Bug 976605 - Group some fields of AsyncPanZoomController into a TouchBlockState structure. r=kats

--HG--
extra : source : 80ac8ba2dec8939065411e86526bcdfa1c4b3f6d

gfx/layers/ipc/AsyncPanZoomController.cpp

@@ -421,9 +421,6 @@ AsyncPanZoomController::AsyncPanZoomController(uint64_t aLayersId,
      mCurrentAsyncScrollOffset(0, 0),
      mAsyncScrollTimeoutTask(nullptr),
      mHandlingTouchQueue(false),
-     mAllowedTouchBehaviorSet(false),
-     mPreventDefault(false),
-     mPreventDefaultSet(false),
      mTreeManager(aTreeManager),
      mScrollParentId(FrameMetrics::NULL_SCROLL_ID),
      mAPZCId(sAsyncPanZoomControllerCount++),
@@ -499,6 +496,12 @@ AsyncPanZoomController::GetTouchStartTolerance()
 }
 
 nsEventStatus AsyncPanZoomController::ReceiveInputEvent(const InputData& aEvent) {
+  if (aEvent.mInputType == MULTITOUCH_INPUT &&
+      aEvent.AsMultiTouchInput().mType == MultiTouchInput::MULTITOUCH_START) {
+    // Starting a new touch block, clear old touch block state.
+    mTouchBlockState = TouchBlockState();
+  }
+
   // If we may have touch listeners and touch action property is enabled, we
   // enable the machinery that allows touch listeners to preventDefault any touch inputs
   // and also waits for the allowed touch behavior values to be received from the outside.
@@ -510,10 +513,6 @@ nsEventStatus AsyncPanZoomController::ReceiveInputEvent(const InputData& aEvent)
       (mState == NOTHING || mState == TOUCHING || IsPanningState(mState))) {
     const MultiTouchInput& multiTouchInput = aEvent.AsMultiTouchInput();
     if (multiTouchInput.mType == MultiTouchInput::MULTITOUCH_START) {
-      mAllowedTouchBehaviors.Clear();
-      mAllowedTouchBehaviorSet = false;
-      mPreventDefault = false;
-      mPreventDefaultSet = false;
       SetState(WAITING_CONTENT_RESPONSE);
     }
   }
@@ -1905,8 +1904,8 @@ void AsyncPanZoomController::ZoomToRect(CSSRect aRect) {
 }
 
 void AsyncPanZoomController::ContentReceivedTouch(bool aPreventDefault) {
-  mPreventDefaultSet = true;
-  mPreventDefault = aPreventDefault;
+  mTouchBlockState.mPreventDefaultSet = true;
+  mTouchBlockState.mPreventDefault = aPreventDefault;
   CheckContentResponse();
 }
 
@@ -1914,11 +1913,11 @@ void AsyncPanZoomController::CheckContentResponse() {
   bool canProceedToTouchState = true;
 
   if (mFrameMetrics.mMayHaveTouchListeners) {
-    canProceedToTouchState &= mPreventDefaultSet;
+    canProceedToTouchState &= mTouchBlockState.mPreventDefaultSet;
   }
 
   if (mTouchActionPropertyEnabled) {
-    canProceedToTouchState &= mAllowedTouchBehaviorSet;
+    canProceedToTouchState &= mTouchBlockState.mAllowedTouchBehaviorSet;
   }
 
   if (!canProceedToTouchState) {
@@ -1931,14 +1930,14 @@ void AsyncPanZoomController::CheckContentResponse() {
   }
 
   if (mState == WAITING_CONTENT_RESPONSE) {
-    if (!mPreventDefault) {
+    if (!mTouchBlockState.mPreventDefault) {
       SetState(NOTHING);
     }
 
     mHandlingTouchQueue = true;
 
     while (!mTouchQueue.IsEmpty()) {
-      if (!mPreventDefault) {
+      if (!mTouchBlockState.mPreventDefault) {
         HandleInputEvent(mTouchQueue[0]);
       }
 
