1 files changed, 245 insertions, 0 deletions
diff --git a/widget/ScreenManager.cpp b/widget/ScreenManager.cpp
new file mode 100644
index 0000000000..90324ebca4
--- /dev/null
+++ b/widget/ScreenManager.cpp
@@ -0,0 +1,245 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "ScreenManager.h"
+
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/DOMTypes.h"
+#include "mozilla/Logging.h"
+#include "mozilla/StaticPtr.h"
+#ifdef MOZ_WAYLAND
+#  include <gdk/gdk.h>
+#  include <gdk/gdkx.h>
+#  include <gdk/gdkwayland.h>
+#endif /* MOZ_WAYLAND */
+
+static mozilla::LazyLogModule sScreenLog("WidgetScreen");
+
+namespace mozilla::widget {
+
+NS_IMPL_ISUPPORTS(ScreenManager, nsIScreenManager)
+
+ScreenManager::ScreenManager() = default;
+
+ScreenManager::~ScreenManager() = default;
+
+static StaticRefPtr<ScreenManager> sSingleton;
+
+ScreenManager& ScreenManager::GetSingleton() {
+  if (!sSingleton) {
+    sSingleton = new ScreenManager();
+    ClearOnShutdown(&sSingleton);
+  }
+  return *sSingleton;
+}
+
+already_AddRefed<ScreenManager> ScreenManager::GetAddRefedSingleton() {
+  RefPtr<ScreenManager> sm = &GetSingleton();
+  return sm.forget();
+}
+
+void ScreenManager::SetHelper(UniquePtr<Helper> aHelper) {
+  mHelper = std::move(aHelper);
+}
+
+void ScreenManager::Refresh(nsTArray<RefPtr<Screen>>&& aScreens) {
+  MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refresh screens"));
+
+  mScreenList = std::move(aScreens);
+
+  CopyScreensToAllRemotesIfIsParent();
+}
+
+void ScreenManager::Refresh(nsTArray<mozilla::dom::ScreenDetails>&& aScreens) {
+  MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refresh screens from IPC"));
+
+  mScreenList.Clear();
+  for (auto& screen : aScreens) {
+    mScreenList.AppendElement(new Screen(screen));
+  }
+
+  CopyScreensToAllRemotesIfIsParent();
+}
+
+template <class Range>
+void ScreenManager::CopyScreensToRemoteRange(Range aRemoteRange) {
+  AutoTArray<dom::ScreenDetails, 4> screens;
+  for (auto& screen : mScreenList) {
+    screens.AppendElement(screen->ToScreenDetails());
+  }
+  for (auto cp : aRemoteRange) {
+    MOZ_LOG(sScreenLog, LogLevel::Debug,
+            ("Send screens to [Pid %d]", cp->Pid()));
+    if (!cp->SendRefreshScreens(screens)) {
+      MOZ_LOG(sScreenLog, LogLevel::Error,
+              ("SendRefreshScreens to [Pid %d] failed", cp->Pid()));
+    }
+  }
+}
+
+void ScreenManager::CopyScreensToRemote(dom::ContentParent* aContentParent) {
+  MOZ_ASSERT(aContentParent);
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  auto range = {aContentParent};
+  CopyScreensToRemoteRange(range);
+}
+
+void ScreenManager::CopyScreensToAllRemotesIfIsParent() {
+  if (XRE_IsContentProcess()) {
+    return;
+  }
+
+  MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refreshing all ContentParents"));
+
+  CopyScreensToRemoteRange(
+      dom::ContentParent::AllProcesses(dom::ContentParent::eLive));
+}
+
+// Returns the screen that contains the rectangle. If the rect overlaps
+// multiple screens, it picks the screen with the greatest area of intersection.
+//
+// The coordinates are in desktop pixels.
+//
+NS_IMETHODIMP
+ScreenManager::ScreenForRect(int32_t aX, int32_t aY, int32_t aWidth,
+                             int32_t aHeight, nsIScreen** aOutScreen) {
+#if defined(MOZ_WAYLAND) && defined(MOZ_LOGGING)
+  static bool inWayland = gdk_display_get_default() &&
+                          !GDK_IS_X11_DISPLAY(gdk_display_get_default());
+  if (inWayland) {
+    MOZ_LOG(sScreenLog, LogLevel::Warning,
+            ("Getting screen in wayland, primary display will be returned."));
+  }
+#endif
+
+  if (mScreenList.IsEmpty()) {
+    MOZ_LOG(sScreenLog, LogLevel::Warning,
+            ("No screen available. This can happen in xpcshell."));
+    RefPtr<Screen> ret = new Screen(
+        LayoutDeviceIntRect(), LayoutDeviceIntRect(), 0, 0,
+        DesktopToLayoutDeviceScale(), CSSToLayoutDeviceScale(), 96 /* dpi */);
+    ret.forget(aOutScreen);
+    return NS_OK;
+  }
+
+  // Optimize for the common case. If the number of screens is only
+  // one then just return the primary screen.
