  if (IsWaylandPopup() && !mPopupUseMoveToRect) {
+    return mBounds.TopLeft();
+  }
+  nsIntPoint origin(0, 0);
+  if (mGdkWindow) {
+    gdk_window_get_origin(mGdkWindow, &origin.x.value, &origin.y.value);
+  }
+  return GdkPointToDevicePixels({origin.x, origin.y});
+}
+
+void nsWindow::CaptureRollupEvents(bool aDoCapture) {
+  LOG("CaptureRollupEvents(%d)\n", aDoCapture);
+  if (mIsDestroyed) {
+    return;
+  }
+
+  static constexpr auto kCaptureEventsMask =
+      GdkEventMask(GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
+                   GDK_POINTER_MOTION_MASK | GDK_TOUCH_MASK);
+
+  static bool sSystemNeedsPointerGrab = [&] {
+    if (GdkIsWaylandDisplay()) {
+      return false;
+    }
+    // We only need to grab the pointer for X servers that move the focus with
+    // the pointer (like twm, sawfish...). Since we roll up popups on focus out,
+    // not grabbing the pointer triggers rollup when the mouse enters the popup
+    // and leaves the main window, see bug 1807482.
+    //
+    // FVWM is also affected but less severely: the pointer can enter the
+    // popup, but if it briefly moves out of the popup and over the main window
+    // then we see a focus change and roll up the popup.
+    //
+    // We don't do it for most common desktops, if only because it causes X11
+    // crashes like bug 1607713.
+    const auto& desktop = GetDesktopEnvironmentIdentifier();
+    return desktop.EqualsLiteral("twm") || desktop.EqualsLiteral("sawfish") ||
+           StringBeginsWith(desktop, "fvwm"_ns);
+  }();
+
+  const bool grabPointer = [] {
+    switch (StaticPrefs::widget_gtk_grab_pointer()) {
+      case 0:
+        return false;
+      case 1:
+        return true;
+      default:
+        return sSystemNeedsPointerGrab;
+    }
+  }();
+
+  if (!grabPointer) {
+    return;
+  }
+
+  mNeedsToRetryCapturingMouse = false;
+  if (aDoCapture) {
+    if (mIsDragPopup || DragInProgress()) {
+      // Don't add a grab if a drag is in progress, or if the widget is a drag
+      // feedback popup. (panels with type="drag").
+      return;
+    }
+
+    if (!mHasMappedToplevel) {
+      // On X, capturing an unmapped window is pointless (returns
+      // GDK_GRAB_NOT_VIEWABLE). Avoid the X server round-trip and just retry
+      // when we're mapped.
+      mNeedsToRetryCapturingMouse = true;
+      return;
+    }
+
+    // gdk_pointer_grab is deprecated in favor of gdk_device_grab, but that
+    // causes a strange bug on X11, most obviously with nested popup menus:
+    // we somehow take the pointer position relative to the top left of the
+    // outer menu and use it as if it were relative to the submenu.  This
+    // doesn't happen with gdk_pointer_grab even though the code is very
+    // similar.  See the video attached to bug 1750721 for a demonstration,
+    // and see also bug 1820542 for when the same thing happened with
+    // another attempt to use gdk_device_grab.
+    //
+    // (gdk_device_grab is deprecated in favor of gdk_seat_grab as of 3.20,
+    // but at the time of this writing we still support older versions of
+    // GTK 3.)
+    GdkGrabStatus status =
+        gdk_pointer_grab(GetToplevelGdkWindow(),
+                         /* owner_events = */ true, kCaptureEventsMask,
+                         /* confine_to = */ nullptr,
+                         /* cursor = */ nullptr, GetLastUserInputTime());
+    Unused << NS_WARN_IF(status != GDK_GRAB_SUCCESS);
+    LOG(" > pointer grab with status %d", int(status));
+    gtk_grab_add(GTK_WIDGET(mContainer));
+  } else {
+    // There may not have been a drag in process when aDoCapture was set,
+    // so make sure to remove any added grab.  This is a no-op if the grab
+    // was not added to this widget.
+    gtk_grab_remove(GTK_WIDGET(mContainer));
+    gdk_pointer_ungrab(GetLastUserInputTime());
+  }
+}
+
+nsresult nsWindow::GetAttention(int32_t aCycleCount) {
+  LOG("nsWindow::GetAttention");
+
+  GtkWidget* top_window = GetToplevelWidget();
+  GtkWidget* top_focused_window =
+      gFocusWindow ? gFocusWindow->GetToplevelWidget() : nullptr;
+
+  // Don't get attention if the window is focused anyway.
+  if (top_window && (gtk_widget_get_visible(top_window)) &&
+      top_window != top_focused_window) {
+    SetUrgencyHint(top_window, true);
+  }
+
+  return NS_OK;
+}
+
+bool nsWindow::HasPendingInputEvent() {
+  // This sucks, but gtk/gdk has no way to answer the question we want while
+  // excluding paint events, and there's no X API that will let us peek
+  // without blocking or removing.  To prevent event reordering, peek
+  // anything except expose events.  Reordering expose and others should be
+  // ok, hopefully.
+  bool haveEvent = false;
+#ifdef MOZ_X11
+  XEvent ev;
+  if (GdkIsX11Display()) {
+    Display* display = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
+    haveEvent = XCheckMaskEvent(
+        display,
+        KeyPressMask | KeyReleaseMask | ButtonPressMask | ButtonReleaseMask |
+            EnterWindowMask | LeaveWindowMask | PointerMotionMask |
+            PointerMotionHintMask | Button1MotionMask | Button2MotionMask |
+            Button3MotionMask | Button4MotionMask | Button5MotionMask |
+            ButtonMotionMask | KeymapStateMask | VisibilityChangeMask |
+            StructureNotifyMask | ResizeRedirectMask | SubstructureNotifyMask |
+            SubstructureRedirectMask | FocusChangeMask | PropertyChangeMask |
+            ColormapChangeMask | OwnerGrabButtonMask,
+        &ev);
+    if (haveEvent) {
+      XPutBackEvent(display, &ev);
+    }
+  }
+#endif
+  return haveEvent;
+}
+
+#ifdef cairo_copy_clip_rectangle_list
+#  error "Looks like we're including Mozilla's cairo instead of system cairo"
+#endif
+static bool ExtractExposeRegion(LayoutDeviceIntRegion& aRegion, cairo_t* cr) {
+  cairo_rectangle_list_t* rects = cairo_copy_clip_rectangle_list(cr);
+  if (rects->status != CAIRO_STATUS_SUCCESS) {
+    NS_WARNING("Failed to obtain cairo rectangle list.");
+    return false;
+  }
+
+  for (int i = 0; i < rects->num_rectangles; i++) {
+    const cairo_rectangle_t& r = rects->rectangles[i];
+    aRegion.Or(aRegion,
+               LayoutDeviceIntRect::Truncate((float)r.x, (float)r.y,
+                                             (float)r.width, (float)r.height));
+  }
+
+  cairo_rectangle_list_destroy(rects);
+  return true;
+}
+
+#ifdef MOZ_WAYLAND
+void nsWindow::CreateCompositorVsyncDispatcher() {
+  LOG_VSYNC("nsWindow::CreateCompositorVsyncDispatcher()");
+  if (!mWaylandVsyncSource) {
+    LOG_VSYNC(
+        "  mWaylandVsyncSource is missing, create "
+        "nsBaseWidget::CompositorVsyncDispatcher()");
+    nsBaseWidget::CreateCompositorVsyncDispatcher();
+    return;
+  }
+  if (!mCompositorVsyncDispatcherLock) {
+    mCompositorVsyncDispatcherLock =
+        MakeUnique<Mutex>("mCompositorVsyncDispatcherLock");
+  }
+  MutexAutoLock lock(*mCompositorVsyncDispatcherLock);
+  if (!mCompositorVsyncDispatcher) {
+    LOG_VSYNC("  create CompositorVsyncDispatcher()");
+    mCompositorVsyncDispatcher =
+        new CompositorVsyncDispatcher(mWaylandVsyncDispatcher);
+  }
+}
+#endif
+
+gboolean nsWindow::OnExposeEvent(cairo_t* cr) {
+  // This might destroy us.
+  NotifyOcclusionState(OcclusionState::VISIBLE);
+  if (mIsDestroyed) {
+    return FALSE;
+  }
+
+  // Send any pending resize events so that layout can update.
+  // May run event loop and destroy us.
+  MaybeDispatchResized();
+  if (mIsDestroyed) {
+    return FALSE;
+  }
+
+  // Windows that are not visible will be painted after they become visible.
+  if (!mGdkWindow || !mHasMappedToplevel) {
+    return FALSE;
+  }
+#ifdef MOZ_WAYLAND
+  if (GdkIsWaylandDisplay() && !moz_container_wayland_can_draw(mContainer)) {
+    return FALSE;
+  }
+#endif
+
+  nsIWidgetListener* listener = GetListener();
+  if (!listener) return FALSE;
+
+  LOG("nsWindow::OnExposeEvent GdkWindow [%p] XWindow [0x%lx]", mGdkWindow,
+      GetX11Window());
+
+  LayoutDeviceIntRegion exposeRegion;
+  if (!ExtractExposeRegion(exposeRegion, cr)) {
+    LOG("  no rects, quit");
+    return FALSE;
+  }
+
+  gint scale = GdkCeiledScaleFactor();
+  LayoutDeviceIntRegion region = exposeRegion;
+  region.ScaleRoundOut(scale, scale);
+
+  WindowRenderer* renderer = GetWindowRenderer();
+  WebRenderLayerManager* layerManager = renderer->AsWebRender();
+  KnowsCompositor* knowsCompositor = renderer->AsKnowsCompositor();
+
+  if (knowsCompositor && layerManager && mCompositorSession) {
+    if (!mConfiguredClearColor && !IsPopup()) {
+      layerManager->WrBridge()->SendSetDefaultClearColor(LookAndFeel::Color(
+          LookAndFeel::ColorID::Window, LookAndFeel::ColorSchemeForChrome(),
+          LookAndFeel::UseStandins::No));
+      mConfiguredClearColor = true;
+    }
+
+    // We need to paint to the screen even if nothing changed, since if we
+    // don't have a compositing window manager, our pixels could be stale.
+    layerManager->SetNeedsComposite(true);
+    layerManager->SendInvalidRegion(region.ToUnknownRegion());
+  }
+
+  RefPtr<nsWindow> strongThis(this);
+
+  // Dispatch WillPaintWindow notification to allow scripts etc. to run
+  // before we paint
+  {
+    listener->WillPaintWindow(this);
+
+    // If the window has been destroyed during the will paint notification,
+    // there is nothing left to do.
+    if (!mGdkWindow) return TRUE;
+
+    // Re-get the listener since the will paint notification might have
+    // killed it.
+    listener = GetListener();
+    if (!listener) return FALSE;
+  }
+
+  if (knowsCompositor && layerManager && layerManager->NeedsComposite()) {
+    layerManager->ScheduleComposite(wr::RenderReasons::WIDGET);
+    layerManager->SetNeedsComposite(false);
+  }
+
+  // Our bounds may have changed after calling WillPaintWindow.  Clip
+  // to the new bounds here.  The region is relative to this
+  // window.
+  region.And(region, LayoutDeviceIntRect(0, 0, mBounds.width, mBounds.height));
+
+  bool shaped = false;
+  if (TransparencyMode::Transparent == GetTransparencyMode()) {
+    auto* window = static_cast<nsWindow*>(GetTopLevelWidget());
+    if (mTransparencyBitmapForTitlebar) {
+      if (mSizeMode == nsSizeMode_Normal) {
+        window->UpdateTitlebarTransparencyBitmap();
+      } else {
+        window->ClearTransparencyBitmap();
+      }
+    } else {
+      if (mHasAlphaVisual) {
+        // Remove possible shape mask from when window manger was not
+        // previously compositing.
+        window->ClearTransparencyBitmap();
+      } else {
+        shaped = true;
+      }
+    }
+  }
+
+  if (region.IsEmpty()) {
+    return TRUE;
+  }
+
+  // If this widget uses OMTC...
+  if (renderer->GetBackendType() == LayersBackend::LAYERS_WR) {
+    listener->PaintWindow(this, region);
+
+    // Re-get the listener since the will paint notification might have
+    // killed it.
+    listener = GetListener();
+    if (!listener) return TRUE;
+
+    listener->DidPaintWindow();
+    return TRUE;
+  }
+
+  BufferMode layerBuffering = BufferMode::BUFFERED;
+  RefPtr<DrawTarget> dt = StartRemoteDrawingInRegion(region, &layerBuffering);
+  if (!dt || !dt->IsValid()) {
+    return FALSE;
+  }
+  Maybe<gfxContext> ctx;
+  IntRect boundsRect = region.GetBounds().ToUnknownRect();
+  IntPoint offset(0, 0);
+  if (dt->GetSize() == boundsRect.Size()) {
+    offset = boundsRect.TopLeft();
+    dt->SetTransform(Matrix::Translation(-offset));
+  }
+
+#ifdef MOZ_X11
+  if (shaped) {
+    // Collapse update area to the bounding box. This is so we only have to
+    // call UpdateTranslucentWindowAlpha once. After we have dropped
+    // support for non-Thebes graphics, UpdateTranslucentWindowAlpha will be
+    // our private interface so we can rework things to avoid this.
+    dt->PushClipRect(Rect(boundsRect));
+
+    // The double buffering is done here to extract the shape mask.
+    // (The shape mask won't be necessary when a visual with an alpha
+    // channel is used on compositing window managers.)
+    layerBuffering = BufferMode::BUFFER_NONE;
+    RefPtr<DrawTarget> destDT =
+        dt->CreateSimilarDrawTarget(boundsRect.Size(), SurfaceFormat::B8G8R8A8);
+    if (!destDT || !destDT->IsValid()) {
+      return FALSE;
+    }
+    destDT->SetTransform(Matrix::Translation(-boundsRect.TopLeft()));
+    ctx.emplace(destDT, /* aPreserveTransform */ true);
+  } else {
+    gfxUtils::ClipToRegion(dt, region.ToUnknownRegion());
+    ctx.emplace(dt, /* aPreserveTransform */ true);
+  }
+
+#  if 0
+    // NOTE: Paint flashing region would be wrong for cairo, since
+    // cairo inflates the update region, etc.  So don't paint flash
+    // for cairo.
+#    ifdef DEBUG
+    // XXX aEvent->region may refer to a newly-invalid area.  FIXME
+    if (0 && WANT_PAINT_FLASHING && gtk_widget_get_window(aEvent))
+        gdk_window_flash(mGdkWindow, 1, 100, aEvent->region);
+#    endif
+#  endif
+
+#endif  // MOZ_X11
+
+  bool painted = false;
+  {
+    if (renderer->GetBackendType() == LayersBackend::LAYERS_NONE) {
+      if (GetTransparencyMode() == TransparencyMode::Transparent &&
+          layerBuffering == BufferMode::BUFFER_NONE && mHasAlphaVisual) {
+        // If our draw target is unbuffered and we use an alpha channel,
+        // clear the image beforehand to ensure we don't get artifacts from a
+        // reused SHM image. See bug 1258086.
+        dt->ClearRect(Rect(boundsRect));
+      }
+      AutoLayerManagerSetup setupLayerManager(
+          this, ctx.isNothing() ? nullptr : &ctx.ref(), layerBuffering);
+      painted = listener->PaintWindow(this, region);
+
+      // Re-get the listener since the will paint notification might have
+      // killed it.
+      listener = GetListener();
+      if (!listener) return TRUE;
+    }
+  }
+
+#ifdef MOZ_X11
+  // PaintWindow can Destroy us (bug 378273), avoid doing any paint
+  // operations below if that happened - it will lead to XError and exit().
+  if (shaped) {
+    if (MOZ_LIKELY(!mIsDestroyed)) {
+      if (painted) {
+        RefPtr<SourceSurface> surf = ctx->GetDrawTarget()->Snapshot();
+
+        UpdateAlpha(surf, boundsRect);
+
+        dt->DrawSurface(surf, Rect(boundsRect),
+                        Rect(0, 0, boundsRect.width, boundsRect.height),
+                        DrawSurfaceOptions(SamplingFilter::POINT),
+                        DrawOptions(1.0f, CompositionOp::OP_SOURCE));
+      }
+    }
+  }
+
+  ctx.reset();
+  dt->PopClip();
+
+#endif  // MOZ_X11
+
+  EndRemoteDrawingInRegion(dt, region);
+
+  listener->DidPaintWindow();
+
+  // Synchronously flush any new dirty areas
+  cairo_region_t* dirtyArea = gdk_window_get_update_area(mGdkWindow);
+
+  if (dirtyArea) {
+    gdk_window_invalidate_region(mGdkWindow, dirtyArea, false);
+    cairo_region_destroy(dirtyArea);
+    gdk_window_process_updates(mGdkWindow, false);
+  }
+
+  // check the return value!
+  return TRUE;
+}
+
+void nsWindow::UpdateAlpha(SourceSurface* aSourceSurface,
+                           nsIntRect aBoundsRect) {
+  // We need to create our own buffer to force the stride to match the
+  // expected stride.
+  int32_t stride =
+      GetAlignedStride<4>(aBoundsRect.width, BytesPerPixel(SurfaceFormat::A8));
+  if (stride == 0) {
+    return;
+  }
+  int32_t bufferSize = stride * aBoundsRect.height;
+  auto imageBuffer = MakeUniqueFallible<uint8_t[]>(bufferSize);
+  {
+    RefPtr<DrawTarget> drawTarget = gfxPlatform::CreateDrawTargetForData(
+        imageBuffer.get(), aBoundsRect.Size(), stride, SurfaceFormat::A8);
+
+    if (drawTarget) {
+      drawTarget->DrawSurface(aSourceSurface,
+                              Rect(0, 0, aBoundsRect.width, aBoundsRect.height),
+                              Rect(0, 0, aSourceSurface->GetSize().width,
+                                   aSourceSurface->GetSize().height),
+                              DrawSurfaceOptions(SamplingFilter::POINT),
+                              DrawOptions(1.0f, CompositionOp::OP_SOURCE));
+    }
+  }
+  UpdateTranslucentWindowAlphaInternal(aBoundsRect, imageBuffer.get(), stride);
+}
+
+gboolean nsWindow::OnConfigureEvent(GtkWidget* aWidget,
+                                    GdkEventConfigure* aEvent) {
+  // These events are only received on toplevel windows.
+  //
+  // GDK ensures that the coordinates are the client window top-left wrt the
+  // root window.
+  //
+  //   GDK calculates the cordinates for real ConfigureNotify events on
+  //   managed windows (that would normally be relative to the parent
+  //   window).
+  //
+  //   Synthetic ConfigureNotify events are from the window manager and
+  //   already relative to the root window.  GDK creates all X windows with
+  //   border_width = 0, so synthetic events also indicate the top-left of
+  //   the client window.
+  //
+  //   Override-redirect windows are children of the root window so parent
+  //   coordinates are root coordinates.
+
+  LOG("configure event %d,%d -> %d x %d scale %d\n", aEvent->x, aEvent->y,
+      aEvent->width, aEvent->height,
+      mGdkWindow ? gdk_window_get_scale_factor(mGdkWindow) : -1);
+
+  if (mPendingConfigures > 0) {
+    mPendingConfigures--;
+  }
+
+  // Don't fire configure event for scale changes, we handle that
+  // OnScaleChanged event. Skip that for toplevel windows only.
+  if (mGdkWindow && (mWindowType == WindowType::TopLevel ||
+                     mWindowType == WindowType::Dialog)) {
+    if (mWindowScaleFactor != gdk_window_get_scale_factor(mGdkWindow)) {
+      LOG("  scale factor changed to %d,return early",
+          gdk_window_get_scale_factor(mGdkWindow));
+      return FALSE;
+    }
+  }
+
+  LayoutDeviceIntRect screenBounds = GetScreenBounds();
+
+  if (mWindowType == WindowType::TopLevel ||
+      mWindowType == WindowType::Dialog) {
+    // This check avoids unwanted rollup on spurious configure events from
+    // Cygwin/X (bug 672103).
+    if (mBounds.x != screenBounds.x || mBounds.y != screenBounds.y) {
+      RollupAllMenus();
+    }
+  }
+
+  NS_ASSERTION(GTK_IS_WINDOW(aWidget),
+               "Configure event on widget that is not a GtkWindow");
+  if (mGdkWindow &&
+      gtk_window_get_window_type(GTK_WINDOW(aWidget)) == GTK_WINDOW_POPUP) {
+    // Override-redirect window
+    //
+    // These windows should not be moved by the window manager, and so any
+    // change in position is a result of our direction.  mBounds has
+    // already been set in std::move() or Resize(), and that is more
+    // up-to-date than the position in the ConfigureNotify event if the
+    // event is from an earlier window move.
+    //
+    // Skipping the WindowMoved call saves context menus from an infinite
+    // loop when nsXULPopupManager::PopupMoved moves the window to the new
+    // position and nsMenuPopupFrame::SetPopupPosition adds
+    // offsetForContextMenu on each iteration.
+
+    // Our back buffer might have been invalidated while we drew the last
+    // frame, and its contents might be incorrect. See bug 1280653 comment 7
+    // and comment 10. Specifically we must ensure we recomposite the frame
+    // as soon as possible to avoid the corrupted frame being displayed.
+    GetWindowRenderer()->FlushRendering(wr::RenderReasons::WIDGET);
+    return FALSE;
+  }
+
+  mBounds.MoveTo(screenBounds.TopLeft());
+  RecomputeClientOffset(/* aNotify = */ false);
+
+  // XXX mozilla will invalidate the entire window after this move
+  // complete.  wtf?
+  NotifyWindowMoved(mBounds.x, mBounds.y);
+
+  return FALSE;
+}
+
+void nsWindow::OnMap() {
+  LOG("nsWindow::OnMap");
+  // Gtk mapped widget to screen. Configure underlying GdkWindow properly
+  // as our rendering target.
+  // This call means we have X11 (or Wayland) window we can render to by GL
+  // so we need to notify compositor about it.
+  mIsMapped = true;
+  ConfigureGdkWindow();
+}
+
+void nsWindow::OnUnmap() {
+  LOG("nsWindow::OnUnmap");
+
+  // Mark window as unmapped. It can be still used for rendering on X11
+  // untill OnUnrealize is called.
+  mIsMapped = false;
+
+  if (mSourceDragContext) {
+    static auto sGtkDragCancel =
+        (void (*)(GdkDragContext*))dlsym(RTLD_DEFAULT, "gtk_drag_cancel");
+    if (sGtkDragCancel) {
+      sGtkDragCancel(mSourceDragContext);
+      mSourceDragContext = nullptr;
+    }
+  }
+
+#ifdef MOZ_WAYLAND
+  // wl_surface owned by mContainer is going to be deleted.
+  // Make sure we don't paint to it on Wayland.
+  if (GdkIsWaylandDisplay()) {
+    if (mCompositorWidgetDelegate) {
+      mCompositorWidgetDelegate->DisableRendering();
+    }
+    if (moz_container_wayland_has_egl_window(mContainer)) {
+      // Widget is backed by OpenGL EGLSurface created over wl_surface
+      // owned by mContainer.
+      // RenderCompositorEGL::Resume() deletes recent EGLSurface based on
+      // wl_surface owned by mContainer and creates a new fallback EGLSurface.
+      // Then we can delete wl_surface in moz_container_wayland_unmap().
+      // We don't want to pause compositor as it may lead to whole
+      // browser freeze (Bug 1777664).
+      if (CompositorBridgeChild* remoteRenderer = GetRemoteRenderer()) {
+        remoteRenderer->SendResume();
+      }
+    }
+    if (GdkIsWaylandDisplay()) {
+      moz_container_wayland_unmap(GTK_WIDGET(mContainer));
+    }
+  }
+#endif
+  moz_container_unmap(GTK_WIDGET(mContainer));
+}
+
+void nsWindow::OnUnrealize() {
+  // The GdkWindows are about to be destroyed (but not deleted), so remove
+  // their references back to their container widget while the GdkWindow
+  // hierarchy is still available.
+  // This call means we *don't* have X11 (or Wayland) window we can render to.
+  LOG("nsWindow::OnUnrealize GdkWindow %p", mGdkWindow);
+  ReleaseGdkWindow();
+}
+
+void nsWindow::OnSizeAllocate(GtkAllocation* aAllocation) {
+  LOG("nsWindow::OnSizeAllocate %d,%d -> %d x %d\n", aAllocation->x,
+      aAllocation->y, aAllocation->width, aAllocation->height);
+
+  // Client offset are updated by _NET_FRAME_EXTENTS on X11 when system titlebar
+  // is enabled. In either cases (Wayland or system titlebar is off on X11)
+  // we don't get _NET_FRAME_EXTENTS X11 property notification so we derive
+  // it from mContainer position.
+  RecomputeClientOffset(/* aNotify = */ true);
+
+  mHasReceivedSizeAllocate = true;
+
+  LayoutDeviceIntSize size = GdkRectToDevicePixels(*aAllocation).Size();
+
+  // Sometimes the window manager gives us garbage sizes (way past the maximum
+  // texture size) causing crashes if we don't enforce size constraints again
+  // here.
+  ConstrainSize(&size.width, &size.height);
+
+  if (mBounds.Size() == size) {
+    LOG("  Already the same size");
+    // mBounds was set at Create() or Resize().
+    if (mNeedsDispatchSize != LayoutDeviceIntSize(-1, -1)) {
+      LOG("  No longer needs to dispatch %dx%d", mNeedsDispatchSize.width,
+          mNeedsDispatchSize.height);
+      mNeedsDispatchSize = LayoutDeviceIntSize(-1, -1);
+    }
+    return;
+  }
+
+  // Invalidate the new part of the window now for the pending paint to
+  // minimize background flashes (GDK does not do this for external resizes
+  // of toplevels.)
+  if (mGdkWindow) {
+    if (mBounds.width < size.width) {
+      GdkRectangle rect = DevicePixelsToGdkRectRoundOut(LayoutDeviceIntRect(
+          mBounds.width, 0, size.width - mBounds.width, size.height));
+      gdk_window_invalidate_rect(mGdkWindow, &rect, FALSE);
+    }
+    if (mBounds.height < size.height) {
+      GdkRectangle rect = DevicePixelsToGdkRectRoundOut(LayoutDeviceIntRect(
+          0, mBounds.height, size.width, size.height - mBounds.height));
+      gdk_window_invalidate_rect(mGdkWindow, &rect, FALSE);
+    }
+  }
+
+  // If we update mBounds here, then inner/outerHeight are out of sync until
+  // we call WindowResized.
+  mNeedsDispatchSize = size;
+
+  // Gecko permits running nested event loops during processing of events,
+  // GtkWindow callers of gtk_widget_size_allocate expect the signal
+  // handlers to return sometime in the near future.
+  NS_DispatchToCurrentThread(NewRunnableMethod(
+      "nsWindow::MaybeDispatchResized", this, &nsWindow::MaybeDispatchResized));
+}
+
+void nsWindow::OnDeleteEvent() {
+  if (mWidgetListener) mWidgetListener->RequestWindowClose(this);
+}
+
+void nsWindow::OnEnterNotifyEvent(GdkEventCrossing* aEvent) {
+  LOG("enter notify (win=%p, sub=%p): %f, %f mode %d, detail %d\n",
+      aEvent->window, aEvent->subwindow, aEvent->x, aEvent->y, aEvent->mode,
+      aEvent->detail);
+  // This skips NotifyVirtual and NotifyNonlinearVirtual enter notify events
+  // when the pointer enters a child window.  If the destination window is a
+  // Gecko window then we'll catch the corresponding event on that window,
+  // but we won't notice when the pointer directly enters a foreign (plugin)
+  // child window without passing over a visible portion of a Gecko window.
+  if (aEvent->subwindow) {
+    return;
+  }
+
+  // Check before checking for ungrab as the button state may have
+  // changed while a non-Gecko ancestor window had a pointer grab.
+  DispatchMissedButtonReleases(aEvent);
+
+  WidgetMouseEvent event(true, eMouseEnterIntoWidget, this,
+                         WidgetMouseEvent::eReal);
+
+  event.mRefPoint = GdkEventCoordsToDevicePixels(aEvent->x, aEvent->y);
+  event.AssignEventTime(GetWidgetEventTime(aEvent->time));
+
+  LOG("OnEnterNotify");
+
+  DispatchInputEvent(&event);
+}
+
+// Some window managers send a bogus top-level leave-notify event on every
+// click. That confuses our event handling code in ways that can break websites,
+// see bug 1805939 for details.
+//
+// Make sure to only check this on bogus environments, since for environments
+// with CSD, gdk_device_get_window_at_position could return the window even when
+// the pointer is in the decoration area.
+static bool IsBogusLeaveNotifyEvent(GdkWindow* aWindow,
+                                    GdkEventCrossing* aEvent) {
+  static bool sBogusWm = [] {
+    if (GdkIsWaylandDisplay()) {
+      return false;
+    }
+    const auto& desktopEnv = GetDesktopEnvironmentIdentifier();
+    return desktopEnv.EqualsLiteral("fluxbox") ||   // Bug 1805939 comment 0.
+           desktopEnv.EqualsLiteral("blackbox") ||  // Bug 1805939 comment 32.
+           desktopEnv.EqualsLiteral("lg3d") ||      // Bug 1820405.
+           desktopEnv.EqualsLiteral("pekwm") ||     // Bug 1822911.
+           StringBeginsWith(desktopEnv, "fvwm"_ns);
+  }();
+
+  const bool shouldCheck = [] {
+    switch (StaticPrefs::widget_gtk_ignore_bogus_leave_notify()) {
+      case 0:
+        return false;
+      case 1:
+        return true;
+      default:
+        return sBogusWm;
+    }
+  }();
+
+  if (!shouldCheck) {
+    return false;
+  }
+  GdkDevice* pointer = GdkGetPointer();
+  GdkWindow* winAtPt =
+      gdk_device_get_window_at_position(pointer, nullptr, nullptr);
+  if (!winAtPt) {
+    return false;
+  }
+  // We're still in the same top level window, ignore this leave notify event.
+  GdkWindow* topLevelAtPt = gdk_window_get_toplevel(winAtPt);
+  GdkWindow* topLevelWidget = gdk_window_get_toplevel(aWindow);
+  return topLevelAtPt == topLevelWidget;
+}
+
+void nsWindow::OnLeaveNotifyEvent(GdkEventCrossing* aEvent) {
+  LOG("leave notify (win=%p, sub=%p): %f, %f mode %d, detail %d\n",
+      aEvent->window, aEvent->subwindow, aEvent->x, aEvent->y, aEvent->mode,
+      aEvent->detail);
+
+  // This ignores NotifyVirtual and NotifyNonlinearVirtual leave notify
+  // events when the pointer leaves a child window.  If the destination
+  // window is a Gecko window then we'll catch the corresponding event on
+  // that window.
+  //
+  // XXXkt However, we will miss toplevel exits when the pointer directly
+  // leaves a foreign (plugin) child window without passing over a visible
+  // portion of a Gecko window.
+  if (aEvent->subwindow) {
+    return;
+  }
+
+  // The filter out for subwindows should make sure that this is targeted to
+  // this nsWindow.
+  const bool leavingTopLevel =
+      mWindowType == WindowType::TopLevel || mWindowType == WindowType::Dialog;
+
+  if (leavingTopLevel && IsBogusLeaveNotifyEvent(mGdkWindow, aEvent)) {
+    return;
+  }
+
+  WidgetMouseEvent event(true, eMouseExitFromWidget, this,
+                         WidgetMouseEvent::eReal);
+
+  event.mRefPoint = GdkEventCoordsToDevicePixels(aEvent->x, aEvent->y);
+  event.AssignEventTime(GetWidgetEventTime(aEvent->time));
+  event.mExitFrom = Some(leavingTopLevel ? WidgetMouseEvent::ePlatformTopLevel
+                                         : WidgetMouseEvent::ePlatformChild);
+
+  LOG("OnLeaveNotify");
+
+  DispatchInputEvent(&event);
+}
+
+Maybe<GdkWindowEdge> nsWindow::CheckResizerEdge(
+    const LayoutDeviceIntPoint& aPoint) {
+  const bool canResize = [&] {
+    // Don't allow resizing maximized/fullscreen windows.
