Bug 1355944 - Back out cset 456dbb5c2b93 (bug 1180799) for causing unexpected behaviour. r=backout

MozReview-Commit-ID: FW1DDt7ax9U

gfx/layers/apz/src/AsyncPanZoomController.cpp

@@ -1150,19 +1150,17 @@ nsEventStatus AsyncPanZoomController::OnTouchMove(const MultiTouchInput& aEvent)
         return nsEventStatus_eIgnore;
       }
 
-      ParentLayerPoint touchPoint = GetFirstTouchPoint(aEvent);
-
       MOZ_ASSERT(GetCurrentTouchBlock());
       if (gfxPrefs::TouchActionEnabled() && GetCurrentTouchBlock()->TouchActionAllowsPanningXY()) {
         // User tries to trigger a touch behavior. If allowed touch behavior is vertical pan
         // + horizontal pan (touch-action value is equal to AUTO) we can return ConsumeNoDefault
         // status immediately to trigger cancel event further. It should happen independent of
         // the parent type (whether it is scrolling or not).
-        StartPanning(touchPoint);
+        StartPanning(aEvent);
         return nsEventStatus_eConsumeNoDefault;
       }
 
-      return StartPanning(touchPoint);
+      return StartPanning(aEvent);
     }
 
     case PANNING:
@@ -1253,9 +1251,43 @@ nsEventStatus AsyncPanZoomController::OnTouchEnd(const MultiTouchInput& aEvent)
   case PAN_MOMENTUM:
   {
     MOZ_ASSERT(GetCurrentTouchBlock());
+    GetCurrentTouchBlock()->GetOverscrollHandoffChain()->FlushRepaints();
     mX.EndTouch(aEvent.mTime);
     mY.EndTouch(aEvent.mTime);
-    return HandleEndOfPan();
+    ParentLayerPoint flingVelocity = GetVelocityVector();
+    // Clear our velocities; if DispatchFling() gives the fling to us,
+    // the fling velocity gets *added* to our existing velocity in
+    // AcceptFling().
+    mX.SetVelocity(0);
+    mY.SetVelocity(0);
+    // Clear our state so that we don't stay in the PANNING state
+    // if DispatchFling() gives the fling to somone else. However,
+    // don't send the state change notification until we've determined
+    // what our final state is to avoid notification churn.
+    StateChangeNotificationBlocker blocker(this);
+    SetState(NOTHING);
+
+    APZC_LOG("%p starting a fling animation if %f >= %f\n", this,
+        flingVelocity.Length().value, gfxPrefs::APZFlingMinVelocityThreshold());
+
+    if (flingVelocity.Length() < gfxPrefs::APZFlingMinVelocityThreshold()) {
+      // Relieve overscroll now if needed, since we will not transition to a fling
+      // animation and then an overscroll animation, and relieve it then.
+      GetCurrentTouchBlock()->GetOverscrollHandoffChain()->SnapBackOverscrolledApzc(this);
+      return nsEventStatus_eConsumeNoDefault;
+    }
+
+    // Make a local copy of the tree manager pointer and check that it's not
+    // null before calling DispatchFling(). This is necessary because Destroy(),
+    // which nulls out mTreeManager, could be called concurrently.
+    if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) {
+      FlingHandoffState handoffState{flingVelocity,
+                                     GetCurrentTouchBlock()->GetOverscrollHandoffChain(),
+                                     false /* not handoff */,
+                                     GetCurrentTouchBlock()->GetScrolledApzc()};
+      treeManagerLocal->DispatchFling(this, handoffState);
+    }
+    return nsEventStatus_eConsumeNoDefault;
   }
   case PINCHING:
     SetState(NOTHING);
@@ -1286,8 +1318,6 @@ nsEventStatus AsyncPanZoomController::OnScaleBegin(const PinchGestureInput& aEve
   APZC_LOG("%p got a scale-begin in state %d\n", this, mState);
 
   mPinchPaintTimerSet = false;
-  mX.StartTouch(aEvent.mLocalFocusPoint.x, aEvent.mTime);
-  mY.StartTouch(aEvent.mLocalFocusPoint.y, aEvent.mTime);
   // Note that there may not be a touch block at this point, if we received the
   // PinchGestureEvent directly from widget code without any touch events.
   if (HasReadyTouchBlock() && !GetCurrentTouchBlock()->TouchActionAllowsPinchZoom()) {
@@ -1312,8 +1342,6 @@ nsEventStatus AsyncPanZoomController::OnScaleBegin(const PinchGestureInput& aEve
 
