Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 999 insertions, 0 deletions

diff --git a/view/nsViewManager.cpp b/view/nsViewManager.cpp
new file mode 100644
index 0000000000..842237f4db
--- /dev/null
+++ b/view/nsViewManager.cpp
@@ -0,0 +1,999 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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 "nsViewManager.h"
+
+#include "mozilla/MouseEvents.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/PresShellInlines.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/StartupTimeline.h"
+#include "mozilla/dom/Document.h"
+#include "nsGfxCIID.h"
+#include "nsView.h"
+#include "nsCOMPtr.h"
+#include "nsRegion.h"
+#include "nsCOMArray.h"
+#include "nsXULPopupManager.h"
+#include "nsPresContext.h"
+#include "nsRefreshDriver.h"
+#include "nsContentUtils.h"  // for nsAutoScriptBlocker
+#include "nsLayoutUtils.h"
+#include "gfxPlatform.h"
+#include "WindowRenderer.h"
+
+/**
+   XXX TODO XXX
+
+   DeCOMify newly private methods
+   Optimize view storage
+*/
+
+/**
+   A note about platform assumptions:
+
+   We assume that a widget is z-ordered on top of its parent.
+
+   We do NOT assume anything about the relative z-ordering of sibling widgets.
+   Even though we ask for a specific z-order, we don't assume that widget
+   z-ordering actually works.
+*/
+
+using namespace mozilla;
+using namespace mozilla::layers;
+
+#define NSCOORD_NONE INT32_MIN
+
+#undef DEBUG_MOUSE_LOCATION
+
+// Weakly held references to all of the view managers
+StaticAutoPtr<nsTArray<nsViewManager*>> nsViewManager::gViewManagers;
+uint32_t nsViewManager::gLastUserEventTime = 0;
+
+nsViewManager::nsViewManager()
+    : mPresShell(nullptr),
+      mDelayedResize(NSCOORD_NONE, NSCOORD_NONE),
+      mRootView(nullptr),
+      mRefreshDisableCount(0),
+      mPainting(false),
+      mRecursiveRefreshPending(false),
+      mHasPendingWidgetGeometryChanges(false) {
+  if (gViewManagers == nullptr) {
+    // Create an array to hold a list of view managers
+    gViewManagers = new nsTArray<nsViewManager*>;
+  }
+
+  gViewManagers->AppendElement(this);
+}
+
+nsViewManager::~nsViewManager() {
+  if (mRootView) {
+    // Destroy any remaining views
+    mRootView->Destroy();
+    mRootView = nullptr;
+  }
+
+  mRootViewManager = nullptr;
+
+  NS_ASSERTION(gViewManagers != nullptr, "About to use null gViewManagers");
+
+#ifdef DEBUG
+  bool removed =
+#endif
+      gViewManagers->RemoveElement(this);
+  NS_ASSERTION(
+      removed,
+      "Viewmanager instance was not in the global list of viewmanagers");
+
+  if (gViewManagers->IsEmpty()) {
+    // There aren't any more view managers so
+    // release the global array of view managers
+    gViewManagers = nullptr;
+  }
+
+  MOZ_RELEASE_ASSERT(!mPresShell,
+                     "Releasing nsViewManager without having called Destroy on "
+                     "the PresShell!");
+}
+
+// We don't hold a reference to the presentation context because it
+// holds a reference to us.
+nsresult nsViewManager::Init(nsDeviceContext* aContext) {
+  MOZ_ASSERT(nullptr != aContext, "null ptr");
+
+  if (nullptr == aContext) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  if (nullptr != mContext) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+  mContext = aContext;
+
+  return NS_OK;
+}
+
+nsView* nsViewManager::CreateView(const nsRect& aBounds, nsView* aParent,
+                                  ViewVisibility aVisibilityFlag) {
+  auto* v = new nsView(this, aVisibilityFlag);
+  v->SetParent(aParent);
+  v->SetPosition(aBounds.X(), aBounds.Y());
+  nsRect dim(0, 0, aBounds.Width(), aBounds.Height());
+  v->SetDimensions(dim, false);
+  return v;
+}
+
+void nsViewManager::SetRootView(nsView* aView) {
+  MOZ_ASSERT(!aView || aView->GetViewManager() == this,
+             "Unexpected viewmanager on root view");
+
+  // Do NOT destroy the current root view. It's the caller's responsibility
+  // to destroy it
+  mRootView = aView;
+
+  if (mRootView) {
+    nsView* parent = mRootView->GetParent();
+    if (parent) {
+      // Calling InsertChild on |parent| will InvalidateHierarchy() on us, so
+      // no need to set mRootViewManager ourselves here.