+  if (mScreenList.Length() == 1) {
+    return GetPrimaryScreen(aOutScreen);
+  }
+
+  // which screen should we return?
+  Screen* which = mScreenList[0].get();
+
+  // walk the list of screens and find the one that has the most
+  // surface area.
+  uint32_t area = 0;
+  DesktopIntRect windowRect(aX, aY, aWidth, aHeight);
+  for (auto& screen : mScreenList) {
+    int32_t x, y, width, height;
+    x = y = width = height = 0;
+    screen->GetRectDisplayPix(&x, &y, &width, &height);
+    // calculate the surface area
+    DesktopIntRect screenRect(x, y, width, height);
+    screenRect.IntersectRect(screenRect, windowRect);
+    uint32_t tempArea = screenRect.Area();
+    if (tempArea > area) {
+      which = screen.get();
+      area = tempArea;
+    }
+  }
+
+  // If the rect intersects one or more screen,
+  // return the screen that has the largest intersection.
+  if (area > 0) {
+    RefPtr<Screen> ret = which;
+    ret.forget(aOutScreen);
+    return NS_OK;
+  }
+
+  // If the rect does not intersect a screen, find
+  // a screen that is nearest to the rect.
+  uint32_t distance = UINT32_MAX;
+  for (auto& screen : mScreenList) {
+    int32_t x, y, width, height;
+    x = y = width = height = 0;
+    screen->GetRectDisplayPix(&x, &y, &width, &height);
+
+    uint32_t distanceX = 0;
+    if (aX > (x + width)) {
+      distanceX = aX - (x + width);
+    } else if ((aX + aWidth) < x) {
+      distanceX = x - (aX + aWidth);
+    }
+
+    uint32_t distanceY = 0;
+    if (aY > (y + height)) {
+      distanceY = aY - (y + height);
+    } else if ((aY + aHeight) < y) {
+      distanceY = y - (aY + aHeight);
+    }
+
+    uint32_t tempDistance = distanceX * distanceX + distanceY * distanceY;
+    if (tempDistance < distance) {
+      which = screen.get();
+      distance = tempDistance;
+      if (distance == 0) {
+        break;
+      }
+    }
+  }
+
+  RefPtr<Screen> ret = which;
+  ret.forget(aOutScreen);
+  return NS_OK;
+}
+
+// The screen with the menubar/taskbar. This shouldn't be needed very
+// often.
+//
+NS_IMETHODIMP
+ScreenManager::GetPrimaryScreen(nsIScreen** aPrimaryScreen) {
+  if (mScreenList.IsEmpty()) {
+    MOZ_LOG(sScreenLog, LogLevel::Warning,
+            ("No screen available. This can happen in xpcshell."));
+    RefPtr<Screen> ret = new Screen(
+        LayoutDeviceIntRect(), LayoutDeviceIntRect(), 0, 0,
+        DesktopToLayoutDeviceScale(), CSSToLayoutDeviceScale(), 96 /* dpi */);
+    ret.forget(aPrimaryScreen);
+    return NS_OK;
+  }
+
+  RefPtr<Screen> ret = mScreenList[0];
+  ret.forget(aPrimaryScreen);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ScreenManager::GetTotalScreenPixels(int64_t* aTotalScreenPixels) {
+  MOZ_ASSERT(aTotalScreenPixels);
+
+  if (mScreenList.IsEmpty()) {
+    MOZ_LOG(sScreenLog, LogLevel::Warning,
+            ("No screen available. This can happen in xpcshell."));
+    *aTotalScreenPixels = 0;
+    return NS_OK;
+  }
+
+  int64_t pixels = 0;
+  for (auto& screen : mScreenList) {
+    int32_t x, y, width, height;
+    x = y = width = height = 0;
+    screen->GetRect(&x, &y, &width, &height);
+    pixels += width * height;
+  }
+
+  *aTotalScreenPixels = pixels;
+  return NS_OK;
+}
+
+}  // namespace mozilla::widget