Bug 833795 - Use screen relative co-ordinates for gestures; r=drs

dom/ipc/TabParent.cpp

@@ -637,6 +637,10 @@ TabParent::TryCapture(const nsGUIEvent& aEvent)
 {
   MOZ_ASSERT(sEventCapturer == this && mEventCaptureDepth > 0);
 
+  if (mIsDestroyed) {
+    return false;
+  }
+
   if (aEvent.eventStructType != NS_TOUCH_EVENT) {
     // Only capture of touch events is implemented, for now.
     return false;
@@ -657,19 +661,29 @@ TabParent::TryCapture(const nsGUIEvent& aEvent)
     return false;
   }
 
-  // Adjust the widget coordinates to be relative to our frame.
-  nsRefPtr<nsFrameLoader> frameLoader = GetFrameLoader();
+  if (RenderFrameParent* rfp = GetRenderFrame()) {
+    // We need to process screen relative events co-ordinates for gestures to
+    // avoid phantom movement when the frame moves.
+    rfp->NotifyInputEvent(event);
 
-  if (!frameLoader) {
-    // No frame anymore?
-    sEventCapturer = nullptr;
-    return false;
+    // Adjust the widget coordinates to be relative to our frame.
+    nsRefPtr<nsFrameLoader> frameLoader = GetFrameLoader();
+
+    if (!frameLoader) {
+      // No frame anymore?
+      sEventCapturer = nullptr;
+      return false;
+    }
+
+    // Remove the frame offset and compensate for zoom.
+    nsEventStateManager::MapEventCoordinatesForChildProcess(frameLoader,
+                                                            &event);
+    rfp->ApplyZoomCompensationToEvent(&event);
   }
 
-  nsEventStateManager::MapEventCoordinatesForChildProcess(frameLoader, &event);
-
-  SendRealTouchEvent(event);
-  return true;
+  return (event.message == NS_TOUCH_MOVE) ?
+    PBrowserParent::SendRealTouchMoveEvent(event) :
+    PBrowserParent::SendRealTouchEvent(event);
 }
 
 bool
@@ -1381,7 +1395,8 @@ TabParent::MaybeForwardEventToRenderFrame(const nsInputEvent& aEvent,
                                           nsInputEvent* aOutEvent)
 {
   if (RenderFrameParent* rfp = GetRenderFrame()) {
-    rfp->NotifyInputEvent(aEvent, aOutEvent);
+    rfp->NotifyInputEvent(aEvent);
+    rfp->ApplyZoomCompensationToEvent(aOutEvent);
   }
 }
 

gfx/layers/ipc/AsyncPanZoomController.cpp

@@ -225,20 +225,8 @@ WidgetSpaceToCompensatedViewportSpace(const gfx::Point& aPoint,
 }
 
 nsEventStatus
-AsyncPanZoomController::ReceiveInputEvent(const nsInputEvent& aEvent,
-                                          nsInputEvent* aOutEvent)
+AsyncPanZoomController::ReceiveMainThreadInputEvent(const nsInputEvent& aEvent)
 {
-  gfxFloat currentResolution;
-  gfx::Point currentScrollOffset, lastScrollOffset;
-  {
-    MonitorAutoLock monitor(mMonitor);
-    currentResolution = CalculateResolution(mFrameMetrics).width;
-    currentScrollOffset = gfx::Point(mFrameMetrics.mScrollOffset.x,
-                                     mFrameMetrics.mScrollOffset.y);
-    lastScrollOffset = gfx::Point(mLastContentPaintMetrics.mScrollOffset.x,
-                                  mLastContentPaintMetrics.mScrollOffset.y);
-  }
-
   nsEventStatus status;
   switch (aEvent.eventStructType) {
   case NS_TOUCH_EVENT: {
@@ -256,9 +244,21 @@ AsyncPanZoomController::ReceiveInputEvent(const nsInputEvent& aEvent,
     break;
   }
 