+      parent->InsertChild(mRootView, nullptr);
+    } else {
+      InvalidateHierarchy();
+    }
+
+    mRootView->SetZIndex(false, 0);
+  }
+  // Else don't touch mRootViewManager
+}
+
+void nsViewManager::GetWindowDimensions(nscoord* aWidth, nscoord* aHeight) {
+  if (nullptr != mRootView) {
+    if (mDelayedResize == nsSize(NSCOORD_NONE, NSCOORD_NONE)) {
+      nsRect dim = mRootView->GetDimensions();
+      *aWidth = dim.Width();
+      *aHeight = dim.Height();
+    } else {
+      *aWidth = mDelayedResize.width;
+      *aHeight = mDelayedResize.height;
+    }
+  } else {
+    *aWidth = 0;
+    *aHeight = 0;
+  }
+}
+
+void nsViewManager::DoSetWindowDimensions(nscoord aWidth, nscoord aHeight) {
+  nsRect oldDim = mRootView->GetDimensions();
+  nsRect newDim(0, 0, aWidth, aHeight);
+  // We care about resizes even when one dimension is already zero.
+  if (oldDim.IsEqualEdges(newDim)) {
+    return;
+  }
+  // Don't resize the widget. It is already being set elsewhere.
+  mRootView->SetDimensions(newDim, true, false);
+  if (RefPtr<PresShell> presShell = mPresShell) {
+    presShell->ResizeReflow(aWidth, aHeight);
+  }
+}
+
+bool nsViewManager::ShouldDelayResize() const {
+  MOZ_ASSERT(mRootView);
+  if (!mRootView->IsEffectivelyVisible() || !mPresShell ||
+      !mPresShell->IsVisible()) {
+    return true;
+  }
+  if (nsRefreshDriver* rd = mPresShell->GetRefreshDriver()) {
+    if (rd->IsResizeSuppressed()) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void nsViewManager::SetWindowDimensions(nscoord aWidth, nscoord aHeight,
+                                        bool aDelayResize) {
+  if (mRootView) {
+    if (!ShouldDelayResize() && !aDelayResize) {
+      if (mDelayedResize != nsSize(NSCOORD_NONE, NSCOORD_NONE) &&
+          mDelayedResize != nsSize(aWidth, aHeight)) {
+        // We have a delayed resize; that now obsolete size may already have
+        // been flushed to the PresContext so we need to update the PresContext
+        // with the new size because if the new size is exactly the same as the
+        // root view's current size then DoSetWindowDimensions will not
+        // request a resize reflow (which would correct it). See bug 617076.
+        mDelayedResize = nsSize(aWidth, aHeight);
+        FlushDelayedResize();
+      }
+      mDelayedResize.SizeTo(NSCOORD_NONE, NSCOORD_NONE);
+      DoSetWindowDimensions(aWidth, aHeight);
+    } else {
+      mDelayedResize.SizeTo(aWidth, aHeight);
+      if (mPresShell) {
+        mPresShell->SetNeedStyleFlush();
+        mPresShell->SetNeedLayoutFlush();
+      }
+    }
+  }
+}
+
+void nsViewManager::FlushDelayedResize() {
+  if (mDelayedResize != nsSize(NSCOORD_NONE, NSCOORD_NONE)) {
+    DoSetWindowDimensions(mDelayedResize.width, mDelayedResize.height);
+    mDelayedResize.SizeTo(NSCOORD_NONE, NSCOORD_NONE);
+  }
+}
+
+// Convert aIn from being relative to and in appunits of aFromView, to being
+// relative to and in appunits of aToView.
+static nsRegion ConvertRegionBetweenViews(const nsRegion& aIn,
+                                          nsView* aFromView, nsView* aToView) {
+  nsRegion out = aIn;
+  out.MoveBy(aFromView->GetOffsetTo(aToView));
+  out = out.ScaleToOtherAppUnitsRoundOut(
+      aFromView->GetViewManager()->AppUnitsPerDevPixel(),
+      aToView->GetViewManager()->AppUnitsPerDevPixel());
+  return out;
+}
+
+nsView* nsViewManager::GetDisplayRootFor(nsView* aView) {
+  nsView* displayRoot = aView;
+  for (;;) {
+    nsView* displayParent = displayRoot->GetParent();
+    if (!displayParent) return displayRoot;
+
+    if (displayRoot->GetFloating() && !displayParent->GetFloating())
+      return displayRoot;
+
+    // If we have a combobox dropdown popup within a panel popup, both the view
+    // for the dropdown popup and its parent will be floating, so we need to
+    // distinguish this situation. We do this by looking for a widget. Any view
+    // with a widget is a display root.