 nsEventStatus AsyncPanZoomController::OnScale(const PinchGestureInput& aEvent) {
   APZC_LOG("%p got a scale in state %d\n", this, mState);
-  mX.UpdateWithTouchAtDevicePoint(aEvent.mLocalFocusPoint.x, 0, aEvent.mTime);
-  mY.UpdateWithTouchAtDevicePoint(aEvent.mLocalFocusPoint.y, 0, aEvent.mTime);
  
   if (HasReadyTouchBlock() && !GetCurrentTouchBlock()->TouchActionAllowsPinchZoom()) {
     return nsEventStatus_eIgnore;
@@ -1449,6 +1477,8 @@ nsEventStatus AsyncPanZoomController::OnScaleEnd(const PinchGestureInput& aEvent
     }
   }
 
+  SetState(NOTHING);
+
   {
     ReentrantMonitorAutoEnter lock(mMonitor);
     ScheduleComposite();
@@ -1458,86 +1488,32 @@ nsEventStatus AsyncPanZoomController::OnScaleEnd(const PinchGestureInput& aEvent
 
   // Non-negative focus point would indicate that one finger is still down
   if (aEvent.mLocalFocusPoint.x != -1 && aEvent.mLocalFocusPoint.y != -1) {
-    if (mZoomConstraints.mAllowZoom) {
-      mPanDirRestricted = false;
-      SetState(TOUCHING);
-    } else {
-      StartPanning(aEvent.mLocalFocusPoint);
-    }
+    mPanDirRestricted = false;
+    mX.StartTouch(aEvent.mLocalFocusPoint.x, aEvent.mTime);
+    mY.StartTouch(aEvent.mLocalFocusPoint.y, aEvent.mTime);
+    SetState(TOUCHING);
   } else {
     // Otherwise, handle the fingers being lifted.
-    mX.EndTouch(aEvent.mTime);
-    mY.EndTouch(aEvent.mTime);
-    if (mZoomConstraints.mAllowZoom) {
-      ReentrantMonitorAutoEnter lock(mMonitor);
+    ReentrantMonitorAutoEnter lock(mMonitor);
 
-      // We can get into a situation where we are overscrolled at the end of a
-      // pinch if we go into overscroll with a two-finger pan, and then turn
-      // that into a pinch by increasing the span sufficiently. In such a case,
-      // there is no snap-back animation to get us out of overscroll, so we need
-      // to get out of it somehow.
-      // Moreover, in cases of scroll handoff, the overscroll can be on an APZC
-      // further up in the handoff chain rather than on the current APZC, so
-      // we need to clear overscroll along the entire handoff chain.
-      if (HasReadyTouchBlock()) {
-        GetCurrentTouchBlock()->GetOverscrollHandoffChain()->ClearOverscroll();
-      } else {
-        ClearOverscroll();
-      }
-      // Along with clearing the overscroll, we also want to snap to the nearest
-      // snap point as appropriate.
-      ScrollSnap();
+    // We can get into a situation where we are overscrolled at the end of a
+    // pinch if we go into overscroll with a two-finger pan, and then turn
+    // that into a pinch by increasing the span sufficiently. In such a case,
+    // there is no snap-back animation to get us out of overscroll, so we need
+    // to get out of it somehow.
+    // Moreover, in cases of scroll handoff, the overscroll can be on an APZC
+    // further up in the handoff chain rather than on the current APZC, so
+    // we need to clear overscroll along the entire handoff chain.
+    if (HasReadyTouchBlock()) {
+      GetCurrentTouchBlock()->GetOverscrollHandoffChain()->ClearOverscroll();
     } else {
-      // when zoom is not allowed
-      if (mState == PINCHING) {
-        // still pinching
-        if (HasReadyTouchBlock()) {
-          return HandleEndOfPan();
-        }
-      }
+      ClearOverscroll();
     }
-  }
-  return nsEventStatus_eConsumeNoDefault;
-}
-
-nsEventStatus AsyncPanZoomController::HandleEndOfPan()
-{
-  MOZ_ASSERT(GetCurrentTouchBlock());
-  GetCurrentTouchBlock()->GetOverscrollHandoffChain()->FlushRepaints();
-  ParentLayerPoint flingVelocity = GetVelocityVector();
-
-  // Clear our velocities; if DispatchFling() gives the fling to us,
-  // the fling velocity gets *added* to our existing velocity in
-  // AcceptFling().
-  mX.SetVelocity(0);
-  mY.SetVelocity(0);
-  // Clear our state so that we don't stay in the PANNING state
-  // if DispatchFling() gives the fling to somone else. However,
-  // don't send the state change notification until we've determined
-  // what our final state is to avoid notification churn.
-  StateChangeNotificationBlocker blocker(this);
-  SetState(NOTHING);
-
-  APZC_LOG("%p starting a fling animation if %f >= %f\n", this,
-      flingVelocity.Length().value, gfxPrefs::APZFlingMinVelocityThreshold());
-
-  if (flingVelocity.Length() < gfxPrefs::APZFlingMinVelocityThreshold()) {
-    // Relieve overscroll now if needed, since we will not transition to a fling
-    // animation and then an overscroll animation, and relieve it then.
-    GetCurrentTouchBlock()->GetOverscrollHandoffChain()->SnapBackOverscrolledApzc(this);
-    return nsEventStatus_eConsumeNoDefault;
+    // Along with clearing the overscroll, we also want to snap to the nearest
+    // snap point as appropriate.
+    ScrollSnap();
   }
 