+    if (mSizeMode != nsSizeMode_Normal) {
+      return false;
+    }
+    if (mIsPIPWindow) {
+      // Note that since we do show resizers on left/right sides on PIP windows,
+      // we still want the resizers there, even when tiled.
+      return true;
+    }
+    if (!mDrawInTitlebar) {
+      return false;
+    }
+    // On KDE, allow for 1 extra pixel at the top of regular windows when
+    // drawing to the titlebar. This matches the native titlebar behavior on
+    // that environment. See bug 1813554.
+    //
+    // Don't do that on GNOME (see bug 1822764). If we wanted to do this on
+    // GNOME we'd need an extra check for mIsTiled, since the window is "stuck"
+    // to the top and bottom.
+    //
+    // Other DEs are untested.
+    return mDrawInTitlebar && IsKdeDesktopEnvironment();
+  }();
+
+  if (!canResize) {
+    return {};
+  }
+
+  // If we're not in a PiP window, allow 1px resizer edge from the top edge,
+  // and nothing else.
+  // This is to allow resizes of tiled windows on KDE, see bug 1813554.
+  const int resizerSize = (mIsPIPWindow ? 15 : 1) * GdkCeiledScaleFactor();
+
+  const int topDist = aPoint.y;
+  const int leftDist = aPoint.x;
+  const int rightDist = mBounds.width - aPoint.x;
+  const int bottomDist = mBounds.height - aPoint.y;
+
+  if (topDist <= resizerSize) {
+    if (rightDist <= resizerSize) {
+      return Some(GDK_WINDOW_EDGE_NORTH_EAST);
+    }
+    if (leftDist <= resizerSize) {
+      return Some(GDK_WINDOW_EDGE_NORTH_WEST);
+    }
+    return Some(GDK_WINDOW_EDGE_NORTH);
+  }
+
+  if (!mIsPIPWindow) {
+    return {};
+  }
+
+  if (bottomDist <= resizerSize) {
+    if (leftDist <= resizerSize) {
+      return Some(GDK_WINDOW_EDGE_SOUTH_WEST);
+    }
+    if (rightDist <= resizerSize) {
+      return Some(GDK_WINDOW_EDGE_SOUTH_EAST);
+    }
+    return Some(GDK_WINDOW_EDGE_SOUTH);
+  }
+
+  if (leftDist <= resizerSize) {
+    return Some(GDK_WINDOW_EDGE_WEST);
+  }
+  if (rightDist <= resizerSize) {
+    return Some(GDK_WINDOW_EDGE_EAST);
+  }
+  return {};
+}
+
+template <typename Event>
+static LayoutDeviceIntPoint GetRefPoint(nsWindow* aWindow, Event* aEvent) {
+  if (aEvent->window == aWindow->GetGdkWindow()) {
+    // we are the window that the event happened on so no need for expensive
+    // WidgetToScreenOffset
+    return aWindow->GdkEventCoordsToDevicePixels(aEvent->x, aEvent->y);
+  }
+  // XXX we're never quite sure which GdkWindow the event came from due to our
+  // custom bubbling in scroll_event_cb(), so use ScreenToWidget to translate
+  // the screen root coordinates into coordinates relative to this widget.
+  return aWindow->GdkEventCoordsToDevicePixels(aEvent->x_root, aEvent->y_root) -
+         aWindow->WidgetToScreenOffset();
+}
+
+void nsWindow::OnMotionNotifyEvent(GdkEventMotion* aEvent) {
+  if (!mGdkWindow) {
+    return;
+  }
+
+  if (mWindowShouldStartDragging) {
+    mWindowShouldStartDragging = false;
+    // find the top-level window
+    GdkWindow* gdk_window = gdk_window_get_toplevel(mGdkWindow);
+    MOZ_ASSERT(gdk_window, "gdk_window_get_toplevel should not return null");
+
+    bool canDrag = true;
+#ifdef MOZ_X11
+    if (GdkIsX11Display()) {
+      // Workaround for https://bugzilla.gnome.org/show_bug.cgi?id=789054
+      // To avoid crashes disable double-click on WM without _NET_WM_MOVERESIZE.
+      // See _should_perform_ewmh_drag() at gdkwindow-x11.c
+      GdkScreen* screen = gdk_window_get_screen(gdk_window);
+      GdkAtom atom = gdk_atom_intern("_NET_WM_MOVERESIZE", FALSE);
+      if (!gdk_x11_screen_supports_net_wm_hint(screen, atom)) {
+        canDrag = false;
+      }
+    }
+#endif
+
+    if (canDrag) {
+      gdk_window_begin_move_drag(gdk_window, 1, aEvent->x_root, aEvent->y_root,
+                                 aEvent->time);
+      return;
+    }
+  }
+
+  mWidgetCursorLocked = false;
+  const auto refPoint = GetRefPoint(this, aEvent);
+  if (auto edge = CheckResizerEdge(refPoint)) {
+    nsCursor cursor = eCursor_none;
+    switch (*edge) {
+      case GDK_WINDOW_EDGE_SOUTH:
+      case GDK_WINDOW_EDGE_NORTH:
+        cursor = eCursor_ns_resize;
+        break;
+      case GDK_WINDOW_EDGE_WEST:
+      case GDK_WINDOW_EDGE_EAST:
+        cursor = eCursor_ew_resize;
+        break;
+      case GDK_WINDOW_EDGE_NORTH_WEST:
+      case GDK_WINDOW_EDGE_SOUTH_EAST:
+        cursor = eCursor_nwse_resize;
+        break;
+      case GDK_WINDOW_EDGE_NORTH_EAST:
+      case GDK_WINDOW_EDGE_SOUTH_WEST:
+        cursor = eCursor_nesw_resize;
+        break;
+    }
+    SetCursor(Cursor{cursor});
+    // If we set resize cursor on widget level keep it locked and prevent layout
+    // to switch it back to default (by synthetic mouse events for instance)
+    // until resize is finished.
+    mWidgetCursorLocked = true;
+    return;
+  }
+
+  WidgetMouseEvent event(true, eMouseMove, this, WidgetMouseEvent::eReal);
+
+  gdouble pressure = 0;
+  gdk_event_get_axis((GdkEvent*)aEvent, GDK_AXIS_PRESSURE, &pressure);
+  // Sometime gdk generate 0 pressure value between normal values
+  // We have to ignore that and use last valid value
+  if (pressure) {
+    mLastMotionPressure = pressure;
+  }
+  event.mPressure = mLastMotionPressure;
+  event.mRefPoint = refPoint;
+  event.AssignEventTime(GetWidgetEventTime(aEvent->time));
+
+  KeymapWrapper::InitInputEvent(event, aEvent->state);
+
+  DispatchInputEvent(&event);
+}
+
+// If the automatic pointer grab on ButtonPress has deactivated before
+// ButtonRelease, and the mouse button is released while the pointer is not
+// over any a Gecko window, then the ButtonRelease event will not be received.
+// (A similar situation exists when the pointer is grabbed with owner_events
+// True as the ButtonRelease may be received on a foreign [plugin] window).
+// Use this method to check for released buttons when the pointer returns to a
+// Gecko window.
+void nsWindow::DispatchMissedButtonReleases(GdkEventCrossing* aGdkEvent) {
+  guint changed = aGdkEvent->state ^ gButtonState;
+  // Only consider button releases.
+  // (Ignore button presses that occurred outside Gecko.)
+  guint released = changed & gButtonState;
+  gButtonState = aGdkEvent->state;
+
+  // Loop over each button, excluding mouse wheel buttons 4 and 5 for which
+  // GDK ignores releases.
+  for (guint buttonMask = GDK_BUTTON1_MASK; buttonMask <= GDK_BUTTON3_MASK;
+       buttonMask <<= 1) {
+    if (released & buttonMask) {
+      int16_t buttonType;
+      switch (buttonMask) {
+        case GDK_BUTTON1_MASK:
+          buttonType = MouseButton::ePrimary;
+          break;
+        case GDK_BUTTON2_MASK:
+          buttonType = MouseButton::eMiddle;
+          break;
+        default:
+          NS_ASSERTION(buttonMask == GDK_BUTTON3_MASK,
+                       "Unexpected button mask");
+          buttonType = MouseButton::eSecondary;
+      }
+
+      LOG("Synthesized button %u release", guint(buttonType + 1));
+
+      // Dispatch a synthesized button up event to tell Gecko about the
+      // change in state.  This event is marked as synthesized so that
+      // it is not dispatched as a DOM event, because we don't know the
+      // position, widget, modifiers, or time/order.
+      WidgetMouseEvent synthEvent(true, eMouseUp, this,
+                                  WidgetMouseEvent::eSynthesized);
+      synthEvent.mButton = buttonType;
+      DispatchInputEvent(&synthEvent);
+    }
+  }
+}
+
+void nsWindow::InitButtonEvent(WidgetMouseEvent& aEvent,
+                               GdkEventButton* aGdkEvent,
+                               const LayoutDeviceIntPoint& aRefPoint) {
+  aEvent.mRefPoint = aRefPoint;
+
+  guint modifierState = aGdkEvent->state;
+  // aEvent's state includes the button state from immediately before this
+  // event.  If aEvent is a mousedown or mouseup event, we need to update
+  // the button state.
+  guint buttonMask = 0;
+  switch (aGdkEvent->button) {
+    case 1:
+      buttonMask = GDK_BUTTON1_MASK;
+      break;
+    case 2:
+      buttonMask = GDK_BUTTON2_MASK;
+      break;
+    case 3:
+      buttonMask = GDK_BUTTON3_MASK;
+      break;
+  }
+  if (aGdkEvent->type == GDK_BUTTON_RELEASE) {
+    modifierState &= ~buttonMask;
+  } else {
+    modifierState |= buttonMask;
+  }
+
+  KeymapWrapper::InitInputEvent(aEvent, modifierState);
+
+  aEvent.AssignEventTime(GetWidgetEventTime(aGdkEvent->time));
+
+  switch (aGdkEvent->type) {
+    case GDK_2BUTTON_PRESS:
+      aEvent.mClickCount = 2;
+      break;
+    case GDK_3BUTTON_PRESS:
+      aEvent.mClickCount = 3;
+      break;
+      // default is one click
+    default:
+      aEvent.mClickCount = 1;
+  }
+}
+
+static guint ButtonMaskFromGDKButton(guint button) {
+  return GDK_BUTTON1_MASK << (button - 1);
+}
+
+void nsWindow::DispatchContextMenuEventFromMouseEvent(
+    uint16_t domButton, GdkEventButton* aEvent,
+    const LayoutDeviceIntPoint& aRefPoint) {
+  if (domButton == MouseButton::eSecondary && MOZ_LIKELY(!mIsDestroyed)) {
+    WidgetMouseEvent contextMenuEvent(true, eContextMenu, this,
+                                      WidgetMouseEvent::eReal);
+    InitButtonEvent(contextMenuEvent, aEvent, aRefPoint);
+    contextMenuEvent.mPressure = mLastMotionPressure;
+    DispatchInputEvent(&contextMenuEvent);
+  }
+}
+
+void nsWindow::TryToShowNativeWindowMenu(GdkEventButton* aEvent) {
+  if (!gdk_window_show_window_menu(GetToplevelGdkWindow(), (GdkEvent*)aEvent)) {
+    NS_WARNING("Native context menu wasn't shown");
+  }
+}
+
+void nsWindow::OnButtonPressEvent(GdkEventButton* aEvent) {
+  LOG("Button %u press\n", aEvent->button);
+
+  SetLastMousePressEvent((GdkEvent*)aEvent);
+
+  // If you double click in GDK, it will actually generate a second
+  // GDK_BUTTON_PRESS before sending the GDK_2BUTTON_PRESS, and this is
+  // different than the DOM spec.  GDK puts this in the queue
+  // programatically, so it's safe to assume that if there's a
+  // double click in the queue, it was generated so we can just drop
+  // this click.
+  GUniquePtr<GdkEvent> peekedEvent(gdk_event_peek());
+  if (peekedEvent) {
+    GdkEventType type = peekedEvent->any.type;
+    if (type == GDK_2BUTTON_PRESS || type == GDK_3BUTTON_PRESS) {
+      return;
+    }
+  }
+
+  nsWindow* containerWindow = GetContainerWindow();
+  if (!gFocusWindow && containerWindow) {
+    containerWindow->DispatchActivateEvent();
+  }
+
+  const auto refPoint = GetRefPoint(this, aEvent);
+
+  // check to see if we should rollup
+  if (CheckForRollup(aEvent->x_root, aEvent->y_root, false, false)) {
+    if (aEvent->button == 3 && mDraggableRegion.Contains(refPoint)) {
+      GUniquePtr<GdkEvent> eventCopy;
+      if (aEvent->type != GDK_BUTTON_PRESS) {
+        // If the user double-clicks too fast we'll get a 2BUTTON_PRESS event
+        // instead, and that isn't handled by open_window_menu, so coerce it
+        // into a regular press.
+        eventCopy.reset(gdk_event_copy((GdkEvent*)aEvent));
+        eventCopy->type = GDK_BUTTON_PRESS;
+      }
+      TryToShowNativeWindowMenu(eventCopy ? &eventCopy->button : aEvent);
+    }
+    return;
+  }
+
+  // Check to see if the event is within our window's resize region
+  if (auto edge = CheckResizerEdge(refPoint)) {
+    gdk_window_begin_resize_drag(gtk_widget_get_window(mShell), *edge,
+                                 aEvent->button, aEvent->x_root, aEvent->y_root,
+                                 aEvent->time);
+    return;
+  }
+
+  gdouble pressure = 0;
+  gdk_event_get_axis((GdkEvent*)aEvent, GDK_AXIS_PRESSURE, &pressure);
+  mLastMotionPressure = pressure;
+
+  uint16_t domButton;
+  switch (aEvent->button) {
+    case 1:
+      domButton = MouseButton::ePrimary;
+      break;
+    case 2:
+      domButton = MouseButton::eMiddle;
+      break;
+    case 3:
+      domButton = MouseButton::eSecondary;
+      break;
+    // These are mapped to horizontal scroll
+    case 6:
+    case 7:
+      NS_WARNING("We're not supporting legacy horizontal scroll event");
+      return;
+    // Map buttons 8-9 to back/forward
+    case 8:
+      if (!Preferences::GetBool("mousebutton.4th.enabled", true)) {
+        return;
+      }
+      DispatchCommandEvent(nsGkAtoms::Back);
+      return;
+    case 9:
+      if (!Preferences::GetBool("mousebutton.5th.enabled", true)) {
+        return;
+      }
+      DispatchCommandEvent(nsGkAtoms::Forward);
+      return;
+    default:
+      return;
+  }
+
+  gButtonState |= ButtonMaskFromGDKButton(aEvent->button);
+
+  WidgetMouseEvent event(true, eMouseDown, this, WidgetMouseEvent::eReal);
+  event.mButton = domButton;
+  InitButtonEvent(event, aEvent, refPoint);
+  event.mPressure = mLastMotionPressure;
+
+  nsIWidget::ContentAndAPZEventStatus eventStatus = DispatchInputEvent(&event);
+
+  if ((mIsWaylandPanelWindow || mDraggableRegion.Contains(refPoint)) &&
+      domButton == MouseButton::ePrimary &&
+      eventStatus.mContentStatus != nsEventStatus_eConsumeNoDefault) {
+    mWindowShouldStartDragging = true;
+  }
+
+  // right menu click on linux should also pop up a context menu
+  if (!StaticPrefs::ui_context_menus_after_mouseup() &&
+      eventStatus.mApzStatus != nsEventStatus_eConsumeNoDefault) {
+    DispatchContextMenuEventFromMouseEvent(domButton, aEvent, refPoint);
+  }
+}
+
+void nsWindow::OnButtonReleaseEvent(GdkEventButton* aEvent) {
+  LOG("Button %u release\n", aEvent->button);
+
+  SetLastMousePressEvent(nullptr);
+
+  if (!mGdkWindow) {
+    return;
+  }
+
+  if (mWindowShouldStartDragging) {
+    mWindowShouldStartDragging = false;
+  }
+
+  uint16_t domButton;
+  switch (aEvent->button) {
+    case 1:
+      domButton = MouseButton::ePrimary;
+      break;
+    case 2:
+      domButton = MouseButton::eMiddle;
+      break;
+    case 3:
+      domButton = MouseButton::eSecondary;
+      break;
+    default:
+      return;
+  }
+
+  gButtonState &= ~ButtonMaskFromGDKButton(aEvent->button);
+
+  const auto refPoint = GetRefPoint(this, aEvent);
+
+  WidgetMouseEvent event(true, eMouseUp, this, WidgetMouseEvent::eReal);
+  event.mButton = domButton;
+  InitButtonEvent(event, aEvent, refPoint);
+  gdouble pressure = 0;
+  gdk_event_get_axis((GdkEvent*)aEvent, GDK_AXIS_PRESSURE, &pressure);
+  event.mPressure = pressure ? (float)pressure : (float)mLastMotionPressure;
+
+  // The mRefPoint is manipulated in DispatchInputEvent, we're saving it
+  // to use it for the doubleclick position check.
+  const LayoutDeviceIntPoint pos = event.mRefPoint;
+
+  nsIWidget::ContentAndAPZEventStatus eventStatus = DispatchInputEvent(&event);
+
+  const bool defaultPrevented =
+      eventStatus.mContentStatus == nsEventStatus_eConsumeNoDefault;
+  // Check if mouse position in titlebar and doubleclick happened to
+  // trigger restore/maximize.
+  if (!defaultPrevented && mDrawInTitlebar &&
+      event.mButton == MouseButton::ePrimary && event.mClickCount == 2 &&
+      mDraggableRegion.Contains(pos)) {
+    if (mSizeMode == nsSizeMode_Maximized) {
+      SetSizeMode(nsSizeMode_Normal);
+    } else if (mSizeMode == nsSizeMode_Normal) {
+      SetSizeMode(nsSizeMode_Maximized);
+    }
+  }
+  mLastMotionPressure = pressure;
+
+  // right menu click on linux should also pop up a context menu
+  if (StaticPrefs::ui_context_menus_after_mouseup() &&
+      eventStatus.mApzStatus != nsEventStatus_eConsumeNoDefault) {
+    DispatchContextMenuEventFromMouseEvent(domButton, aEvent, refPoint);
+  }
+
+  // Open window manager menu on PIP window to allow user
+  // to place it on top / all workspaces.
+  if (mAlwaysOnTop && aEvent->button == 3) {
+    TryToShowNativeWindowMenu(aEvent);
+  }
+}
+
+void nsWindow::OnContainerFocusInEvent(GdkEventFocus* aEvent) {
+  LOG("OnContainerFocusInEvent");
+
+  // Unset the urgency hint, if possible
+  GtkWidget* top_window = GetToplevelWidget();
+  if (top_window && (gtk_widget_get_visible(top_window))) {
+    SetUrgencyHint(top_window, false);
+  }
+
+  // Return if being called within SetFocus because the focus manager
+  // already knows that the window is active.
+  if (gBlockActivateEvent) {
+    LOG("activated notification is blocked");
+    return;
+  }
+
+  // If keyboard input will be accepted, the focus manager will call
+  // SetFocus to set the correct window.
+  gFocusWindow = nullptr;
+
+  DispatchActivateEvent();
+
+  if (!gFocusWindow) {
+    // We don't really have a window for dispatching key events, but
+    // setting a non-nullptr value here prevents OnButtonPressEvent() from
+    // dispatching an activation notification if the widget is already
+    // active.
+    gFocusWindow = this;
+  }
+
+  LOG("Events sent from focus in event");
+}
+
+void nsWindow::OnContainerFocusOutEvent(GdkEventFocus* aEvent) {
+  LOG("OnContainerFocusOutEvent");
+
+  if (mWindowType == WindowType::TopLevel ||
+      mWindowType == WindowType::Dialog) {
+    // Rollup menus when a window is focused out unless a drag is occurring.
+    // This check is because drags grab the keyboard and cause a focus out on
+    // versions of GTK before 2.18.
+    const bool shouldRollupMenus = [&] {
+      nsCOMPtr<nsIDragService> dragService =
+          do_GetService("@mozilla.org/widget/dragservice;1");
+      nsCOMPtr<nsIDragSession> dragSession;
+      dragService->GetCurrentSession(getter_AddRefs(dragSession));
+      if (!dragSession) {
+        return true;
+      }
+      // We also roll up when a drag is from a different application
+      nsCOMPtr<nsINode> sourceNode;
+      dragSession->GetSourceNode(getter_AddRefs(sourceNode));
+      return !sourceNode;
+    }();
+
+    if (shouldRollupMenus) {
+      RollupAllMenus();
+    }
+
+    if (RefPtr pm = nsXULPopupManager::GetInstance()) {
+      pm->RollupTooltips();
+    }
+  }
+
+  if (gFocusWindow) {
+    RefPtr<nsWindow> kungFuDeathGrip = gFocusWindow;
+    if (gFocusWindow->mIMContext) {
+      gFocusWindow->mIMContext->OnBlurWindow(gFocusWindow);
+    }
+    gFocusWindow = nullptr;
+  }
+
+  DispatchDeactivateEvent();
+
+  if (IsChromeWindowTitlebar()) {
+    // DispatchDeactivateEvent() ultimately results in a call to
+    // BrowsingContext::SetIsActiveBrowserWindow(), which resets
+    // the state.  We call UpdateMozWindowActive() to keep it in
+    // sync with GDK_WINDOW_STATE_FOCUSED.
+    UpdateMozWindowActive();
+  }
+
+  LOG("Done with container focus out");
+}
+
+bool nsWindow::DispatchCommandEvent(nsAtom* aCommand) {
+  nsEventStatus status;
+  WidgetCommandEvent appCommandEvent(true, aCommand, this);
+  DispatchEvent(&appCommandEvent, status);
+  return TRUE;
+}
+
+bool nsWindow::DispatchContentCommandEvent(EventMessage aMsg) {
+  nsEventStatus status;
+  WidgetContentCommandEvent event(true, aMsg, this);
+  DispatchEvent(&event, status);
+  return TRUE;
+}
+
+WidgetEventTime nsWindow::GetWidgetEventTime(guint32 aEventTime) {
+  return WidgetEventTime(GetEventTimeStamp(aEventTime));
+}
+
+TimeStamp nsWindow::GetEventTimeStamp(guint32 aEventTime) {
+  if (MOZ_UNLIKELY(!mGdkWindow)) {
+    // nsWindow has been Destroy()ed.
+    return TimeStamp::Now();
+  }
+  if (aEventTime == 0) {
+    // Some X11 and GDK events may be received with a time of 0 to indicate
+    // that they are synthetic events. Some input method editors do this.
+    // In this case too, just return the current timestamp.
+    return TimeStamp::Now();
+  }
+
+  TimeStamp eventTimeStamp;
+
+  if (GdkIsWaylandDisplay()) {
+    // Wayland compositors use monotonic time to set timestamps.
+    int64_t timestampTime = g_get_monotonic_time() / 1000;
+    guint32 refTimeTruncated = guint32(timestampTime);
+
+    timestampTime -= refTimeTruncated - aEventTime;
+    int64_t tick =
+        BaseTimeDurationPlatformUtils::TicksFromMilliseconds(timestampTime);
+    eventTimeStamp = TimeStamp::FromSystemTime(tick);
+  } else {
+#ifdef MOZ_X11
+    CurrentX11TimeGetter* getCurrentTime = GetCurrentTimeGetter();
+    MOZ_ASSERT(getCurrentTime,
+               "Null current time getter despite having a window");
+    eventTimeStamp =
+        TimeConverter().GetTimeStampFromSystemTime(aEventTime, *getCurrentTime);
+#endif
+  }
+  return eventTimeStamp;
+}
+
+#ifdef MOZ_X11
+mozilla::CurrentX11TimeGetter* nsWindow::GetCurrentTimeGetter() {
+  MOZ_ASSERT(mGdkWindow, "Expected mGdkWindow to be set");
+  if (MOZ_UNLIKELY(!mCurrentTimeGetter)) {
+    mCurrentTimeGetter = MakeUnique<CurrentX11TimeGetter>(mGdkWindow);
+  }
+  return mCurrentTimeGetter.get();
+}
+#endif
+
+gboolean nsWindow::OnKeyPressEvent(GdkEventKey* aEvent) {
+  LOG("OnKeyPressEvent");
+
+  KeymapWrapper::HandleKeyPressEvent(this, aEvent);
+  return TRUE;
+}
+
+gboolean nsWindow::OnKeyReleaseEvent(GdkEventKey* aEvent) {
+  LOG("OnKeyReleaseEvent");
+  if (NS_WARN_IF(!KeymapWrapper::HandleKeyReleaseEvent(this, aEvent))) {
+    return FALSE;
+  }
+  return TRUE;
+}
+
+void nsWindow::OnScrollEvent(GdkEventScroll* aEvent) {
+  // check to see if we should rollup
+  if (CheckForRollup(aEvent->x_root, aEvent->y_root, true, false)) {
+    return;
+  }
+
+  // check for duplicate legacy scroll event, see GNOME bug 726878
+  if (aEvent->direction != GDK_SCROLL_SMOOTH &&
+      mLastScrollEventTime == aEvent->time) {
+    LOG("[%d] duplicate legacy scroll event %d\n", aEvent->time,
+        aEvent->direction);
+    return;
+  }
+  WidgetWheelEvent wheelEvent(true, eWheel, this);
+  wheelEvent.mDeltaMode = dom::WheelEvent_Binding::DOM_DELTA_LINE;
+  switch (aEvent->direction) {
+    case GDK_SCROLL_SMOOTH: {
+      // As of GTK 3.4, all directional scroll events are provided by
+      // the GDK_SCROLL_SMOOTH direction on XInput2 and Wayland devices.
+      mLastScrollEventTime = aEvent->time;
+
+      // Special handling for touchpads to support flings
+      // (also known as kinetic/inertial/momentum scrolling)
+      GdkDevice* device = gdk_event_get_source_device((GdkEvent*)aEvent);
+      GdkInputSource source = gdk_device_get_source(device);
+      if (source == GDK_SOURCE_TOUCHSCREEN || source == GDK_SOURCE_TOUCHPAD ||
+          mCurrentSynthesizedTouchpadPan.mTouchpadGesturePhase.isSome()) {
+        if (StaticPrefs::apz_gtk_pangesture_enabled() &&
+            gtk_check_version(3, 20, 0) == nullptr) {
+          static auto sGdkEventIsScrollStopEvent =
+              (gboolean(*)(const GdkEvent*))dlsym(
+                  RTLD_DEFAULT, "gdk_event_is_scroll_stop_event");
+
+          LOG("[%d] pan smooth event dx=%f dy=%f inprogress=%d\n", aEvent->time,
+              aEvent->delta_x, aEvent->delta_y, mPanInProgress);
+          PanGestureInput::PanGestureType eventType =
+              PanGestureInput::PANGESTURE_PAN;
+          if (sGdkEventIsScrollStopEvent((GdkEvent*)aEvent)) {
+            eventType = PanGestureInput::PANGESTURE_END;
+            mPanInProgress = false;
+          } else if (!mPanInProgress) {
+            eventType = PanGestureInput::PANGESTURE_START;
+            mPanInProgress = true;
+          } else if (mCurrentSynthesizedTouchpadPan.mTouchpadGesturePhase
+                         .isSome()) {
+            switch (*mCurrentSynthesizedTouchpadPan.mTouchpadGesturePhase) {
+              case PHASE_BEGIN:
+                // we should never hit this because we'll hit the above case
+                // before this.
+                MOZ_ASSERT_UNREACHABLE();
+                eventType = PanGestureInput::PANGESTURE_START;
+                mPanInProgress = true;
+                break;
+              case PHASE_UPDATE:
+                // nothing to do here, eventtype should already be set
+                MOZ_ASSERT(mPanInProgress);
+                MOZ_ASSERT(eventType == PanGestureInput::PANGESTURE_PAN);
+                eventType = PanGestureInput::PANGESTURE_PAN;
+                break;
+              case PHASE_END:
+                MOZ_ASSERT(mPanInProgress);
+                eventType = PanGestureInput::PANGESTURE_END;
+                mPanInProgress = false;
+                break;
+              default:
+                MOZ_ASSERT_UNREACHABLE();
+                break;
+            }
+          }
+
+          mCurrentSynthesizedTouchpadPan.mTouchpadGesturePhase.reset();
+
+          const bool isPageMode =
+              StaticPrefs::apz_gtk_pangesture_delta_mode() != 2;
+          const double multiplier =
+              isPageMode
+                  ? StaticPrefs::apz_gtk_pangesture_page_delta_mode_multiplier()
+                  : StaticPrefs::
+                            apz_gtk_pangesture_pixel_delta_mode_multiplier() *
+                        FractionalScaleFactor();
+
+          ScreenPoint deltas(float(aEvent->delta_x * multiplier),
+                             float(aEvent->delta_y * multiplier));
+
+          LayoutDeviceIntPoint touchPoint = GetRefPoint(this, aEvent);
+          PanGestureInput panEvent(
+              eventType, GetEventTimeStamp(aEvent->time),
+              ScreenPoint(touchPoint.x, touchPoint.y), deltas,
+              KeymapWrapper::ComputeKeyModifiers(aEvent->state));
+          panEvent.mDeltaType = isPageMode ? PanGestureInput::PANDELTA_PAGE
+                                           : PanGestureInput::PANDELTA_PIXEL;
+          panEvent.mSimulateMomentum =
+              StaticPrefs::apz_gtk_kinetic_scroll_enabled();
+
+          DispatchPanGesture(panEvent);
+
+          if (mCurrentSynthesizedTouchpadPan.mSavedObserver != 0) {
+            mozilla::widget::AutoObserverNotifier::NotifySavedObserver(
+                mCurrentSynthesizedTouchpadPan.mSavedObserver,
+                "touchpadpanevent");
+            mCurrentSynthesizedTouchpadPan.mSavedObserver = 0;
+          }
+
+          return;
+        }
+
+        // Older GTK doesn't support stop events, so we can't support fling
+        wheelEvent.mScrollType = WidgetWheelEvent::SCROLL_ASYNCHRONOUSLY;
+      }
+
+      // TODO - use a more appropriate scrolling unit than lines.
+      // Multiply event deltas by 3 to emulate legacy behaviour.
+      wheelEvent.mDeltaX = aEvent->delta_x * 3;
+      wheelEvent.mDeltaY = aEvent->delta_y * 3;
+      wheelEvent.mWheelTicksX = aEvent->delta_x;
+      wheelEvent.mWheelTicksY = aEvent->delta_y;
+      wheelEvent.mIsNoLineOrPageDelta = true;
+
+      break;
+    }
+    case GDK_SCROLL_UP:
+      wheelEvent.mDeltaY = wheelEvent.mLineOrPageDeltaY = -3;
+      wheelEvent.mWheelTicksY = -1;
+      break;
+    case GDK_SCROLL_DOWN:
+      wheelEvent.mDeltaY = wheelEvent.mLineOrPageDeltaY = 3;
+      wheelEvent.mWheelTicksY = 1;
+      break;
+    case GDK_SCROLL_LEFT:
+      wheelEvent.mDeltaX = wheelEvent.mLineOrPageDeltaX = -1;
+      wheelEvent.mWheelTicksX = -1;
+      break;
+    case GDK_SCROLL_RIGHT:
+      wheelEvent.mDeltaX = wheelEvent.mLineOrPageDeltaX = 1;
+      wheelEvent.mWheelTicksX = 1;
+      break;
+  }
+
+  wheelEvent.mRefPoint = GetRefPoint(this, aEvent);
+
+  KeymapWrapper::InitInputEvent(wheelEvent, aEvent->state);
+
+  wheelEvent.AssignEventTime(GetWidgetEventTime(aEvent->time));
+
+  DispatchInputEvent(&wheelEvent);
+}
+
+void nsWindow::DispatchPanGesture(PanGestureInput& aPanInput) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (mSwipeTracker) {
+    // Give the swipe tracker a first pass at the event. If a new pan gesture
+    // has been started since the beginning of the swipe, the swipe tracker
+    // will know to ignore the event.