+    nsIWidget* widget = displayRoot->GetWidget();
+    if (widget && widget->GetWindowType() == widget::WindowType::Popup) {
+      NS_ASSERTION(displayRoot->GetFloating() && displayParent->GetFloating(),
+                   "this should only happen with floating views that have "
+                   "floating parents");
+      return displayRoot;
+    }
+
+    displayRoot = displayParent;
+  }
+}
+
+/**
+   aRegion is given in device coordinates!!
+   aContext may be null, in which case layers should be used for
+   rendering.
+*/
+void nsViewManager::Refresh(nsView* aView,
+                            const LayoutDeviceIntRegion& aRegion) {
+  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");
+
+  if (mPresShell && mPresShell->IsNeverPainting()) {
+    return;
+  }
+
+  if (aRegion.IsEmpty()) {
+    return;
+  }
+
+  nsIWidget* widget = aView->GetWidget();
+  if (!widget) {
+    return;
+  }
+
+  NS_ASSERTION(!IsPainting(), "recursive painting not permitted");
+  if (IsPainting()) {
+    RootViewManager()->mRecursiveRefreshPending = true;
+    return;
+  }
+
+  {
+    nsAutoScriptBlocker scriptBlocker;
+    SetPainting(true);
+
+    NS_ASSERTION(GetDisplayRootFor(aView) == aView,
+                 "Widgets that we paint must all be display roots");
+
+    if (RefPtr<PresShell> presShell = mPresShell) {
+#ifdef MOZ_DUMP_PAINTING
+      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
+        printf_stderr("--COMPOSITE-- %p\n", presShell.get());
+      }
+#endif
+      WindowRenderer* renderer = widget->GetWindowRenderer();
+      if (!renderer->NeedsWidgetInvalidation()) {
+        renderer->FlushRendering(wr::RenderReasons::WIDGET);
+      } else {
+        presShell->SyncPaintFallback(aView);
+      }
+#ifdef MOZ_DUMP_PAINTING
+      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
+        printf_stderr("--ENDCOMPOSITE--\n");
+      }
+#endif
+      mozilla::StartupTimeline::RecordOnce(
+          mozilla::StartupTimeline::FIRST_PAINT);
+    }
+
+    SetPainting(false);
+  }
+
+  if (RootViewManager()->mRecursiveRefreshPending) {
+    RootViewManager()->mRecursiveRefreshPending = false;
+    InvalidateAllViews();
+  }
+}
+
+void nsViewManager::ProcessPendingUpdatesForView(nsView* aView,
+                                                 bool aFlushDirtyRegion) {
+  NS_ASSERTION(IsRootVM(), "Updates will be missed");
+  if (!aView) {
+    return;
+  }
+
+  RefPtr<PresShell> rootPresShell = mPresShell;
+  AutoTArray<nsCOMPtr<nsIWidget>, 1> widgets;
+  aView->GetViewManager()->ProcessPendingUpdatesRecurse(aView, widgets);
+  for (uint32_t i = 0; i < widgets.Length(); ++i) {
+    nsView* view = nsView::GetViewFor(widgets[i]);
+    if (view) {
+      if (view->mNeedsWindowPropertiesSync) {
+        view->mNeedsWindowPropertiesSync = false;
+        if (nsViewManager* vm = view->GetViewManager()) {
+          if (PresShell* presShell = vm->GetPresShell()) {
+            presShell->SyncWindowProperties(/* aSync */ true);
+          }
+        }
+      }
+    }
+    view = nsView::GetViewFor(widgets[i]);
+    if (view) {
+      view->ResetWidgetBounds(false, true);
+    }
+  }
+  if (rootPresShell->GetViewManager() != this) {
+    return;  // presentation might have been torn down
+  }
+  if (aFlushDirtyRegion) {
+    nsAutoScriptBlocker scriptBlocker;
+    SetPainting(true);
+    for (uint32_t i = 0; i < widgets.Length(); ++i) {
+      nsIWidget* widget = widgets[i];
+      nsView* view = nsView::GetViewFor(widget);
+      if (view) {
+        RefPtr<nsViewManager> viewManager = view->GetViewManager();
+        viewManager->ProcessPendingUpdatesPaint(MOZ_KnownLive(widget));
+      }
+    }
+    SetPainting(false);
+  }
+}
+
+void nsViewManager::ProcessPendingUpdatesRecurse(
+    nsView* aView, AutoTArray<nsCOMPtr<nsIWidget>, 1>& aWidgets) {
+  if (mPresShell && mPresShell->IsNeverPainting()) {
+    return;
+  }
+
+  for (nsView* childView = aView->GetFirstChild(); childView;
+       childView = childView->GetNextSibling()) {
+    childView->GetViewManager()->ProcessPendingUpdatesRecurse(childView,
+                                                              aWidgets);
+  }
+
+  nsIWidget* widget = aView->GetWidget();
+  if (widget) {
+    aWidgets.AppendElement(widget);
+  } else {
+    FlushDirtyRegionToWidget(aView);
+  }
+}
+
+void nsViewManager::ProcessPendingUpdatesPaint(nsIWidget* aWidget) {
+  if (aWidget->NeedsPaint()) {
+    // If an ancestor widget was hidden and then shown, we could
+    // have a delayed resize to handle.
