Bug 920036 - Send touch inputs through the APZ before sending them to the gecko thread. r=mwu,dvander,smaug

dom/ipc/TabParent.cpp

@@ -2208,7 +2208,11 @@ TabParent::MaybeForwardEventToRenderFrame(WidgetInputEvent& aEvent,
                                           ScrollableLayerGuid* aOutTargetGuid,
                                           uint64_t* aOutInputBlockId)
 {
-  if (aEvent.mClass == eWheelEventClass) {
+  if (aEvent.mClass == eWheelEventClass
+#ifdef MOZ_WIDGET_GONK
+      || aEvent.mClass == eTouchEventClass
+#endif
+     ) {
     // Wheel events must be sent to APZ directly from the widget. New APZ-
     // aware events should follow suit and move there as well. However, we
     // do need to inform the child process of the correct target and block

widget/gonk/GeckoTouchDispatcher.cpp

@@ -24,7 +24,6 @@
 #include "gfxPrefs.h"
 #include "libui/Input.h"
 #include "mozilla/ClearOnShutdown.h"
-#include "mozilla/MouseEvents.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/TouchEvents.h"
@@ -333,21 +332,6 @@ GeckoTouchDispatcher::ResampleTouchMoves(MultiTouchInput& aOutTouch, TimeStamp a
   aOutTouch.mTimeStamp = sampleTime;
 }
 
-// Some touch events get sent as mouse events. If APZ doesn't capture the event
-// and if a touch only has 1 touch input, we can send a mouse event.
-void
-GeckoTouchDispatcher::DispatchMouseEvent(MultiTouchInput& aMultiTouch,
-                                         bool aForwardToChildren)
-{
-  WidgetMouseEvent mouseEvent = aMultiTouch.ToWidgetMouseEvent(nullptr);
-  if (mouseEvent.message == NS_EVENT_NULL) {
-    return;
-  }
-
-  mouseEvent.mFlags.mNoCrossProcessBoundaryForwarding = !aForwardToChildren;
-  nsWindow::DispatchInputEvent(mouseEvent);
-}
-
 static bool
 IsExpired(const MultiTouchInput& aTouch)
 {
@@ -372,9 +356,7 @@ GeckoTouchDispatcher::DispatchTouchEvent(MultiTouchInput& aMultiTouch)
     return;
   }
 
-  bool captured = false;
-  WidgetTouchEvent event = aMultiTouch.ToWidgetTouchEvent(nullptr);
-  nsEventStatus status = nsWindow::DispatchInputEvent(event, &captured);
+  nsWindow::DispatchTouchInput(aMultiTouch);
 
   if (mEnabledUniformityInfo && profiler_is_active()) {
     const char* touchAction = "Invalid";
@@ -395,11 +377,6 @@ GeckoTouchDispatcher::DispatchTouchEvent(MultiTouchInput& aMultiTouch)
     TouchDataPayload* payload = new TouchDataPayload(touchPoint);
     PROFILER_MARKER_PAYLOAD(touchAction, payload);
   }
-
-  if (!captured && (aMultiTouch.mTouches.Length() == 1)) {
-    bool forwardToChildren = status != nsEventStatus_eConsumeNoDefault;
-    DispatchMouseEvent(aMultiTouch, forwardToChildren);
-  }
 }
 
 } // namespace mozilla

widget/gonk/nsWindow.cpp

@@ -47,6 +47,9 @@
 #include "mozilla/gfx/2D.h"
 #include "mozilla/layers/APZCTreeManager.h"
 #include "mozilla/layers/CompositorParent.h"
+#include "mozilla/layers/InputAPZContext.h"
+#include "mozilla/MouseEvents.h"
+#include "mozilla/TouchEvents.h"
 #include "nsThreadUtils.h"
 #include "HwcComposer2D.h"
 
@@ -227,33 +230,89 @@ nsWindow::NotifyVsync(TimeStamp aVsyncTimestamp)
     }
 }
 
-nsEventStatus
-nsWindow::DispatchInputEvent(WidgetGUIEvent& aEvent, bool* aWasCaptured)
+/*static*/ nsEventStatus
+nsWindow::DispatchInputEvent(WidgetGUIEvent& aEvent)
 {
-    if (aWasCaptured) {
-        *aWasCaptured = false;
-    }
     if (!gFocusedWindow) {
         return nsEventStatus_eIgnore;
     }
 
     gFocusedWindow->UserActivity();
 
+    nsEventStatus status;
     aEvent.widget = gFocusedWindow;
+    gFocusedWindow->DispatchEvent(&aEvent, status);
+    return status;
+}
 