+    nsEventStatus status = mSwipeTracker->ProcessEvent(aPanInput);
+    if (status == nsEventStatus_eConsumeNoDefault) {
+      return;
+    }
+  }
+
+  APZEventResult result;
+  if (mAPZC) {
+    MOZ_ASSERT(APZThreadUtils::IsControllerThread());
+
+    result = mAPZC->InputBridge()->ReceiveInputEvent(aPanInput);
+    if (result.GetStatus() == nsEventStatus_eConsumeNoDefault) {
+      return;
+    }
+  }
+
+  WidgetWheelEvent event = aPanInput.ToWidgetEvent(this);
+  if (!mAPZC) {
+    if (MayStartSwipeForNonAPZ(aPanInput)) {
+      return;
+    }
+  } else {
+    event = MayStartSwipeForAPZ(aPanInput, result);
+  }
+
+  ProcessUntransformedAPZEvent(&event, result);
+}
+
+void nsWindow::OnWindowStateEvent(GtkWidget* aWidget,
+                                  GdkEventWindowState* aEvent) {
+  LOG("nsWindow::OnWindowStateEvent for %p changed 0x%x new_window_state "
+      "0x%x\n",
+      aWidget, aEvent->changed_mask, aEvent->new_window_state);
+
+  if (IS_MOZ_CONTAINER(aWidget)) {
+    // This event is notifying the container widget of changes to the
+    // toplevel window.  Just detect changes affecting whether windows are
+    // viewable.
+    //
+    // (A visibility notify event is sent to each window that becomes
+    // viewable when the toplevel is mapped, but we can't rely on that for
+    // setting mHasMappedToplevel because these toplevel window state
+    // events are asynchronous.  The windows in the hierarchy now may not
+    // be the same windows as when the toplevel was mapped, so they may
+    // not get VisibilityNotify events.)
+    bool mapped = !(aEvent->new_window_state &
+                    (GDK_WINDOW_STATE_ICONIFIED | GDK_WINDOW_STATE_WITHDRAWN));
+    SetHasMappedToplevel(mapped);
+    LOG("\tquick return because IS_MOZ_CONTAINER(aWidget) is true\n");
+    return;
+  }
+  // else the widget is a shell widget.
+
+  // The block below is a bit evil.
+  //
+  // When a window is resized before it is shown, gtk_window_resize() delays
+  // resizes until the window is shown.  If gtk_window_state_event() sees a
+  // GDK_WINDOW_STATE_MAXIMIZED change [1] before the window is shown, then
+  // gtk_window_compute_configure_request_size() ignores the values from the
+  // resize [2].  See bug 1449166 for an example of how this could happen.
+  //
+  // [1] https://gitlab.gnome.org/GNOME/gtk/blob/3.22.30/gtk/gtkwindow.c#L7967
+  // [2] https://gitlab.gnome.org/GNOME/gtk/blob/3.22.30/gtk/gtkwindow.c#L9377
+  //
+  // In order to provide a sensible size for the window when the user exits
+  // maximized state, we hide the GDK_WINDOW_STATE_MAXIMIZED change from
+  // gtk_window_state_event() so as to trick GTK into using the values from
+  // gtk_window_resize() in its configure request.
+  //
+  // We instead notify gtk_window_state_event() of the maximized state change
+  // once the window is shown.
+  //
+  // See https://gitlab.gnome.org/GNOME/gtk/issues/1044
+  //
+  // This may be fixed in Gtk 3.24+ but it's still live and kicking
+  // (Bug 1791779).
+  if (!mIsShown) {
+    aEvent->changed_mask = static_cast<GdkWindowState>(
+        aEvent->changed_mask & ~GDK_WINDOW_STATE_MAXIMIZED);
+  } else if (aEvent->changed_mask & GDK_WINDOW_STATE_WITHDRAWN &&
+             aEvent->new_window_state & GDK_WINDOW_STATE_MAXIMIZED) {
+    aEvent->changed_mask = static_cast<GdkWindowState>(
+        aEvent->changed_mask | GDK_WINDOW_STATE_MAXIMIZED);
+  }
+
+  // This is a workaround for https://gitlab.gnome.org/GNOME/gtk/issues/1395
+  // Gtk+ controls window active appearance by window-state-event signal.
+  if (IsChromeWindowTitlebar() &&
+      (aEvent->changed_mask & GDK_WINDOW_STATE_FOCUSED)) {
+    // Emulate what Gtk+ does at gtk_window_state_event().
+    // We can't check GTK_STATE_FLAG_BACKDROP directly as it's set by Gtk+
+    // *after* this window-state-event handler.
+    mTitlebarBackdropState =
+        !(aEvent->new_window_state & GDK_WINDOW_STATE_FOCUSED);
+
+    // keep IsActiveBrowserWindow in sync with GDK_WINDOW_STATE_FOCUSED
+    UpdateMozWindowActive();
+
+    ForceTitlebarRedraw();
+  }
+
+  // We don't care about anything but changes in the maximized/icon/fullscreen
+  // states but we need a workaround for bug in Wayland:
+  // https://gitlab.gnome.org/GNOME/gtk/issues/67
+  // Under wayland the gtk_window_iconify implementation does NOT synthetize
+  // window_state_event where the GDK_WINDOW_STATE_ICONIFIED is set.
+  // During restore we  won't get aEvent->changed_mask with
+  // the GDK_WINDOW_STATE_ICONIFIED so to detect that change we use the stored
+  // mSizeMode and obtaining a focus.
+  bool waylandWasIconified =
+      (GdkIsWaylandDisplay() &&
+       aEvent->changed_mask & GDK_WINDOW_STATE_FOCUSED &&
+       aEvent->new_window_state & GDK_WINDOW_STATE_FOCUSED &&
+       mSizeMode == nsSizeMode_Minimized);
+  if (!waylandWasIconified &&
+      (aEvent->changed_mask &
+       (GDK_WINDOW_STATE_ICONIFIED | GDK_WINDOW_STATE_MAXIMIZED |
+        GDK_WINDOW_STATE_TILED | GDK_WINDOW_STATE_FULLSCREEN)) == 0) {
+    LOG("\tearly return because no interesting bits changed\n");
+    return;
+  }
+
+  auto oldSizeMode = mSizeMode;
+  if (aEvent->new_window_state & GDK_WINDOW_STATE_ICONIFIED) {
+    LOG("\tIconified\n");
+    mSizeMode = nsSizeMode_Minimized;
+#ifdef ACCESSIBILITY
+    DispatchMinimizeEventAccessible();
+#endif  // ACCESSIBILITY
+  } else if (aEvent->new_window_state & GDK_WINDOW_STATE_FULLSCREEN) {
+    LOG("\tFullscreen\n");
+    mSizeMode = nsSizeMode_Fullscreen;
+  } else if (aEvent->new_window_state & GDK_WINDOW_STATE_MAXIMIZED) {
+    LOG("\tMaximized\n");
+    mSizeMode = nsSizeMode_Maximized;
+#ifdef ACCESSIBILITY
+    DispatchMaximizeEventAccessible();
+#endif  // ACCESSIBILITY
+  } else {
+    LOG("\tNormal\n");
+    mSizeMode = nsSizeMode_Normal;
+#ifdef ACCESSIBILITY
+    DispatchRestoreEventAccessible();
+#endif  // ACCESSIBILITY
+  }
+
+  mIsTiled = aEvent->new_window_state & GDK_WINDOW_STATE_TILED;
+  LOG("\tTiled: %d\n", int(mIsTiled));
+
+  if (mWidgetListener && mSizeMode != oldSizeMode) {
+    mWidgetListener->SizeModeChanged(mSizeMode);
+  }
+
+  if (mDrawInTitlebar && mTransparencyBitmapForTitlebar) {
+    if (mSizeMode == nsSizeMode_Normal && !mIsTiled) {
+      UpdateTitlebarTransparencyBitmap();
+    } else {
+      ClearTransparencyBitmap();
+    }
+  }
+}
+
+void nsWindow::OnDPIChanged() {
+  // Update menu's font size etc.
+  // This affects style / layout because it affects system font sizes.
+  if (mWidgetListener) {
+    if (PresShell* presShell = mWidgetListener->GetPresShell()) {
+      presShell->BackingScaleFactorChanged();
+    }
+    mWidgetListener->UIResolutionChanged();
+  }
+  NotifyThemeChanged(ThemeChangeKind::StyleAndLayout);
+}
+
+void nsWindow::OnCheckResize() { mPendingConfigures++; }
+
+void nsWindow::OnCompositedChanged() {
+  // Update CSD after the change in alpha visibility. This only affects
+  // system metrics, not other theme shenanigans.
+  NotifyThemeChanged(ThemeChangeKind::MediaQueriesOnly);
+  mCompositedScreen = gdk_screen_is_composited(gdk_screen_get_default());
+}
+
+void nsWindow::OnScaleChanged() {
+  // Force scale factor recalculation
+  if (!mGdkWindow) {
+    mWindowScaleFactorChanged = true;
+    return;
+  }
+  LOG("OnScaleChanged -> %d\n", gdk_window_get_scale_factor(mGdkWindow));
+
+  // Gtk supply us sometimes with doubled events so stay calm in such case.
+  if (gdk_window_get_scale_factor(mGdkWindow) == mWindowScaleFactor) {
+    return;
+  }
+
+  // We pause compositor to avoid rendering of obsoleted remote content which
+  // produces flickering.
+  // Re-enable compositor again when remote content is updated or
+  // timeout happens.
+  PauseCompositorFlickering();
+
+  // Force scale factor recalculation
+  mWindowScaleFactorChanged = true;
+
+  GtkAllocation allocation;
+  gtk_widget_get_allocation(GTK_WIDGET(mContainer), &allocation);
+  LayoutDeviceIntSize size = GdkRectToDevicePixels(allocation).Size();
+  mBounds.SizeTo(size);
+  // Check mBounds size
+  if (mCompositorSession &&
+      !wr::WindowSizeSanityCheck(mBounds.width, mBounds.height)) {
+    gfxCriticalNoteOnce << "Invalid mBounds in OnScaleChanged " << mBounds;
+  }
+
+  if (mWidgetListener) {
+    if (PresShell* presShell = mWidgetListener->GetPresShell()) {
+      presShell->BackingScaleFactorChanged();
+    }
+  }
+  // This affects style / layout because it affects system font sizes.
+  // Update menu's font size etc.
+  NotifyThemeChanged(ThemeChangeKind::StyleAndLayout);
+
+  DispatchResized();
+
+  if (mCompositorWidgetDelegate) {
+    mCompositorWidgetDelegate->NotifyClientSizeChanged(GetClientSize());
+  }
+
+  if (mCursor.IsCustom()) {
+    mUpdateCursor = true;
+    SetCursor(Cursor{mCursor});
+  }
+}
+
+void nsWindow::DispatchDragEvent(EventMessage aMsg,
+                                 const LayoutDeviceIntPoint& aRefPoint,
+                                 guint aTime) {
+  LOGDRAG("nsWindow::DispatchDragEvent");
+  WidgetDragEvent event(true, aMsg, this);
+
+  InitDragEvent(event);
+
+  event.mRefPoint = aRefPoint;
+  event.AssignEventTime(GetWidgetEventTime(aTime));
+
+  DispatchInputEvent(&event);
+}
+
+void nsWindow::OnDragDataReceivedEvent(GtkWidget* aWidget,
+                                       GdkDragContext* aDragContext, gint aX,
+                                       gint aY,
+                                       GtkSelectionData* aSelectionData,
+                                       guint aInfo, guint aTime,
+                                       gpointer aData) {
+  LOGDRAG("nsWindow::OnDragDataReceived");
+
+  RefPtr<nsDragService> dragService = nsDragService::GetInstance();
+  nsDragService::AutoEventLoop loop(dragService);
+  dragService->TargetDataReceived(aWidget, aDragContext, aX, aY, aSelectionData,
+                                  aInfo, aTime);
+}
+
+nsWindow* nsWindow::GetTransientForWindowIfPopup() {
+  if (mWindowType != WindowType::Popup) {
+    return nullptr;
+  }
+  GtkWindow* toplevel = gtk_window_get_transient_for(GTK_WINDOW(mShell));
+  if (toplevel) {
+    return get_window_for_gtk_widget(GTK_WIDGET(toplevel));
+  }
+  return nullptr;
+}
+
+bool nsWindow::IsHandlingTouchSequence(GdkEventSequence* aSequence) {
+  return mHandleTouchEvent && mTouches.Contains(aSequence);
+}
+
+gboolean nsWindow::OnTouchpadPinchEvent(GdkEventTouchpadPinch* aEvent) {
+  if (!StaticPrefs::apz_gtk_touchpad_pinch_enabled()) {
+    return TRUE;
+  }
+  // Do not respond to pinch gestures involving more than two fingers
+  // unless specifically preffed on. These are sometimes hooked up to other
+  // actions at the desktop environment level and having the browser also
+  // pinch can be undesirable.
+  if (aEvent->n_fingers > 2 &&
+      !StaticPrefs::apz_gtk_touchpad_pinch_three_fingers_enabled()) {
+    return FALSE;
+  }
+  auto pinchGestureType = PinchGestureInput::PINCHGESTURE_SCALE;
+  ScreenCoord currentSpan;
+  ScreenCoord previousSpan;
+
+  switch (aEvent->phase) {
+    case GDK_TOUCHPAD_GESTURE_PHASE_BEGIN:
+      pinchGestureType = PinchGestureInput::PINCHGESTURE_START;
+      currentSpan = aEvent->scale;
+      mCurrentTouchpadFocus = ViewAs<ScreenPixel>(
+          GetRefPoint(this, aEvent),
+          PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent);
+
+      // Assign PreviousSpan --> 0.999 to make mDeltaY field of the
+      // WidgetWheelEvent that this PinchGestureInput event will be converted
+      // to not equal Zero as our discussion because we observed that the
+      // scale of the PHASE_BEGIN event is 1.
+      previousSpan = 0.999;
+      break;
+
+    case GDK_TOUCHPAD_GESTURE_PHASE_UPDATE:
+      pinchGestureType = PinchGestureInput::PINCHGESTURE_SCALE;
+      mCurrentTouchpadFocus += ScreenPoint(aEvent->dx, aEvent->dy);
+      if (aEvent->scale == mLastPinchEventSpan) {
+        return FALSE;
+      }
+      currentSpan = aEvent->scale;
+      previousSpan = mLastPinchEventSpan;
+      break;
+
+    case GDK_TOUCHPAD_GESTURE_PHASE_END:
+      pinchGestureType = PinchGestureInput::PINCHGESTURE_END;
+      currentSpan = aEvent->scale;
+      previousSpan = mLastPinchEventSpan;
+      break;
+
+    default:
+      return FALSE;
+  }
+
+  PinchGestureInput event(
+      pinchGestureType, PinchGestureInput::TRACKPAD,
+      GetEventTimeStamp(aEvent->time), ExternalPoint(0, 0),
+      mCurrentTouchpadFocus,
+      100.0 * ((aEvent->phase == GDK_TOUCHPAD_GESTURE_PHASE_END)
+                   ? ScreenCoord(1.f)
+                   : currentSpan),
+      100.0 * ((aEvent->phase == GDK_TOUCHPAD_GESTURE_PHASE_END)
+                   ? ScreenCoord(1.f)
+                   : previousSpan),
+      KeymapWrapper::ComputeKeyModifiers(aEvent->state));
+
+  if (!event.SetLineOrPageDeltaY(this)) {
+    return FALSE;
+  }
+
+  mLastPinchEventSpan = aEvent->scale;
+  DispatchPinchGestureInput(event);
+  return TRUE;
+}
+
+gboolean nsWindow::OnTouchEvent(GdkEventTouch* aEvent) {
+  LOG("OnTouchEvent: x=%f y=%f type=%d\n", aEvent->x, aEvent->y, aEvent->type);
+  if (!mHandleTouchEvent) {
+    // If a popup window was spawned (e.g. as the result of a long-press)
+    // and touch events got diverted to that window within a touch sequence,
+    // ensure the touch event gets sent to the original window instead. We
+    // keep the checks here very conservative so that we only redirect
+    // events in this specific scenario.
+    nsWindow* targetWindow = GetTransientForWindowIfPopup();
+    if (targetWindow &&
+        targetWindow->IsHandlingTouchSequence(aEvent->sequence)) {
+      return targetWindow->OnTouchEvent(aEvent);
+    }
+
+    return FALSE;
+  }
+
+  EventMessage msg;
+  switch (aEvent->type) {
+    case GDK_TOUCH_BEGIN:
+      // check to see if we should rollup
+      if (CheckForRollup(aEvent->x_root, aEvent->y_root, false, false)) {
+        return FALSE;
+      }
+      msg = eTouchStart;
+      break;
+    case GDK_TOUCH_UPDATE:
+      msg = eTouchMove;
+      // Start dragging when motion events happens in the dragging area
+      if (mWindowShouldStartDragging) {
+        mWindowShouldStartDragging = false;
+        GdkWindow* gdk_window = gdk_window_get_toplevel(mGdkWindow);
+        MOZ_ASSERT(gdk_window,
+                   "gdk_window_get_toplevel should not return null");
+
+        LOG("  start window dragging window\n");
+        gdk_window_begin_move_drag(gdk_window, 1, aEvent->x_root,
+                                   aEvent->y_root, aEvent->time);
+
+        // Cancel the event sequence. gdk will steal all subsequent events
+        // (including TOUCH_END).
+        msg = eTouchCancel;
+      }
+      break;
+    case GDK_TOUCH_END:
+      msg = eTouchEnd;
+      if (mWindowShouldStartDragging) {
+        LOG("  end of window dragging window\n");
+        mWindowShouldStartDragging = false;
+      }
+      break;
+    case GDK_TOUCH_CANCEL:
+      msg = eTouchCancel;
+      break;
+    default:
+      return FALSE;
+  }
+
+  const LayoutDeviceIntPoint touchPoint = GetRefPoint(this, aEvent);
+
+  int32_t id;
+  RefPtr<dom::Touch> touch;
+  if (mTouches.Remove(aEvent->sequence, getter_AddRefs(touch))) {
+    id = touch->mIdentifier;
+  } else {
+    id = ++gLastTouchID & 0x7FFFFFFF;
+  }
+
+  touch =
+      new dom::Touch(id, touchPoint, LayoutDeviceIntPoint(1, 1), 0.0f, 0.0f);
+
+  WidgetTouchEvent event(true, msg, this);
+  KeymapWrapper::InitInputEvent(event, aEvent->state);
+
+  if (msg == eTouchStart || msg == eTouchMove) {
+    mTouches.InsertOrUpdate(aEvent->sequence, std::move(touch));
+    // add all touch points to event object
+    for (const auto& data : mTouches.Values()) {
+      event.mTouches.AppendElement(new dom::Touch(*data));
+    }
+  } else if (msg == eTouchEnd || msg == eTouchCancel) {
+    *event.mTouches.AppendElement() = std::move(touch);
+  }
+
+  nsIWidget::ContentAndAPZEventStatus eventStatus = DispatchInputEvent(&event);
+
+  // There's a chance that we are in drag area and the event is not consumed
+  // by something on it.
+  if (msg == eTouchStart && mDraggableRegion.Contains(touchPoint) &&
+      eventStatus.mApzStatus != nsEventStatus_eConsumeNoDefault) {
+    mWindowShouldStartDragging = true;
+  }
+  return TRUE;
+}
+
+// Return true if toplevel window is transparent.
+// It's transparent when we're running on composited screens
+// and we can draw main window without system titlebar.
+bool nsWindow::IsToplevelWindowTransparent() {
+  static bool transparencyConfigured = false;
+
+  if (!transparencyConfigured) {
+    if (gdk_screen_is_composited(gdk_screen_get_default())) {
+      // Some Gtk+ themes use non-rectangular toplevel windows. To fully
+      // support such themes we need to make toplevel window transparent
+      // with ARGB visual.
+      // It may cause performanance issue so make it configurable
+      // and enable it by default for selected window managers.
+      if (Preferences::HasUserValue("mozilla.widget.use-argb-visuals")) {
+        // argb visual is explicitly required so use it
+        sTransparentMainWindow =
+            Preferences::GetBool("mozilla.widget.use-argb-visuals");
+      } else {
+        // Enable transparent toplevel window if we can draw main window
+        // without system titlebar as Gtk+ themes use titlebar round corners.
+        sTransparentMainWindow =
+            GetSystemGtkWindowDecoration() != GTK_DECORATION_NONE;
+      }
+    }
+    transparencyConfigured = true;
+  }
+
+  return sTransparentMainWindow;
+}
+
+#ifdef MOZ_X11
+// Configure GL visual on X11.
+bool nsWindow::ConfigureX11GLVisual() {
+  auto* screen = gtk_widget_get_screen(mShell);
+  int visualId = 0;
+  bool haveVisual = false;
+
+  if (gfxVars::UseEGL()) {
+    haveVisual = GLContextEGL::FindVisual(&visualId);
+  }
+
+  // We are on GLX or use it as a fallback on Mesa, see
+  // https://gitlab.freedesktop.org/mesa/mesa/-/issues/149
+  if (!haveVisual) {
+    auto* display = GDK_DISPLAY_XDISPLAY(gtk_widget_get_display(mShell));
+    int screenNumber = GDK_SCREEN_XNUMBER(screen);
+    haveVisual = GLContextGLX::FindVisual(display, screenNumber, &visualId);
+  }
+
+  GdkVisual* gdkVisual = nullptr;
+  if (haveVisual) {
+    // If we're using CSD, rendering will go through mContainer, but
+    // it will inherit this visual as it is a child of mShell.
+    gdkVisual = gdk_x11_screen_lookup_visual(screen, visualId);
+  }
+  if (!gdkVisual) {
+    NS_WARNING("We're missing X11 Visual!");
+    // We try to use a fallback alpha visual
+    GdkScreen* screen = gtk_widget_get_screen(mShell);
+    gdkVisual = gdk_screen_get_rgba_visual(screen);
+  }
+  if (gdkVisual) {
+    gtk_widget_set_visual(mShell, gdkVisual);
+    mHasAlphaVisual = true;
+    return true;
+  }
+
+  return false;
+}
+#endif
+
+nsAutoCString nsWindow::GetFrameTag() const {
+  if (nsIFrame* frame = GetFrame()) {
+#ifdef DEBUG_FRAME_DUMP
+    return frame->ListTag();
+#else
+    nsAutoCString buf;
+    buf.AppendPrintf("Frame(%p)", frame);
+    if (nsIContent* content = frame->GetContent()) {
+      buf.Append(' ');
+      AppendUTF16toUTF8(content->NodeName(), buf);
+    }
+    return buf;
+#endif
+  }
+  return nsAutoCString("(no frame)");
+}
+
+nsCString nsWindow::GetPopupTypeName() {
+  switch (mPopupHint) {
+    case PopupType::Menu:
+      return nsCString("Menu");
+    case PopupType::Tooltip:
+      return nsCString("Tooltip");
+    case PopupType::Panel:
+      return nsCString("Panel/Utility");
+    default:
+      return nsCString("Unknown");
+  }
+}
+
+// Disables all rendering of GtkWidget from Gtk side.
+// We do our best to persuade Gtk/Gdk to ignore all painting
+// to the widget.
+static void GtkWidgetDisableUpdates(GtkWidget* aWidget) {
+  // Clear exposure mask - it disabled synthesized events.
+  GdkWindow* window = gtk_widget_get_window(aWidget);
+  gdk_window_set_events(window, (GdkEventMask)(gdk_window_get_events(window) &
+                                               (~GDK_EXPOSURE_MASK)));
+
+  // Remove before/after paint handles from frame clock.
+  // It disables widget content updates.
+  GdkFrameClock* frame_clock = gdk_window_get_frame_clock(window);
+  g_signal_handlers_disconnect_by_data(frame_clock, window);
+}
+
+Window nsWindow::GetX11Window() {
+#ifdef MOZ_X11
+  if (GdkIsX11Display()) {
+    return mGdkWindow ? gdk_x11_window_get_xid(mGdkWindow) : X11None;
+  }
+#endif
+  return (Window) nullptr;
+}
+
+void nsWindow::EnsureGdkWindow() {
+  if (!mGdkWindow) {
+    mGdkWindow = gtk_widget_get_window(mDrawToContainer ? GTK_WIDGET(mContainer)
+                                                        : mShell);
+    g_object_set_data(G_OBJECT(mGdkWindow), "nsWindow", this);
+  }
+}
+
+bool nsWindow::GetShapedState() {
+  return mIsTransparent && !mHasAlphaVisual && !mTransparencyBitmapForTitlebar;
+}
+
+void nsWindow::ConfigureCompositor() {
+  MOZ_DIAGNOSTIC_ASSERT(mCompositorState == COMPOSITOR_ENABLED);
+  MOZ_DIAGNOSTIC_ASSERT(mIsMapped);
+
+  LOG("nsWindow::ConfigureCompositor()");
+  auto startCompositing = [self = RefPtr{this}, this]() -> void {
+    LOG("  moz_container_wayland_add_or_fire_initial_draw_callback "
+        "ConfigureCompositor");
+
+    // too late
+    if (mIsDestroyed || !mIsMapped) {
+      LOG("  quit, mIsDestroyed = %d mIsMapped = %d", !!mIsDestroyed,
+          mIsMapped);
+      return;
+    }
+    // Compositor will be resumed later by ResumeCompositorFlickering().
+    if (mCompositorState == COMPOSITOR_PAUSED_FLICKERING) {
+      LOG("  quit, will be resumed by ResumeCompositorFlickering.");
+      return;
+    }
+    // Compositor will be resumed at nsWindow::SetCompositorWidgetDelegate().
+    if (!mCompositorWidgetDelegate) {
+      LOG("  quit, missing mCompositorWidgetDelegate");
+      return;
+    }
+
+    ResumeCompositorImpl();
+  };
+
+  if (GdkIsWaylandDisplay()) {
+#ifdef MOZ_WAYLAND
+    moz_container_wayland_add_or_fire_initial_draw_callback(mContainer,
+                                                            startCompositing);
+#endif
+  } else {
+    startCompositing();
+  }
+}
+
+void nsWindow::ConfigureGdkWindow() {
+  LOG("nsWindow::ConfigureGdkWindow()");
+
+  EnsureGdkWindow();
+
+#ifdef MOZ_X11
+  if (GdkIsX11Display()) {
+    GdkVisual* gdkVisual = gdk_window_get_visual(mGdkWindow);
+    Visual* visual = gdk_x11_visual_get_xvisual(gdkVisual);
+    int depth = gdk_visual_get_depth(gdkVisual);
+    mSurfaceProvider.Initialize(GetX11Window(), visual, depth,
+                                GetShapedState());
+
+    // Set window manager hint to keep fullscreen windows composited.
+    //
+    // If the window were to get unredirected, there could be visible
+    // tearing because Gecko does not align its framebuffer updates with
+    // vblank.
+    SetCompositorHint(GTK_WIDGET_COMPOSIDED_ENABLED);
+  }
+#endif
+#ifdef MOZ_WAYLAND
+  if (GdkIsWaylandDisplay()) {
+    mSurfaceProvider.Initialize(this);
+  }
+#endif
+
+  if (mIsDragPopup) {
+    if (GdkIsWaylandDisplay()) {
+      // Disable painting to the widget on Wayland as we paint directly to the
+      // widget. Wayland compositors does not paint wl_subsurface
+      // of D&D widget.
+      if (GtkWidget* parent = gtk_widget_get_parent(mShell)) {
+        GtkWidgetDisableUpdates(parent);
+      }
+      GtkWidgetDisableUpdates(mShell);
+      GtkWidgetDisableUpdates(GTK_WIDGET(mContainer));
+    } else {
+      // Disable rendering of parent container on X11 to avoid flickering.
+      if (GtkWidget* parent = gtk_widget_get_parent(mShell)) {
+        gtk_widget_set_opacity(parent, 0.0);
+      }
+    }
+  }
+
+  if (mWindowType == WindowType::Popup) {
+    if (mNoAutoHide) {
+      gint wmd = ConvertBorderStyles(mBorderStyle);
+      if (wmd != -1) {
+        gdk_window_set_decorations(mGdkWindow, (GdkWMDecoration)wmd);
+      }
+    }
+    // If the popup ignores mouse events, set an empty input shape.
+    SetInputRegion(mInputRegion);
+  }
+
+  RefreshWindowClass();
+
+  // We're not mapped yet but we have already created compositor.
+  if (mCompositorWidgetDelegate) {
+    ConfigureCompositor();
+  }
+
+  LOG("  finished, new GdkWindow %p XID 0x%lx\n", mGdkWindow, GetX11Window());
+}
+
+void nsWindow::ReleaseGdkWindow() {
+  LOG("nsWindow::ReleaseGdkWindow()");
+
+  DestroyChildWindows();
+
+  if (mCompositorWidgetDelegate) {
+    mCompositorWidgetDelegate->DisableRendering();
+  }
+
+  if (mGdkWindow) {
+    g_object_set_data(G_OBJECT(mGdkWindow), "nsWindow", nullptr);
+    mGdkWindow = nullptr;
+  }
+
+  mSurfaceProvider.CleanupResources();
+}
+
+nsresult nsWindow::Create(nsIWidget* aParent, nsNativeWidget aNativeParent,
+                          const LayoutDeviceIntRect& aRect,
+                          widget::InitData* aInitData) {
+  LOG("nsWindow::Create\n");
+
+  // only set the base parent if we're going to be a dialog or a
+  // toplevel
+  nsIWidget* baseParent =
+      aInitData && (aInitData->mWindowType == WindowType::Dialog ||
+                    aInitData->mWindowType == WindowType::TopLevel ||
+                    aInitData->mWindowType == WindowType::Invisible)
+          ? nullptr
+          : aParent;
+
+#ifdef ACCESSIBILITY
+  // Send a DBus message to check whether a11y is enabled
+  a11y::PreInit();
+#endif
+
+#ifdef MOZ_WAYLAND
+  // Ensure that KeymapWrapper is created on Wayland as we need it for
+  // keyboard focus tracking.
+  if (GdkIsWaylandDisplay()) {
+    KeymapWrapper::EnsureInstance();
+  }
+#endif
+
+  // Ensure that the toolkit is created.
+  nsGTKToolkit::GetToolkit();
+
+  // initialize all the common bits of this class
+  BaseCreate(baseParent, aInitData);
+
+  // and do our common creation
+  mParent = aParent;
+  mCreated = true;
+  // save our bounds
+  mBounds = aRect;
+  LOG("  mBounds: x:%d y:%d w:%d h:%d\n", mBounds.x, mBounds.y, mBounds.width,
+      mBounds.height);
+
+  ConstrainSize(&mBounds.width, &mBounds.height);
+  mLastSizeRequest = mBounds.Size();
+
+  GtkWidget* eventWidget = nullptr;
+  bool popupNeedsAlphaVisual = mWindowType == WindowType::Popup &&
+                               (aInitData && aInitData->mTransparencyMode ==
+                                                 TransparencyMode::Transparent);
+
+  // Figure out our parent window - only used for WindowType::Child
+  GdkWindow* parentGdkWindow = nullptr;
+  nsWindow* parentnsWindow = nullptr;
+
+  if (aParent) {
+    parentnsWindow = static_cast<nsWindow*>(aParent);
+    parentGdkWindow = parentnsWindow->mGdkWindow;
+  } else if (aNativeParent && GDK_IS_WINDOW(aNativeParent)) {
+    parentGdkWindow = GDK_WINDOW(aNativeParent);
+    parentnsWindow = get_window_for_gdk_window(parentGdkWindow);
+    if (!parentnsWindow) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  if (mWindowType == WindowType::Child) {
+    // We don't support WindowType::Child directly but emulate it by popup
+    // windows.