+    for (RefPtr<nsViewManager> vm = this; vm;
+         vm = vm->mRootView->GetParent()
+                  ? vm->mRootView->GetParent()->GetViewManager()
+                  : nullptr) {
+      if (vm->mDelayedResize != nsSize(NSCOORD_NONE, NSCOORD_NONE) &&
+          vm->mRootView->IsEffectivelyVisible() && vm->mPresShell &&
+          vm->mPresShell->IsVisible()) {
+        vm->FlushDelayedResize();
+      }
+    }
+    nsView* view = nsView::GetViewFor(aWidget);
+
+    if (!view) {
+      NS_ERROR("FlushDelayedResize destroyed the nsView?");
+      return;
+    }
+
+    nsIWidgetListener* previousListener =
+        aWidget->GetPreviouslyAttachedWidgetListener();
+
+    if (previousListener && previousListener != view &&
+        view->IsPrimaryFramePaintSuppressed()) {
+      return;
+    }
+
+    if (RefPtr<PresShell> presShell = mPresShell) {
+#ifdef MOZ_DUMP_PAINTING
+      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
+        printf_stderr(
+            "---- PAINT START ----PresShell(%p), nsView(%p), nsIWidget(%p)\n",
+            presShell.get(), view, aWidget);
+      }
+#endif
+
+      presShell->PaintAndRequestComposite(view, PaintFlags::None);
+      view->SetForcedRepaint(false);
+
+#ifdef MOZ_DUMP_PAINTING
+      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
+        printf_stderr("---- PAINT END ----\n");
+      }
+#endif
+    }
+  }
+  FlushDirtyRegionToWidget(nsView::GetViewFor(aWidget));
+}
+
+void nsViewManager::FlushDirtyRegionToWidget(nsView* aView) {
+  NS_ASSERTION(aView->GetViewManager() == this,
+               "FlushDirtyRegionToWidget called on view we don't own");
+
+  if (!aView->HasNonEmptyDirtyRegion()) {
+    return;
+  }
+
+  nsRegion& dirtyRegion = aView->GetDirtyRegion();
+  nsView* nearestViewWithWidget = aView;
+  while (!nearestViewWithWidget->HasWidget() &&
+         nearestViewWithWidget->GetParent()) {
+    nearestViewWithWidget = nearestViewWithWidget->GetParent();
+  }
+  nsRegion r =
+      ConvertRegionBetweenViews(dirtyRegion, aView, nearestViewWithWidget);
+
+  nsViewManager* widgetVM = nearestViewWithWidget->GetViewManager();
+  widgetVM->InvalidateWidgetArea(nearestViewWithWidget, r);
+  dirtyRegion.SetEmpty();
+}
+
+void nsViewManager::InvalidateView(nsView* aView) {
+  // Mark the entire view as damaged
+  InvalidateView(aView, aView->GetDimensions());
+}
+
+static void AddDirtyRegion(nsView* aView, const nsRegion& aDamagedRegion) {
+  nsRegion& dirtyRegion = aView->GetDirtyRegion();
+  dirtyRegion.Or(dirtyRegion, aDamagedRegion);
+  dirtyRegion.SimplifyOutward(8);
+}
+
+void nsViewManager::PostPendingUpdate() {
+  nsViewManager* rootVM = RootViewManager();
+  rootVM->mHasPendingWidgetGeometryChanges = true;
+  if (rootVM->mPresShell) {
+    rootVM->mPresShell->ScheduleViewManagerFlush();
+  }
+}
+
+/**
+ * @param aDamagedRegion this region, relative to aWidgetView, is invalidated in
+ * every widget child of aWidgetView, plus aWidgetView's own widget
+ */
+void nsViewManager::InvalidateWidgetArea(nsView* aWidgetView,
+                                         const nsRegion& aDamagedRegion) {
+  NS_ASSERTION(aWidgetView->GetViewManager() == this,
+               "InvalidateWidgetArea called on view we don't own");
+  nsIWidget* widget = aWidgetView->GetWidget();
+
+#if 0
+  nsRect dbgBounds = aDamagedRegion.GetBounds();
+  printf("InvalidateWidgetArea view:%X (%d) widget:%X region: %d, %d, %d, %d\n",
+    aWidgetView, aWidgetView->IsAttachedToTopLevel(),
+    widget, dbgBounds.x, dbgBounds.y, dbgBounds.width, dbgBounds.height);
+#endif
+
+  // If the widget is hidden, it don't cover nothing
+  if (widget && !widget->IsVisible()) {
+    return;
+  }
+
+  if (!widget) {
+    // The root view or a scrolling view might not have a widget
+    // (for example, during printing). We get here when we scroll
+    // during printing to show selected options in a listbox, for example.
