Bug 1437941: Don't ignore mousemove after fullscreen transition r=handyman

MozReview-Commit-ID: Hr9dcKVeYEC

--HG--
extra : rebase_source : fe9d1f3526704dd5c37bcbeb7c6a62de368be12c

dom/base/nsGlobalWindowOuter.cpp

@@ -4174,6 +4174,7 @@ FullscreenTransitionTask::Run()
                                          this);
   } else if (stage == eEnd) {
     PROFILER_ADD_MARKER("Fullscreen transition end");
+    mWidget->CleanupFullscreenTransition();
   }
   return NS_OK;
 }

widget/nsBaseWidget.h

@@ -192,6 +192,7 @@ public:
                                            uint16_t aDuration,
                                            nsISupports* aData,
                                            nsIRunnable* aCallback) override;
+  virtual void CleanupFullscreenTransition() override {};
   virtual already_AddRefed<nsIScreen> GetWidgetScreen() override;
   virtual nsresult        MakeFullScreen(bool aFullScreen,
                                          nsIScreen* aScreen = nullptr) override;

widget/nsIWidget.h

@@ -1212,6 +1212,11 @@ class nsIWidget : public nsISupports
                                              nsISupports* aData,
                                              nsIRunnable* aCallback) = 0;
 
+    /**
+      * Perform any actions needed after the fullscreen transition has ended.
+      */
+    virtual void CleanupFullscreenTransition() = 0;
+
     /**
      * Return the screen the widget is in, or null if we don't know.
      */

widget/windows/nsWindow.cpp

@@ -271,9 +271,6 @@ bool            nsWindow::sHaveInitializedPrefs   = false;
 
 TriStateBool nsWindow::sHasBogusPopupsDropShadowOnMultiMonitor = TRI_UNKNOWN;
 
-WPARAM nsWindow::sMouseExitwParam = 0;
-LPARAM nsWindow::sMouseExitlParamScreen = 0;
-
 static SystemTimeConverter<DWORD>&
 TimeConverter() {
   static SystemTimeConverter<DWORD> timeConverterSingleton;
@@ -1965,8 +1962,6 @@ nsWindow::Resize(double aX, double aY, double aWidth,
       // the system unexpectedly when we leave fullscreen state.
       ::SetWindowPos(mTransitionWnd, HWND_TOPMOST, 0, 0, 0, 0,
                      SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE);
-      // Every transition window is only used once.
-      mTransitionWnd = nullptr;
     }
     SetThemeRegion();
   }
@@ -3441,6 +3436,7 @@ nsWindow::PrepareForFullscreenTransition(nsISupports** aData)
   }
 
   mTransitionWnd = initData.mWnd;
+
   auto data = new FullscreenTransitionData(initData.mWnd);
   *aData = data;
   NS_ADDREF(data);
@@ -3460,6 +3456,15 @@ nsWindow::PerformFullscreenTransition(FullscreenTransitionStage aStage,
   ::PostMessage(data->mWnd, msg, wparam, (LPARAM)aDuration);
 }
 
+/* virtual */ void
+nsWindow::CleanupFullscreenTransition()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "CleanupFullscreenTransition "
+             "should only run on the main thread");
+
+  mTransitionWnd = nullptr;
+}
+
 nsresult
 nsWindow::MakeFullScreen(bool aFullScreen, nsIScreen* aTargetScreen)
 {
@@ -3509,17 +3514,6 @@ nsWindow::MakeFullScreen(bool aFullScreen, nsIScreen* aTargetScreen)
     mWidgetListener->FullscreenChanged(aFullScreen);
   }
 
-  // Send a eMouseEnterIntoWidget event since Windows has already sent
-  // a WM_MOUSELEAVE that caused us to send a eMouseExitFromWidget event.
-  if (aFullScreen && !sCurrentWindow) {
-    sCurrentWindow = this;
-    LPARAM pos = sCurrentWindow->lParamToClient(sMouseExitlParamScreen);
-    sCurrentWindow->DispatchMouseEvent(eMouseEnterIntoWidget,
-                                       sMouseExitwParam, pos, false,
-                                       WidgetMouseEvent::eLeftButton,
-                                       MOUSE_INPUT_SOURCE());
-  }
-
   return NS_OK;
 }
 
@@ -4656,8 +4650,6 @@ nsWindow::DispatchMouseEvent(EventMessage aEventMessage, WPARAM wParam,
         }
       }
     } else if (aEventMessage == eMouseExitFromWidget) {
-      sMouseExitwParam = wParam;
-      sMouseExitlParamScreen = lParamToScreen(lParam);
       if (sCurrentWindow == this) {
         sCurrentWindow = nullptr;
       }
@@ -4710,13 +4702,18 @@ void nsWindow::DispatchFocusToTopLevelWindow(bool aIsActivate)
   }
 }
 
-bool nsWindow::IsTopLevelMouseExit(HWND aWnd)
+HWND nsWindow::WindowAtMouse()
 {
   DWORD pos = ::GetMessagePos();
   POINT mp;
   mp.x = GET_X_LPARAM(pos);
   mp.y = GET_Y_LPARAM(pos);
-  HWND mouseWnd = ::WindowFromPoint(mp);
+  return ::WindowFromPoint(mp);
+}
+
+bool nsWindow::IsTopLevelMouseExit(HWND aWnd)
+{
+  HWND mouseWnd = WindowAtMouse();
 
   // WinUtils::GetTopLevelHWND() will return a HWND for the window frame
   // (which includes the non-client area).  If the mouse has moved into
@@ -5646,6 +5643,14 @@ nsWindow::ProcessMessage(UINT msg, WPARAM& wParam, LPARAM& lParam,
         break;
       mMousePresent = false;
 
+      // Check if the mouse is over the fullscreen transition window, if so
+      // clear sLastMouseMovePoint. This way the WM_MOUSEMOVE we get after the
+      // transition window disappears will not be ignored, even if the mouse
+      // hasn't moved.
+      if (mTransitionWnd && WindowAtMouse() == mTransitionWnd) {
+        sLastMouseMovePoint = {0};
+      }
+
       // We need to check mouse button states and put them in for
       // wParam.
       WPARAM mouseState = (GetKeyState(VK_LBUTTON) ? MK_LBUTTON : 0)

widget/windows/nsWindow.h

@@ -156,6 +156,7 @@ public:
                                            uint16_t aDuration,
                                            nsISupports* aData,
                                            nsIRunnable* aCallback) override;
+  virtual void CleanupFullscreenTransition() override;
   virtual nsresult        MakeFullScreen(bool aFullScreen,
                                          nsIScreen* aScreen = nullptr) override;
   virtual void            HideWindowChrome(bool aShouldHide) override;
@@ -493,6 +494,7 @@ protected:
    * Misc.
    */
   void                    StopFlashing();
+  static HWND             WindowAtMouse();
   static bool             IsTopLevelMouseExit(HWND aWnd);
   virtual nsresult        SetWindowClipRegion(const nsTArray<LayoutDeviceIntRect>& aRects,
                                               bool aIntersectWithExisting) override;
@@ -672,13 +674,6 @@ protected:
 
   double mSizeConstraintsScale; // scale in effect when setting constraints
 
-  // Used to remember the wParam (i.e. currently pressed modifier keys)
-  // and lParam (i.e. last mouse position) in screen coordinates from
-  // the previous mouse-exit.  Static since it is not
-  // associated with a particular widget (since we exited the widget).
-  static WPARAM sMouseExitwParam;
-  static LPARAM sMouseExitlParamScreen;
-
   // Pointer events processing and management
   WinPointerEvents mPointerEvents;
 };