+    mWindowType = WindowType::Popup;
+    if (!parentnsWindow) {
+      if (aNativeParent && GTK_IS_CONTAINER(aNativeParent)) {
+        parentnsWindow = get_window_for_gtk_widget(GTK_WIDGET(aNativeParent));
+      }
+    }
+    mIsChildWindow = true;
+    LOG("  child widget, switch to popup. parent nsWindow %p", parentnsWindow);
+  }
+
+  if (mWindowType == WindowType::Popup && !parentnsWindow) {
+    LOG("  popup window without parent!");
+    if (GdkIsWaylandDisplay()) {
+      LOG("  switch to toplevel on Wayland.");
+      // Wayland does not allow to create popup without parent so switch to
+      // toplevel and mark as wayland panel.
+      mIsWaylandPanelWindow = true;
+      mWindowType = WindowType::TopLevel;
+    }
+  }
+
+  if (mWindowType != WindowType::Dialog && mWindowType != WindowType::Popup &&
+      mWindowType != WindowType::TopLevel &&
+      mWindowType != WindowType::Invisible) {
+    MOZ_ASSERT_UNREACHABLE("Unexpected eWindowType");
+    return NS_ERROR_FAILURE;
+  }
+
+  mAlwaysOnTop = aInitData && aInitData->mAlwaysOnTop;
+  mIsPIPWindow = aInitData && aInitData->mPIPWindow;
+  // mNoAutoHide seems to be always false here.
+  // The mNoAutoHide state is set later on nsMenuPopupFrame level
+  // and can be changed so we use WaylandPopupIsPermanent() to get
+  // recent popup config (Bug 1728952).
+  mNoAutoHide = aInitData && aInitData->mNoAutoHide;
+
+  // Popups that are not noautohide are only temporary. The are used
+  // for menus and the like and disappear when another window is used.
+  // For most popups, use the standard GtkWindowType GTK_WINDOW_POPUP,
+  // which will use a Window with the override-redirect attribute
+  // (for temporary windows).
+  // For long-lived windows, their stacking order is managed by the
+  // window manager, as indicated by GTK_WINDOW_TOPLEVEL.
+  // For Wayland we have to always use GTK_WINDOW_POPUP to control
+  // popup window position.
+  GtkWindowType type = GTK_WINDOW_TOPLEVEL;
+  if (mWindowType == WindowType::Popup) {
+    MOZ_ASSERT(aInitData);
+    type = GTK_WINDOW_POPUP;
+    if (GdkIsX11Display() && mNoAutoHide) {
+      type = GTK_WINDOW_TOPLEVEL;
+    }
+  }
+  mShell = gtk_window_new(type);
+
+  // Ensure gfxPlatform is initialized, since that is what initializes
+  // gfxVars, used below.
+  Unused << gfxPlatform::GetPlatform();
+
+  if (mWindowType == WindowType::TopLevel ||
+      mWindowType == WindowType::Dialog) {
+    mGtkWindowDecoration = GetSystemGtkWindowDecoration();
+  }
+
+  // Don't use transparency for PictureInPicture windows.
+  bool toplevelNeedsAlphaVisual = false;
+  if (mWindowType == WindowType::TopLevel && !mIsPIPWindow) {
+    toplevelNeedsAlphaVisual = IsToplevelWindowTransparent();
+  }
+
+  bool isGLVisualSet = false;
+  mIsAccelerated = ComputeShouldAccelerate();
+#ifdef MOZ_X11
+  if (GdkIsX11Display() && mIsAccelerated) {
+    isGLVisualSet = ConfigureX11GLVisual();
+  }
+#endif
+  if (!isGLVisualSet && (popupNeedsAlphaVisual || toplevelNeedsAlphaVisual)) {
+    // We're running on composited screen so we can use alpha visual
+    // for both toplevel and popups.
+    if (mCompositedScreen) {
+      GdkVisual* visual =
+          gdk_screen_get_rgba_visual(gtk_widget_get_screen(mShell));
+      if (visual) {
+        gtk_widget_set_visual(mShell, visual);
+        mHasAlphaVisual = true;
+      }
+    }
+  }
+
+  // Use X shape mask to draw round corners of Firefox titlebar.
+  // We don't use shape masks any more as we switched to ARGB visual
+  // by default and non-compositing screens use solid-csd decorations
+  // without round corners.
+  // Leave the shape mask code here as it can be used to draw round
+  // corners on EGL (https://gitlab.freedesktop.org/mesa/mesa/-/issues/149)
+  // or when custom titlebar theme is used.
+  mTransparencyBitmapForTitlebar = TitlebarUseShapeMask();
+
+  // We have a toplevel window with transparency.
+  // Calls to UpdateTitlebarTransparencyBitmap() from OnExposeEvent()
+  // occur before SetTransparencyMode() receives TransparencyMode::Transparent
+  // from layout, so set mIsTransparent here.
+  if (mWindowType == WindowType::TopLevel &&
+      (mHasAlphaVisual || mTransparencyBitmapForTitlebar)) {
+    mIsTransparent = true;
+  }
+
+  // We only move a general managed toplevel window if someone has
+  // actually placed the window somewhere.  If no placement has taken
+  // place, we just let the window manager Do The Right Thing.
+  if (AreBoundsSane()) {
+    GdkRectangle size = DevicePixelsToGdkSizeRoundUp(mBounds.Size());
+    LOG("nsWindow::Create() Initial resize to %d x %d\n", size.width,
+        size.height);
+    gtk_window_resize(GTK_WINDOW(mShell), size.width, size.height);
+  }
+  if (mIsPIPWindow) {
+    LOG("    Is PIP Window\n");
+    gtk_window_set_type_hint(GTK_WINDOW(mShell), GDK_WINDOW_TYPE_HINT_UTILITY);
+  } else if (mWindowType == WindowType::Dialog) {
+    mGtkWindowRoleName = "Dialog";
+
+    SetDefaultIcon();
+    gtk_window_set_type_hint(GTK_WINDOW(mShell), GDK_WINDOW_TYPE_HINT_DIALOG);
+    LOG("nsWindow::Create(): dialog");
+    if (parentnsWindow) {
+      GtkWindowSetTransientFor(GTK_WINDOW(mShell),
+                               GTK_WINDOW(parentnsWindow->GetGtkWidget()));
+      LOG("    set parent window [%p]\n", parentnsWindow);
+    }
+  } else if (mWindowType == WindowType::Popup) {
+    MOZ_ASSERT(aInitData);
+    mGtkWindowRoleName = "Popup";
+    mPopupHint = aInitData->mPopupHint;
+
+    LOG("nsWindow::Create() Popup");
+
+    if (mNoAutoHide) {
+      // ... but the window manager does not decorate this window,
+      // nor provide a separate taskbar icon.
+      if (mBorderStyle == BorderStyle::Default) {
+        gtk_window_set_decorated(GTK_WINDOW(mShell), FALSE);
+      } else {
+        bool decorate = bool(mBorderStyle & BorderStyle::Title);
+        gtk_window_set_decorated(GTK_WINDOW(mShell), decorate);
+        if (decorate) {
+          gtk_window_set_deletable(GTK_WINDOW(mShell),
+                                   bool(mBorderStyle & BorderStyle::Close));
+        }
+      }
+      gtk_window_set_skip_taskbar_hint(GTK_WINDOW(mShell), TRUE);
+      // Element focus is managed by the parent window so the
+      // WM_HINTS input field is set to False to tell the window
+      // manager not to set input focus to this window ...
+      gtk_window_set_accept_focus(GTK_WINDOW(mShell), FALSE);
+#ifdef MOZ_X11
+      // ... but when the window manager offers focus through
+      // WM_TAKE_FOCUS, focus is requested on the parent window.
+      if (GdkIsX11Display()) {
+        gtk_widget_realize(mShell);
+        gdk_window_add_filter(gtk_widget_get_window(mShell),
+                              popup_take_focus_filter, nullptr);
+      }
+#endif
+    }
+
+    if (aInitData->mIsDragPopup) {
+      gtk_window_set_type_hint(GTK_WINDOW(mShell), GDK_WINDOW_TYPE_HINT_DND);
+      mIsDragPopup = true;
+      LOG("nsWindow::Create() Drag popup\n");
+    } else if (GdkIsX11Display()) {
+      // Set the window hints on X11 only. Wayland popups are configured
+      // at WaylandPopupConfigure().
+      GdkWindowTypeHint gtkTypeHint;
+      switch (mPopupHint) {
+        case PopupType::Menu:
+          gtkTypeHint = GDK_WINDOW_TYPE_HINT_POPUP_MENU;
+          break;
+        case PopupType::Tooltip:
+          gtkTypeHint = GDK_WINDOW_TYPE_HINT_TOOLTIP;
+          break;
+        default:
+          gtkTypeHint = GDK_WINDOW_TYPE_HINT_UTILITY;
+          break;
+      }
+      gtk_window_set_type_hint(GTK_WINDOW(mShell), gtkTypeHint);
+      LOG("nsWindow::Create() popup type %s", GetPopupTypeName().get());
+    }
+    if (parentnsWindow) {
+      LOG("    set parent window [%p] %s", parentnsWindow,
+          parentnsWindow->mGtkWindowRoleName.get());
+      GtkWindow* parentWidget = GTK_WINDOW(parentnsWindow->GetGtkWidget());
+      GtkWindowSetTransientFor(GTK_WINDOW(mShell), parentWidget);
+
+      // If popup parent is modal, we need to make popup modal too.
+      if (mPopupHint != PopupType::Tooltip &&
+          gtk_window_get_modal(parentWidget)) {
+        gtk_window_set_modal(GTK_WINDOW(mShell), true);
+      }
+    }
+
+    // We need realized mShell at NativeMoveResize().
+    gtk_widget_realize(mShell);
+
+    // With popup windows, we want to set their position.
+    // Place them immediately on X11 and save initial popup position
+    // on Wayland as we place Wayland popup on show.
+    if (GdkIsX11Display()) {
+      NativeMoveResize(/* move */ true, /* resize */ false);
+    } else if (AreBoundsSane()) {
+      GdkRectangle rect = DevicePixelsToGdkRectRoundOut(mBounds);
+      mPopupPosition = {rect.x, rect.y};
+    }
+  } else {  // must be WindowType::TopLevel
+    mGtkWindowRoleName = "Toplevel";
+    SetDefaultIcon();
+
+    LOG("nsWindow::Create() Toplevel\n");
+
+    // each toplevel window gets its own window group
+    GtkWindowGroup* group = gtk_window_group_new();
+    gtk_window_group_add_window(group, GTK_WINDOW(mShell));
+    g_object_unref(group);
+  }
+
+  if (mAlwaysOnTop) {
+    gtk_window_set_keep_above(GTK_WINDOW(mShell), TRUE);
+  }
+
+  // It is important that this happens before the realize() call below, so that
+  // we don't get bogus CSD margins on Wayland, see bug 1794577.
+  if (IsAlwaysUndecoratedWindow()) {
+    LOG("    Is undecorated Window\n");
+    gtk_window_set_titlebar(GTK_WINDOW(mShell), gtk_fixed_new());
+    gtk_window_set_decorated(GTK_WINDOW(mShell), false);
+  }
+
+  // Create a container to hold child windows and child GtkWidgets.
+  GtkWidget* container = moz_container_new();
+  mContainer = MOZ_CONTAINER(container);
+
+  // "csd" style is set when widget is realized so we need to call
+  // it explicitly now.
+  gtk_widget_realize(mShell);
+
+  /* There are several cases here:
+   *
+   * 1) We're running on Gtk+ without client side decorations.
+   *    Content is rendered to mShell window and we listen
+   *    to the Gtk+ events on mShell
+   * 2) We're running on Gtk+ and client side decorations
+   *    are drawn by Gtk+ to mShell. Content is rendered to mContainer
+   *    and we listen to the Gtk+ events on mContainer.
+   * 3) We're running on Wayland. All gecko content is rendered
+   *    to mContainer and we listen to the Gtk+ events on mContainer.
+   */
+  GtkStyleContext* style = gtk_widget_get_style_context(mShell);
+  mDrawToContainer = GdkIsWaylandDisplay() ||
+                     mGtkWindowDecoration == GTK_DECORATION_CLIENT ||
+                     gtk_style_context_has_class(style, "csd");
+  eventWidget = mDrawToContainer ? container : mShell;
+
+  // Prevent GtkWindow from painting a background to avoid flickering.
+  gtk_widget_set_app_paintable(
+      eventWidget, StaticPrefs::widget_transparent_windows_AtStartup());
+
+  gtk_widget_add_events(eventWidget, kEvents);
+
+  if (mDrawToContainer) {
+    gtk_widget_add_events(mShell, GDK_PROPERTY_CHANGE_MASK);
+    gtk_widget_set_app_paintable(
+        mShell, StaticPrefs::widget_transparent_windows_AtStartup());
+  }
+  if (mTransparencyBitmapForTitlebar) {
+    moz_container_force_default_visual(mContainer);
+  }
+
+  // If we draw to mContainer window then configure it now because
+  // gtk_container_add() realizes the child widget.
+  gtk_widget_set_has_window(container, mDrawToContainer);
+
+  gtk_container_add(GTK_CONTAINER(mShell), container);
+
+  // alwaysontop windows are generally used for peripheral indicators,
+  // so we don't focus them by default.
+  if (mAlwaysOnTop) {
+    gtk_window_set_focus_on_map(GTK_WINDOW(mShell), FALSE);
+  }
+
+  gtk_widget_realize(container);
+
+  // make sure this is the focus widget in the container
+  gtk_widget_show(container);
+
+  if (!mAlwaysOnTop) {
+    gtk_widget_grab_focus(container);
+  }
+
+#ifdef MOZ_WAYLAND
+  if (mIsDragPopup && GdkIsWaylandDisplay()) {
+    LOG("  set commit to parent");
+    moz_container_wayland_set_commit_to_parent(mContainer);
+  }
+#endif
+
+  if (mWindowType == WindowType::Popup) {
+    MOZ_ASSERT(aInitData);
+    // gdk does not automatically set the cursor for "temporary"
+    // windows, which are what gtk uses for popups.
+
+    // force SetCursor to actually set the cursor, even though our internal
+    // state indicates that we already have the standard cursor.
+    mUpdateCursor = true;
+    SetCursor(Cursor{eCursor_standard});
+  }
+
+  if (mIsChildWindow && parentnsWindow) {
+    GdkWindow* window = GetToplevelGdkWindow();
+    GdkWindow* parentWindow = parentnsWindow->GetToplevelGdkWindow();
+    LOG("  child GdkWindow %p set parent GdkWindow %p", window, parentWindow);
+    gdk_window_reparent(window, parentWindow,
+                        DevicePixelsToGdkCoordRoundDown(mBounds.x),
+                        DevicePixelsToGdkCoordRoundDown(mBounds.y));
+  }
+
+  if (mDrawToContainer) {
+    // Also label mShell toplevel window,
+    // property_notify_event_cb callback also needs to find its way home
+    g_object_set_data(G_OBJECT(gtk_widget_get_window(mShell)), "nsWindow",
+                      this);
+  }
+
+  g_object_set_data(G_OBJECT(mContainer), "nsWindow", this);
+  g_object_set_data(G_OBJECT(mShell), "nsWindow", this);
+
+  // attach listeners for events
+  g_signal_connect(mShell, "configure_event", G_CALLBACK(configure_event_cb),
+                   nullptr);
+  g_signal_connect(mShell, "delete_event", G_CALLBACK(delete_event_cb),
+                   nullptr);
+  g_signal_connect(mShell, "window_state_event",
+                   G_CALLBACK(window_state_event_cb), nullptr);
+  g_signal_connect(mShell, "check-resize", G_CALLBACK(check_resize_cb),
+                   nullptr);
+  g_signal_connect(mShell, "composited-changed",
+                   G_CALLBACK(widget_composited_changed_cb), nullptr);
+  g_signal_connect(mShell, "property-notify-event",
+                   G_CALLBACK(property_notify_event_cb), nullptr);
+
+  if (mWindowType == WindowType::TopLevel) {
+    g_signal_connect_after(mShell, "size_allocate",
+                           G_CALLBACK(toplevel_window_size_allocate_cb),
+                           nullptr);
+  }
+
+  GdkScreen* screen = gtk_widget_get_screen(mShell);
+  if (!g_signal_handler_find(screen, G_SIGNAL_MATCH_FUNC, 0, 0, nullptr,
+                             FuncToGpointer(screen_composited_changed_cb),
+                             nullptr)) {
+    g_signal_connect(screen, "composited-changed",
+                     G_CALLBACK(screen_composited_changed_cb), nullptr);
+  }
+
+  gtk_drag_dest_set((GtkWidget*)mShell, (GtkDestDefaults)0, nullptr, 0,
+                    (GdkDragAction)0);
+  g_signal_connect(mShell, "drag_motion", G_CALLBACK(drag_motion_event_cb),
+                   nullptr);
+  g_signal_connect(mShell, "drag_leave", G_CALLBACK(drag_leave_event_cb),
+                   nullptr);
+  g_signal_connect(mShell, "drag_drop", G_CALLBACK(drag_drop_event_cb),
+                   nullptr);
+  g_signal_connect(mShell, "drag_data_received",
+                   G_CALLBACK(drag_data_received_event_cb), nullptr);
+
+  GtkSettings* default_settings = gtk_settings_get_default();
+  g_signal_connect_after(default_settings, "notify::gtk-xft-dpi",
+                         G_CALLBACK(settings_xft_dpi_changed_cb), this);
+
+  // Widget signals
+  g_signal_connect(mContainer, "map", G_CALLBACK(widget_map_cb), nullptr);
+  g_signal_connect(mContainer, "unmap", G_CALLBACK(widget_unmap_cb), nullptr);
+  g_signal_connect(mContainer, "unrealize", G_CALLBACK(widget_unrealize_cb),
+                   nullptr);
+  g_signal_connect_after(mContainer, "size_allocate",
+                         G_CALLBACK(size_allocate_cb), nullptr);
+  g_signal_connect(mContainer, "hierarchy-changed",
+                   G_CALLBACK(hierarchy_changed_cb), nullptr);
+  g_signal_connect(mContainer, "notify::scale-factor",
+                   G_CALLBACK(scale_changed_cb), nullptr);
+  // Initialize mHasMappedToplevel.
+  hierarchy_changed_cb(GTK_WIDGET(mContainer), nullptr);
+  // Expose, focus, key, and drag events are sent even to GTK_NO_WINDOW
+  // widgets.
+  g_signal_connect(G_OBJECT(mContainer), "draw", G_CALLBACK(expose_event_cb),
+                   nullptr);
+  g_signal_connect(mContainer, "focus_in_event", G_CALLBACK(focus_in_event_cb),
+                   nullptr);
+  g_signal_connect(mContainer, "focus_out_event",
+                   G_CALLBACK(focus_out_event_cb), nullptr);
+  g_signal_connect(mContainer, "key_press_event",
+                   G_CALLBACK(key_press_event_cb), nullptr);
+  g_signal_connect(mContainer, "key_release_event",
+                   G_CALLBACK(key_release_event_cb), nullptr);
+
+#ifdef MOZ_X11
+  if (GdkIsX11Display()) {
+    GtkWidget* widgets[] = {GTK_WIDGET(mContainer),
+                            !mDrawToContainer ? mShell : nullptr};
+    for (size_t i = 0; i < ArrayLength(widgets) && widgets[i]; ++i) {
+      // Double buffering is controlled by the window's owning
+      // widget. Disable double buffering for painting directly to the
+      // X Window.
+      gtk_widget_set_double_buffered(widgets[i], FALSE);
+    }
+  }
+#endif
+#ifdef MOZ_WAYLAND
+  // Initialize the window specific VsyncSource early in order to avoid races
+  // with BrowserParent::UpdateVsyncParentVsyncDispatcher().
+  // Only use for toplevel windows for now, see bug 1619246.
+  if (GdkIsWaylandDisplay() &&
+      StaticPrefs::widget_wayland_vsync_enabled_AtStartup() &&
+      mWindowType == WindowType::TopLevel) {
+    mWaylandVsyncSource = new WaylandVsyncSource(this);
+    mWaylandVsyncDispatcher = new VsyncDispatcher(mWaylandVsyncSource);
+    LOG_VSYNC("  created WaylandVsyncSource");
+  }
+#endif
+
+  // We create input contexts for all containers, except for
+  // toplevel popup windows
+  if (mWindowType != WindowType::Popup) {
+    mIMContext = new IMContextWrapper(this);
+  }
+
+  // These events are sent to the owning widget of the relevant window
+  // and propagate up to the first widget that handles the events, so we
+  // need only connect on mShell, if it exists, to catch events on its
+  // window and windows of mContainer.
+  g_signal_connect(eventWidget, "enter-notify-event",
+                   G_CALLBACK(enter_notify_event_cb), nullptr);
+  g_signal_connect(eventWidget, "leave-notify-event",
+                   G_CALLBACK(leave_notify_event_cb), nullptr);
+  g_signal_connect(eventWidget, "motion-notify-event",
+                   G_CALLBACK(motion_notify_event_cb), nullptr);
+  g_signal_connect(eventWidget, "button-press-event",
+                   G_CALLBACK(button_press_event_cb), nullptr);
+  g_signal_connect(eventWidget, "button-release-event",
+                   G_CALLBACK(button_release_event_cb), nullptr);
+  g_signal_connect(eventWidget, "scroll-event", G_CALLBACK(scroll_event_cb),
+                   nullptr);
+  if (gtk_check_version(3, 18, 0) == nullptr) {
+    g_signal_connect(eventWidget, "event", G_CALLBACK(generic_event_cb),
+                     nullptr);
+  }
+  g_signal_connect(eventWidget, "touch-event", G_CALLBACK(touch_event_cb),
+                   nullptr);
+
+  LOG("  nsWindow type %d %s\n", int(mWindowType),
+      mIsPIPWindow ? "PIP window" : "");
+  LOG("  mShell %p mContainer %p mGdkWindow %p XID 0x%lx\n", mShell, mContainer,
+      mGdkWindow, GetX11Window());
+
+  // Set default application name when it's empty.
+  if (mGtkWindowAppName.IsEmpty()) {
+    mGtkWindowAppName = gAppData->name;
+  }
+
+  return NS_OK;
+}
+
+void nsWindow::RefreshWindowClass(void) {
+  GdkWindow* gdkWindow = gtk_widget_get_window(mShell);
+  if (!gdkWindow) {
+    return;
+  }
+
+  if (!mGtkWindowRoleName.IsEmpty()) {
+    gdk_window_set_role(gdkWindow, mGtkWindowRoleName.get());
+  }
+
+#ifdef MOZ_X11
+  if (GdkIsX11Display()) {
+    XClassHint* class_hint = XAllocClassHint();
+    if (!class_hint) return;
+
+    const char* res_name =
+        !mGtkWindowAppName.IsEmpty() ? mGtkWindowAppName.get() : gAppData->name;
+
+    const char* res_class = !mGtkWindowAppClass.IsEmpty()
+                                ? mGtkWindowAppClass.get()
+                                : gdk_get_program_class();
+
+    if (!res_name || !res_class) {
+      XFree(class_hint);
+      return;
+    }
+
+    class_hint->res_name = const_cast<char*>(res_name);
+    class_hint->res_class = const_cast<char*>(res_class);
+
+    // Can't use gtk_window_set_wmclass() for this; it prints
+    // a warning & refuses to make the change.
+    GdkDisplay* display = gdk_display_get_default();
+    XSetClassHint(GDK_DISPLAY_XDISPLAY(display),
+                  gdk_x11_window_get_xid(gdkWindow), class_hint);
+    XFree(class_hint);
+  }
+#endif /* MOZ_X11 */
+}
+
+void nsWindow::SetWindowClass(const nsAString& xulWinType,
+                              const nsAString& xulWinClass,
+                              const nsAString& xulWinName) {
+  if (!mShell) return;
+
+  // If window type attribute is set, parse it into name and role
+  if (!xulWinType.IsEmpty()) {
+    char* res_name = ToNewCString(xulWinType, mozilla::fallible);
+    const char* role = nullptr;
+
+    if (res_name) {
+      // Parse res_name into a name and role. Characters other than
+      // [A-Za-z0-9_-] are converted to '_'. Anything after the first
+      // colon is assigned to role; if there's no colon, assign the
+      // whole thing to both role and res_name.
+      for (char* c = res_name; *c; c++) {
+        if (':' == *c) {
+          *c = 0;
+          role = c + 1;
+        } else if (!isascii(*c) ||
+                   (!isalnum(*c) && ('_' != *c) && ('-' != *c))) {
+          *c = '_';
+        }
+      }
+      res_name[0] = (char)toupper(res_name[0]);
+      if (!role) role = res_name;
+
+      mGtkWindowAppName = res_name;
+      mGtkWindowRoleName = role;
+      free(res_name);
+    }
+  }
+
+  // If window class attribute is set, store it as app class
+  // If this attribute is not set, reset app class to default
+  if (!xulWinClass.IsEmpty()) {
+    CopyUTF16toUTF8(xulWinClass, mGtkWindowAppClass);
+  } else {
+    mGtkWindowAppClass = nullptr;
+  }
+
+  // If window class attribute is set, store it as app name
+  // If both name and type are not set, reset app name to default
+  if (!xulWinName.IsEmpty()) {
+    CopyUTF16toUTF8(xulWinName, mGtkWindowAppName);
+  } else if (xulWinType.IsEmpty()) {
+    mGtkWindowAppClass = nullptr;
+  }
+
+  RefreshWindowClass();
+}
+
+nsAutoCString nsWindow::GetDebugTag() const {
+  nsAutoCString tag;
+  tag.AppendPrintf("[%p]", this);
+  return tag;
+}
+
+void nsWindow::NativeMoveResize(bool aMoved, bool aResized) {
+  GdkPoint topLeft = [&] {
+    auto target = mBounds.TopLeft();
+    // gtk_window_move will undo the csd offset, but nothing else, so only add
+    // the client offset if drawing to the csd titlebar.
+    if (DrawsToCSDTitlebar()) {
+      target += mClientOffset;
+    }
+    return DevicePixelsToGdkPointRoundDown(target);
+  }();
+  GdkRectangle size = DevicePixelsToGdkSizeRoundUp(mLastSizeRequest);
+
+  LOG("nsWindow::NativeMoveResize move %d resize %d to %d,%d -> %d x %d\n",
+      aMoved, aResized, topLeft.x, topLeft.y, size.width, size.height);
+
+  if (aResized && !AreBoundsSane()) {
+    LOG("  bounds are insane, hidding the window");
+    // We have been resized but to incorrect size.
+    // If someone has set this so that the needs show flag is false
+    // and it needs to be hidden, update the flag and hide the
+    // window.  This flag will be cleared the next time someone
+    // hides the window or shows it.  It also prevents us from
+    // calling NativeShow(false) excessively on the window which
+    // causes unneeded X traffic.
+    if (!mNeedsShow && mIsShown) {
+      mNeedsShow = true;
+      NativeShow(false);
+    }
+    if (aMoved) {
+      LOG("  moving to %d x %d", topLeft.x, topLeft.y);
+      gtk_window_move(GTK_WINDOW(mShell), topLeft.x, topLeft.y);
+    }
+    return;
+  }
+
+  // Set position to hidden window on X11 may fail, so save the position
+  // and move it when it's shown.
+  if (aMoved && GdkIsX11Display() && IsPopup() &&
+      !gtk_widget_get_visible(GTK_WIDGET(mShell))) {
+    LOG("  store position of hidden popup window");
+    mHiddenPopupPositioned = true;
+    mPopupPosition = {topLeft.x, topLeft.y};
+  }
+
+  if (IsWaylandPopup()) {
+    NativeMoveResizeWaylandPopup(aMoved, aResized);
+  } else {
+    // x and y give the position of the window manager frame top-left.
+    if (aMoved) {
+      gtk_window_move(GTK_WINDOW(mShell), topLeft.x, topLeft.y);
+    }
+    if (aResized) {
+      gtk_window_resize(GTK_WINDOW(mShell), size.width, size.height);
+      if (mIsDragPopup) {
+        // DND window is placed inside container so we need to make hard size
+        // request to ensure parent container is resized too.
+        gtk_widget_set_size_request(GTK_WIDGET(mShell), size.width,
+                                    size.height);
+      }
+    }
+  }
+
+  if (aResized) {
+    // Recompute the input region, in case the window grew or shrunk.
+    SetInputRegion(mInputRegion);
+  }
+
+  // Does it need to be shown because bounds were previously insane?
+  if (mNeedsShow && mIsShown && aResized) {
+    NativeShow(true);
+  }
+}
+
+// We pause compositor to avoid rendering of obsoleted remote content which
+// produces flickering.
+// Re-enable compositor again when remote content is updated or
+// timeout happens.
+
+// Define maximal compositor pause when it's paused to avoid flickering,
+// in milliseconds.
+#define COMPOSITOR_PAUSE_TIMEOUT (1000)
+
+void nsWindow::PauseCompositorFlickering() {
+  bool pauseCompositor = (mWindowType == WindowType::TopLevel) &&
+                         mCompositorState == COMPOSITOR_ENABLED &&
+                         mCompositorWidgetDelegate && !mIsDestroyed;
+  if (!pauseCompositor) {
+    return;
+  }
+
+  LOG("nsWindow::PauseCompositorFlickering()");
+
+  MozClearHandleID(mCompositorPauseTimeoutID, g_source_remove);
+
+  CompositorBridgeChild* remoteRenderer = GetRemoteRenderer();
+  if (remoteRenderer) {
+    remoteRenderer->SendPause();
+    mCompositorState = COMPOSITOR_PAUSED_FLICKERING;
+    mCompositorPauseTimeoutID = (int)g_timeout_add(
+        COMPOSITOR_PAUSE_TIMEOUT,
+        [](void* data) -> gint {
+          nsWindow* window = static_cast<nsWindow*>(data);
+          if (!window->IsDestroyed()) {
+            window->ResumeCompositorFlickering();
+          }
+          return true;
+        },
+        this);
+  }
+}
+
+bool nsWindow::IsWaitingForCompositorResume() {
+  return mCompositorState == COMPOSITOR_PAUSED_FLICKERING;
+}
+
+void nsWindow::ResumeCompositorFlickering() {
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+
+  LOG("nsWindow::ResumeCompositorFlickering()\n");
+
+  if (mIsDestroyed || !IsWaitingForCompositorResume()) {
+    LOG("  early quit\n");
+    return;
+  }
+
+  MozClearHandleID(mCompositorPauseTimeoutID, g_source_remove);
+
+  // mCompositorWidgetDelegate can be deleted during timeout.
+  // In such case just flip compositor back to enabled and let
+  // SetCompositorWidgetDelegate() or Map event resume it.
+  if (!mCompositorWidgetDelegate) {
+    mCompositorState = COMPOSITOR_ENABLED;
+    return;
+  }
+
+  ResumeCompositorImpl();
+}
+
+void nsWindow::ResumeCompositorFromCompositorThread() {
+  nsCOMPtr<nsIRunnable> event =
+      NewRunnableMethod("nsWindow::ResumeCompositorFlickering", this,
+                        &nsWindow::ResumeCompositorFlickering);
+  NS_DispatchToMainThread(event.forget());
+}
+
+void nsWindow::ResumeCompositorImpl() {
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+
+  LOG("nsWindow::ResumeCompositorImpl()\n");
+
+  MOZ_DIAGNOSTIC_ASSERT(mCompositorWidgetDelegate);
+  mCompositorWidgetDelegate->EnableRendering(GetX11Window(), GetShapedState());
+
+  // As WaylandStartVsync needs mCompositorWidgetDelegate this is the right
+  // time to start it.