+    return;
+  }
+
+  if (!aDamagedRegion.IsEmpty()) {
+    for (auto iter = aDamagedRegion.RectIter(); !iter.Done(); iter.Next()) {
+      LayoutDeviceIntRect bounds = ViewToWidget(aWidgetView, iter.Get());
+      widget->Invalidate(bounds);
+    }
+  }
+}
+
+static bool ShouldIgnoreInvalidation(nsViewManager* aVM) {
+  while (aVM) {
+    PresShell* presShell = aVM->GetPresShell();
+    if (!presShell || presShell->ShouldIgnoreInvalidation()) {
+      return true;
+    }
+    nsView* view = aVM->GetRootView()->GetParent();
+    aVM = view ? view->GetViewManager() : nullptr;
+  }
+  return false;
+}
+
+void nsViewManager::InvalidateView(nsView* aView, const nsRect& aRect) {
+  // If painting is suppressed in the presshell or an ancestor drop all
+  // invalidates, it will invalidate everything when it unsuppresses.
+  if (ShouldIgnoreInvalidation(this)) {
+    return;
+  }
+
+  InvalidateViewNoSuppression(aView, aRect);
+}
+
+void nsViewManager::InvalidateViewNoSuppression(nsView* aView,
+                                                const nsRect& aRect) {
+  MOZ_ASSERT(nullptr != aView, "null view");
+
+  NS_ASSERTION(aView->GetViewManager() == this,
+               "InvalidateViewNoSuppression called on view we don't own");
+
+  nsRect damagedRect(aRect);
+  if (damagedRect.IsEmpty()) {
+    return;
+  }
+
+  nsView* displayRoot = GetDisplayRootFor(aView);
+  nsViewManager* displayRootVM = displayRoot->GetViewManager();
+  // Propagate the update to the displayRoot, since iframes, for example,
+  // can overlap each other and be translucent.  So we have to possibly
+  // invalidate our rect in each of the widgets we have lying about.
+  damagedRect.MoveBy(aView->GetOffsetTo(displayRoot));
+  int32_t rootAPD = displayRootVM->AppUnitsPerDevPixel();
+  int32_t APD = AppUnitsPerDevPixel();
+  damagedRect = damagedRect.ScaleToOtherAppUnitsRoundOut(APD, rootAPD);
+
+  // accumulate this rectangle in the view's dirty region, so we can
+  // process it later.
+  AddDirtyRegion(displayRoot, nsRegion(damagedRect));
+}
+
+void nsViewManager::InvalidateAllViews() {
+  if (RootViewManager() != this) {
+    return RootViewManager()->InvalidateAllViews();
+  }
+
+  InvalidateViews(mRootView);
+}
+
+void nsViewManager::InvalidateViews(nsView* aView) {
+  // Invalidate this view.
+  InvalidateView(aView);
+
+  // Invalidate all children as well.
+  nsView* childView = aView->GetFirstChild();
+  while (nullptr != childView) {
+    childView->GetViewManager()->InvalidateViews(childView);
+    childView = childView->GetNextSibling();
+  }
+}
+
+void nsViewManager::WillPaintWindow(nsIWidget* aWidget) {
+  if (aWidget) {
+    nsView* view = nsView::GetViewFor(aWidget);
+    WindowRenderer* renderer = aWidget->GetWindowRenderer();
+    if (view &&
+        (view->ForcedRepaint() || !renderer->NeedsWidgetInvalidation())) {
+      ProcessPendingUpdates();
+      // Re-get the view pointer here since the ProcessPendingUpdates might have
+      // destroyed it during CallWillPaintOnObservers.
+      view = nsView::GetViewFor(aWidget);
+      if (view) {
+        view->SetForcedRepaint(false);
+      }
+    }
+  }
+}
+
+bool nsViewManager::PaintWindow(nsIWidget* aWidget,
+                                const LayoutDeviceIntRegion& aRegion) {
+  if (!aWidget || !mContext) return false;
+
+  NS_ASSERTION(
+      IsPaintingAllowed(),
+      "shouldn't be receiving paint events while painting is disallowed!");
+
+  // Get the view pointer here since NS_WILL_PAINT might have
+  // destroyed it during CallWillPaintOnObservers (bug 378273).
