Bug 914829 - MetroInput should forward touch input to apz first, then to content. r=kats, tabraldes

gfx/layers/composite/APZCTreeManager.cpp

@@ -213,6 +213,7 @@ ApplyTransform(nsIntPoint* aPoint, const gfx3DMatrix& aMatrix)
 nsEventStatus
 APZCTreeManager::ReceiveInputEvent(const InputData& aEvent)
 {
+  nsEventStatus result = nsEventStatus_eIgnore;
   gfx3DMatrix transformToApzc;
   gfx3DMatrix transformToScreen;
   switch (aEvent.mInputType) {
@@ -238,7 +239,7 @@ APZCTreeManager::ReceiveInputEvent(const InputData& aEvent)
         for (size_t i = 0; i < inputForApzc.mTouches.Length(); i++) {
           ApplyTransform(&(inputForApzc.mTouches[i].mScreenPoint), transformToApzc);
         }
-        mApzcForInputBlock->ReceiveInputEvent(inputForApzc);
+        result = mApzcForInputBlock->ReceiveInputEvent(inputForApzc);
         // If we have an mApzcForInputBlock and it's the end of the touch sequence
         // then null it out so we don't keep a dangling reference and leak things.
         if (multiTouchInput.mType == MultiTouchInput::MULTITOUCH_CANCEL ||
@@ -254,7 +255,7 @@ APZCTreeManager::ReceiveInputEvent(const InputData& aEvent)
         GetInputTransforms(apzc, transformToApzc, transformToScreen);
         PinchGestureInput inputForApzc(pinchInput);
         ApplyTransform(&(inputForApzc.mFocusPoint), transformToApzc);
-        apzc->ReceiveInputEvent(inputForApzc);
+        result = apzc->ReceiveInputEvent(inputForApzc);
       }
       break;
     } case TAPGESTURE_INPUT: {
@@ -264,12 +265,12 @@ APZCTreeManager::ReceiveInputEvent(const InputData& aEvent)
         GetInputTransforms(apzc, transformToApzc, transformToScreen);
         TapGestureInput inputForApzc(tapInput);
         ApplyTransform(&(inputForApzc.mPoint), transformToApzc);
-        apzc->ReceiveInputEvent(inputForApzc);
+        result = apzc->ReceiveInputEvent(inputForApzc);
       }
       break;
     }
   }
-  return nsEventStatus_eIgnore;
+  return result;
 }
 
 nsEventStatus

widget/windows/winrt/MetroInput.cpp

@@ -179,6 +179,20 @@ namespace {
     aData->mChanged = false;
     return PL_DHASH_NEXT;
   }
+
+  // Helper for making sure event ptrs get freed.
+  class AutoDeleteEvent
+  {
+  public:
+    AutoDeleteEvent(nsGUIEvent* aPtr) :
+      mPtr(aPtr) {}
+    ~AutoDeleteEvent() {
+      if (mPtr) {
+        delete mPtr;
+      }
+    }
+    nsGUIEvent* mPtr;
+  };
 }
 
 namespace mozilla {
@@ -431,6 +445,8 @@ MetroInput::OnPointerPressed(UI::Core::ICoreWindow* aSender,
     mTouchStartDefaultPrevented = false;
     mTouchMoveDefaultPrevented = false;
     mIsFirstTouchMove = true;
+    mCancelable = true;
+    mTouchCancelSent = false;
     InitTouchEventTouchList(touchEvent);
     DispatchAsyncTouchEventWithCallback(touchEvent, &MetroInput::OnPointerPressedCallback);
   } else {
@@ -449,10 +465,12 @@ MetroInput::OnPointerPressedCallback()
 {
   nsEventStatus status = DeliverNextQueuedTouchEvent();
   mTouchStartDefaultPrevented = (nsEventStatus_eConsumeNoDefault == status);
-  // If content cancelled the first touchstart don't generate any gesture based
-  // input - clear the recognizer state without sending any events.
   if (mTouchStartDefaultPrevented) {
+    // If content canceled the first touchstart don't generate any gesture based
+    // input - clear the recognizer state without sending any events.
     mGestureRecognizer->CompleteGesture();
+    // Let the apz know content wants to consume touch events.
+    mWidget->ApzContentConsumingTouch();
   }
 }
 
@@ -549,12 +567,15 @@ MetroInput::OnPointerMoved(UI::Core::ICoreWindow* aSender,
 void
 MetroInput::OnFirstPointerMoveCallback()
 {
-  nsTouchEvent* event = static_cast<nsTouchEvent*>(mInputEventQueue.PopFront());
-  MOZ_ASSERT(event);
-  nsEventStatus status;
-  mWidget->DispatchEvent(event, status);
+  nsEventStatus status = DeliverNextQueuedTouchEvent();
+  mCancelable = false;
   mTouchMoveDefaultPrevented = (nsEventStatus_eConsumeNoDefault == status);
-  delete event;
+  // Let the apz know whether content wants to consume touch events
+  if (mTouchMoveDefaultPrevented) {
+    mWidget->ApzContentConsumingTouch();
+  } else if (!mTouchMoveDefaultPrevented && !mTouchStartDefaultPrevented) {
+    mWidget->ApzContentIgnoringTouch();
+  }
 }
 