+  WaylandStartVsync();
+
+  CompositorBridgeChild* remoteRenderer = GetRemoteRenderer();
+  MOZ_RELEASE_ASSERT(remoteRenderer);
+  remoteRenderer->SendResume();
+  remoteRenderer->SendForcePresent(wr::RenderReasons::WIDGET);
+  mCompositorState = COMPOSITOR_ENABLED;
+}
+
+void nsWindow::WaylandStartVsync() {
+#ifdef MOZ_WAYLAND
+  if (!mWaylandVsyncSource) {
+    return;
+  }
+
+  LOG_VSYNC("nsWindow::WaylandStartVsync");
+
+  MOZ_DIAGNOSTIC_ASSERT(mCompositorWidgetDelegate);
+  if (mCompositorWidgetDelegate->AsGtkCompositorWidget() &&
+      mCompositorWidgetDelegate->AsGtkCompositorWidget()
+          ->GetNativeLayerRoot()) {
+    LOG_VSYNC("  use source NativeLayerRootWayland");
+    mWaylandVsyncSource->MaybeUpdateSource(
+        mCompositorWidgetDelegate->AsGtkCompositorWidget()
+            ->GetNativeLayerRoot()
+            ->AsNativeLayerRootWayland());
+  } else {
+    LOG_VSYNC("  use source mContainer");
+    mWaylandVsyncSource->MaybeUpdateSource(mContainer);
+  }
+
+  mWaylandVsyncSource->EnableMonitor();
+#endif
+}
+
+void nsWindow::WaylandStopVsync() {
+#ifdef MOZ_WAYLAND
+  if (!mWaylandVsyncSource) {
+    return;
+  }
+
+  LOG_VSYNC("nsWindow::WaylandStopVsync");
+
+  // The widget is going to be hidden, so clear the surface of our
+  // vsync source.
+  mWaylandVsyncSource->DisableMonitor();
+  mWaylandVsyncSource->MaybeUpdateSource(nullptr);
+#endif
+}
+
+void nsWindow::NativeShow(bool aAction) {
+  if (aAction) {
+    // unset our flag now that our window has been shown
+    mNeedsShow = true;
+    auto removeShow = MakeScopeExit([&] { mNeedsShow = false; });
+
+    LOG("nsWindow::NativeShow show\n");
+
+    if (IsWaylandPopup()) {
+      mPopupClosed = false;
+      if (WaylandPopupConfigure()) {
+        AddWindowToPopupHierarchy();
+        UpdateWaylandPopupHierarchy();
+        if (mPopupClosed) {
+          return;
+        }
+      }
+    }
+    // Set up usertime/startupID metadata for the created window.
+    // On X11 we use gtk_window_set_startup_id() so we need to call it
+    // before show.
+    if (GdkIsX11Display()) {
+      SetUserTimeAndStartupTokenForActivatedWindow();
+    }
+    if (GdkIsWaylandDisplay()) {
+      if (IsWaylandPopup()) {
+        ShowWaylandPopupWindow();
+      } else {
+        ShowWaylandToplevelWindow();
+      }
+    } else {
+      LOG("  calling gtk_widget_show(mShell)\n");
+      gtk_widget_show(mShell);
+    }
+    if (GdkIsWaylandDisplay()) {
+      SetUserTimeAndStartupTokenForActivatedWindow();
+#ifdef MOZ_WAYLAND
+      auto token = std::move(mWindowActivationTokenFromEnv);
+      if (!token.IsEmpty()) {
+        FocusWaylandWindow(token.get());
+      }
+#endif
+    }
+    if (mHiddenPopupPositioned && IsPopup()) {
+      LOG("  re-position hidden popup window");
+      gtk_window_move(GTK_WINDOW(mShell), mPopupPosition.x, mPopupPosition.y);
+      mHiddenPopupPositioned = false;
+    }
+  } else {
+    LOG("nsWindow::NativeShow hide\n");
+    if (GdkIsWaylandDisplay()) {
+      if (IsWaylandPopup()) {
+        // We can't close tracked popups directly as they may have visible
+        // child popups. Just mark is as closed and let
+        // UpdateWaylandPopupHierarchy() do the job.
+        if (IsInPopupHierarchy()) {
+          WaylandPopupMarkAsClosed();
+          UpdateWaylandPopupHierarchy();
+        } else {
+          // Close untracked popups directly.
+          HideWaylandPopupWindow(/* aTemporaryHide */ false,
+                                 /* aRemoveFromPopupList */ true);
+        }
+      } else {
+        HideWaylandToplevelWindow();
+      }
+    } else {
+      // Workaround window freezes on GTK versions before 3.21.2 by
+      // ensuring that configure events get dispatched to windows before
+      // they are unmapped. See bug 1225044.
+      if (gtk_check_version(3, 21, 2) != nullptr && mPendingConfigures > 0) {
+        GtkAllocation allocation;
+        gtk_widget_get_allocation(GTK_WIDGET(mShell), &allocation);
+
+        GdkEventConfigure event;
+        PodZero(&event);
+        event.type = GDK_CONFIGURE;
+        event.window = mGdkWindow;
+        event.send_event = TRUE;
+        event.x = allocation.x;
+        event.y = allocation.y;
+        event.width = allocation.width;
+        event.height = allocation.height;
+
+        auto* shellClass = GTK_WIDGET_GET_CLASS(mShell);
+        for (unsigned int i = 0; i < mPendingConfigures; i++) {
+          Unused << shellClass->configure_event(mShell, &event);
+        }
+        mPendingConfigures = 0;
+      }
+      gtk_widget_hide(mShell);
+
+      ClearTransparencyBitmap();  // Release some resources
+    }
+  }
+}
+
+void nsWindow::SetHasMappedToplevel(bool aState) {
+  LOG("nsWindow::SetHasMappedToplevel(%d)", aState);
+  if (aState == mHasMappedToplevel) {
+    return;
+  }
+  // Even when aState == mHasMappedToplevel (as when this method is called
+  // from Show()), child windows need to have their state checked, so don't
+  // return early.
+  mHasMappedToplevel = aState;
+  if (aState && mNeedsToRetryCapturingMouse) {
+    CaptureRollupEvents(true);
+    MOZ_ASSERT(!mNeedsToRetryCapturingMouse);
+  }
+}
+
+LayoutDeviceIntSize nsWindow::GetSafeWindowSize(LayoutDeviceIntSize aSize) {
+  // The X protocol uses CARD32 for window sizes, but the server (1.11.3)
+  // reads it as CARD16.  Sizes of pixmaps, used for drawing, are (unsigned)
+  // CARD16 in the protocol, but the server's ProcCreatePixmap returns
+  // BadAlloc if dimensions cannot be represented by signed shorts.
+  // Because we are creating Cairo surfaces to represent window buffers,
+  // we also must ensure that the window can fit in a Cairo surface.
+  LayoutDeviceIntSize result = aSize;
+  int32_t maxSize = 32767;
+  if (mWindowRenderer && mWindowRenderer->AsKnowsCompositor()) {
+    maxSize = std::min(
+        maxSize, mWindowRenderer->AsKnowsCompositor()->GetMaxTextureSize());
+  }
+  if (result.width > maxSize) {
+    result.width = maxSize;
+  }
+  if (result.height > maxSize) {
+    result.height = maxSize;
+  }
+  return result;
+}
+
+void nsWindow::SetTransparencyMode(TransparencyMode aMode) {
+  bool isTransparent = aMode == TransparencyMode::Transparent;
+
+  if (mIsTransparent == isTransparent) {
+    return;
+  }
+
+  if (mWindowType != WindowType::Popup) {
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1344839 reported
+    // problems cleaning the layer manager for toplevel windows.
+    // Ignore the request so as to workaround that.
+    // mIsTransparent is set in Create() if transparency may be required.
+    if (isTransparent) {
+      NS_WARNING("Transparent mode not supported on non-popup windows.");
+    }
+    return;
+  }
+
+  if (!isTransparent) {
+    ClearTransparencyBitmap();
+  }  // else the new default alpha values are "all 1", so we don't
+  // need to change anything yet
+
+  mIsTransparent = isTransparent;
+
+  if (!mHasAlphaVisual) {
+    // The choice of layer manager depends on
+    // GtkCompositorWidgetInitData::Shaped(), which will need to change, so
+    // clean out the old layer manager.
+    DestroyLayerManager();
+  }
+}
+
+TransparencyMode nsWindow::GetTransparencyMode() {
+  return mIsTransparent ? TransparencyMode::Transparent
+                        : TransparencyMode::Opaque;
+}
+
+gint nsWindow::GetInputRegionMarginInGdkCoords() {
+  return DevicePixelsToGdkCoordRoundDown(mInputRegion.mMargin);
+}
+
+void nsWindow::SetInputRegion(const InputRegion& aInputRegion) {
+  mInputRegion = aInputRegion;
+
+  GdkWindow* window =
+      mDrawToContainer ? gtk_widget_get_window(mShell) : mGdkWindow;
+  if (!window) {
+    return;
+  }
+
+  LOG("nsWindow::SetInputRegion(%d, %d)", aInputRegion.mFullyTransparent,
+      int(aInputRegion.mMargin));
+
+  cairo_rectangle_int_t rect = {0, 0, 0, 0};
+  cairo_region_t* region = nullptr;
+  auto releaseRegion = MakeScopeExit([&] {
+    if (region) {
+      cairo_region_destroy(region);
+    }
+  });
+
+  if (aInputRegion.mFullyTransparent) {
+    region = cairo_region_create_rectangle(&rect);
+  } else if (aInputRegion.mMargin != 0) {
+    LayoutDeviceIntRect inputRegion(LayoutDeviceIntPoint(), mLastSizeRequest);
+    inputRegion.Deflate(aInputRegion.mMargin);
+    GdkRectangle gdkRect = DevicePixelsToGdkRectRoundOut(inputRegion);
+    rect = {gdkRect.x, gdkRect.y, gdkRect.width, gdkRect.height};
+    region = cairo_region_create_rectangle(&rect);
+  }
+
+  gdk_window_input_shape_combine_region(window, region, 0, 0);
+
+  // On Wayland gdk_window_input_shape_combine_region() call is cached and
+  // applied to underlying wl_surface when GdkWindow is repainted.
+  // Force repaint of GdkWindow to apply the change immediately.
+  if (GdkIsWaylandDisplay()) {
+    gdk_window_invalidate_rect(window, nullptr, false);
+  }
+}
+
+// For setting the draggable titlebar region from CSS
+// with -moz-window-dragging: drag.
+void nsWindow::UpdateWindowDraggingRegion(
+    const LayoutDeviceIntRegion& aRegion) {
+  if (mDraggableRegion != aRegion) {
+    mDraggableRegion = aRegion;
+  }
+}
+
+LayoutDeviceIntCoord nsWindow::GetTitlebarRadius() {
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+  int32_t cssCoord = LookAndFeel::GetInt(LookAndFeel::IntID::TitlebarRadius);
+  return GdkCoordToDevicePixels(cssCoord);
+}
+
+// See subtract_corners_from_region() at gtk/gtkwindow.c
+// We need to subtract corners from toplevel window opaque region
+// to draw transparent corners of default Gtk titlebar.
+// Both implementations (cairo_region_t and wl_region) needs to be synced.
+static void SubtractTitlebarCorners(cairo_region_t* aRegion, int aX, int aY,
+                                    int aWindowWidth, int aTitlebarRadius) {
+  if (!aTitlebarRadius) {
+    return;
+  }
+  cairo_rectangle_int_t rect = {aX, aY, aTitlebarRadius, aTitlebarRadius};
+  cairo_region_subtract_rectangle(aRegion, &rect);
+  rect = {
+      aX + aWindowWidth - aTitlebarRadius,
+      aY,
+      aTitlebarRadius,
+      aTitlebarRadius,
+  };
+  cairo_region_subtract_rectangle(aRegion, &rect);
+}
+
+void nsWindow::UpdateTopLevelOpaqueRegion(void) {
+  if (!mCompositedScreen) {
+    return;
+  }
+
+  GdkWindow* window =
+      mDrawToContainer ? gtk_widget_get_window(mShell) : mGdkWindow;
+  if (!window) {
+    return;
+  }
+  MOZ_ASSERT(gdk_window_get_window_type(window) == GDK_WINDOW_TOPLEVEL);
+
+  int x = 0;
+  int y = 0;
+
+  if (mDrawToContainer) {
+    gdk_window_get_position(mGdkWindow, &x, &y);
+  }
+
+  int width = DevicePixelsToGdkCoordRoundDown(mBounds.width);
+  int height = DevicePixelsToGdkCoordRoundDown(mBounds.height);
+
+  cairo_region_t* region = cairo_region_create();
+  cairo_rectangle_int_t rect = {x, y, width, height};
+  cairo_region_union_rectangle(region, &rect);
+
+  int radius = DoDrawTilebarCorners() ? int(GetTitlebarRadius()) : 0;
+  SubtractTitlebarCorners(region, x, y, width, radius);
+
+  gdk_window_set_opaque_region(window, region);
+
+  cairo_region_destroy(region);
+
+#ifdef MOZ_WAYLAND
+  if (GdkIsWaylandDisplay()) {
+    moz_container_wayland_update_opaque_region(mContainer, radius);
+  }
+#endif
+}
+
+bool nsWindow::IsChromeWindowTitlebar() {
+  return mDrawInTitlebar && !mIsPIPWindow &&
+         mWindowType == WindowType::TopLevel;
+}
+
+bool nsWindow::DoDrawTilebarCorners() {
+  return IsChromeWindowTitlebar() && mSizeMode == nsSizeMode_Normal &&
+         !mIsTiled;
+}
+
+void nsWindow::ResizeTransparencyBitmap() {
+  if (!mTransparencyBitmap) return;
+
+  if (mBounds.width == mTransparencyBitmapWidth &&
+      mBounds.height == mTransparencyBitmapHeight) {
+    return;
+  }
+
+  int32_t newRowBytes = GetBitmapStride(mBounds.width);
+  int32_t newSize = newRowBytes * mBounds.height;
+  auto* newBits = new gchar[newSize];
+  // fill new mask with "transparent", first
+  memset(newBits, 0, newSize);
+
+  // Now copy the intersection of the old and new areas into the new mask
+  int32_t copyWidth = std::min(mBounds.width, mTransparencyBitmapWidth);
+  int32_t copyHeight = std::min(mBounds.height, mTransparencyBitmapHeight);
+  int32_t oldRowBytes = GetBitmapStride(mTransparencyBitmapWidth);
+  int32_t copyBytes = GetBitmapStride(copyWidth);
+
+  int32_t i;
+  gchar* fromPtr = mTransparencyBitmap;
+  gchar* toPtr = newBits;
+  for (i = 0; i < copyHeight; i++) {
+    memcpy(toPtr, fromPtr, copyBytes);
+    fromPtr += oldRowBytes;
+    toPtr += newRowBytes;
+  }
+
+  delete[] mTransparencyBitmap;
+  mTransparencyBitmap = newBits;
+  mTransparencyBitmapWidth = mBounds.width;
+  mTransparencyBitmapHeight = mBounds.height;
+}
+
+static bool ChangedMaskBits(gchar* aMaskBits, int32_t aMaskWidth,
+                            int32_t aMaskHeight, const nsIntRect& aRect,
+                            uint8_t* aAlphas, int32_t aStride) {
+  int32_t x, y, xMax = aRect.XMost(), yMax = aRect.YMost();
+  int32_t maskBytesPerRow = GetBitmapStride(aMaskWidth);
+  for (y = aRect.y; y < yMax; y++) {
+    gchar* maskBytes = aMaskBits + y * maskBytesPerRow;
+    uint8_t* alphas = aAlphas;
+    for (x = aRect.x; x < xMax; x++) {
+      bool newBit = *alphas > 0x7f;
+      alphas++;
+
+      gchar maskByte = maskBytes[x >> 3];
+      bool maskBit = (maskByte & (1 << (x & 7))) != 0;
+
+      if (maskBit != newBit) {
+        return true;
+      }
+    }
+    aAlphas += aStride;
+  }
+
+  return false;
+}
+
+static void UpdateMaskBits(gchar* aMaskBits, int32_t aMaskWidth,
+                           int32_t aMaskHeight, const nsIntRect& aRect,
+                           uint8_t* aAlphas, int32_t aStride) {
+  int32_t x, y, xMax = aRect.XMost(), yMax = aRect.YMost();
+  int32_t maskBytesPerRow = GetBitmapStride(aMaskWidth);
+  for (y = aRect.y; y < yMax; y++) {
+    gchar* maskBytes = aMaskBits + y * maskBytesPerRow;
+    uint8_t* alphas = aAlphas;
+    for (x = aRect.x; x < xMax; x++) {
+      bool newBit = *alphas > 0x7f;
+      alphas++;
+
+      gchar mask = 1 << (x & 7);
+      gchar maskByte = maskBytes[x >> 3];
+      // Note: '-newBit' turns 0 into 00...00 and 1 into 11...11
+      maskBytes[x >> 3] = (maskByte & ~mask) | (-newBit & mask);
+    }
+    aAlphas += aStride;
+  }
+}
+
+void nsWindow::ApplyTransparencyBitmap() {
+#ifdef MOZ_X11
+  // We use X11 calls where possible, because GDK handles expose events
+  // for shaped windows in a way that's incompatible with us (Bug 635903).
+  // It doesn't occur when the shapes are set through X.
+  Display* xDisplay = GDK_WINDOW_XDISPLAY(mGdkWindow);
+  Window xDrawable = GDK_WINDOW_XID(mGdkWindow);
+  Pixmap maskPixmap = XCreateBitmapFromData(
+      xDisplay, xDrawable, mTransparencyBitmap, mTransparencyBitmapWidth,
+      mTransparencyBitmapHeight);
+  XShapeCombineMask(xDisplay, xDrawable, ShapeBounding, 0, 0, maskPixmap,
+                    ShapeSet);
+  XFreePixmap(xDisplay, maskPixmap);
+#endif  // MOZ_X11
+}
+
+void nsWindow::ClearTransparencyBitmap() {
+  if (!mTransparencyBitmap) return;
+
+  delete[] mTransparencyBitmap;
+  mTransparencyBitmap = nullptr;
+  mTransparencyBitmapWidth = 0;
+  mTransparencyBitmapHeight = 0;
+
+  if (!mShell) return;
+
+#ifdef MOZ_X11
+  if (MOZ_UNLIKELY(!mGdkWindow)) {
+    return;
+  }
+
+  Display* xDisplay = GDK_WINDOW_XDISPLAY(mGdkWindow);
+  Window xWindow = gdk_x11_window_get_xid(mGdkWindow);
+
+  XShapeCombineMask(xDisplay, xWindow, ShapeBounding, 0, 0, X11None, ShapeSet);
+#endif
+}
+
+nsresult nsWindow::UpdateTranslucentWindowAlphaInternal(const nsIntRect& aRect,
+                                                        uint8_t* aAlphas,
+                                                        int32_t aStride) {
+  NS_ASSERTION(mIsTransparent, "Window is not transparent");
+  NS_ASSERTION(!mTransparencyBitmapForTitlebar,
+               "Transparency bitmap is already used for titlebar rendering");
+
+  if (mTransparencyBitmap == nullptr) {
+    int32_t size = GetBitmapStride(mBounds.width) * mBounds.height;
+    mTransparencyBitmap = new gchar[size];
+    memset(mTransparencyBitmap, 255, size);
+    mTransparencyBitmapWidth = mBounds.width;
+    mTransparencyBitmapHeight = mBounds.height;
+  } else {
+    ResizeTransparencyBitmap();
+  }
+
+  nsIntRect rect;
+  rect.IntersectRect(aRect, nsIntRect(0, 0, mBounds.width, mBounds.height));
+
+  if (!ChangedMaskBits(mTransparencyBitmap, mBounds.width, mBounds.height, rect,
+                       aAlphas, aStride)) {
+    // skip the expensive stuff if the mask bits haven't changed; hopefully
+    // this is the common case
+    return NS_OK;
+  }
+
+  UpdateMaskBits(mTransparencyBitmap, mBounds.width, mBounds.height, rect,
+                 aAlphas, aStride);
+
+  if (!mNeedsShow) {
+    ApplyTransparencyBitmap();
+  }
+  return NS_OK;
+}
+
+#define TITLEBAR_HEIGHT 10
+
+LayoutDeviceIntRect nsWindow::GetTitlebarRect() {
+  if (!mGdkWindow || !mDrawInTitlebar) {
+    return LayoutDeviceIntRect();
+  }
+
+  int height = 0;
+  if (DoDrawTilebarCorners()) {
+    height = GdkCeiledScaleFactor() * TITLEBAR_HEIGHT;
+  }
+  return LayoutDeviceIntRect(0, 0, mBounds.width, height);
+}
+
+void nsWindow::UpdateTitlebarTransparencyBitmap() {
+  NS_ASSERTION(mTransparencyBitmapForTitlebar,
+               "Transparency bitmap is already used to draw window shape");
+
+  if (!mGdkWindow || !mDrawInTitlebar ||
+      (mBounds.width == mTransparencyBitmapWidth &&
+       mBounds.height == mTransparencyBitmapHeight)) {
+    return;
+  }
+
+  bool maskCreate =
+      !mTransparencyBitmap || mBounds.width > mTransparencyBitmapWidth;
+
+  bool maskUpdate =
+      !mTransparencyBitmap || mBounds.width != mTransparencyBitmapWidth;
+
+  LayoutDeviceIntCoord radius = GetTitlebarRadius();
+  if (maskCreate) {
+    delete[] mTransparencyBitmap;
+    int32_t size = GetBitmapStride(mBounds.width) * radius;
+    mTransparencyBitmap = new gchar[size];
+    mTransparencyBitmapWidth = mBounds.width;
+  } else {
+    mTransparencyBitmapWidth = mBounds.width;
+  }
+  mTransparencyBitmapHeight = mBounds.height;
+
+  if (maskUpdate) {
+    cairo_surface_t* surface = cairo_image_surface_create(
+        CAIRO_FORMAT_A8, mTransparencyBitmapWidth, radius);
+    if (!surface) return;
+
+    cairo_t* cr = cairo_create(surface);
+
+    GtkWidgetState state;
+    memset((void*)&state, 0, sizeof(state));
+    GdkRectangle rect = {0, 0, mTransparencyBitmapWidth, radius};
+
+    moz_gtk_widget_paint(MOZ_GTK_HEADER_BAR, cr, &rect, &state, 0,
+                         GTK_TEXT_DIR_NONE);
+
+    cairo_destroy(cr);
+    cairo_surface_mark_dirty(surface);
+    cairo_surface_flush(surface);
+
+    UpdateMaskBits(mTransparencyBitmap, mTransparencyBitmapWidth, radius,
+                   nsIntRect(0, 0, mTransparencyBitmapWidth, radius),
+                   cairo_image_surface_get_data(surface),
+                   cairo_format_stride_for_width(CAIRO_FORMAT_A8,
+                                                 mTransparencyBitmapWidth));
+
+    cairo_surface_destroy(surface);
+  }
+
+#ifdef MOZ_X11
+  if (!mNeedsShow) {
+    Display* xDisplay = GDK_WINDOW_XDISPLAY(mGdkWindow);
+    Window xDrawable = GDK_WINDOW_XID(mGdkWindow);
+
+    Pixmap maskPixmap =
+        XCreateBitmapFromData(xDisplay, xDrawable, mTransparencyBitmap,
+                              mTransparencyBitmapWidth, radius);
+
+    XShapeCombineMask(xDisplay, xDrawable, ShapeBounding, 0, 0, maskPixmap,
+                      ShapeSet);
+
+    if (mTransparencyBitmapHeight > radius) {
+      XRectangle rect = {0, 0, (unsigned short)mTransparencyBitmapWidth,
+                         (unsigned short)(mTransparencyBitmapHeight - radius)};
+      XShapeCombineRectangles(xDisplay, xDrawable, ShapeBounding, 0, radius,
+                              &rect, 1, ShapeUnion, 0);
+    }
+
+    XFreePixmap(xDisplay, maskPixmap);
+  }
+#endif
+}
+
+GtkWidget* nsWindow::GetToplevelWidget() const { return mShell; }
+
+GdkWindow* nsWindow::GetToplevelGdkWindow() const {
+  return gtk_widget_get_window(mShell);
+}
+
+nsWindow* nsWindow::GetContainerWindow() const {
+  GtkWidget* owningWidget = GTK_WIDGET(mContainer);
+  if (!owningWidget) {
+    return nullptr;
+  }
+
+  nsWindow* window = get_window_for_gtk_widget(owningWidget);
+  NS_ASSERTION(window, "No nsWindow for container widget");
+  return window;
+}
+
+void nsWindow::SetUrgencyHint(GtkWidget* top_window, bool state) {
+  LOG("  nsWindow::SetUrgencyHint widget %p\n", top_window);
+
+  if (!top_window) return;
+
+  // TODO: Use xdg-activation on Wayland?
+  gdk_window_set_urgency_hint(gtk_widget_get_window(top_window), state);
+}
+
+void nsWindow::SetDefaultIcon(void) { SetIcon(u"default"_ns); }
+
+gint nsWindow::ConvertBorderStyles(BorderStyle aStyle) {
+  gint w = 0;
+
+  if (aStyle == BorderStyle::Default) return -1;
+
+  // note that we don't handle BorderStyle::Close yet
+  if (aStyle & BorderStyle::All) w |= GDK_DECOR_ALL;
+  if (aStyle & BorderStyle::Border) w |= GDK_DECOR_BORDER;
+  if (aStyle & BorderStyle::ResizeH) w |= GDK_DECOR_RESIZEH;
+  if (aStyle & BorderStyle::Title) w |= GDK_DECOR_TITLE;
+  if (aStyle & BorderStyle::Menu) w |= GDK_DECOR_MENU;
+  if (aStyle & BorderStyle::Minimize) w |= GDK_DECOR_MINIMIZE;
+  if (aStyle & BorderStyle::Maximize) w |= GDK_DECOR_MAXIMIZE;
+
+  return w;
+}
+
+class FullscreenTransitionWindow final : public nsISupports {
+ public:
+  NS_DECL_ISUPPORTS
+
+  explicit FullscreenTransitionWindow(GtkWidget* aWidget);
+
+  GtkWidget* mWindow;
+
+ private:
+  ~FullscreenTransitionWindow();
+};
+
+NS_IMPL_ISUPPORTS0(FullscreenTransitionWindow)
+
+FullscreenTransitionWindow::FullscreenTransitionWindow(GtkWidget* aWidget) {
+  mWindow = gtk_window_new(GTK_WINDOW_POPUP);
+  GtkWindow* gtkWin = GTK_WINDOW(mWindow);
+
+  gtk_window_set_type_hint(gtkWin, GDK_WINDOW_TYPE_HINT_SPLASHSCREEN);
+  GtkWindowSetTransientFor(gtkWin, GTK_WINDOW(aWidget));
+  gtk_window_set_decorated(gtkWin, false);
+
+  GdkWindow* gdkWin = gtk_widget_get_window(aWidget);
+  GdkScreen* screen = gtk_widget_get_screen(aWidget);
+  gint monitorNum = gdk_screen_get_monitor_at_window(screen, gdkWin);
+  GdkRectangle monitorRect;
+  gdk_screen_get_monitor_geometry(screen, monitorNum, &monitorRect);
+  gtk_window_set_screen(gtkWin, screen);
+  gtk_window_move(gtkWin, monitorRect.x, monitorRect.y);
+  MOZ_ASSERT(monitorRect.width > 0 && monitorRect.height > 0,
+             "Can't resize window smaller than 1x1.");
+  gtk_window_resize(gtkWin, monitorRect.width, monitorRect.height);
+
+  GdkRGBA bgColor;
+  bgColor.red = bgColor.green = bgColor.blue = 0.0;
+  bgColor.alpha = 1.0;
+  gtk_widget_override_background_color(mWindow, GTK_STATE_FLAG_NORMAL,
+                                       &bgColor);
+
+  gtk_widget_set_opacity(mWindow, 0.0);
+  gtk_widget_show(mWindow);
+}
+
+FullscreenTransitionWindow::~FullscreenTransitionWindow() {
+  gtk_widget_destroy(mWindow);
+}
+
+class FullscreenTransitionData {
+ public:
+  FullscreenTransitionData(nsIWidget::FullscreenTransitionStage aStage,
+                           uint16_t aDuration, nsIRunnable* aCallback,
+                           FullscreenTransitionWindow* aWindow)
+      : mStage(aStage),
+        mStartTime(TimeStamp::Now()),
+        mDuration(TimeDuration::FromMilliseconds(aDuration)),
+        mCallback(aCallback),
+        mWindow(aWindow) {}
+
+  static const guint sInterval = 1000 / 30;  // 30fps
+  static gboolean TimeoutCallback(gpointer aData);
+
+ private:
+  nsIWidget::FullscreenTransitionStage mStage;
+  TimeStamp mStartTime;
+  TimeDuration mDuration;
+  nsCOMPtr<nsIRunnable> mCallback;
+  RefPtr<FullscreenTransitionWindow> mWindow;
+};
+
+/* static */
+gboolean FullscreenTransitionData::TimeoutCallback(gpointer aData) {
+  bool finishing = false;
+  auto* data = static_cast<FullscreenTransitionData*>(aData);
+  gdouble opacity = (TimeStamp::Now() - data->mStartTime) / data->mDuration;
+  if (opacity >= 1.0) {
+    opacity = 1.0;
+    finishing = true;
+  }
+  if (data->mStage == nsIWidget::eAfterFullscreenToggle) {
+    opacity = 1.0 - opacity;
+  }
+  gtk_widget_set_opacity(data->mWindow->mWindow, opacity);
+
+  if (!finishing) {
+    return TRUE;
+  }
+  NS_DispatchToMainThread(data->mCallback.forget());
+  delete data;
+  return FALSE;
+}
+
+/* virtual */
+bool nsWindow::PrepareForFullscreenTransition(nsISupports** aData) {
+  if (!mCompositedScreen) {
+    return false;
+  }
+  *aData = do_AddRef(new FullscreenTransitionWindow(mShell)).take();
+  return true;
+}
+
+/* virtual */
+void nsWindow::PerformFullscreenTransition(FullscreenTransitionStage aStage,
+                                           uint16_t aDuration,
+                                           nsISupports* aData,
+                                           nsIRunnable* aCallback) {
+  auto* data = static_cast<FullscreenTransitionWindow*>(aData);
+  // This will be released at the end of the last timeout callback for it.
+  auto* transitionData =
+      new FullscreenTransitionData(aStage, aDuration, aCallback, data);
+  g_timeout_add_full(G_PRIORITY_HIGH, FullscreenTransitionData::sInterval,
+                     FullscreenTransitionData::TimeoutCallback, transitionData,
+                     nullptr);
+}
+
+already_AddRefed<widget::Screen> nsWindow::GetWidgetScreen() {
+  // Wayland can read screen directly
+  if (GdkIsWaylandDisplay()) {
+    if (RefPtr<Screen> screen = ScreenHelperGTK::GetScreenForWindow(this)) {
+      return screen.forget();
+    }
+  }
+
+  // GetScreenBounds() is slow for the GTK port so we override and use
+  // mBounds directly.
