ash: SystemGestureEventFilter should not process gestures while a drag drop is

in progress.

BUG=236493

Review URL: https://chromiumcodereview.appspot.com/14184010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@197612 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 84 insertions, 0 deletions

diff --git a/ash/drag_drop/drag_drop_controller.cc b/ash/drag_drop/drag_drop_controller.cc
index 933c0d1..90d3010 100644
--- a/ash/drag_drop/drag_drop_controller.cc
+++ b/ash/drag_drop/drag_drop_controller.cc
@@ -226,6 +226,12 @@ int DragDropController::StartDragAndDrop(
   if (cancel_animation_)
     cancel_animation_->End();
 
+  // Become the first event handler since we should get first shot at handling
+  // any events during the drag drop session.
+  Shell::GetInstance()->RemovePreTargetHandler(this);
+  Shell::GetInstance()->PrependPreTargetHandler(this);
+
+
 #if !defined(OS_MACOSX)
   if (should_block_during_drag_drop_) {
     base::RunLoop run_loop(aura::Env::GetInstance()->GetDispatcher());
diff --git a/ash/drag_drop/drag_drop_controller_unittest.cc b/ash/drag_drop/drag_drop_controller_unittest.cc
index df87dfc..822dede 100644
--- a/ash/drag_drop/drag_drop_controller_unittest.cc
+++ b/ash/drag_drop/drag_drop_controller_unittest.cc
@@ -1082,5 +1082,83 @@ TEST_F(DragDropControllerTest, MAYBE_DragCancelAcrossDisplays) {
   }
 }
 
+class SimpleEventHandler : public ui::EventHandler {
+ public:
+  SimpleEventHandler()
+      : handled_event_received_(false),
+        unhandled_event_received_(false) {
+    ash::Shell::GetInstance()->PrependPreTargetHandler(this);
+  }
+
+  virtual ~SimpleEventHandler() {
+    ash::Shell::GetInstance()->RemovePreTargetHandler(this);
+  }
+
+  bool handled_event_received() { return handled_event_received_; }
+  bool unhandled_event_received() { return unhandled_event_received_; }
+
+  void Reset() {
+    handled_event_received_ = false;
+    unhandled_event_received_ = false;
+  }
+
+ private:
+  // Overridden from ui::EventHandler.
+  virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE {
+    if (event->handled())
+      handled_event_received_ = true;
+    else
+      unhandled_event_received_ = true;
+  }
+
+  bool handled_event_received_;
+  bool unhandled_event_received_;
+
+  DISALLOW_COPY_AND_ASSIGN(SimpleEventHandler);
+};
+
+TEST_F(DragDropControllerTest,
+       DragDropControllerReceivesAllEventsDuringDragDrop) {
+  CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kEnableTouchDragDrop);
+  scoped_ptr<views::Widget> widget(CreateNewWidget());
+  DragTestView* drag_view = new DragTestView;
+  AddViewToWidgetAndResize(widget.get(), drag_view);
+  aura::test::EventGenerator generator(Shell::GetPrimaryRootWindow(),
+                                       widget->GetNativeView());
+  ui::OSExchangeData data;
+  data.SetString(UTF8ToUTF16("I am being dragged"));
+  SimpleEventHandler handler;
+
+  // Since we are not in drag/drop, |handler| should receive unhandled events.
+  generator.PressTouch();
+  gfx::Point point = gfx::Rect(drag_view->bounds()).CenterPoint();
+  handler.Reset();
+  DispatchGesture(ui::ET_GESTURE_LONG_PRESS, point);
+  EXPECT_TRUE(handler.unhandled_event_received());
+  EXPECT_FALSE(handler.handled_event_received());
+
+  EXPECT_TRUE(drag_drop_controller_->drag_start_received_);
+
+  // Since dragging has started, |handler| should not receive unhandled events.
+  UpdateDragData(&data);
+  gfx::Point gesture_location = point;
+  int num_drags = drag_view->width();
+  for (int i = 0; i < num_drags; ++i) {
+    gesture_location.Offset(1, 0);
+    handler.Reset();
+    DispatchGesture(ui::ET_GESTURE_SCROLL_UPDATE, gesture_location);
+    EXPECT_TRUE(handler.handled_event_received());
+    EXPECT_FALSE(handler.unhandled_event_received());
+
+    // Execute any scheduled draws to process deferred mouse events.
+    RunAllPendingInMessageLoop();
+  }
+
+  // End dragging.
+  DispatchGesture(ui::ET_GESTURE_SCROLL_END, gesture_location);
+  EXPECT_TRUE(drag_drop_controller_->drop_received_);
+}
+
 }  // namespace test
 }  // namespace aura