-  // Make a local copy of the tree manager pointer and check that it's not
-  // null before calling DispatchFling(). This is necessary because Destroy(),
-  // which nulls out mTreeManager, could be called concurrently.
-  if (APZCTreeManager* treeManagerLocal = GetApzcTreeManager()) {
-    FlingHandoffState handoffState{flingVelocity,
-                                  GetCurrentTouchBlock()->GetOverscrollHandoffChain(),
-                                  false /* not handoff */,
-                                  GetCurrentTouchBlock()->GetScrolledApzc()};
-    treeManagerLocal->DispatchFling(this, handoffState);
-  }
   return nsEventStatus_eConsumeNoDefault;
 }
 
@@ -2348,12 +2324,12 @@ void AsyncPanZoomController::HandlePanningUpdate(const ScreenPoint& aPanDistance
   }
 }
 
-nsEventStatus
-AsyncPanZoomController::StartPanning(const ParentLayerPoint& aStartPoint) {
+nsEventStatus AsyncPanZoomController::StartPanning(const MultiTouchInput& aEvent) {
   ReentrantMonitorAutoEnter lock(mMonitor);
 
-  float dx = mX.PanDistance(aStartPoint.x);
-  float dy = mY.PanDistance(aStartPoint.y);
+  ParentLayerPoint point = GetFirstTouchPoint(aEvent);
+  float dx = mX.PanDistance(point.x);
+  float dy = mY.PanDistance(point.y);
 
   double angle = atan2(dy, dx); // range [-pi, pi]
   angle = fabs(angle); // range [0, pi]

gfx/layers/apz/src/AsyncPanZoomController.h

@@ -457,7 +457,6 @@ protected:
   nsEventStatus OnPanEnd(const PanGestureInput& aEvent);
   nsEventStatus OnPanMomentumStart(const PanGestureInput& aEvent);
   nsEventStatus OnPanMomentumEnd(const PanGestureInput& aEvent);
-  nsEventStatus HandleEndOfPan();
 
   /**
    * Helper methods for handling scroll wheel events.
@@ -577,7 +576,7 @@ protected:
    * Sets up anything needed for panning. This takes us out of the "TOUCHING"
    * state and starts actually panning us.
    */
-  nsEventStatus StartPanning(const ParentLayerPoint& aStartPoint);
+  nsEventStatus StartPanning(const MultiTouchInput& aStartPoint);
 
   /**
    * Wrapper for Axis::UpdateWithTouchAtDevicePoint(). Calls this function for

gfx/layers/apz/test/gtest/InputUtils.h

@@ -138,7 +138,7 @@ PinchWithPinchInput(const RefPtr<InputReceiver>& aTarget,
       CreatePinchGestureInput(PinchGestureInput::PINCHGESTURE_END,
                               // note: negative values here tell APZC
                               //       not to turn the pinch into a pan
-                              ScreenIntPoint(-1, -1), 10.0 * aScale, 10.0 * aScale),
+                              aFocus, -1.0, -1.0),
       nullptr);
   if (aOutEventStatuses) {
     (*aOutEventStatuses)[2] = actualStatus;