+  ScreenManager& screenManager = ScreenManager::GetSingleton();
+  LayoutDeviceIntRect bounds = mBounds;
+  DesktopIntRect deskBounds = RoundedToInt(bounds / GetDesktopToDeviceScale());
+  return screenManager.ScreenForRect(deskBounds);
+}
+
+RefPtr<VsyncDispatcher> nsWindow::GetVsyncDispatcher() {
+#ifdef MOZ_WAYLAND
+  if (mWaylandVsyncDispatcher) {
+    return mWaylandVsyncDispatcher;
+  }
+#endif
+  return nullptr;
+}
+
+bool nsWindow::SynchronouslyRepaintOnResize() {
+  if (GdkIsWaylandDisplay()) {
+    // See Bug 1734368
+    // Don't request synchronous repaint on HW accelerated backend - mesa can be
+    // deadlocked when it's missing back buffer and main event loop is blocked.
+    return false;
+  }
+
+  // default is synced repaint.
+  return true;
+}
+
+static bool IsFullscreenSupported(GtkWidget* aShell) {
+#ifdef MOZ_X11
+  GdkScreen* screen = gtk_widget_get_screen(aShell);
+  GdkAtom atom = gdk_atom_intern("_NET_WM_STATE_FULLSCREEN", FALSE);
+  return gdk_x11_screen_supports_net_wm_hint(screen, atom);
+#else
+  return true;
+#endif
+}
+
+nsresult nsWindow::MakeFullScreen(bool aFullScreen) {
+  LOG("nsWindow::MakeFullScreen aFullScreen %d\n", aFullScreen);
+
+  if (GdkIsX11Display() && !IsFullscreenSupported(mShell)) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (aFullScreen) {
+    if (mSizeMode != nsSizeMode_Fullscreen &&
+        mSizeMode != nsSizeMode_Minimized) {
+      mLastSizeModeBeforeFullscreen = mSizeMode;
+    }
+    if (mIsPIPWindow) {
+      gtk_window_set_type_hint(GTK_WINDOW(mShell), GDK_WINDOW_TYPE_HINT_NORMAL);
+      if (gUseAspectRatio) {
+        mAspectRatioSaved = mAspectRatio;
+        mAspectRatio = 0.0f;
+        ApplySizeConstraints();
+      }
+    }
+
+    gtk_window_fullscreen(GTK_WINDOW(mShell));
+  } else {
+    gtk_window_unfullscreen(GTK_WINDOW(mShell));
+
+    if (mIsPIPWindow) {
+      gtk_window_set_type_hint(GTK_WINDOW(mShell),
+                               GDK_WINDOW_TYPE_HINT_UTILITY);
+      if (gUseAspectRatio) {
+        mAspectRatio = mAspectRatioSaved;
+        // ApplySizeConstraints();
+      }
+    }
+  }
+
+  MOZ_ASSERT(mLastSizeModeBeforeFullscreen != nsSizeMode_Fullscreen);
+  return NS_OK;
+}
+
+void nsWindow::SetWindowDecoration(BorderStyle aStyle) {
+  LOG("nsWindow::SetWindowDecoration() Border style %x\n", int(aStyle));
+
+  // We can't use mGdkWindow directly here as it can be
+  // derived from mContainer which is not a top-level GdkWindow.
+  GdkWindow* window = gtk_widget_get_window(mShell);
+
+  // Sawfish, metacity, and presumably other window managers get
+  // confused if we change the window decorations while the window
+  // is visible.
+  bool wasVisible = false;
+  if (gdk_window_is_visible(window)) {
+    gdk_window_hide(window);
+    wasVisible = true;
+  }
+
+  gint wmd = ConvertBorderStyles(aStyle);
+  if (wmd != -1) gdk_window_set_decorations(window, (GdkWMDecoration)wmd);
+
+  if (wasVisible) gdk_window_show(window);
+
+    // For some window managers, adding or removing window decorations
+    // requires unmapping and remapping our toplevel window.  Go ahead
+    // and flush the queue here so that we don't end up with a BadWindow
+    // error later when this happens (when the persistence timer fires
+    // and GetWindowPos is called)
+#ifdef MOZ_X11
+  if (GdkIsX11Display()) {
+    XSync(GDK_DISPLAY_XDISPLAY(gdk_display_get_default()), X11False);
+  } else
+#endif /* MOZ_X11 */
+  {
+    gdk_flush();
+  }
+}
+
+void nsWindow::HideWindowChrome(bool aShouldHide) {
+  SetWindowDecoration(aShouldHide ? BorderStyle::None : mBorderStyle);
+}
+
+bool nsWindow::CheckForRollup(gdouble aMouseX, gdouble aMouseY, bool aIsWheel,
+                              bool aAlwaysRollup) {
+  LOG("nsWindow::CheckForRollup() aAlwaysRollup %d", aAlwaysRollup);
+  nsIRollupListener* rollupListener = GetActiveRollupListener();
+  nsCOMPtr<nsIWidget> rollupWidget;
+  if (rollupListener) {
+    rollupWidget = rollupListener->GetRollupWidget();
+  }
+  if (!rollupWidget) {
+    return false;
+  }
+
+  auto* currentPopup =
+      (GdkWindow*)rollupWidget->GetNativeData(NS_NATIVE_WINDOW);
+  if (!aAlwaysRollup && is_mouse_in_window(currentPopup, aMouseX, aMouseY)) {
+    return false;
+  }
+  bool retVal = false;
+  if (aIsWheel) {
+    retVal = rollupListener->ShouldConsumeOnMouseWheelEvent();
+    if (!rollupListener->ShouldRollupOnMouseWheelEvent()) {
+      return retVal;
+    }
+  }
+  LayoutDeviceIntPoint point;
+  nsIRollupListener::RollupOptions options{0,
+                                           nsIRollupListener::FlushViews::Yes};
+  // if we're dealing with menus, we probably have submenus and
+  // we don't want to rollup if the click is in a parent menu of
+  // the current submenu
+  if (!aAlwaysRollup) {
+    AutoTArray<nsIWidget*, 5> widgetChain;
+    uint32_t sameTypeCount =
+        rollupListener->GetSubmenuWidgetChain(&widgetChain);
+    for (unsigned long i = 0; i < widgetChain.Length(); ++i) {
+      nsIWidget* widget = widgetChain[i];
+      auto* currWindow = (GdkWindow*)widget->GetNativeData(NS_NATIVE_WINDOW);
+      if (is_mouse_in_window(currWindow, aMouseX, aMouseY)) {
+        // Don't roll up if the mouse event occurred within a menu of the same
+        // type.
+        // If the mouse event occurred in a menu higher than that, roll up, but
+        // pass the number of popups to Rollup so that only those of the same
+        // type close up.
+        if (i < sameTypeCount) {
+          return retVal;
+        }
+        options.mCount = sameTypeCount;
+        break;
+      }
+    }  // foreach parent menu widget
+    if (!aIsWheel) {
+      point = GdkEventCoordsToDevicePixels(aMouseX, aMouseY);
+      options.mPoint = &point;
+    }
+  }
+
+  if (mSizeMode == nsSizeMode_Minimized) {
+    // When we try to rollup in a minimized window, transitionend events for
+    // panels might not fire and thus we might not hide the popup after all,
+    // see bug 1810797.
+    options.mAllowAnimations = nsIRollupListener::AllowAnimations::No;
+  }
+
+  if (rollupListener->Rollup(options)) {
+    retVal = true;
+  }
+  return retVal;
+}
+
+/* static */
+bool nsWindow::DragInProgress() {
+  nsCOMPtr<nsIDragService> dragService =
+      do_GetService("@mozilla.org/widget/dragservice;1");
+  if (!dragService) {
+    return false;
+  }
+
+  nsCOMPtr<nsIDragSession> currentDragSession;
+  dragService->GetCurrentSession(getter_AddRefs(currentDragSession));
+  return !!currentDragSession;
+}
+
+// This is an ugly workaround for
+// https://bugzilla.mozilla.org/show_bug.cgi?id=1622107
+// We try to detect when Wayland compositor / gtk fails to deliver
+// info about finished D&D operations and cancel it on our own.
+MOZ_CAN_RUN_SCRIPT static void WaylandDragWorkaround(GdkEventButton* aEvent) {
+  static int buttonPressCountWithDrag = 0;
+
+  // We track only left button state as Firefox performs D&D on left
+  // button only.
+  if (aEvent->button != 1 || aEvent->type != GDK_BUTTON_PRESS) {
+    return;
+  }
+
+  nsCOMPtr<nsIDragService> dragService =
+      do_GetService("@mozilla.org/widget/dragservice;1");
+  if (!dragService) {
+    return;
+  }
+  nsCOMPtr<nsIDragSession> currentDragSession;
+  dragService->GetCurrentSession(getter_AddRefs(currentDragSession));
+
+  if (!currentDragSession) {
+    buttonPressCountWithDrag = 0;
+    return;
+  }
+
+  buttonPressCountWithDrag++;
+  if (buttonPressCountWithDrag > 1) {
+    NS_WARNING(
+        "Quit unfinished Wayland Drag and Drop operation. Buggy Wayland "
+        "compositor?");
+    buttonPressCountWithDrag = 0;
+    dragService->EndDragSession(false, 0);
+  }
+}
+
+static nsWindow* get_window_for_gtk_widget(GtkWidget* widget) {
+  gpointer user_data = g_object_get_data(G_OBJECT(widget), "nsWindow");
+  return static_cast<nsWindow*>(user_data);
+}
+
+static nsWindow* get_window_for_gdk_window(GdkWindow* window) {
+  gpointer user_data = g_object_get_data(G_OBJECT(window), "nsWindow");
+  return static_cast<nsWindow*>(user_data);
+}
+
+static bool is_mouse_in_window(GdkWindow* aWindow, gdouble aMouseX,
+                               gdouble aMouseY) {
+  GdkWindow* window = aWindow;
+  if (!window) {
+    return false;
+  }
+
+  gint x = 0;
+  gint y = 0;
+
+  {
+    gint offsetX = 0;
+    gint offsetY = 0;
+
+    while (window) {
+      gint tmpX = 0;
+      gint tmpY = 0;
+
+      gdk_window_get_position(window, &tmpX, &tmpY);
+      GtkWidget* widget = get_gtk_widget_for_gdk_window(window);
+
+      // if this is a window, compute x and y given its origin and our
+      // offset
+      if (GTK_IS_WINDOW(widget)) {
+        x = tmpX + offsetX;
+        y = tmpY + offsetY;
+        break;
+      }
+
+      offsetX += tmpX;
+      offsetY += tmpY;
+      window = gdk_window_get_parent(window);
+    }
+  }
+
+  gint margin = 0;
+  if (nsWindow* w = get_window_for_gdk_window(aWindow)) {
+    margin = w->GetInputRegionMarginInGdkCoords();
+  }
+
+  x += margin;
+  y += margin;
+
+  gint w = gdk_window_get_width(aWindow) - margin;
+  gint h = gdk_window_get_height(aWindow) - margin;
+
+  return aMouseX > x && aMouseX < x + w && aMouseY > y && aMouseY < y + h;
+}
+
+static GtkWidget* get_gtk_widget_for_gdk_window(GdkWindow* window) {
+  gpointer user_data = nullptr;
+  gdk_window_get_user_data(window, &user_data);
+
+  return GTK_WIDGET(user_data);
+}
+
+static GdkCursor* get_gtk_cursor(nsCursor aCursor) {
+  GdkCursor* gdkcursor = nullptr;
+  uint8_t newType = 0xff;
+
+  if ((gdkcursor = gCursorCache[aCursor])) {
+    return gdkcursor;
+  }
+
+  GdkDisplay* defaultDisplay = gdk_display_get_default();
+
+  // The strategy here is to use standard GDK cursors, and, if not available,
+  // load by standard name with gdk_cursor_new_from_name.
+  // Spec is here: http://www.freedesktop.org/wiki/Specifications/cursor-spec/
+  switch (aCursor) {
+    case eCursor_standard:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_LEFT_PTR);
+      break;
+    case eCursor_wait:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_WATCH);
+      break;
+    case eCursor_select:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_XTERM);
+      break;
+    case eCursor_hyperlink:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_HAND2);
+      break;
+    case eCursor_n_resize:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_TOP_SIDE);
+      break;
+    case eCursor_s_resize:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_BOTTOM_SIDE);
+      break;
+    case eCursor_w_resize:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_LEFT_SIDE);
+      break;
+    case eCursor_e_resize:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_RIGHT_SIDE);
+      break;
+    case eCursor_nw_resize:
+      gdkcursor =
+          gdk_cursor_new_for_display(defaultDisplay, GDK_TOP_LEFT_CORNER);
+      break;
+    case eCursor_se_resize:
+      gdkcursor =
+          gdk_cursor_new_for_display(defaultDisplay, GDK_BOTTOM_RIGHT_CORNER);
+      break;
+    case eCursor_ne_resize:
+      gdkcursor =
+          gdk_cursor_new_for_display(defaultDisplay, GDK_TOP_RIGHT_CORNER);
+      break;
+    case eCursor_sw_resize:
+      gdkcursor =
+          gdk_cursor_new_for_display(defaultDisplay, GDK_BOTTOM_LEFT_CORNER);
+      break;
+    case eCursor_crosshair:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_CROSSHAIR);
+      break;
+    case eCursor_move:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_FLEUR);
+      break;
+    case eCursor_help:
+      gdkcursor =
+          gdk_cursor_new_for_display(defaultDisplay, GDK_QUESTION_ARROW);
+      break;
+    case eCursor_copy:  // CSS3
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "copy");
+      if (!gdkcursor) newType = MOZ_CURSOR_COPY;
+      break;
+    case eCursor_alias:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "alias");
+      if (!gdkcursor) newType = MOZ_CURSOR_ALIAS;
+      break;
+    case eCursor_context_menu:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "context-menu");
+      if (!gdkcursor) newType = MOZ_CURSOR_CONTEXT_MENU;
+      break;
+    case eCursor_cell:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_PLUS);
+      break;
+    // Those two aren’t standardized. Trying both KDE’s and GNOME’s names
+    case eCursor_grab:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "openhand");
+      if (!gdkcursor) newType = MOZ_CURSOR_HAND_GRAB;
+      break;
+    case eCursor_grabbing:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "closedhand");
+      if (!gdkcursor) {
+        gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "grabbing");
+      }
+      if (!gdkcursor) newType = MOZ_CURSOR_HAND_GRABBING;
+      break;
+    case eCursor_spinning:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "progress");
+      if (!gdkcursor) newType = MOZ_CURSOR_SPINNING;
+      break;
+    case eCursor_zoom_in:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "zoom-in");
+      if (!gdkcursor) newType = MOZ_CURSOR_ZOOM_IN;
+      break;
+    case eCursor_zoom_out:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "zoom-out");
+      if (!gdkcursor) newType = MOZ_CURSOR_ZOOM_OUT;
+      break;
+    case eCursor_not_allowed:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "not-allowed");
+      if (!gdkcursor) {  // nonstandard, yet common
+        gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "crossed_circle");
+      }
+      if (!gdkcursor) newType = MOZ_CURSOR_NOT_ALLOWED;
+      break;
+    case eCursor_no_drop:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "no-drop");
+      if (!gdkcursor) {  // this nonstandard sequence makes it work on KDE and
+                         // GNOME
+        gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "forbidden");
+      }
+      if (!gdkcursor) {
+        gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "circle");
+      }
+      if (!gdkcursor) newType = MOZ_CURSOR_NOT_ALLOWED;
+      break;
+    case eCursor_vertical_text:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "vertical-text");
+      if (!gdkcursor) {
+        newType = MOZ_CURSOR_VERTICAL_TEXT;
+      }
+      break;
+    case eCursor_all_scroll:
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_FLEUR);
+      break;
+    case eCursor_nesw_resize:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "size_bdiag");
+      if (!gdkcursor) newType = MOZ_CURSOR_NESW_RESIZE;
+      break;
+    case eCursor_nwse_resize:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "size_fdiag");
+      if (!gdkcursor) newType = MOZ_CURSOR_NWSE_RESIZE;
+      break;
+    case eCursor_ns_resize:
+      gdkcursor =
+          gdk_cursor_new_for_display(defaultDisplay, GDK_SB_V_DOUBLE_ARROW);
+      break;
+    case eCursor_ew_resize:
+      gdkcursor =
+          gdk_cursor_new_for_display(defaultDisplay, GDK_SB_H_DOUBLE_ARROW);
+      break;
+    // Here, two better fitting cursors exist in some cursor themes. Try those
+    // first
+    case eCursor_row_resize:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "split_v");
+      if (!gdkcursor) {
+        gdkcursor =
+            gdk_cursor_new_for_display(defaultDisplay, GDK_SB_V_DOUBLE_ARROW);
+      }
+      break;
+    case eCursor_col_resize:
+      gdkcursor = gdk_cursor_new_from_name(defaultDisplay, "split_h");
+      if (!gdkcursor) {
+        gdkcursor =
+            gdk_cursor_new_for_display(defaultDisplay, GDK_SB_H_DOUBLE_ARROW);
+      }
+      break;
+    case eCursor_none:
+      newType = MOZ_CURSOR_NONE;
+      break;
+    default:
+      NS_ASSERTION(aCursor, "Invalid cursor type");
+      gdkcursor = gdk_cursor_new_for_display(defaultDisplay, GDK_LEFT_PTR);
+      break;
+  }
+
+  // If by now we don't have a xcursor, this means we have to make a custom
+  // one. First, we try creating a named cursor based on the hash of our
+  // custom bitmap, as libXcursor has some magic to convert bitmapped cursors
+  // to themed cursors
+  if (newType != 0xFF && GtkCursors[newType].hash) {
+    gdkcursor =
+        gdk_cursor_new_from_name(defaultDisplay, GtkCursors[newType].hash);
+  }
+
+  // If we still don't have a xcursor, we now really create a bitmap cursor
+  if (newType != 0xff && !gdkcursor) {
+    GdkPixbuf* cursor_pixbuf =
+        gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, 32, 32);
+    if (!cursor_pixbuf) return nullptr;
+
+    guchar* data = gdk_pixbuf_get_pixels(cursor_pixbuf);
+
+    // Read data from GtkCursors and compose RGBA surface from 1bit bitmap and
+    // mask GtkCursors bits and mask are 32x32 monochrome bitmaps (1 bit for
+    // each pixel) so it's 128 byte array (4 bytes for are one bitmap row and
+    // there are 32 rows here).
+    const unsigned char* bits = GtkCursors[newType].bits;
+    const unsigned char* mask_bits = GtkCursors[newType].mask_bits;
+
+    for (int i = 0; i < 128; i++) {
+      char bit = (char)*bits++;
+      char mask = (char)*mask_bits++;
+      for (int j = 0; j < 8; j++) {
+        unsigned char pix = ~(((bit >> j) & 0x01) * 0xff);
+        *data++ = pix;
+        *data++ = pix;
+        *data++ = pix;
+        *data++ = (((mask >> j) & 0x01) * 0xff);
+      }
+    }
+
+    gdkcursor = gdk_cursor_new_from_pixbuf(
+        gdk_display_get_default(), cursor_pixbuf, GtkCursors[newType].hot_x,
+        GtkCursors[newType].hot_y);
+
+    g_object_unref(cursor_pixbuf);
+  }
+
+  gCursorCache[aCursor] = gdkcursor;
+
+  return gdkcursor;
+}
+
+// gtk callbacks
+
+void draw_window_of_widget(GtkWidget* widget, GdkWindow* aWindow, cairo_t* cr) {
+  if (gtk_cairo_should_draw_window(cr, aWindow)) {
+    RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+    if (!window) {
+      NS_WARNING("Cannot get nsWindow from GtkWidget");
+    } else {
+      cairo_save(cr);
+      gtk_cairo_transform_to_window(cr, widget, aWindow);
+      // TODO - window->OnExposeEvent() can destroy this or other windows,
+      // do we need to handle it somehow?
+      window->OnExposeEvent(cr);
+      cairo_restore(cr);
+    }
+  }
+}
+
+/* static */
+gboolean expose_event_cb(GtkWidget* widget, cairo_t* cr) {
+  draw_window_of_widget(widget, gtk_widget_get_window(widget), cr);
+
+  // A strong reference is already held during "draw" signal emission,
+  // but GTK+ 3.4 wants the object to live a little longer than that
+  // (bug 1225970).
+  g_object_ref(widget);
+  g_idle_add(
+      [](gpointer data) -> gboolean {
+        g_object_unref(data);
+        return G_SOURCE_REMOVE;
+      },
+      widget);
+
+  return FALSE;
+}
+
+static gboolean configure_event_cb(GtkWidget* widget,
+                                   GdkEventConfigure* event) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return FALSE;
+  }
+
+  return window->OnConfigureEvent(widget, event);
+}
+
+// Some Gtk widget code may call gtk_widget_unrealize() which destroys
+// mGdkWindow. We need to listen on this signal and re-create
+// mGdkWindow when we're already mapped.
+static void widget_map_cb(GtkWidget* widget) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return;
+  }
+  window->OnMap();
+}
+
+static void widget_unmap_cb(GtkWidget* widget) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return;
+  }
+  window->OnUnmap();
+}
+
+static void widget_unrealize_cb(GtkWidget* widget) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return;
+  }
+  window->OnUnrealize();
+}
+
+static void size_allocate_cb(GtkWidget* widget, GtkAllocation* allocation) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return;
+  }
+
+  window->OnSizeAllocate(allocation);
+}
+
+static void toplevel_window_size_allocate_cb(GtkWidget* widget,
+                                             GtkAllocation* allocation) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return;
+  }
+
+  window->UpdateTopLevelOpaqueRegion();
+}
+
+static gboolean delete_event_cb(GtkWidget* widget, GdkEventAny* event) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return FALSE;
+  }
+
+  window->OnDeleteEvent();
+
+  return TRUE;
+}
+
+static gboolean enter_notify_event_cb(GtkWidget* widget,
+                                      GdkEventCrossing* event) {
+  RefPtr<nsWindow> window = get_window_for_gdk_window(event->window);
+  if (!window) {
+    return TRUE;
+  }
+
+  // We have stored leave notify - check if it's the correct one and
+  // fire it before enter notify in such case.
+  if (sStoredLeaveNotifyEvent) {
+    auto clearNofityEvent =
+        MakeScopeExit([&] { sStoredLeaveNotifyEvent = nullptr; });
+    if (event->x_root == sStoredLeaveNotifyEvent->x_root &&
+        event->y_root == sStoredLeaveNotifyEvent->y_root &&
+        window->ApplyEnterLeaveMutterWorkaround()) {
+      // Enter/Leave notify events has the same coordinates
+      // and uses know buggy window config.
+      // Consider it as a bogus one.
+      return TRUE;
+    }
+    RefPtr<nsWindow> leftWindow =
+        get_window_for_gdk_window(sStoredLeaveNotifyEvent->window);
+    if (leftWindow) {
+      leftWindow->OnLeaveNotifyEvent(sStoredLeaveNotifyEvent.get());
+    }
+  }
+
+  window->OnEnterNotifyEvent(event);
+  return TRUE;
+}
+
+static gboolean leave_notify_event_cb(GtkWidget* widget,
+                                      GdkEventCrossing* event) {
+  RefPtr<nsWindow> window = get_window_for_gdk_window(event->window);
+  if (!window) {
+    return TRUE;
+  }
+
+  if (window->ApplyEnterLeaveMutterWorkaround()) {
+    // The leave event is potentially wrong, don't fire it now but store
+    // it for further check at enter_notify_event_cb().
+    sStoredLeaveNotifyEvent.reset(reinterpret_cast<GdkEventCrossing*>(
+        gdk_event_copy(reinterpret_cast<GdkEvent*>(event))));
+  } else {
+    sStoredLeaveNotifyEvent = nullptr;
+    window->OnLeaveNotifyEvent(event);
+  }
+
+  return TRUE;
+}
+
+static nsWindow* GetFirstNSWindowForGDKWindow(GdkWindow* aGdkWindow) {
+  nsWindow* window;
+  while (!(window = get_window_for_gdk_window(aGdkWindow))) {
+    // The event has bubbled to the moz_container widget as passed into each
+    // caller's *widget parameter, but its corresponding nsWindow is an ancestor
+    // of the window that we need.  Instead, look at event->window and find the
+    // first ancestor nsWindow of it because event->window may be in a plugin.
+    aGdkWindow = gdk_window_get_parent(aGdkWindow);
+    if (!aGdkWindow) {
+      window = nullptr;
+      break;
+    }
+  }
+  return window;
+}
+
+static gboolean motion_notify_event_cb(GtkWidget* widget,
+                                       GdkEventMotion* event) {
+  UpdateLastInputEventTime(event);
+
+  RefPtr<nsWindow> window = GetFirstNSWindowForGDKWindow(event->window);
+  if (!window) return FALSE;
+
+  window->OnMotionNotifyEvent(event);
+
+  return TRUE;
+}
+
+static gboolean button_press_event_cb(GtkWidget* widget,
+                                      GdkEventButton* event) {
+  UpdateLastInputEventTime(event);
+
+  RefPtr<nsWindow> window = GetFirstNSWindowForGDKWindow(event->window);
+  if (!window) return FALSE;
+
+  window->OnButtonPressEvent(event);
+
+  if (GdkIsWaylandDisplay()) {
+    WaylandDragWorkaround(event);
+  }
+
+  return TRUE;
+}
+
+static gboolean button_release_event_cb(GtkWidget* widget,
+                                        GdkEventButton* event) {
+  UpdateLastInputEventTime(event);
+
+  RefPtr<nsWindow> window = GetFirstNSWindowForGDKWindow(event->window);
+  if (!window) return FALSE;
+
+  window->OnButtonReleaseEvent(event);
+
+  return TRUE;
+}
+
+static gboolean focus_in_event_cb(GtkWidget* widget, GdkEventFocus* event) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) return FALSE;
+
+  window->OnContainerFocusInEvent(event);
+
+  return FALSE;
+}
+
+static gboolean focus_out_event_cb(GtkWidget* widget, GdkEventFocus* event) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) return FALSE;
+
+  window->OnContainerFocusOutEvent(event);
+
+  return FALSE;
+}
+
+#ifdef MOZ_X11
+// For long-lived popup windows that don't really take focus themselves but
+// may have elements that accept keyboard input when the parent window is
+// active, focus is handled specially.  These windows include noautohide
+// panels.  (This special handling is not necessary for temporary popups where
+// the keyboard is grabbed.)
+//
+// Mousing over or clicking on these windows should not cause them to steal
+// focus from their parent windows, so, the input field of WM_HINTS is set to
+// False to request that the window manager not set the input focus to this
+// window.  http://tronche.com/gui/x/icccm/sec-4.html#s-4.1.7
+//
+// However, these windows can still receive WM_TAKE_FOCUS messages from the
+// window manager, so they can still detect when the user has indicated that
+// they wish to direct keyboard input at these windows.  When the window
+// manager offers focus to these windows (after a mouse over or click, for
+// example), a request to make the parent window active is issued.  When the
+// parent window becomes active, keyboard events will be received.
+
+static GdkFilterReturn popup_take_focus_filter(GdkXEvent* gdk_xevent,
+                                               GdkEvent* event, gpointer data) {
+  auto* xevent = static_cast<XEvent*>(gdk_xevent);
+  if (xevent->type != ClientMessage) return GDK_FILTER_CONTINUE;
+
+  XClientMessageEvent& xclient = xevent->xclient;
+  if (xclient.message_type != gdk_x11_get_xatom_by_name("WM_PROTOCOLS")) {
+    return GDK_FILTER_CONTINUE;
+  }
+
+  Atom atom = xclient.data.l[0];
+  if (atom != gdk_x11_get_xatom_by_name("WM_TAKE_FOCUS")) {
+    return GDK_FILTER_CONTINUE;
+  }
+
+  guint32 timestamp = xclient.data.l[1];
+
+  GtkWidget* widget = get_gtk_widget_for_gdk_window(event->any.window);
+  if (!widget) return GDK_FILTER_CONTINUE;
+
+  GtkWindow* parent = gtk_window_get_transient_for(GTK_WINDOW(widget));
+  if (!parent) return GDK_FILTER_CONTINUE;
+
+  if (gtk_window_is_active(parent)) {
+    return GDK_FILTER_REMOVE;  // leave input focus on the parent
+  }
+
+  GdkWindow* parent_window = gtk_widget_get_window(GTK_WIDGET(parent));
+  if (!parent_window) return GDK_FILTER_CONTINUE;
+
+  // In case the parent has not been deconified.
+  gdk_window_show_unraised(parent_window);
+
+  // Request focus on the parent window.
+  // Use gdk_window_focus rather than gtk_window_present to avoid
+  // raising the parent window.
+  gdk_window_focus(parent_window, timestamp);
+  return GDK_FILTER_REMOVE;
+}
+#endif /* MOZ_X11 */
+
+static gboolean key_press_event_cb(GtkWidget* widget, GdkEventKey* event) {
+  LOGW("key_press_event_cb\n");
+
+  UpdateLastInputEventTime(event);
+
+  // find the window with focus and dispatch this event to that widget
+  nsWindow* window = get_window_for_gtk_widget(widget);
+  if (!window) return FALSE;
+
+  RefPtr<nsWindow> focusWindow = gFocusWindow ? gFocusWindow : window;
+
+#ifdef MOZ_X11
+  // Keyboard repeat can cause key press events to queue up when there are
+  // slow event handlers (bug 301029).  Throttle these events by removing
+  // consecutive pending duplicate KeyPress events to the same window.
+  // We use the event time of the last one.
+  // Note: GDK calls XkbSetDetectableAutorepeat so that KeyRelease events
+  // are generated only when the key is physically released.
+#  define NS_GDKEVENT_MATCH_MASK 0x1FFF  // GDK_SHIFT_MASK .. GDK_BUTTON5_MASK
+  // Our headers undefine X11 KeyPress - let's redefine it here.
+#  ifndef KeyPress
+#    define KeyPress 2
+#  endif
+  GdkDisplay* gdkDisplay = gtk_widget_get_display(widget);
+  if (GdkIsX11Display(gdkDisplay)) {
+    Display* dpy = GDK_DISPLAY_XDISPLAY(gdkDisplay);
+    while (XPending(dpy)) {
+      XEvent next_event;
+      XPeekEvent(dpy, &next_event);
+      GdkWindow* nextGdkWindow =
+          gdk_x11_window_lookup_for_display(gdkDisplay, next_event.xany.window);
+      if (nextGdkWindow != event->window || next_event.type != KeyPress ||
+          next_event.xkey.keycode != event->hardware_keycode ||
+          next_event.xkey.state != (event->state & NS_GDKEVENT_MATCH_MASK)) {
+        break;
+      }
+      XNextEvent(dpy, &next_event);
+      event->time = next_event.xkey.time;
+    }
+  }
+#endif
+
+  return focusWindow->OnKeyPressEvent(event);
+}
+
+static gboolean key_release_event_cb(GtkWidget* widget, GdkEventKey* event) {
+  LOGW("key_release_event_cb\n");
+
+  UpdateLastInputEventTime(event);
+
+  // find the window with focus and dispatch this event to that widget
+  nsWindow* window = get_window_for_gtk_widget(widget);
+  if (!window) return FALSE;
+
+  RefPtr<nsWindow> focusWindow = gFocusWindow ? gFocusWindow : window;
+  return focusWindow->OnKeyReleaseEvent(event);
+}
+
+static gboolean property_notify_event_cb(GtkWidget* aWidget,
+                                         GdkEventProperty* aEvent) {
+  RefPtr<nsWindow> window = get_window_for_gdk_window(aEvent->window);
+  if (!window) return FALSE;
+
+  return window->OnPropertyNotifyEvent(aWidget, aEvent);
+}
+
+static gboolean scroll_event_cb(GtkWidget* widget, GdkEventScroll* event) {
+  RefPtr<nsWindow> window = GetFirstNSWindowForGDKWindow(event->window);
+  if (!window) return FALSE;
+
+  window->OnScrollEvent(event);
+
+  return TRUE;
+}
+
+static void hierarchy_changed_cb(GtkWidget* widget,
+                                 GtkWidget* previous_toplevel) {
+  GtkWidget* toplevel = gtk_widget_get_toplevel(widget);
+  GdkWindowState old_window_state = GDK_WINDOW_STATE_WITHDRAWN;
+  GdkEventWindowState event;
+
+  event.new_window_state = GDK_WINDOW_STATE_WITHDRAWN;
+
+  if (GTK_IS_WINDOW(previous_toplevel)) {
+    g_signal_handlers_disconnect_by_func(
+        previous_toplevel, FuncToGpointer(window_state_event_cb), widget);
+    GdkWindow* win = gtk_widget_get_window(previous_toplevel);
+    if (win) {
+      old_window_state = gdk_window_get_state(win);
+    }
+  }
+
+  if (GTK_IS_WINDOW(toplevel)) {
+    g_signal_connect_swapped(toplevel, "window-state-event",
+                             G_CALLBACK(window_state_event_cb), widget);
+    GdkWindow* win = gtk_widget_get_window(toplevel);
+    if (win) {
+      event.new_window_state = gdk_window_get_state(win);
+    }
+  }
+
+  event.changed_mask =
+      static_cast<GdkWindowState>(old_window_state ^ event.new_window_state);
+
+  if (event.changed_mask) {
+    event.type = GDK_WINDOW_STATE;
+    event.window = nullptr;
+    event.send_event = TRUE;
+    window_state_event_cb(widget, &event);
+  }
+}
+
+static gboolean window_state_event_cb(GtkWidget* widget,
+                                      GdkEventWindowState* event) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) return FALSE;
+
+  window->OnWindowStateEvent(widget, event);
+
+  return FALSE;
+}
+
+static void settings_xft_dpi_changed_cb(GtkSettings* gtk_settings,
+                                        GParamSpec* pspec, nsWindow* data) {
+  RefPtr<nsWindow> window = data;
+  window->OnDPIChanged();
+  // Even though the window size in screen pixels has not changed,
+  // nsViewManager stores the dimensions in app units.
