Eager Gesture Recognition on Aura

ui/aura/window_event_dispatcher.cc

Index: ui/aura/window_event_dispatcher.cc
diff --git a/ui/aura/window_event_dispatcher.cc b/ui/aura/window_event_dispatcher.cc
index 2e42a9559614609352bad7f2b3e80ff9ba60bdd0..b248d6bd2b6b5c6f15e0933c1b3e0b5d6e4d0b6b 100644
--- a/ui/aura/window_event_dispatcher.cc
+++ b/ui/aura/window_event_dispatcher.cc
@@ -24,6 +24,7 @@
 #include "ui/events/event.h"
 #include "ui/events/gestures/gesture_recognizer.h"
 #include "ui/events/gestures/gesture_types.h"
+#include "ui/events/gestures/unified_gesture_detector_enabled.h"
 
 typedef ui::EventDispatchDetails DispatchDetails;
 
@@ -161,13 +162,28 @@ void WindowEventDispatcher::ProcessedTouchEvent(ui::TouchEvent* event,
                                                 Window* window,
                                                 ui::EventResult result) {
   scoped_ptr<ui::GestureRecognizer::Gestures> gestures;
-  gestures.reset(ui::GestureRecognizer::Get()->
-      ProcessTouchEventForGesture(*event, result, window));
+
+  if (!ui::IsUnifiedGestureDetectorEnabled()) {
+    gestures.reset(ui::GestureRecognizer::Get()->ProcessTouchEventForGesture(
+        *event, result, window));
+  } else {
+    gestures.reset(
+        ui::GestureRecognizer::Get()->AckTouchEventForGesture(result, window));
+  }
+
   DispatchDetails details = ProcessGestures(gestures.get());
   if (details.dispatcher_destroyed)
     return;
 }
 
+void WindowEventDispatcher::OnForwardingTouchEvent(ui::TouchEvent* event,
+                                                    Window* window) {
+  if (ui::IsUnifiedGestureDetectorEnabled()) {
+    ui::GestureRecognizer::Get()->ProcessTouchEventForGesture(
+        *event, event->result(), window);
+  }
+}
+
 void WindowEventDispatcher::HoldPointerMoves() {
   if (!move_hold_count_)
     held_event_factory_.InvalidateWeakPtrs();
@@ -487,11 +503,18 @@ ui::EventDispatchDetails WindowEventDispatcher::PostDispatchEvent(
         !held_move_event_->IsTouchEvent()) {
       ui::TouchEvent orig_event(static_cast<const ui::TouchEvent&>(event),
                                 static_cast<Window*>(event.target()), window());
-      // Get the list of GestureEvents from GestureRecognizer.
+      // If the event isn't being handled asynchronously, handle it now.
       scoped_ptr<ui::GestureRecognizer::Gestures> gestures;
       gestures.reset(ui::GestureRecognizer::Get()->
           ProcessTouchEventForGesture(orig_event, event.result(),
                                       static_cast<Window*>(target)));
+
+      if (ui::IsUnifiedGestureDetectorEnabled()) {
+        if (!(event.result() & ui::ER_CONSUMED)) {
+          gestures.reset(ui::GestureRecognizer::Get()->AckTouchEventForGesture(
+              event.result(), static_cast<Window*>(target)));
+        }
+      }

[sadrul, 2014/07/16 21:07:49]

Should this be something like:
  if (unified && !consumed) {
    gestures_.reset(AckTouchEventForGesture(....));
  else
    gestures_.reset(ProcessTouchEventForGesture(....));

to avoid creating gestures in line 508, and then discarding them in line 514?

[tdresser, 2014/07/28 18:22:09]

This issue has been addressed in the most recent patch.

       return ProcessGestures(gestures.get());
     }
   }