@@ -1962,8 +1961,8 @@ bool AsyncPanZoomController::TouchActionAllowZoom() {
 
   // Pointer events specification implies all touch points to allow zoom
   // to perform it.
-  for (size_t i = 0; i < mAllowedTouchBehaviors.Length(); i++) {
-    if (!(mAllowedTouchBehaviors[i] & AllowedTouchBehavior::ZOOM)) {
+  for (size_t i = 0; i < mTouchBlockState.mAllowedTouchBehaviors.Length(); i++) {
+    if (!(mTouchBlockState.mAllowedTouchBehaviors[i] & AllowedTouchBehavior::ZOOM)) {
       return false;
     }
   }
@@ -1973,8 +1972,8 @@ bool AsyncPanZoomController::TouchActionAllowZoom() {
 
 AsyncPanZoomController::TouchBehaviorFlags
 AsyncPanZoomController::GetTouchBehavior(uint32_t touchIndex) {
-  if (touchIndex < mAllowedTouchBehaviors.Length()) {
-    return mAllowedTouchBehaviors[touchIndex];
+  if (touchIndex < mTouchBlockState.mAllowedTouchBehaviors.Length()) {
+    return mTouchBlockState.mAllowedTouchBehaviors[touchIndex];
   }
   return DefaultTouchBehavior;
 }
@@ -1988,9 +1987,9 @@ AsyncPanZoomController::GetAllowedTouchBehavior(ScreenIntPoint& aPoint) {
 }
 
 void AsyncPanZoomController::SetAllowedTouchBehavior(const nsTArray<TouchBehaviorFlags>& aBehaviors) {
-  mAllowedTouchBehaviors.Clear();
-  mAllowedTouchBehaviors.AppendElements(aBehaviors);
-  mAllowedTouchBehaviorSet = true;
+  mTouchBlockState.mAllowedTouchBehaviors.Clear();
+  mTouchBlockState.mAllowedTouchBehaviors.AppendElements(aBehaviors);
+  mTouchBlockState.mAllowedTouchBehaviorSet = true;
   CheckContentResponse();
 }
 

gfx/layers/ipc/AsyncPanZoomController.h

@@ -562,6 +562,32 @@ private:
                                  was not set yet. we still need to abort animations. */
   };
 
+  // State related to a single touch block. Does not persist across touch blocks.
+  struct TouchBlockState {
+
+    TouchBlockState()
+      :  mAllowedTouchBehaviorSet(false),
+         mPreventDefault(false),
+         mPreventDefaultSet(false)
+    {}
+
+    // Values of allowed touch behavior for touch points of this touch block.
+    // Since there are maybe a few current active touch points per time (multitouch case)
+    // and each touch point should have its own value of allowed touch behavior- we're
+    // keeping an array of allowed touch behavior values, not the single value.
+    nsTArray<TouchBehaviorFlags> mAllowedTouchBehaviors;
+
+    // Specifies whether mAllowedTouchBehaviors is set for this touch events block.
+    bool mAllowedTouchBehaviorSet;
+
+    // Flag used to specify that content prevented the default behavior of this
+    // touch events block.
+    bool mPreventDefault;
+
+    // Specifies whether mPreventDefault property is set for this touch events block.
+    bool mPreventDefaultSet;
+  };
+
   /*
    * Returns whether current touch behavior values allow zooming.
    */
@@ -725,21 +751,8 @@ private:
   // and we don't want to queue the events back up again.
   bool mHandlingTouchQueue;
 
-  // Values of allowed touch behavior for current touch points.
-  // Since there are maybe a few current active touch points per time (multitouch case)
-  // and each touch point should have its own value of allowed touch behavior- we're
-  // keeping an array of allowed touch behavior values, not the single value.
-  nsTArray<TouchBehaviorFlags> mAllowedTouchBehaviors;
-
-  // Specifies whether mAllowedTouchBehaviors is set for current touch events block.
-  bool mAllowedTouchBehaviorSet;
-
-  // Flag used to specify that content prevented the default behavior of the current
-  // touch events block.
-  bool mPreventDefault;
-
-  // Specifies whether mPreventDefault property is set for current touch events block.
-  bool mPreventDefaultSet;
+  // Stores information about the current touch block.
+  TouchBlockState mTouchBlockState;
 
   // Extra offset to add in SampleContentTransformForFrame for testing
   CSSPoint mTestAsyncScrollOffset;