+  // DispatchResized() updates those.
+  window->DispatchResized();
+}
+
+static void check_resize_cb(GtkContainer* container, gpointer user_data) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(GTK_WIDGET(container));
+  if (!window) {
+    return;
+  }
+  window->OnCheckResize();
+}
+
+static void screen_composited_changed_cb(GdkScreen* screen,
+                                         gpointer user_data) {
+  // This callback can run before gfxPlatform::Init() in rare
+  // cases involving the profile manager. When this happens,
+  // we have no reason to reset any compositors as graphics
+  // hasn't been initialized yet.
+  if (GPUProcessManager::Get()) {
+    GPUProcessManager::Get()->ResetCompositors();
+  }
+}
+
+static void widget_composited_changed_cb(GtkWidget* widget,
+                                         gpointer user_data) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return;
+  }
+  window->OnCompositedChanged();
+}
+
+static void scale_changed_cb(GtkWidget* widget, GParamSpec* aPSpec,
+                             gpointer aPointer) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+  if (!window) {
+    return;
+  }
+
+  window->OnScaleChanged();
+}
+
+static gboolean touch_event_cb(GtkWidget* aWidget, GdkEventTouch* aEvent) {
+  UpdateLastInputEventTime(aEvent);
+
+  RefPtr<nsWindow> window = GetFirstNSWindowForGDKWindow(aEvent->window);
+  if (!window) {
+    return FALSE;
+  }
+
+  return window->OnTouchEvent(aEvent);
+}
+
+// This function called generic because there is no signal specific to touchpad
+// pinch events.
+static gboolean generic_event_cb(GtkWidget* widget, GdkEvent* aEvent) {
+  if (aEvent->type != GDK_TOUCHPAD_PINCH) {
+    return FALSE;
+  }
+  // Using reinterpret_cast because the touchpad_pinch field of GdkEvent is not
+  // available in GTK+ versions lower than v3.18
+  GdkEventTouchpadPinch* event =
+      reinterpret_cast<GdkEventTouchpadPinch*>(aEvent);
+
+  RefPtr<nsWindow> window = GetFirstNSWindowForGDKWindow(event->window);
+
+  if (!window) {
+    return FALSE;
+  }
+  return window->OnTouchpadPinchEvent(event);
+}
+
+//////////////////////////////////////////////////////////////////////
+// These are all of our drag and drop operations
+
+void nsWindow::InitDragEvent(WidgetDragEvent& aEvent) {
+  // set the keyboard modifiers
+  guint modifierState = KeymapWrapper::GetCurrentModifierState();
+  KeymapWrapper::InitInputEvent(aEvent, modifierState);
+}
+
+static LayoutDeviceIntPoint GetWindowDropPosition(nsWindow* aWindow, int aX,
+                                                  int aY) {
+  // Workaround for Bug 1710344
+  // Caused by Gtk issue https://gitlab.gnome.org/GNOME/gtk/-/issues/4437
+  if (aWindow->IsWaylandPopup()) {
+    int tx = 0, ty = 0;
+    gdk_window_get_position(aWindow->GetToplevelGdkWindow(), &tx, &ty);
+    aX += tx;
+    aY += ty;
+  }
+  LOGDRAG("WindowDropPosition [%d, %d]", aX, aY);
+  return aWindow->GdkPointToDevicePixels({aX, aY});
+}
+
+gboolean WindowDragMotionHandler(GtkWidget* aWidget,
+                                 GdkDragContext* aDragContext, gint aX, gint aY,
+                                 guint aTime) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(aWidget);
+  if (!window) {
+    return FALSE;
+  }
+
+  // figure out which internal widget this drag motion actually happened on
+  nscoord retx = 0;
+  nscoord rety = 0;
+
+  GdkWindow* innerWindow = get_inner_gdk_window(gtk_widget_get_window(aWidget),
+                                                aX, aY, &retx, &rety);
+  RefPtr<nsWindow> innerMostWindow = get_window_for_gdk_window(innerWindow);
+  if (!innerMostWindow) {
+    innerMostWindow = window;
+  }
+  LOGDRAG("WindowDragMotionHandler target nsWindow [%p]",
+          innerMostWindow.get());
+
+  RefPtr<nsDragService> dragService = nsDragService::GetInstance();
+  nsDragService::AutoEventLoop loop(dragService);
+  if (!dragService->ScheduleMotionEvent(
+          innerMostWindow, aDragContext,
+          GetWindowDropPosition(innerMostWindow, retx, rety), aTime)) {
+    return FALSE;
+  }
+  return TRUE;
+}
+
+static gboolean drag_motion_event_cb(GtkWidget* aWidget,
+                                     GdkDragContext* aDragContext, gint aX,
+                                     gint aY, guint aTime, gpointer aData) {
+  return WindowDragMotionHandler(aWidget, aDragContext, aX, aY, aTime);
+}
+
+void WindowDragLeaveHandler(GtkWidget* aWidget) {
+  LOGDRAG("WindowDragLeaveHandler()\n");
+
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(aWidget);
+  if (!window) {
+    LOGDRAG("    Failed - can't find nsWindow!\n");
+    return;
+  }
+
+  RefPtr<nsDragService> dragService = nsDragService::GetInstance();
+  nsDragService::AutoEventLoop loop(dragService);
+
+  nsWindow* mostRecentDragWindow = dragService->GetMostRecentDestWindow();
+  if (!mostRecentDragWindow) {
+    // This can happen when the target will not accept a drop.  A GTK drag
+    // source sends the leave message to the destination before the
+    // drag-failed signal on the source widget, but the leave message goes
+    // via the X server, and so doesn't get processed at least until the
+    // event loop runs again.
+    LOGDRAG("    Failed - GetMostRecentDestWindow()!\n");
+    return;
+  }
+
+  if (aWidget != window->GetGtkWidget()) {
+    // When the drag moves between widgets, GTK can send leave signal for
+    // the old widget after the motion or drop signal for the new widget.
+    // We'll send the leave event when the motion or drop event is run.
+    LOGDRAG("    Failed - GtkWidget mismatch!\n");
+    return;
+  }
+
+  LOGDRAG("WindowDragLeaveHandler nsWindow %p\n", (void*)mostRecentDragWindow);
+  dragService->ScheduleLeaveEvent();
+}
+
+static void drag_leave_event_cb(GtkWidget* aWidget,
+                                GdkDragContext* aDragContext, guint aTime,
+                                gpointer aData) {
+  WindowDragLeaveHandler(aWidget);
+}
+
+gboolean WindowDragDropHandler(GtkWidget* aWidget, GdkDragContext* aDragContext,
+                               gint aX, gint aY, guint aTime) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(aWidget);
+  if (!window) return FALSE;
+
+  // figure out which internal widget this drag motion actually happened on
+  nscoord retx = 0;
+  nscoord rety = 0;
+
+  GdkWindow* innerWindow = get_inner_gdk_window(gtk_widget_get_window(aWidget),
+                                                aX, aY, &retx, &rety);
+  RefPtr<nsWindow> innerMostWindow = get_window_for_gdk_window(innerWindow);
+
+  if (!innerMostWindow) {
+    innerMostWindow = window;
+  }
+
+  LOGDRAG("WindowDragDropHandler nsWindow [%p]", innerMostWindow.get());
+  RefPtr<nsDragService> dragService = nsDragService::GetInstance();
+  nsDragService::AutoEventLoop loop(dragService);
+  return dragService->ScheduleDropEvent(
+      innerMostWindow, aDragContext,
+      GetWindowDropPosition(innerMostWindow, retx, rety), aTime);
+}
+
+static gboolean drag_drop_event_cb(GtkWidget* aWidget,
+                                   GdkDragContext* aDragContext, gint aX,
+                                   gint aY, guint aTime, gpointer aData) {
+  return WindowDragDropHandler(aWidget, aDragContext, aX, aY, aTime);
+}
+
+static void drag_data_received_event_cb(GtkWidget* aWidget,
+                                        GdkDragContext* aDragContext, gint aX,
+                                        gint aY,
+                                        GtkSelectionData* aSelectionData,
+                                        guint aInfo, guint aTime,
+                                        gpointer aData) {
+  RefPtr<nsWindow> window = get_window_for_gtk_widget(aWidget);
+  if (!window) return;
+
+  window->OnDragDataReceivedEvent(aWidget, aDragContext, aX, aY, aSelectionData,
+                                  aInfo, aTime, aData);
+}
+
+static nsresult initialize_prefs(void) {
+  if (Preferences::HasUserValue("widget.use-aspect-ratio")) {
+    gUseAspectRatio = Preferences::GetBool("widget.use-aspect-ratio", true);
+  } else {
+    gUseAspectRatio = IsGnomeDesktopEnvironment() || IsKdeDesktopEnvironment();
+  }
+  return NS_OK;
+}
+
+// TODO: Can we simplify it for mShell/mContainer only scenario?
+static GdkWindow* get_inner_gdk_window(GdkWindow* aWindow, gint x, gint y,
+                                       gint* retx, gint* rety) {
+  gint cx, cy, cw, ch;
+  GList* children = gdk_window_peek_children(aWindow);
+  for (GList* child = g_list_last(children); child;
+       child = g_list_previous(child)) {
+    auto* childWindow = (GdkWindow*)child->data;
+    if (get_window_for_gdk_window(childWindow)) {
+      gdk_window_get_geometry(childWindow, &cx, &cy, &cw, &ch);
+      if ((cx < x) && (x < (cx + cw)) && (cy < y) && (y < (cy + ch)) &&
+          gdk_window_is_visible(childWindow)) {
+        return get_inner_gdk_window(childWindow, x - cx, y - cy, retx, rety);
+      }
+    }
+  }
+  *retx = x;
+  *rety = y;
+  return aWindow;
+}
+
+#ifdef ACCESSIBILITY
+void nsWindow::CreateRootAccessible() {
+  if (!mRootAccessible) {
+    LOG("nsWindow:: Create Toplevel Accessibility\n");
+    mRootAccessible = GetRootAccessible();
+  }
+}
+
+void nsWindow::DispatchEventToRootAccessible(uint32_t aEventType) {
+  if (!a11y::ShouldA11yBeEnabled()) {
+    return;
+  }
+
+  nsAccessibilityService* accService = GetOrCreateAccService();
+  if (!accService) {
+    return;
+  }
+
+  // Get the root document accessible and fire event to it.
+  a11y::LocalAccessible* acc = GetRootAccessible();
+  if (acc) {
+    accService->FireAccessibleEvent(aEventType, acc);
+  }
+}
+
+void nsWindow::DispatchActivateEventAccessible(void) {
+  DispatchEventToRootAccessible(nsIAccessibleEvent::EVENT_WINDOW_ACTIVATE);
+}
+
+void nsWindow::DispatchDeactivateEventAccessible(void) {
+  DispatchEventToRootAccessible(nsIAccessibleEvent::EVENT_WINDOW_DEACTIVATE);
+}
+
+void nsWindow::DispatchMaximizeEventAccessible(void) {
+  DispatchEventToRootAccessible(nsIAccessibleEvent::EVENT_WINDOW_MAXIMIZE);
+}
+
+void nsWindow::DispatchMinimizeEventAccessible(void) {
+  DispatchEventToRootAccessible(nsIAccessibleEvent::EVENT_WINDOW_MINIMIZE);
+}
+
+void nsWindow::DispatchRestoreEventAccessible(void) {
+  DispatchEventToRootAccessible(nsIAccessibleEvent::EVENT_WINDOW_RESTORE);
+}
+
+#endif /* #ifdef ACCESSIBILITY */
+
+void nsWindow::SetInputContext(const InputContext& aContext,
+                               const InputContextAction& aAction) {
+  if (!mIMContext) {
+    return;
+  }
+  mIMContext->SetInputContext(this, &aContext, &aAction);
+}
+
+InputContext nsWindow::GetInputContext() {
+  InputContext context;
+  if (!mIMContext) {
+    context.mIMEState.mEnabled = IMEEnabled::Disabled;
+    context.mIMEState.mOpen = IMEState::OPEN_STATE_NOT_SUPPORTED;
+  } else {
+    context = mIMContext->GetInputContext();
+  }
+  return context;
+}
+
+TextEventDispatcherListener* nsWindow::GetNativeTextEventDispatcherListener() {
+  if (NS_WARN_IF(!mIMContext)) {
+    return nullptr;
+  }
+  return mIMContext;
+}
+
+bool nsWindow::GetEditCommands(NativeKeyBindingsType aType,
+                               const WidgetKeyboardEvent& aEvent,
+                               nsTArray<CommandInt>& aCommands) {
+  // Validate the arguments.
+  if (NS_WARN_IF(!nsIWidget::GetEditCommands(aType, aEvent, aCommands))) {
+    return false;
+  }
+
+  Maybe<WritingMode> writingMode;
+  if (aEvent.NeedsToRemapNavigationKey()) {
+    if (RefPtr<TextEventDispatcher> dispatcher = GetTextEventDispatcher()) {
+      writingMode = dispatcher->MaybeQueryWritingModeAtSelection();
+    }
+  }
+
+  NativeKeyBindings* keyBindings = NativeKeyBindings::GetInstance(aType);
+  keyBindings->GetEditCommands(aEvent, writingMode, aCommands);
+  return true;
+}
+
+already_AddRefed<DrawTarget> nsWindow::StartRemoteDrawingInRegion(
+    const LayoutDeviceIntRegion& aInvalidRegion, BufferMode* aBufferMode) {
+  return mSurfaceProvider.StartRemoteDrawingInRegion(aInvalidRegion,
+                                                     aBufferMode);
+}
+
+void nsWindow::EndRemoteDrawingInRegion(
+    DrawTarget* aDrawTarget, const LayoutDeviceIntRegion& aInvalidRegion) {
+  mSurfaceProvider.EndRemoteDrawingInRegion(aDrawTarget, aInvalidRegion);
+}
+
+bool nsWindow::GetDragInfo(WidgetMouseEvent* aMouseEvent, GdkWindow** aWindow,
+                           gint* aButton, gint* aRootX, gint* aRootY) {
+  if (aMouseEvent->mButton != MouseButton::ePrimary) {
+    // we can only begin a move drag with the left mouse button
+    return false;
+  }
+  *aButton = 1;
+
+  // get the gdk window for this widget
+  GdkWindow* gdk_window = mGdkWindow;
+  if (!gdk_window) {
+    return false;
+  }
+#ifdef DEBUG
+  // GDK_IS_WINDOW(...) expands to a statement-expression, and
+  // statement-expressions are not allowed in template-argument lists. So we
+  // have to make the MOZ_ASSERT condition indirect.
+  if (!GDK_IS_WINDOW(gdk_window)) {
+    MOZ_ASSERT(false, "must really be window");
+  }
+#endif
+
+  // find the top-level window
+  gdk_window = gdk_window_get_toplevel(gdk_window);
+  MOZ_ASSERT(gdk_window, "gdk_window_get_toplevel should not return null");
+  *aWindow = gdk_window;
+
+  if (!aMouseEvent->mWidget) {
+    return false;
+  }
+
+#ifdef MOZ_X11
+  if (GdkIsX11Display()) {
+    // Workaround for https://bugzilla.gnome.org/show_bug.cgi?id=789054
+    // To avoid crashes disable double-click on WM without _NET_WM_MOVERESIZE.
+    // See _should_perform_ewmh_drag() at gdkwindow-x11.c
+    // XXXsmaug remove this old hack. gtk should be fixed now.
+    GdkScreen* screen = gdk_window_get_screen(gdk_window);
+    GdkAtom atom = gdk_atom_intern("_NET_WM_MOVERESIZE", FALSE);
+    if (!gdk_x11_screen_supports_net_wm_hint(screen, atom)) {
+      static TimeStamp lastTimeStamp;
+      if (lastTimeStamp != aMouseEvent->mTimeStamp) {
+        lastTimeStamp = aMouseEvent->mTimeStamp;
+      } else {
+        return false;
+      }
+    }
+  }
+#endif
+
+  // FIXME: It would be nice to have the widget position at the time
+  // of the event, but it's relatively unlikely that the widget has
+  // moved since the mousedown.  (On the other hand, it's quite likely
+  // that the mouse has moved, which is why we use the mouse position
+  // from the event.)
+  LayoutDeviceIntPoint offset = aMouseEvent->mWidget->WidgetToScreenOffset();
+  *aRootX = aMouseEvent->mRefPoint.x + offset.x;
+  *aRootY = aMouseEvent->mRefPoint.y + offset.y;
+
+  return true;
+}
+
+nsIWidget::WindowRenderer* nsWindow::GetWindowRenderer() {
+  if (mIsDestroyed) {
+    // Prevent external code from triggering the re-creation of the
+    // LayerManager/Compositor during shutdown. Just return what we currently
+    // have, which is most likely null.
+    return mWindowRenderer;
+  }
+
+  return nsBaseWidget::GetWindowRenderer();
+}
+
+void nsWindow::DidGetNonBlankPaint() {
+  if (mGotNonBlankPaint) {
+    return;
+  }
+  mGotNonBlankPaint = true;
+  if (!mConfiguredClearColor) {
+    // Nothing to do, we hadn't overridden the clear color.
+    mConfiguredClearColor = true;
+    return;
+  }
+  // Reset the clear color set in the expose event to transparent.
+  GetWindowRenderer()->AsWebRender()->WrBridge()->SendSetDefaultClearColor(
+      NS_TRANSPARENT);
+}
+
+/* nsWindow::SetCompositorWidgetDelegate() sets remote GtkCompositorWidget
+ * to render into with compositor.
+ *
+ * SetCompositorWidgetDelegate(delegate) is called from
+ * nsBaseWidget::CreateCompositor(), i.e. nsWindow::GetWindowRenderer().
+ *
+ * SetCompositorWidgetDelegate(null) is called from
+ * nsBaseWidget::DestroyCompositor().
+ */
+void nsWindow::SetCompositorWidgetDelegate(CompositorWidgetDelegate* delegate) {
+  LOG("nsWindow::SetCompositorWidgetDelegate %p mIsMapped %d "
+      "mCompositorWidgetDelegate %p\n",
+      delegate, mIsMapped, mCompositorWidgetDelegate);
+
+  if (delegate) {
+    mCompositorWidgetDelegate = delegate->AsPlatformSpecificDelegate();
+    MOZ_ASSERT(mCompositorWidgetDelegate,
+               "nsWindow::SetCompositorWidgetDelegate called with a "
+               "non-PlatformCompositorWidgetDelegate");
+    if (mIsMapped) {
+      ConfigureCompositor();
+    }
+  } else {
+    mCompositorWidgetDelegate = nullptr;
+  }
+}
+
+nsresult nsWindow::SetNonClientMargins(const LayoutDeviceIntMargin& aMargins) {
+  SetDrawsInTitlebar(aMargins.top == 0);
+  return NS_OK;
+}
+
+bool nsWindow::IsAlwaysUndecoratedWindow() const {
+  if (mIsPIPWindow || mIsWaylandPanelWindow) {
+    return true;
+  }
+  if (mWindowType == WindowType::Dialog &&
+      mBorderStyle != BorderStyle::Default &&
+      mBorderStyle != BorderStyle::All &&
+      !(mBorderStyle & BorderStyle::Title) &&
+      !(mBorderStyle & BorderStyle::ResizeH)) {
+    return true;
+  }
+  return false;
+}
+
+void nsWindow::SetDrawsInTitlebar(bool aState) {
+  LOG("nsWindow::SetDrawsInTitlebar() State %d mGtkWindowDecoration %d\n",
+      aState, (int)mGtkWindowDecoration);
+
+  if (mGtkWindowDecoration == GTK_DECORATION_NONE ||
+      aState == mDrawInTitlebar) {
+    LOG("  already set, quit");
+    return;
+  }
+
+  if (IsAlwaysUndecoratedWindow()) {
+    MOZ_ASSERT(aState, "Unexpected decoration request");
+    MOZ_ASSERT(!gtk_window_get_decorated(GTK_WINDOW(mShell)));
+    return;
+  }
+
+  if (mGtkWindowDecoration == GTK_DECORATION_SYSTEM) {
+    SetWindowDecoration(aState ? BorderStyle::Border : mBorderStyle);
+  } else if (mGtkWindowDecoration == GTK_DECORATION_CLIENT) {
+    LOG("    Using CSD mode\n");
+
+    /* Window manager does not support GDK_DECOR_BORDER,
+     * emulate it by CSD.
+     *
+     * gtk_window_set_titlebar() works on unrealized widgets only,
+     * we need to handle mShell carefully here.
+     * When CSD is enabled mGdkWindow is owned by mContainer which is good
+     * as we can't delete our mGdkWindow. To make mShell unrealized while
+     * mContainer is preserved we temporary reparent mContainer to an
+     * invisible GtkWindow.
+     */
+    bool visible = !mNeedsShow && mIsShown;
+    if (visible) {
+      NativeShow(false);
+    }
+
+    // Using GTK_WINDOW_POPUP rather than
+    // GTK_WINDOW_TOPLEVEL in the hope that POPUP results in less
+    // initialization and window manager interaction.
+    GtkWidget* tmpWindow = gtk_window_new(GTK_WINDOW_POPUP);
+    gtk_widget_realize(tmpWindow);
+
+    gtk_widget_reparent(GTK_WIDGET(mContainer), tmpWindow);
+    gtk_widget_unrealize(GTK_WIDGET(mShell));
+
+    if (aState) {
+      // Add a hidden titlebar widget to trigger CSD, but disable the default
+      // titlebar.  GtkFixed is a somewhat random choice for a simple unused
+      // widget. gtk_window_set_titlebar() takes ownership of the titlebar
+      // widget.
+      gtk_window_set_titlebar(GTK_WINDOW(mShell), gtk_fixed_new());
+    } else {
+      gtk_window_set_titlebar(GTK_WINDOW(mShell), nullptr);
+    }
+
+    /* A workaround for https://bugzilla.gnome.org/show_bug.cgi?id=791081
+     * gtk_widget_realize() throws:
+     * "In pixman_region32_init_rect: Invalid rectangle passed"
+     * when mShell has default 1x1 size.
+     */
+    GtkAllocation allocation = {0, 0, 0, 0};
+    gtk_widget_get_preferred_width(GTK_WIDGET(mShell), nullptr,
+                                   &allocation.width);
+    gtk_widget_get_preferred_height(GTK_WIDGET(mShell), nullptr,
+                                    &allocation.height);
+    gtk_widget_size_allocate(GTK_WIDGET(mShell), &allocation);
+
+    gtk_widget_realize(GTK_WIDGET(mShell));
+    gtk_widget_reparent(GTK_WIDGET(mContainer), GTK_WIDGET(mShell));
+
+    // Label mShell toplevel window so property_notify_event_cb callback
+    // can find its way home.
+    g_object_set_data(G_OBJECT(gtk_widget_get_window(mShell)), "nsWindow",
+                      this);
+
+    if (AreBoundsSane()) {
+      GdkRectangle size = DevicePixelsToGdkSizeRoundUp(mBounds.Size());
+      LOG("    resize to %d x %d\n", size.width, size.height);
+      gtk_window_resize(GTK_WINDOW(mShell), size.width, size.height);
+    }
+
+    if (visible) {
+      mNeedsShow = true;
+      NativeShow(true);
+    }
+
+    gtk_widget_destroy(tmpWindow);
+  }
+
+  mDrawInTitlebar = aState;
+
+  if (mTransparencyBitmapForTitlebar) {
+    if (mDrawInTitlebar && mSizeMode == nsSizeMode_Normal && !mIsTiled) {
+      UpdateTitlebarTransparencyBitmap();
+    } else {
+      ClearTransparencyBitmap();
+    }
+  }
+}
+
+GtkWindow* nsWindow::GetCurrentTopmostWindow() const {
+  GtkWindow* parentWindow = GTK_WINDOW(GetGtkWidget());
+  GtkWindow* topmostParentWindow = nullptr;
+  while (parentWindow) {
+    topmostParentWindow = parentWindow;
+    parentWindow = gtk_window_get_transient_for(parentWindow);
+  }
+  return topmostParentWindow;
+}
+
+gint nsWindow::GdkCeiledScaleFactor() {
+  // We depend on notify::scale-factor callback which is reliable for toplevel
+  // windows only, so don't use scale cache for popup windows.
+  if (mWindowType == WindowType::TopLevel && !mWindowScaleFactorChanged) {
+    return mWindowScaleFactor;
+  }
+
+  GdkWindow* scaledGdkWindow = nullptr;
+  if (GdkIsWaylandDisplay()) {
+    // For popup windows/dialogs with parent window we need to get scale factor
+    // of the topmost window. Otherwise the scale factor of the popup is
+    // not updated during it's hidden.
+    if (mWindowType == WindowType::Popup || mWindowType == WindowType::Dialog) {
+      // Get toplevel window for scale factor:
+      GtkWindow* topmostParentWindow = GetCurrentTopmostWindow();
+      if (topmostParentWindow) {
+        scaledGdkWindow =
+            gtk_widget_get_window(GTK_WIDGET(topmostParentWindow));
+      } else {
+        NS_WARNING("Popup/Dialog has no parent.");
+      }
+    }
+  }
+  // Fallback for windows which parent has been unrealized.
+  if (!scaledGdkWindow) {
+    scaledGdkWindow = mGdkWindow;
+  }
+  if (scaledGdkWindow) {
+    mWindowScaleFactor = gdk_window_get_scale_factor(scaledGdkWindow);
+    mWindowScaleFactorChanged = false;
+  } else {
+    mWindowScaleFactor = ScreenHelperGTK::GetGTKMonitorScaleFactor();
+  }
+  return mWindowScaleFactor;
+}
+
+bool nsWindow::UseFractionalScale() const {
+#ifdef MOZ_WAYLAND
+  return GdkIsWaylandDisplay() &&
+         StaticPrefs::widget_wayland_fractional_buffer_scale_AtStartup() > 0 &&
+         WaylandDisplayGet()->GetViewporter();
+#else
+  return false;
+#endif
+}
+
+double nsWindow::FractionalScaleFactor() {
+#ifdef MOZ_WAYLAND
+  if (UseFractionalScale()) {
+    double scale =
+        StaticPrefs::widget_wayland_fractional_buffer_scale_AtStartup();
+    scale = std::max(scale, 0.5);
+    scale = std::min(scale, 8.0);
+    return scale;
+  }
+#endif
+  return GdkCeiledScaleFactor();
+}
+
+gint nsWindow::DevicePixelsToGdkCoordRoundUp(int aPixels) {
+  double scale = FractionalScaleFactor();
+  return ceil(aPixels / scale);
+}
+
+gint nsWindow::DevicePixelsToGdkCoordRoundDown(int aPixels) {
+  double scale = FractionalScaleFactor();
+  return floor(aPixels / scale);
+}
+
+GdkPoint nsWindow::DevicePixelsToGdkPointRoundDown(
+    const LayoutDeviceIntPoint& aPoint) {
+  double scale = FractionalScaleFactor();
+  return {int(aPoint.x / scale), int(aPoint.y / scale)};
+}
+
+GdkRectangle nsWindow::DevicePixelsToGdkRectRoundOut(
+    const LayoutDeviceIntRect& aRect) {
+  double scale = FractionalScaleFactor();
+  int x = floor(aRect.x / scale);
+  int y = floor(aRect.y / scale);
+  int right = ceil((aRect.x + aRect.width) / scale);
+  int bottom = ceil((aRect.y + aRect.height) / scale);
+  return {x, y, right - x, bottom - y};
+}
+
+GdkRectangle nsWindow::DevicePixelsToGdkSizeRoundUp(
+    const LayoutDeviceIntSize& aSize) {
+  double scale = FractionalScaleFactor();
+  gint width = ceil(aSize.width / scale);
+  gint height = ceil(aSize.height / scale);
+  return {0, 0, width, height};
+}
+
+int nsWindow::GdkCoordToDevicePixels(gint aCoord) {
+  return (int)(aCoord * FractionalScaleFactor());
+}
+
+LayoutDeviceIntPoint nsWindow::GdkEventCoordsToDevicePixels(gdouble aX,
+                                                            gdouble aY) {
+  double scale = FractionalScaleFactor();
+  return LayoutDeviceIntPoint::Floor((float)(aX * scale), (float)(aY * scale));
+}
+
+LayoutDeviceIntPoint nsWindow::GdkPointToDevicePixels(const GdkPoint& aPoint) {
+  double scale = FractionalScaleFactor();
+  return LayoutDeviceIntPoint::Floor((float)(aPoint.x * scale),
+                                     (float)(aPoint.y * scale));
+}
+
+LayoutDeviceIntRect nsWindow::GdkRectToDevicePixels(const GdkRectangle& aRect) {
+  double scale = FractionalScaleFactor();
+  return LayoutDeviceIntRect::RoundIn(
+      (float)(aRect.x * scale), (float)(aRect.y * scale),
+      (float)(aRect.width * scale), (float)(aRect.height * scale));
+}
+
+nsresult nsWindow::SynthesizeNativeMouseEvent(
+    LayoutDeviceIntPoint aPoint, NativeMouseMessage aNativeMessage,
+    MouseButton aButton, nsIWidget::Modifiers aModifierFlags,
+    nsIObserver* aObserver) {
+  LOG("SynthesizeNativeMouseEvent(%d, %d, %d, %d, %d)", aPoint.x.value,
+      aPoint.y.value, int(aNativeMessage), int(aButton), int(aModifierFlags));
+
+  AutoObserverNotifier notifier(aObserver, "mouseevent");
+
+  if (!mGdkWindow) {
+    return NS_OK;
+  }
+
+  // When a button-press/release event is requested, create it here and put it
+  // in the event queue. This will not emit a motion event - this needs to be
+  // done explicitly *before* requesting a button-press/release. You will also
+  // need to wait for the motion event to be dispatched before requesting a
+  // button-press/release event to maintain the desired event order.
