Support targeting for gestures in ViewTargeter

ui/views/view_targeter.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/view_targeter.h"
 
 #include "ui/events/event_target.h"
 #include "ui/views/focus/focus_manager.h"
 #include "ui/views/view.h"
 #include "ui/views/view_targeter_delegate.h"
@@ skipping 21 matching lines @@
   View* view = static_cast<View*>(root);
 
   if (event->IsKeyEvent())
     return FindTargetForKeyEvent(view, *static_cast<ui::KeyEvent*>(event));
 
   if (event->IsScrollEvent()) {
     return FindTargetForScrollEvent(view,
                                     *static_cast<ui::ScrollEvent*>(event));
   }
 
+  if (event->IsGestureEvent())
+    return FindTargetForGestureEvent(view, *(event->AsGestureEvent()));
+
   NOTREACHED() << "ViewTargeter does not yet support this event type.";
   return NULL;
 }
 
 ui::EventTarget* ViewTargeter::FindNextBestTarget(
     ui::EventTarget* previous_target,
     ui::Event* event) {
+  if (!previous_target)
+    return NULL;
+
+  if (event->IsGestureEvent()) {
+    return FindNextBestTargetForGestureEvent(previous_target,
+                                             *(event->AsGestureEvent()));
+  }
+
   return previous_target->GetParentTarget();
 }
 
 bool ViewTargeter::SubtreeCanAcceptEvent(
     ui::EventTarget* target,
     const ui::LocatedEvent& event) const {
   NOTREACHED();
   return false;
 }
 
 bool ViewTargeter::EventLocationInsideBounds(
     ui::EventTarget* target,
     const ui::LocatedEvent& event) const {
   NOTREACHED();
   return false;
 }
 
 View* ViewTargeter::FindTargetForKeyEvent(View* root, const ui::KeyEvent& key) {
   if (root->GetFocusManager())
     return root->GetFocusManager()->GetFocusedView();
   return NULL;
 }
 
 View* ViewTargeter::FindTargetForScrollEvent(View* root,
                                              const ui::ScrollEvent& scroll) {
   gfx::Rect rect(scroll.location(), gfx::Size(1, 1));
   return root->GetEffectiveViewTargeter()->TargetForRect(root, rect);
 }
 
+View* ViewTargeter::FindTargetForGestureEvent(View* root,
+                                              const ui::GestureEvent& gesture) {
+  // TODO(tdanderson): The only code path that performs targeting for gestures
+  //                   uses the ViewTargeter installed on the RootView (i.e.,
+  //                   a RootViewTargeter). Provide a default implementation
+  //                   here if we need to be able to perform gesture targeting
+  //                   starting at an arbitrary node in a Views tree.
+  NOTREACHED();
+  return NULL;
+}
+
+ui::EventTarget* ViewTargeter::FindNextBestTargetForGestureEvent(
+    ui::EventTarget* previous_target,
+    const ui::GestureEvent& gesture) {
+  NOTREACHED();
+  return NULL;
+}
+
 }  // namespace views