-  switch (aEvent.eventStructType) {
+  return status;
+}
+
+void
+AsyncPanZoomController::ApplyZoomCompensationToEvent(nsInputEvent* aEvent)
+{
+  gfxFloat currentResolution;
+  {
+    MonitorAutoLock monitor(mMonitor);
+    currentResolution = CalculateResolution(mFrameMetrics).width;
+  }
+
+  switch (aEvent->eventStructType) {
   case NS_TOUCH_EVENT: {
-    nsTouchEvent* touchEvent = static_cast<nsTouchEvent*>(aOutEvent);
+    nsTouchEvent* touchEvent = static_cast<nsTouchEvent*>(aEvent);
     const nsTArray<nsCOMPtr<nsIDOMTouch> >& touches = touchEvent->touches;
     for (uint32_t i = 0; i < touches.Length(); ++i) {
       nsIDOMTouch* touch = touches[i];
@@ -273,14 +273,12 @@ AsyncPanZoomController::ReceiveInputEvent(const nsInputEvent& aEvent,
   }
   default: {
     gfx::Point refPoint = WidgetSpaceToCompensatedViewportSpace(
-      gfx::Point(aOutEvent->refPoint.x, aOutEvent->refPoint.y),
+      gfx::Point(aEvent->refPoint.x, aEvent->refPoint.y),
       currentResolution);
-    aOutEvent->refPoint = nsIntPoint(refPoint.x, refPoint.y);
+    aEvent->refPoint = nsIntPoint(refPoint.x, refPoint.y);
     break;
   }
   }
-
-  return status;
 }
 
 nsEventStatus AsyncPanZoomController::ReceiveInputEvent(const InputData& aEvent) {

gfx/layers/ipc/AsyncPanZoomController.h

@@ -92,17 +92,22 @@ public:
   nsEventStatus ReceiveInputEvent(const InputData& aEvent);
 
   /**
-   * Special handler for nsInputEvents. Also sets |aOutEvent| (which is assumed
-   * to be an already-existing instance of an nsInputEvent which may be an
-   * nsTouchEvent) to have its touch points in DOM space. This is so that the
-   * touches can be passed through the DOM and content can handle them.
+   * Special handler for nsInputEvents. |aEvent| is in screen relative
+   * co-ordinates.
    *
-   * NOTE: Be careful of invoking the nsInputEvent variant. This can only be
-   * called on the main thread. See widget/InputData.h for more information on
-   * why we have InputData and nsInputEvent separated.
+   * NOTE: This can only be called on the main thread. See widget/InputData.h
+   * for more information on why we have InputData and nsInputEvent separated.
    */
-  nsEventStatus ReceiveInputEvent(const nsInputEvent& aEvent,
-                                  nsInputEvent* aOutEvent);
+  nsEventStatus ReceiveMainThreadInputEvent(const nsInputEvent& aEvent);
+
+  /**
+   * Transform from frame relative co-ordinates to DOM relative co-ordinates.
+   * This method updates |aEvent| (which is assumed to be an already-existing
+   * instance of an nsInputEvent which may be an nsTouchEvent) to have its touch
+   * points in DOM space. This is so that the touches can be passed through the
+   * DOM and content can handle them.
+   */
+  void ApplyZoomCompensationToEvent(nsInputEvent* aEvent);
 
   /**
    * Updates the composition bounds, i.e. the dimensions of the final size of

layout/ipc/RenderFrameParent.cpp

@@ -781,11 +781,18 @@ RenderFrameParent::OwnerContentChanged(nsIContent* aContent)
 }
 
 void
-RenderFrameParent::NotifyInputEvent(const nsInputEvent& aEvent,
-                                    nsInputEvent* aOutEvent)
+RenderFrameParent::NotifyInputEvent(const nsInputEvent& aEvent)
 {
   if (mPanZoomController) {
-    mPanZoomController->ReceiveInputEvent(aEvent, aOutEvent);
+    mPanZoomController->ReceiveMainThreadInputEvent(aEvent);
+  }
+}
+
+void
+RenderFrameParent::ApplyZoomCompensationToEvent(nsInputEvent* aEvent)
+{
+  if (mPanZoomController) {
+    mPanZoomController->ApplyZoomCompensationToEvent(aEvent);
   }
 }
 

layout/ipc/RenderFrameParent.h

@@ -92,8 +92,9 @@ public:
 
   void SetBackgroundColor(nscolor aColor) { mBackgroundColor = gfxRGBA(aColor); };
 
-  void NotifyInputEvent(const nsInputEvent& aEvent,
-                        nsInputEvent* aOutEvent);
+  void NotifyInputEvent(const nsInputEvent& aEvent);
+
+  void ApplyZoomCompensationToEvent(nsInputEvent* aEvent);
 
   void NotifyDimensionsChanged(int width, int height);