+  nsView* view = nsView::GetViewFor(aWidget);
+  if (view && !aRegion.IsEmpty()) {
+    Refresh(view, aRegion);
+  }
+
+  return true;
+}
+
+void nsViewManager::DidPaintWindow() {
+  if (RefPtr<PresShell> presShell = mPresShell) {
+    presShell->DidPaintWindow();
+  }
+}
+
+void nsViewManager::DispatchEvent(WidgetGUIEvent* aEvent, nsView* aView,
+                                  nsEventStatus* aStatus) {
+  AUTO_PROFILER_LABEL("nsViewManager::DispatchEvent", OTHER);
+
+  WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
+  if ((mouseEvent &&
+       // Ignore mouse events that we synthesize.
+       mouseEvent->mReason == WidgetMouseEvent::eReal &&
+       // Ignore mouse exit and enter (we'll get moves if the user
+       // is really moving the mouse) since we get them when we
+       // create and destroy widgets.
+       mouseEvent->mMessage != eMouseExitFromWidget &&
+       mouseEvent->mMessage != eMouseEnterIntoWidget) ||
+      aEvent->HasKeyEventMessage() || aEvent->HasIMEEventMessage()) {
+    gLastUserEventTime = PR_IntervalToMicroseconds(PR_IntervalNow());
+  }
+
+  // Find the view whose coordinates system we're in.
+  nsView* view = aView;
+  bool dispatchUsingCoordinates = aEvent->IsUsingCoordinates();
+  if (dispatchUsingCoordinates) {
+    // Will dispatch using coordinates. Pretty bogus but it's consistent
+    // with what presshell does.
+    view = GetDisplayRootFor(view);
+  }
+
+  // If the view has no frame, look for a view that does.
+  nsIFrame* frame = view->GetFrame();
+  if (!frame && (dispatchUsingCoordinates || aEvent->HasKeyEventMessage() ||
+                 aEvent->IsIMERelatedEvent())) {
+    while (view && !view->GetFrame()) {
+      view = view->GetParent();
+    }
+
+    if (view) {
+      frame = view->GetFrame();
+    }
+  }
+
+  if (nullptr != frame) {
+    // Hold a refcount to the presshell. The continued existence of the
+    // presshell will delay deletion of this view hierarchy should the event
+    // want to cause its destruction in, say, some JavaScript event handler.
+    if (RefPtr<PresShell> presShell = view->GetViewManager()->GetPresShell()) {
+      presShell->HandleEvent(frame, aEvent, false, aStatus);
+      return;
+    }
+  }
+
+  *aStatus = nsEventStatus_eIgnore;
+}
+
+// Recursively reparent widgets if necessary
+
+void nsViewManager::ReparentChildWidgets(nsView* aView, nsIWidget* aNewWidget) {
+  MOZ_ASSERT(aNewWidget, "null widget");
+
+  if (aView->HasWidget()) {
+    // Check to see if the parent widget is the
+    // same as the new parent. If not then reparent
+    // the widget, otherwise there is nothing more
+    // to do for the view and its descendants
+    nsIWidget* widget = aView->GetWidget();
+    nsIWidget* parentWidget = widget->GetParent();
+    if (parentWidget) {
+      // Child widget
+      if (parentWidget != aNewWidget) {
+        widget->SetParent(aNewWidget);
+      }
+    } else {
+      // Toplevel widget (popup, dialog, etc)
+      widget->ReparentNativeWidget(aNewWidget);
+    }
+    return;
+  }
+
+  // Need to check each of the views children to see
+  // if they have a widget and reparent it.
+
+  for (nsView* kid = aView->GetFirstChild(); kid; kid = kid->GetNextSibling()) {
+    ReparentChildWidgets(kid, aNewWidget);
+  }
+}
+
+// Reparent a view and its descendant views widgets if necessary
+
+void nsViewManager::ReparentWidgets(nsView* aView, nsView* aParent) {
+  MOZ_ASSERT(aParent, "Must have a parent");
+  MOZ_ASSERT(aView, "Must have a view");
+
+  // Quickly determine whether the view has pre-existing children or a
+  // widget. In most cases the view will not have any pre-existing
+  // children when this is called.  Only in the case
+  // where a view has been reparented by removing it from
+  // a reinserting it into a new location in the view hierarchy do we
+  // have to consider reparenting the existing widgets for the view and
+  // it's descendants.