 // This event is raised when the user lifts the left mouse button, lifts a
@@ -1096,17 +1117,67 @@ MetroInput::DispatchAsyncTouchEventIgnoreStatus(nsTouchEvent* aEvent)
 nsEventStatus
 MetroInput::DeliverNextQueuedTouchEvent()
 {
+  nsEventStatus status;
   nsTouchEvent* event = static_cast<nsTouchEvent*>(mInputEventQueue.PopFront());
   MOZ_ASSERT(event);
-  nsEventStatus status;
+
+  AutoDeleteEvent wrap(event);
+
+  /*
+   * We go through states here and make different decisions in each:
+   *
+   * 1) delivering first touchpoint touchstart or its first touchmove
+   *  Our callers (OnFirstPointerMoveCallback, OnPointerPressedCallback) will
+   *  check our result and set mTouchStartDefaultPrevented or
+   *  mTouchMoveDefaultPrevented appropriately. Deliver touch events to the apz
+   *  (ignoring return result) and to content and return the content event
+   *  status result to our caller.
+   * 2) mTouchStartDefaultPrevented or mTouchMoveDefaultPrevented are true
+   *  Deliver touch directly to content and bypass the apz. Our callers
+   *  handle calling cancel for the touch sequence on the apz.
+   * 3) mTouchStartDefaultPrevented and mTouchMoveDefaultPrevented are false
+   *  Deliver events to the apz. If the apz returns eConsumeNoDefault dispatch
+   *  a touchcancel to content and do not deliver any additional events there.
+   *  (If the apz is doing something with the events we can save ourselves
+   *  the overhead of delivering dom events.)
+   */
+
+  // Check if content called preventDefault on touchstart or first touchmove. If so
+  // send directly to content, do not forward to the apz.
+  if (mTouchStartDefaultPrevented || mTouchMoveDefaultPrevented) {
+    // continue delivering events to content
     mWidget->DispatchEvent(event, status);
-  // Deliver to the apz if content has *not* cancelled touchstart or the first touchmove.
-  if (!mTouchStartDefaultPrevented && !mTouchMoveDefaultPrevented && MetroWidget::sAPZC) {
-    MultiTouchInput inputData(*event);
-    MetroWidget::sAPZC->ReceiveInputEvent(inputData);
-  }
-  delete event;
     return status;
+  }
+
+  // Forward event data to apz. If the apz consumes the event, don't forward to
+  // content if this is not a cancelable event.
+  status = mWidget->ApzReceiveInputEvent(event);
+  if (!mCancelable && status == nsEventStatus_eConsumeNoDefault) {
+    if (!mTouchCancelSent) {
+      mTouchCancelSent = true;
+      DispatchTouchCancel();
+    }
+    return status;
+  }
+
+  // Deliver event to content
+  mWidget->DispatchEvent(event, status);
+  return status;
+}
+
+void
+MetroInput::DispatchTouchCancel()
+{
+  LogFunction();
+  // From the spec: The touch point or points that were removed must be
+  // included in the changedTouches attribute of the TouchEvent, and must
+  // not be included in the touches and targetTouches attributes. 
+  // (We are 'removing' all touch points that have been sent to content
+  // thus far.)
+  nsTouchEvent touchEvent(true, NS_TOUCH_CANCEL, mWidget.Get());
+  InitTouchEventTouchList(&touchEvent);
+  mWidget->DispatchEvent(&touchEvent, sThrowawayStatus);
 }
 
 void

widget/windows/winrt/MetroInput.h

@@ -196,6 +196,8 @@ private:
   bool mTouchStartDefaultPrevented;
   bool mTouchMoveDefaultPrevented;
   bool mIsFirstTouchMove;
+  bool mCancelable;
+  bool mTouchCancelSent;
 
   // In the old Win32 way of doing things, we would receive a WM_TOUCH event
   // that told us the state of every touchpoint on the touch surface.  If
@@ -271,6 +273,7 @@ private:
 
   // Sync event dispatching
   void DispatchEventIgnoreStatus(nsGUIEvent *aEvent);
+  void DispatchTouchCancel();
 
   nsDeque mInputEventQueue;
   static nsEventStatus sThrowawayStatus;

widget/windows/winrt/MetroWidget.cpp

@@ -31,6 +31,7 @@
 #endif
 #include "UIABridgePrivate.h"
 #include "WinMouseScrollHandler.h"
+#include "InputData.h"
 
 using namespace Microsoft::WRL;
 using namespace Microsoft::WRL::Wrappers;
@@ -978,6 +979,39 @@ CompositorParent* MetroWidget::NewCompositorParent(int aSurfaceWidth, int aSurfa
   return compositor;
 }
 
+void
+MetroWidget::ApzContentConsumingTouch()
+{
+  LogFunction();
+  if (!MetroWidget::sAPZC) {
+    return;
+  }
+  MetroWidget::sAPZC->ContentReceivedTouch(mRootLayerTreeId, true);
+}
+
+void
+MetroWidget::ApzContentIgnoringTouch()
+{
+  LogFunction();
+  if (!MetroWidget::sAPZC) {
+    return;
+  }
+  MetroWidget::sAPZC->ContentReceivedTouch(mRootLayerTreeId, false);
+}
+
+nsEventStatus
+MetroWidget::ApzReceiveInputEvent(nsTouchEvent* aEvent)
+{
+  MOZ_ASSERT(aEvent);
+
+  if (!MetroWidget::sAPZC) {
+    return nsEventStatus_eIgnore;
+  }
+
+  MultiTouchInput inputData(*aEvent);
+  return MetroWidget::sAPZC->ReceiveInputEvent(inputData);
+}
+
 LayerManager*
 MetroWidget::GetLayerManager(PLayerTransactionChild* aShadowManager,
                              LayersBackend aBackendHint,

widget/windows/winrt/MetroWidget.h

@@ -196,6 +196,10 @@ public:
   virtual void SetTransparencyMode(nsTransparencyMode aMode);
   virtual nsTransparencyMode GetTransparencyMode();
 
+  // APZ related apis
+  void ApzContentConsumingTouch();
+  void ApzContentIgnoringTouch();
+  nsEventStatus ApzReceiveInputEvent(nsTouchEvent* aEvent);
   nsresult RequestContentScroll();
   void RequestContentRepaintImplMainThread();