+  switch (aNativeMessage) {
+    case NativeMouseMessage::ButtonDown:
+    case NativeMouseMessage::ButtonUp: {
+      GdkEvent event;
+      memset(&event, 0, sizeof(GdkEvent));
+      event.type = aNativeMessage == NativeMouseMessage::ButtonDown
+                       ? GDK_BUTTON_PRESS
+                       : GDK_BUTTON_RELEASE;
+      switch (aButton) {
+        case MouseButton::ePrimary:
+        case MouseButton::eMiddle:
+        case MouseButton::eSecondary:
+        case MouseButton::eX1:
+        case MouseButton::eX2:
+          event.button.button = aButton + 1;
+          break;
+        default:
+          return NS_ERROR_INVALID_ARG;
+      }
+      event.button.state =
+          KeymapWrapper::ConvertWidgetModifierToGdkState(aModifierFlags);
+      event.button.window = mGdkWindow;
+      event.button.time = GDK_CURRENT_TIME;
+
+      // Get device for event source
+      event.button.device = GdkGetPointer();
+
+      event.button.x_root = DevicePixelsToGdkCoordRoundDown(aPoint.x);
+      event.button.y_root = DevicePixelsToGdkCoordRoundDown(aPoint.y);
+
+      LayoutDeviceIntPoint pointInWindow = aPoint - WidgetToScreenOffset();
+      event.button.x = DevicePixelsToGdkCoordRoundDown(pointInWindow.x);
+      event.button.y = DevicePixelsToGdkCoordRoundDown(pointInWindow.y);
+
+      gdk_event_put(&event);
+      return NS_OK;
+    }
+    case NativeMouseMessage::Move: {
+      // We don't support specific events other than button-press/release. In
+      // all other cases we'll synthesize a motion event that will be emitted by
+      // gdk_display_warp_pointer().
+      // XXX How to activate native modifier for the other events?
+#ifdef MOZ_WAYLAND
+      // Impossible to warp the pointer on Wayland.
+      // For pointer lock, pointer-constraints and relative-pointer are used.
+      if (GdkIsWaylandDisplay()) {
+        return NS_OK;
+      }
+#endif
+      GdkScreen* screen = gdk_window_get_screen(mGdkWindow);
+      GdkPoint point = DevicePixelsToGdkPointRoundDown(aPoint);
+      gdk_device_warp(GdkGetPointer(), screen, point.x, point.y);
+      return NS_OK;
+    }
+    case NativeMouseMessage::EnterWindow:
+    case NativeMouseMessage::LeaveWindow:
+      MOZ_ASSERT_UNREACHABLE("Non supported mouse event on Linux");
+      return NS_ERROR_INVALID_ARG;
+  }
+  return NS_ERROR_UNEXPECTED;
+}
+
+void nsWindow::CreateAndPutGdkScrollEvent(mozilla::LayoutDeviceIntPoint aPoint,
+                                          double aDeltaX, double aDeltaY) {
+  GdkEvent event;
+  memset(&event, 0, sizeof(GdkEvent));
+  event.type = GDK_SCROLL;
+  event.scroll.window = mGdkWindow;
+  event.scroll.time = GDK_CURRENT_TIME;
+  // Get device for event source
+  GdkDisplay* display = gdk_window_get_display(mGdkWindow);
+  GdkDeviceManager* device_manager = gdk_display_get_device_manager(display);
+  // See note in nsWindow::SynthesizeNativeTouchpadPan about the device we use
+  // here.
+  event.scroll.device = gdk_device_manager_get_client_pointer(device_manager);
+  event.scroll.x_root = DevicePixelsToGdkCoordRoundDown(aPoint.x);
+  event.scroll.y_root = DevicePixelsToGdkCoordRoundDown(aPoint.y);
+
+  LayoutDeviceIntPoint pointInWindow = aPoint - WidgetToScreenOffset();
+  event.scroll.x = DevicePixelsToGdkCoordRoundDown(pointInWindow.x);
+  event.scroll.y = DevicePixelsToGdkCoordRoundDown(pointInWindow.y);
+
+  // The delta values are backwards on Linux compared to Windows and Cocoa,
+  // hence the negation.
+  event.scroll.direction = GDK_SCROLL_SMOOTH;
+  event.scroll.delta_x = -aDeltaX;
+  event.scroll.delta_y = -aDeltaY;
+
+  gdk_event_put(&event);
+}
+
+nsresult nsWindow::SynthesizeNativeMouseScrollEvent(
+    mozilla::LayoutDeviceIntPoint aPoint, uint32_t aNativeMessage,
+    double aDeltaX, double aDeltaY, double aDeltaZ, uint32_t aModifierFlags,
+    uint32_t aAdditionalFlags, nsIObserver* aObserver) {
+  AutoObserverNotifier notifier(aObserver, "mousescrollevent");
+
+  if (!mGdkWindow) {
+    return NS_OK;
+  }
+
+  CreateAndPutGdkScrollEvent(aPoint, aDeltaX, aDeltaY);
+
+  return NS_OK;
+}
+
+nsresult nsWindow::SynthesizeNativeTouchPoint(uint32_t aPointerId,
+                                              TouchPointerState aPointerState,
+                                              LayoutDeviceIntPoint aPoint,
+                                              double aPointerPressure,
+                                              uint32_t aPointerOrientation,
+                                              nsIObserver* aObserver) {
+  AutoObserverNotifier notifier(aObserver, "touchpoint");
+
+  if (!mGdkWindow) {
+    return NS_OK;
+  }
+
+  GdkEvent event;
+  memset(&event, 0, sizeof(GdkEvent));
+
+  static std::map<uint32_t, GdkEventSequence*> sKnownPointers;
+
+  auto result = sKnownPointers.find(aPointerId);
+  switch (aPointerState) {
+    case TOUCH_CONTACT:
+      if (result == sKnownPointers.end()) {
+        // GdkEventSequence isn't a thing we can instantiate, and never gets
+        // dereferenced in the gtk code. It's an opaque pointer, the only
+        // requirement is that it be distinct from other instances of
+        // GdkEventSequence*.
+        event.touch.sequence = (GdkEventSequence*)((uintptr_t)aPointerId);
+        sKnownPointers[aPointerId] = event.touch.sequence;
+        event.type = GDK_TOUCH_BEGIN;
+      } else {
+        event.touch.sequence = result->second;
+        event.type = GDK_TOUCH_UPDATE;
+      }
+      break;
+    case TOUCH_REMOVE:
+      event.type = GDK_TOUCH_END;
+      if (result == sKnownPointers.end()) {
+        NS_WARNING("Tried to synthesize touch-end for unknown pointer!");
+        return NS_ERROR_UNEXPECTED;
+      }
+      event.touch.sequence = result->second;
+      sKnownPointers.erase(result);
+      break;
+    case TOUCH_CANCEL:
+      event.type = GDK_TOUCH_CANCEL;
+      if (result == sKnownPointers.end()) {
+        NS_WARNING("Tried to synthesize touch-cancel for unknown pointer!");
+        return NS_ERROR_UNEXPECTED;
+      }
+      event.touch.sequence = result->second;
+      sKnownPointers.erase(result);
+      break;
+    case TOUCH_HOVER:
+    default:
+      return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  event.touch.window = mGdkWindow;
+  event.touch.time = GDK_CURRENT_TIME;
+
+  GdkDisplay* display = gdk_window_get_display(mGdkWindow);
+  GdkDeviceManager* device_manager = gdk_display_get_device_manager(display);
+  event.touch.device = gdk_device_manager_get_client_pointer(device_manager);
+
+  event.touch.x_root = DevicePixelsToGdkCoordRoundDown(aPoint.x);
+  event.touch.y_root = DevicePixelsToGdkCoordRoundDown(aPoint.y);
+
+  LayoutDeviceIntPoint pointInWindow = aPoint - WidgetToScreenOffset();
+  event.touch.x = DevicePixelsToGdkCoordRoundDown(pointInWindow.x);
+  event.touch.y = DevicePixelsToGdkCoordRoundDown(pointInWindow.y);
+
+  gdk_event_put(&event);
+
+  return NS_OK;
+}
+
+nsresult nsWindow::SynthesizeNativeTouchPadPinch(
+    TouchpadGesturePhase aEventPhase, float aScale, LayoutDeviceIntPoint aPoint,
+    int32_t aModifierFlags) {
+  if (!mGdkWindow) {
+    return NS_OK;
+  }
+  GdkEvent event;
+  memset(&event, 0, sizeof(GdkEvent));
+
+  GdkEventTouchpadPinch* touchpad_event =
+      reinterpret_cast<GdkEventTouchpadPinch*>(&event);
+  touchpad_event->type = GDK_TOUCHPAD_PINCH;
+
+  const ScreenIntPoint widgetToScreenOffset = ViewAs<ScreenPixel>(
+      WidgetToScreenOffset(),
+      PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent);
+
+  ScreenPoint pointInWindow =
+      ViewAs<ScreenPixel>(
+          aPoint,
+          PixelCastJustification::LayoutDeviceIsScreenForUntransformedEvent) -
+      widgetToScreenOffset;
+
+  gdouble dx = 0, dy = 0;
+
+  switch (aEventPhase) {
+    case PHASE_BEGIN:
+      touchpad_event->phase = GDK_TOUCHPAD_GESTURE_PHASE_BEGIN;
+      mCurrentSynthesizedTouchpadPinch = {pointInWindow, pointInWindow};
+      break;
+    case PHASE_UPDATE:
+      dx = pointInWindow.x - mCurrentSynthesizedTouchpadPinch.mCurrentFocus.x;
+      dy = pointInWindow.y - mCurrentSynthesizedTouchpadPinch.mCurrentFocus.y;
+      mCurrentSynthesizedTouchpadPinch.mCurrentFocus = pointInWindow;
+      touchpad_event->phase = GDK_TOUCHPAD_GESTURE_PHASE_UPDATE;
+      break;
+    case PHASE_END:
+      touchpad_event->phase = GDK_TOUCHPAD_GESTURE_PHASE_END;
+      break;
+
+    default:
+      return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  touchpad_event->window = mGdkWindow;
+  // We only set the fields of GdkEventTouchpadPinch which are
+  // actually used in OnTouchpadPinchEvent().
+  // GdkEventTouchpadPinch has additional fields.
+  // If OnTouchpadPinchEvent() is changed to use other fields, this function
+  // will need to change to set them as well.
+  touchpad_event->time = GDK_CURRENT_TIME;
+  touchpad_event->scale = aScale;
+  touchpad_event->x_root = DevicePixelsToGdkCoordRoundDown(
+      mCurrentSynthesizedTouchpadPinch.mBeginFocus.x +
+      ScreenCoord(widgetToScreenOffset.x));
+  touchpad_event->y_root = DevicePixelsToGdkCoordRoundDown(
+      mCurrentSynthesizedTouchpadPinch.mBeginFocus.y +
+      ScreenCoord(widgetToScreenOffset.y));
+
+  touchpad_event->x = DevicePixelsToGdkCoordRoundDown(
+      mCurrentSynthesizedTouchpadPinch.mBeginFocus.x);
+  touchpad_event->y = DevicePixelsToGdkCoordRoundDown(
+      mCurrentSynthesizedTouchpadPinch.mBeginFocus.y);
+
+  touchpad_event->dx = dx;
+  touchpad_event->dy = dy;
+
+  touchpad_event->state = aModifierFlags;
+
+  gdk_event_put(&event);
+
+  return NS_OK;
+}
+
+nsresult nsWindow::SynthesizeNativeTouchpadPan(TouchpadGesturePhase aEventPhase,
+                                               LayoutDeviceIntPoint aPoint,
+                                               double aDeltaX, double aDeltaY,
+                                               int32_t aModifierFlags,
+                                               nsIObserver* aObserver) {
+  AutoObserverNotifier notifier(aObserver, "touchpadpanevent");
+
+  if (!mGdkWindow) {
+    return NS_OK;
+  }
+
+  // This should/could maybe send GdkEventTouchpadSwipe events, however we don't
+  // currently consume those (either real user input or testing events). So we
+  // send gdk scroll events to be more like what we do for real user input. If
+  // we start consuming GdkEventTouchpadSwipe and get those hooked up to swipe
+  // to nav, then maybe we should test those too.
+
+  mCurrentSynthesizedTouchpadPan.mTouchpadGesturePhase = Some(aEventPhase);
+  MOZ_ASSERT(mCurrentSynthesizedTouchpadPan.mSavedObserver == 0);
+  mCurrentSynthesizedTouchpadPan.mSavedObserver = notifier.SaveObserver();
+
+  // Note that CreateAndPutGdkScrollEvent sets the device source for the created
+  // event as the "client pointer" (a kind of default device) which will
+  // probably be of type mouse. We would ideally want to set the device of the
+  // created event to be a touchpad, but the system might not have a touchpad.
+  // To get around this we use
+  // mCurrentSynthesizedTouchpadPan.mTouchpadGesturePhase being something to
+  // indicate that we should treat the source of the event as touchpad in
+  // OnScrollEvent.
+  CreateAndPutGdkScrollEvent(aPoint, aDeltaX, aDeltaY);
+
+  return NS_OK;
+}
+
+nsWindow::GtkWindowDecoration nsWindow::GetSystemGtkWindowDecoration() {
+  static GtkWindowDecoration sGtkWindowDecoration = [] {
+    // Allow MOZ_GTK_TITLEBAR_DECORATION to override our heuristics
+    if (const char* decorationOverride =
+            getenv("MOZ_GTK_TITLEBAR_DECORATION")) {
+      if (strcmp(decorationOverride, "none") == 0) {
+        return GTK_DECORATION_NONE;
+      }
+      if (strcmp(decorationOverride, "client") == 0) {
+        return GTK_DECORATION_CLIENT;
+      }
+      if (strcmp(decorationOverride, "system") == 0) {
+        return GTK_DECORATION_SYSTEM;
+      }
+    }
+
+    // nsWindow::GetSystemGtkWindowDecoration can be called from various
+    // threads so we can't use gfxPlatformGtk here.
+    if (GdkIsWaylandDisplay()) {
+      return GTK_DECORATION_CLIENT;
+    }
+
+    // GTK_CSD forces CSD mode - use also CSD because window manager
+    // decorations does not work with CSD.
+    // We check GTK_CSD as well as gtk_window_should_use_csd() does.
+    if (const char* csdOverride = getenv("GTK_CSD")) {
+      return *csdOverride == '0' ? GTK_DECORATION_NONE : GTK_DECORATION_CLIENT;
+    }
+
+    // TODO: Consider switching this to GetDesktopEnvironmentIdentifier().
+    const char* currentDesktop = getenv("XDG_CURRENT_DESKTOP");
+    if (!currentDesktop) {
+      return GTK_DECORATION_NONE;
+    }
+    if (strstr(currentDesktop, "i3")) {
+      return GTK_DECORATION_NONE;
+    }
+
+    // Tested desktops: pop:GNOME, KDE, Enlightenment, LXDE, openbox, MATE,
+    // X-Cinnamon, Pantheon, Deepin, GNOME, LXQt, Unity.
+    return GTK_DECORATION_CLIENT;
+  }();
+  return sGtkWindowDecoration;
+}
+
+bool nsWindow::TitlebarUseShapeMask() {
+  static int useShapeMask = []() {
+    // Don't use titlebar shape mask on Wayland
+    if (!GdkIsX11Display()) {
+      return false;
+    }
+
+    // We can't use shape masks on Mutter/X.org as we can't resize Firefox
+    // window there (Bug 1530252).
+    if (IsGnomeDesktopEnvironment()) {
+      return false;
+    }
+
+    return Preferences::GetBool("widget.titlebar-x11-use-shape-mask", false);
+  }();
+  return useShapeMask;
+}
+
+int32_t nsWindow::RoundsWidgetCoordinatesTo() { return GdkCeiledScaleFactor(); }
+
+void nsWindow::GetCompositorWidgetInitData(
+    mozilla::widget::CompositorWidgetInitData* aInitData) {
+  nsCString displayName;
+
+  LOG("nsWindow::GetCompositorWidgetInitData");
+  EnsureGdkWindow();
+
+  *aInitData = mozilla::widget::GtkCompositorWidgetInitData(
+      GetX11Window(), displayName, GetShapedState(), GdkIsX11Display(),
+      GetClientSize());
+
+#ifdef MOZ_X11
+  if (GdkIsX11Display()) {
+    // Make sure the window XID is propagated to X server, we can fail otherwise
+    // in GPU process (Bug 1401634).
+    Display* display = DefaultXDisplay();
+    XFlush(display);
+    displayName = nsCString(XDisplayString(display));
+  }
+#endif
+}
+
+#ifdef MOZ_X11
+/* XApp progress support currently works by setting a property
+ * on a window with this Atom name.  A supporting window manager
+ * will notice this and pass it along to whatever handling has
+ * been implemented on that end (e.g. passing it on to a taskbar
+ * widget.)  There is no issue if WM support is lacking, this is
+ * simply ignored in that case.
+ *
+ * See https://github.com/linuxmint/xapps/blob/master/libxapp/xapp-gtk-window.c
+ * for further details.
+ */
+
+#  define PROGRESS_HINT "_NET_WM_XAPP_PROGRESS"
+
+static void set_window_hint_cardinal(Window xid, const gchar* atom_name,
+                                     gulong cardinal) {
+  GdkDisplay* display;
+
+  display = gdk_display_get_default();
+
+  if (cardinal > 0) {
+    XChangeProperty(GDK_DISPLAY_XDISPLAY(display), xid,
+                    gdk_x11_get_xatom_by_name_for_display(display, atom_name),
+                    XA_CARDINAL, 32, PropModeReplace, (guchar*)&cardinal, 1);
+  } else {
+    XDeleteProperty(GDK_DISPLAY_XDISPLAY(display), xid,
+                    gdk_x11_get_xatom_by_name_for_display(display, atom_name));
+  }
+}
+#endif  // MOZ_X11
+
+void nsWindow::SetProgress(unsigned long progressPercent) {
+#ifdef MOZ_X11
+
+  if (!GdkIsX11Display()) {
+    return;
+  }
+
+  if (!mShell) {
+    return;
+  }
+
+  progressPercent = MIN(progressPercent, 100);
+
+  set_window_hint_cardinal(GDK_WINDOW_XID(gtk_widget_get_window(mShell)),
+                           PROGRESS_HINT, progressPercent);
+#endif  // MOZ_X11
+}
+
+#ifdef MOZ_X11
+void nsWindow::SetCompositorHint(WindowComposeRequest aState) {
+  if (!GdkIsX11Display()) {
+    return;
+  }
+
+  gulong value = aState;
+  GdkAtom cardinal_atom = gdk_x11_xatom_to_atom(XA_CARDINAL);
+  gdk_property_change(gtk_widget_get_window(mShell),
+                      gdk_atom_intern("_NET_WM_BYPASS_COMPOSITOR", FALSE),
+                      cardinal_atom,
+                      32,  // format
+                      GDK_PROP_MODE_REPLACE, (guchar*)&value, 1);
+}
+#endif
+
+nsresult nsWindow::SetSystemFont(const nsCString& aFontName) {
+  GtkSettings* settings = gtk_settings_get_default();
+  g_object_set(settings, "gtk-font-name", aFontName.get(), nullptr);
+  return NS_OK;
+}
+
+nsresult nsWindow::GetSystemFont(nsCString& aFontName) {
+  GtkSettings* settings = gtk_settings_get_default();
+  gchar* fontName = nullptr;
+  g_object_get(settings, "gtk-font-name", &fontName, nullptr);
+  if (fontName) {
+    aFontName.Assign(fontName);
+    g_free(fontName);
+  }
+  return NS_OK;
+}
+
+already_AddRefed<nsIWidget> nsIWidget::CreateTopLevelWindow() {
+  nsCOMPtr<nsIWidget> window = new nsWindow();
+  return window.forget();
+}
+
+already_AddRefed<nsIWidget> nsIWidget::CreateChildWindow() {
+  nsCOMPtr<nsIWidget> window = new nsWindow();
+  return window.forget();
+}
+
+#ifdef MOZ_WAYLAND
+static void relative_pointer_handle_relative_motion(
+    void* data, struct zwp_relative_pointer_v1* pointer, uint32_t time_hi,
+    uint32_t time_lo, wl_fixed_t dx_w, wl_fixed_t dy_w, wl_fixed_t dx_unaccel_w,
+    wl_fixed_t dy_unaccel_w) {
+  RefPtr<nsWindow> window(reinterpret_cast<nsWindow*>(data));
+
+  WidgetMouseEvent event(true, eMouseMove, window, WidgetMouseEvent::eReal);
+
+  event.mRefPoint = window->GetNativePointerLockCenter();
+  event.mRefPoint.x += wl_fixed_to_int(dx_w);
+  event.mRefPoint.y += wl_fixed_to_int(dy_w);
+
+  event.AssignEventTime(window->GetWidgetEventTime(time_lo));
+  window->DispatchInputEvent(&event);
+}
+
+static const struct zwp_relative_pointer_v1_listener relative_pointer_listener =
+    {
+        relative_pointer_handle_relative_motion,
+};
+
+void nsWindow::SetNativePointerLockCenter(
+    const LayoutDeviceIntPoint& aLockCenter) {
+  mNativePointerLockCenter = aLockCenter;
+}
+
+void nsWindow::LockNativePointer() {
+  if (!GdkIsWaylandDisplay()) {
+    return;
+  }
+
+  auto* waylandDisplay = WaylandDisplayGet();
+
+  auto* pointerConstraints = waylandDisplay->GetPointerConstraints();
+  if (!pointerConstraints) {
+    return;
+  }
+
+  auto* relativePointerMgr = waylandDisplay->GetRelativePointerManager();
+  if (!relativePointerMgr) {
+    return;
+  }
+
+  GdkDisplay* display = gdk_display_get_default();
+
+  GdkDeviceManager* manager = gdk_display_get_device_manager(display);
+  MOZ_ASSERT(manager);
+
+  GdkDevice* device = gdk_device_manager_get_client_pointer(manager);
+  if (!device) {
+    NS_WARNING("Could not find Wayland pointer to lock");
+    return;
+  }
+  wl_pointer* pointer = gdk_wayland_device_get_wl_pointer(device);
+  MOZ_ASSERT(pointer);
+
+  wl_surface* surface =
+      gdk_wayland_window_get_wl_surface(gtk_widget_get_window(GetGtkWidget()));
+  if (!surface) {
+    /* Can be null when the window is hidden.
+     * Though it's unlikely that a lock request comes in that case, be
+     * defensive. */
+    return;
+  }
+
+  if (mLockedPointer || mRelativePointer) {
+    UnlockNativePointer();
+  }
+
+  mLockedPointer = zwp_pointer_constraints_v1_lock_pointer(
+      pointerConstraints, surface, pointer, nullptr,
+      ZWP_POINTER_CONSTRAINTS_V1_LIFETIME_PERSISTENT);
+  if (!mLockedPointer) {
+    NS_WARNING("Could not lock Wayland pointer");
+    return;
+  }
+
+  mRelativePointer = zwp_relative_pointer_manager_v1_get_relative_pointer(
+      relativePointerMgr, pointer);
+  if (!mRelativePointer) {
+    NS_WARNING("Could not create relative Wayland pointer");
+    zwp_locked_pointer_v1_destroy(mLockedPointer);
+    mLockedPointer = nullptr;
+    return;
+  }
+
+  zwp_relative_pointer_v1_add_listener(mRelativePointer,
+                                       &relative_pointer_listener, this);
+}
+
+void nsWindow::UnlockNativePointer() {
+  if (!GdkIsWaylandDisplay()) {
+    return;
+  }
+  if (mRelativePointer) {
+    zwp_relative_pointer_v1_destroy(mRelativePointer);
+    mRelativePointer = nullptr;
+  }
+  if (mLockedPointer) {
+    zwp_locked_pointer_v1_destroy(mLockedPointer);
+    mLockedPointer = nullptr;
+  }
+}
+#endif
+
+bool nsWindow::GetTopLevelWindowActiveState(nsIFrame* aFrame) {
+  // Used by window frame and button box rendering. We can end up in here in
+  // the content process when rendering one of these moz styles freely in a
+  // page. Fail in this case, there is no applicable window focus state.
+  if (!XRE_IsParentProcess()) {
+    return false;
+  }
+  // All headless windows are considered active so they are painted.
+  if (gfxPlatform::IsHeadless()) {
+    return true;
+  }
+  // Get the widget. nsIFrame's GetNearestWidget walks up the view chain
+  // until it finds a real window.
+  nsWindow* window = static_cast<nsWindow*>(aFrame->GetNearestWidget());
+  if (!window) {
+    return false;
+  }
+  return !window->mTitlebarBackdropState;
+}
+
+static nsIFrame* FindTitlebarFrame(nsIFrame* aFrame) {
+  for (nsIFrame* childFrame : aFrame->PrincipalChildList()) {
+    StyleAppearance appearance =
+        childFrame->StyleDisplay()->EffectiveAppearance();
+    if (appearance == StyleAppearance::MozWindowTitlebar ||
+        appearance == StyleAppearance::MozWindowTitlebarMaximized) {
+      return childFrame;
+    }
+
+    if (nsIFrame* foundFrame = FindTitlebarFrame(childFrame)) {
+      return foundFrame;
+    }
+  }
+  return nullptr;
+}
+
+nsIFrame* nsWindow::GetFrame() const {
+  nsView* view = nsView::GetViewFor(this);
+  if (!view) {
+    return nullptr;
+  }
+  return view->GetFrame();
+}
+
+void nsWindow::UpdateMozWindowActive() {
+  // Update activation state for the :-moz-window-inactive pseudoclass.
+  // Normally, this follows focus; we override it here to follow
+  // GDK_WINDOW_STATE_FOCUSED.
+  if (mozilla::dom::Document* document = GetDocument()) {
+    if (nsPIDOMWindowOuter* window = document->GetWindow()) {
+      if (RefPtr<mozilla::dom::BrowsingContext> bc =
+              window->GetBrowsingContext()) {
+        bc->SetIsActiveBrowserWindow(!mTitlebarBackdropState);
+      }
+    }
+  }
+}
+
+void nsWindow::ForceTitlebarRedraw() {
+  MOZ_ASSERT(mDrawInTitlebar, "We should not redraw invisible titlebar.");
+
+  if (!mWidgetListener || !mWidgetListener->GetPresShell()) {
+    return;
+  }
+
+  nsIFrame* frame = GetFrame();
+  if (!frame) {
+    return;
+  }
+
+  frame = FindTitlebarFrame(frame);
+  if (frame) {
+    nsIContent* content = frame->GetContent();
+    if (content) {
+      nsLayoutUtils::PostRestyleEvent(content->AsElement(), RestyleHint{0},
+                                      nsChangeHint_RepaintFrame);
+    }
+  }
+}
+
+void nsWindow::LockAspectRatio(bool aShouldLock) {
+  if (!gUseAspectRatio) {
+    return;
+  }
+
+  if (aShouldLock) {
+    int decWidth = 0, decHeight = 0;
+    AddCSDDecorationSize(&decWidth, &decHeight);
+
+    float width =
+        DevicePixelsToGdkCoordRoundDown(mLastSizeRequest.width) + decWidth;
+    float height =
+        DevicePixelsToGdkCoordRoundDown(mLastSizeRequest.height) + decHeight;
+
+    mAspectRatio = width / height;
+    LOG("nsWindow::LockAspectRatio() width %f height %f aspect %f", width,
+        height, mAspectRatio);
+  } else {
+    mAspectRatio = 0.0;
+    LOG("nsWindow::LockAspectRatio() removed aspect ratio");
+  }
+
+  ApplySizeConstraints();
+}
+
+nsWindow* nsWindow::GetFocusedWindow() { return gFocusWindow; }
+
+#ifdef MOZ_WAYLAND
+void nsWindow::SetEGLNativeWindowSize(
+    const LayoutDeviceIntSize& aEGLWindowSize) {
+  if (!mContainer || !GdkIsWaylandDisplay()) {
+    return;
+  }
+  if (moz_container_wayland_egl_window_needs_size_update(
+          mContainer, aEGLWindowSize.ToUnknownSize(), GdkCeiledScaleFactor())) {
+    LOG("nsWindow::SetEGLNativeWindowSize() %d x %d", aEGLWindowSize.width,
+        aEGLWindowSize.height);
+    moz_container_wayland_egl_window_set_size(mContainer,
+                                              aEGLWindowSize.ToUnknownSize());
+    moz_container_wayland_set_scale_factor(mContainer);
+  }
+}
+#endif
+
+nsWindow* nsWindow::GetWindow(GdkWindow* window) {
+  return get_window_for_gdk_window(window);
+}
+
+void nsWindow::ClearRenderingQueue() {
+  LOG("nsWindow::ClearRenderingQueue()");
+
+  if (mWidgetListener) {
+    mWidgetListener->RequestWindowClose(this);
+  }
+  DestroyLayerManager();
+}
+
+// Apply workaround for Mutter compositor bug (mzbz#1777269).
+//
+// When we open a popup window (tooltip for instance) attached to
+// GDK_WINDOW_TYPE_HINT_UTILITY parent popup, Mutter compositor sends bogus
+// leave/enter events to the GDK_WINDOW_TYPE_HINT_UTILITY popup.
+// That leads to immediate tooltip close. As a workaround ignore these
+// bogus events.
+//
+// We need to check two affected window types:
+//
+// - toplevel window with at least two child popups where the first one is
+//   GDK_WINDOW_TYPE_HINT_UTILITY.
+// - GDK_WINDOW_TYPE_HINT_UTILITY popup with a child popup
+//
+// We need to mask two bogus leave/enter sequences:
+//  1) Leave (popup) -> Enter (toplevel)
+//  2) Leave (toplevel) -> Enter (popup)
+//
+// TODO: persistent (non-tracked) popups with tooltip/child popups?
+//
+bool nsWindow::ApplyEnterLeaveMutterWorkaround() {
+  // Leave (toplevel) case
+  if (mWindowType == WindowType::TopLevel && mWaylandPopupNext &&
+      mWaylandPopupNext->mWaylandPopupNext &&
+      gtk_window_get_type_hint(GTK_WINDOW(mWaylandPopupNext->GetGtkWidget())) ==
+          GDK_WINDOW_TYPE_HINT_UTILITY) {
+    LOG("nsWindow::ApplyEnterLeaveMutterWorkaround(): leave toplevel");
+    return true;
+  }
+  // Leave (popup) case
+  if (IsWaylandPopup() && mWaylandPopupNext &&
+      gtk_window_get_type_hint(GTK_WINDOW(mShell)) ==
+          GDK_WINDOW_TYPE_HINT_UTILITY) {
+    LOG("nsWindow::ApplyEnterLeaveMutterWorkaround(): leave popup");
+    return true;
+  }
+  return false;
+}
+
+void nsWindow::NotifyOcclusionState(mozilla::widget::OcclusionState aState) {
+  if (mWindowType != WindowType::TopLevel) {
+    return;
+  }
+
+  bool isFullyOccluded = aState == mozilla::widget::OcclusionState::OCCLUDED;
+  if (mIsFullyOccluded == isFullyOccluded) {
+    return;
+  }
+  mIsFullyOccluded = isFullyOccluded;
+
+  LOG("nsWindow::NotifyOcclusionState() mIsFullyOccluded %d", mIsFullyOccluded);
+  if (mWidgetListener) {
+    mWidgetListener->OcclusionStateChanged(mIsFullyOccluded);
+  }
+}
+
+void nsWindow::SetDragSource(GdkDragContext* aSourceDragContext) {
+  mSourceDragContext = aSourceDragContext;
+  if (IsPopup() &&
+      (widget::GdkIsWaylandDisplay() || widget::IsXWaylandProtocol())) {
+    if (auto* menuPopupFrame = GetMenuPopupFrame(GetFrame())) {
+      menuPopupFrame->SetIsDragSource(!!aSourceDragContext);
+    }
+  }
+}