Cancel active touches when their window can no longer receive events.

|Window::CanAcceptEvent| always returns true for cancel events and gesture events which indicate the end of a gesture.

We fire a cancel event for each active touch on a window when the window is hidden.

BUG=151871
TEST=RootWindowTest.WindowHideCancelsActiveTouches

Review URL: https://codereview.chromium.org/35533002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237357 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 49 insertions, 11 deletions

diff --git a/ui/events/event.h b/ui/events/event.h
index fd33f84..71c8f67 100644
--- a/ui/events/event.h
+++ b/ui/events/event.h
@@ -124,6 +124,8 @@ class EVENTS_EXPORT Event {
       case ET_GESTURE_LONG_TAP:
       case ET_GESTURE_MULTIFINGER_SWIPE:
       case ET_GESTURE_SHOW_PRESS:
+        // When adding a gesture event which is paired with an event which
+        // occurs earlier, add the event to |IsEndingEvent|.
         return true;
 
       case ET_SCROLL_FLING_CANCEL:
@@ -138,6 +140,21 @@ class EVENTS_EXPORT Event {
     return false;
   }
 
+  // An ending event is paired with the event which started it. Setting capture
+  // should not prevent ending events from getting to their initial target.
+  bool IsEndingEvent() const {
+    switch(type_) {
+      case ui::ET_TOUCH_CANCELLED:
+      case ui::ET_GESTURE_TAP_CANCEL:
+      case ui::ET_GESTURE_END:
+      case ui::ET_GESTURE_SCROLL_END:
+      case ui::ET_GESTURE_PINCH_END:
+        return true;
+      default:
+        return false;
+    }
+  }
+
   bool IsScrollEvent() const {
     // Flings can be GestureEvents too. EF_FROM_TOUCH determins if they're
     // Gesture or Scroll events.
diff --git a/ui/events/gestures/gesture_recognizer.h b/ui/events/gestures/gesture_recognizer.h
index fd5136d..88f230f 100644
--- a/ui/events/gestures/gesture_recognizer.h
+++ b/ui/events/gestures/gesture_recognizer.h
@@ -66,6 +66,9 @@ class EVENTS_EXPORT GestureRecognizer {
   virtual bool GetLastTouchPointForTarget(GestureConsumer* consumer,
                                           gfx::Point* point) = 0;
 
+  // Sends a touch cancel event for every active touch.
+  virtual void CancelActiveTouches(GestureConsumer* consumer) = 0;
+
   // Subscribes |helper| for dispatching async gestures such as long press.
   // The Gesture Recognizer does NOT take ownership of |helper| and it is the
   // responsibility of the |helper| to call |RemoveGestureEventHelper()| on
diff --git a/ui/events/gestures/gesture_recognizer_impl.cc b/ui/events/gestures/gesture_recognizer_impl.cc
index a3bb9cc..50a159b 100644
--- a/ui/events/gestures/gesture_recognizer_impl.cc
+++ b/ui/events/gestures/gesture_recognizer_impl.cc
@@ -126,17 +126,7 @@ void GestureRecognizerImpl::TransferEventsTo(GestureConsumer* current_consumer,
     }
   }
 
-  while (!ids.empty()) {
-    int touch_id = ids.begin()->first;
-    GestureConsumer* target = ids.begin()->second;
-    TouchEvent touch_event(ui::ET_TOUCH_CANCELLED, gfx::Point(0, 0),
-                           ui::EF_IS_SYNTHESIZED, touch_id,
-                           ui::EventTimeForNow(), 0.0f, 0.0f, 0.0f, 0.0f);
-    GestureEventHelper* helper = FindDispatchHelperForConsumer(target);
-    if (helper)
-      helper->DispatchCancelTouchEvent(&touch_event);
-    ids.erase(ids.begin());
-  }
+  CancelTouches(&ids);
 
   // Transfer events from |current_consumer| to |new_consumer|.
   if (current_consumer && new_consumer) {
@@ -158,6 +148,17 @@ bool GestureRecognizerImpl::GetLastTouchPointForTarget(
   return true;
 }
 
+void GestureRecognizerImpl::CancelActiveTouches(
+    GestureConsumer* consumer) {
+  std::vector<std::pair<int, GestureConsumer*> > ids;
+  for (TouchIdToConsumerMap::const_iterator i = touch_id_target_.begin();
+       i != touch_id_target_.end(); ++i) {
+    if (i->second == consumer)
+      ids.push_back(std::make_pair(i->first, i->second));
+  }
+  CancelTouches(&ids);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // GestureRecognizerImpl, protected:
 
@@ -191,6 +192,21 @@ void GestureRecognizerImpl::SetupTargets(const TouchEvent& event,
   }
 }
 
+void GestureRecognizerImpl::CancelTouches(
+    std::vector<std::pair<int, GestureConsumer*> >* touches) {
+  while (!touches->empty()) {
+    int touch_id = touches->begin()->first;
+    GestureConsumer* target = touches->begin()->second;
+    TouchEvent touch_event(ui::ET_TOUCH_CANCELLED, gfx::Point(0, 0),
+                           ui::EF_IS_SYNTHESIZED, touch_id,
+                           ui::EventTimeForNow(), 0.0f, 0.0f, 0.0f, 0.0f);
+    GestureEventHelper* helper = FindDispatchHelperForConsumer(target);
+    if (helper)
+      helper->DispatchCancelTouchEvent(&touch_event);
+    touches->erase(touches->begin());
+  }
+}
+
 GestureSequence::Gestures* GestureRecognizerImpl::ProcessTouchEventForGesture(
     const TouchEvent& event,
     ui::EventResult result,
diff --git a/ui/events/gestures/gesture_recognizer_impl.h b/ui/events/gestures/gesture_recognizer_impl.h
index 051454c..6e45c13 100644
--- a/ui/events/gestures/gesture_recognizer_impl.h
+++ b/ui/events/gestures/gesture_recognizer_impl.h
@@ -43,6 +43,7 @@ class EVENTS_EXPORT GestureRecognizerImpl : public GestureRecognizer,
                                 GestureConsumer* new_consumer) OVERRIDE;
   virtual bool GetLastTouchPointForTarget(GestureConsumer* consumer,
                                           gfx::Point* point) OVERRIDE;
+  virtual void CancelActiveTouches(GestureConsumer* consumer) OVERRIDE;
 
  protected:
   virtual GestureSequence* CreateSequence(GestureSequenceDelegate* delegate);
@@ -51,6 +52,7 @@ class EVENTS_EXPORT GestureRecognizerImpl : public GestureRecognizer,
  private:
   // Sets up the target consumer for gestures based on the touch-event.
   void SetupTargets(const TouchEvent& event, GestureConsumer* consumer);
+  void CancelTouches(std::vector<std::pair<int, GestureConsumer*> >* touches);
 
   // Overridden from GestureRecognizer
   virtual Gestures* ProcessTouchEventForGesture(