+  if (aView->HasWidget() || aView->GetFirstChild()) {
+    nsIWidget* parentWidget = aParent->GetNearestWidget(nullptr);
+    if (parentWidget) {
+      ReparentChildWidgets(aView, parentWidget);
+      return;
+    }
+    NS_WARNING("Can not find a widget for the parent view");
+  }
+}
+
+void nsViewManager::InsertChild(nsView* aParent, nsView* aChild,
+                                nsView* aSibling, bool aAfter) {
+  MOZ_ASSERT(nullptr != aParent, "null ptr");
+  MOZ_ASSERT(nullptr != aChild, "null ptr");
+  NS_ASSERTION(aSibling == nullptr || aSibling->GetParent() == aParent,
+               "tried to insert view with invalid sibling");
+  NS_ASSERTION(!IsViewInserted(aChild),
+               "tried to insert an already-inserted view");
+
+  if ((nullptr != aParent) && (nullptr != aChild)) {
+    // if aAfter is set, we will insert the child after 'prev' (i.e. after 'kid'
+    // in document order, otherwise after 'kid' (i.e. before 'kid' in document
+    // order).
+
+    if (nullptr == aSibling) {
+      if (aAfter) {
+        // insert at end of document order, i.e., before first view
+        // this is the common case, by far
+        aParent->InsertChild(aChild, nullptr);
+        ReparentWidgets(aChild, aParent);
+      } else {
+        // insert at beginning of document order, i.e., after last view
+        nsView* kid = aParent->GetFirstChild();
+        nsView* prev = nullptr;
+        while (kid) {
+          prev = kid;
+          kid = kid->GetNextSibling();
+        }
+        // prev is last view or null if there are no children
+        aParent->InsertChild(aChild, prev);
+        ReparentWidgets(aChild, aParent);
+      }
+    } else {
+      nsView* kid = aParent->GetFirstChild();
+      nsView* prev = nullptr;
+      while (kid && aSibling != kid) {
+        // get the next sibling view
+        prev = kid;
+        kid = kid->GetNextSibling();
+      }
+      NS_ASSERTION(kid != nullptr, "couldn't find sibling in child list");
+      if (aAfter) {
+        // insert after 'kid' in document order, i.e. before in view order
+        aParent->InsertChild(aChild, prev);
+        ReparentWidgets(aChild, aParent);
+      } else {
+        // insert before 'kid' in document order, i.e. after in view order
+        aParent->InsertChild(aChild, kid);
+        ReparentWidgets(aChild, aParent);
+      }
+    }
+
+    // if the parent view is marked as "floating", make the newly added view
+    // float as well.
+    if (aParent->GetFloating()) aChild->SetFloating(true);
+  }
+}
+
+void nsViewManager::RemoveChild(nsView* aChild) {
+  NS_ASSERTION(aChild, "aChild must not be null");
+
+  nsView* parent = aChild->GetParent();
+
+  if (nullptr != parent) {
+    NS_ASSERTION(
+        aChild->GetViewManager() == this || parent->GetViewManager() == this,
+        "wrong view manager");
+    parent->RemoveChild(aChild);
+  }
+}
+
+void nsViewManager::MoveViewTo(nsView* aView, nscoord aX, nscoord aY) {
+  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");
+  aView->SetPosition(aX, aY);
+}
+
+void nsViewManager::ResizeView(nsView* aView, const nsRect& aRect,
+                               bool aRepaintExposedAreaOnly) {
+  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");
+
+  nsRect oldDimensions = aView->GetDimensions();
+  if (!oldDimensions.IsEqualEdges(aRect)) {
+    aView->SetDimensions(aRect, true);
+  }
+
+  // Note that if layout resizes the view and the view has a custom clip
+  // region set, then we expect layout to update the clip region too. Thus
+  // in the case where mClipRect has been optimized away to just be a null
+  // pointer, and this resize is implicitly changing the clip rect, it's OK
+  // because layout will change it back again if necessary.