+/*static*/ void
+nsWindow::DispatchTouchInput(MultiTouchInput& aInput)
+{
+    if (!gFocusedWindow) {
+        return;
+    }
+
+    gFocusedWindow->UserActivity();
+    gFocusedWindow->DispatchTouchInputViaAPZ(aInput);
+}
+
+void
+nsWindow::DispatchTouchInputViaAPZ(MultiTouchInput& aInput)
+{
+    if (!mAPZC) {
+        // In general mAPZC should not be null, but during initial setup
+        // it might be, so we handle that case by ignoring touch input there.
+        return;
+    }
+
+    // First send it through the APZ code
+    mozilla::layers::ScrollableLayerGuid guid;
+    uint64_t inputBlockId;
+    nsEventStatus rv = mAPZC->ReceiveInputEvent(aInput, &guid, &inputBlockId);
+    // If the APZ says to drop it, then we drop it
+    if (rv == nsEventStatus_eConsumeNoDefault) {
+        return;
+    }
+
+    // Convert it to an event we can send to Gecko
+    WidgetTouchEvent event = aInput.ToWidgetTouchEvent(this);
+
+    // If there is an event capturing child process, send it directly there.
+    // This happens if we already sent a touchstart event through the root
+    // process hit test and it ended up going to a child process. The event
+    // capturing process should get all subsequent touch events in the same
+    // event block. In this case the TryCapture call below will return true,
+    // and the child process will take care of responding to the event as needed
+    // so we don't need to do anything else here.
     if (TabParent* capturer = TabParent::GetEventCapturer()) {
-        bool captured = capturer->TryCapture(aEvent);
-        if (aWasCaptured) {
-            *aWasCaptured = captured;
-        }
-        if (captured) {
-            return nsEventStatus_eConsumeNoDefault;
+        InputAPZContext context(guid, inputBlockId);
+        if (capturer->TryCapture(event)) {
+            return;
         }
     }
 
-    nsEventStatus status;
-    gFocusedWindow->DispatchEvent(&aEvent, status);
-    return status;
+    // If it didn't get captured, dispatch the event into the gecko root process
+    // for "normal" flow. The event might get sent to the child process still,
+    // but if it doesn't we need to notify the APZ of various things. All of
+    // that happens in DispatchEventForAPZ
+    rv = DispatchEventForAPZ(&event, guid, inputBlockId);
+
+    // Finally, if the touch event had only one touch point, generate a mouse
+    // event for it and send it through the gecko root process.
+    // Technically we should not need to do this if the touch event was routed
+    // to the child process, but that seems to expose a bug in B2G where the
+    // keyboard doesn't go away in some cases.
+    // Also for now we're dispatching mouse events from all touch events because
+    // we need this for click events to work in the chrome process. Once we have
+    // APZ and ChromeProcessController::HandleSingleTap working for the chrome
+    // process we shouldn't need to do this at all.
+    if (event.touches.Length() == 1) {
+        WidgetMouseEvent mouseEvent = aInput.ToWidgetMouseEvent(this);
+        if (mouseEvent.message != NS_EVENT_NULL) {
+            mouseEvent.mFlags.mNoCrossProcessBoundaryForwarding = (rv == nsEventStatus_eConsumeNoDefault);
+            DispatchEvent(&mouseEvent, rv);
+        }
+    }
 }
 
 NS_IMETHODIMP

widget/gonk/nsWindow.h

@@ -16,6 +16,7 @@
 #ifndef nsWindow_h
 #define nsWindow_h
 
+#include "InputData.h"
 #include "nsBaseWidget.h"
 #include "nsRegion.h"
 #include "nsIIdleServiceInternal.h"
@@ -51,8 +52,8 @@ public:
 
     static void NotifyVsync(mozilla::TimeStamp aVsyncTimestamp);
     static void DoDraw(void);
-    static nsEventStatus DispatchInputEvent(mozilla::WidgetGUIEvent& aEvent,
-                                            bool* aWasCaptured = nullptr);
+    static nsEventStatus DispatchInputEvent(mozilla::WidgetGUIEvent& aEvent);
+    static void DispatchTouchInput(mozilla::MultiTouchInput& aInput);
 
     NS_IMETHOD Create(nsIWidget *aParent,
                       void *aNativeParent,
@@ -87,6 +88,7 @@ public:
         return NS_OK;
     }
     virtual nsIntPoint WidgetToScreenOffset();
+    void DispatchTouchInputViaAPZ(mozilla::MultiTouchInput& aInput);
     NS_IMETHOD DispatchEvent(mozilla::WidgetGUIEvent* aEvent,
                              nsEventStatus& aStatus);
     NS_IMETHOD CaptureRollupEvents(nsIRollupListener *aListener,