+}
+
+void nsViewManager::SetViewFloating(nsView* aView, bool aFloating) {
+  NS_ASSERTION(!(nullptr == aView), "no view");
+
+  aView->SetFloating(aFloating);
+}
+
+void nsViewManager::SetViewVisibility(nsView* aView, ViewVisibility aVisible) {
+  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");
+
+  if (aVisible != aView->GetVisibility()) {
+    aView->SetVisibility(aVisible);
+  }
+}
+
+bool nsViewManager::IsViewInserted(nsView* aView) {
+  if (mRootView == aView) {
+    return true;
+  }
+  if (aView->GetParent() == nullptr) {
+    return false;
+  }
+  nsView* view = aView->GetParent()->GetFirstChild();
+  while (view != nullptr) {
+    if (view == aView) {
+      return true;
+    }
+    view = view->GetNextSibling();
+  }
+  return false;
+}
+
+void nsViewManager::SetViewZIndex(nsView* aView, bool aAutoZIndex,
+                                  int32_t aZIndex) {
+  NS_ASSERTION((aView != nullptr), "no view");
+
+  // don't allow the root view's z-index to be changed. It should always be
+  // zero. This could be removed and replaced with a style rule, or just removed
+  // altogether, with interesting consequences
+  if (aView == mRootView) {
+    return;
+  }
+
+  if (aAutoZIndex) {
+    aZIndex = 0;
+  }
+
+  aView->SetZIndex(aAutoZIndex, aZIndex);
+}
+
+nsViewManager* nsViewManager::IncrementDisableRefreshCount() {
+  if (!IsRootVM()) {
+    return RootViewManager()->IncrementDisableRefreshCount();
+  }
+
+  ++mRefreshDisableCount;
+
+  return this;
+}
+
+void nsViewManager::DecrementDisableRefreshCount() {
+  NS_ASSERTION(IsRootVM(), "Should only be called on root");
+  --mRefreshDisableCount;
+  NS_ASSERTION(mRefreshDisableCount >= 0, "Invalid refresh disable count!");
+}
+
+nsIWidget* nsViewManager::GetRootWidget() const {
+  if (!mRootView) {
+    return nullptr;
+  }
+  if (mRootView->HasWidget()) {
+    return mRootView->GetWidget();
+  }
+  if (mRootView->GetParent()) {
+    return mRootView->GetParent()->GetViewManager()->GetRootWidget();
+  }
+  return nullptr;
+}
+
+LayoutDeviceIntRect nsViewManager::ViewToWidget(nsView* aView,
+                                                const nsRect& aRect) const {
+  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");
+
+  // account for the view's origin not lining up with the widget's
+  nsRect rect = aRect + aView->ViewToWidgetOffset();
+
+  // finally, convert to device coordinates.
+  return LayoutDeviceIntRect::FromUnknownRect(
+      rect.ToOutsidePixels(AppUnitsPerDevPixel()));
+}
+
+void nsViewManager::IsPainting(bool& aIsPainting) {
+  aIsPainting = IsPainting();
+}
+
+void nsViewManager::ProcessPendingUpdates() {
+  if (!IsRootVM()) {
+    RefPtr<nsViewManager> rootViewManager = RootViewManager();
+    rootViewManager->ProcessPendingUpdates();
+    return;
+  }
+
+  // Flush things like reflows by calling WillPaint on observer presShells.
+  if (mPresShell) {
+    mPresShell->GetPresContext()->RefreshDriver()->RevokeViewManagerFlush();
+
+    RefPtr<nsViewManager> strongThis(this);
+    CallWillPaintOnObservers();
+
+    ProcessPendingUpdatesForView(mRootView, true);
+    if (mPresShell) {
+      if (nsPresContext* pc = mPresShell->GetPresContext()) {
+        pc->RefreshDriver()->ClearHasScheduleFlush();
+      }
+    }
+  }
+}
+
+void nsViewManager::UpdateWidgetGeometry() {
+  if (!IsRootVM()) {
+    RefPtr<nsViewManager> rootViewManager = RootViewManager();
+    rootViewManager->UpdateWidgetGeometry();
+    return;
+  }
+
+  if (mHasPendingWidgetGeometryChanges) {
+    mHasPendingWidgetGeometryChanges = false;
+    ProcessPendingUpdatesForView(mRootView, false);
+  }
+}
+
+void nsViewManager::CallWillPaintOnObservers() {
+  MOZ_ASSERT(IsRootVM(), "Must be root VM for this to be called!");
+
+  if (NS_WARN_IF(!gViewManagers)) {
+    return;
+  }
+
+  uint32_t index;
+  for (index = 0; index < gViewManagers->Length(); index++) {
+    nsViewManager* vm = gViewManagers->ElementAt(index);
+    if (vm->RootViewManager() == this) {
+      // One of our kids.
+      if (vm->mRootView && vm->mRootView->IsEffectivelyVisible()) {
+        if (RefPtr<PresShell> presShell = vm->GetPresShell()) {
+          presShell->WillPaint();
+        }
+      }
+    }
+  }
+}
+
+void nsViewManager::GetLastUserEventTime(uint32_t& aTime) {
+  aTime = gLastUserEventTime;
+}
+
+void nsViewManager::InvalidateHierarchy() {
+  if (mRootView) {
+    mRootViewManager = nullptr;
+    nsView* parent = mRootView->GetParent();
+    if (parent) {
+      mRootViewManager = parent->GetViewManager()->RootViewManager();
+      NS_ASSERTION(mRootViewManager != this,
+                   "Root view had a parent, but it has the same view manager");
+    }
+    // else, we are implicitly our own root view manager.
+  }
+}