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      1 // Copyright 2014 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "ui/views/view_targeter.h"
      6 
      7 #include "ui/events/event_target.h"
      8 #include "ui/views/focus/focus_manager.h"
      9 #include "ui/views/view.h"
     10 #include "ui/views/view_targeter_delegate.h"
     11 
     12 namespace views {
     13 
     14 ViewTargeter::ViewTargeter(ViewTargeterDelegate* delegate)
     15     : delegate_(delegate) {
     16   DCHECK(delegate_);
     17 }
     18 
     19 ViewTargeter::~ViewTargeter() {}
     20 
     21 bool ViewTargeter::DoesIntersectRect(const View* target,
     22                                      const gfx::Rect& rect) const {
     23   return delegate_->DoesIntersectRect(target, rect);
     24 }
     25 
     26 View* ViewTargeter::TargetForRect(View* root, const gfx::Rect& rect) const {
     27   return delegate_->TargetForRect(root, rect);
     28 }
     29 
     30 ui::EventTarget* ViewTargeter::FindTargetForEvent(ui::EventTarget* root,
     31                                                   ui::Event* event) {
     32   View* view = static_cast<View*>(root);
     33 
     34   if (event->IsKeyEvent())
     35     return FindTargetForKeyEvent(view, *static_cast<ui::KeyEvent*>(event));
     36 
     37   if (event->IsScrollEvent()) {
     38     return FindTargetForScrollEvent(view,
     39                                     *static_cast<ui::ScrollEvent*>(event));
     40   }
     41 
     42   if (event->IsGestureEvent()) {
     43     ui::GestureEvent* gesture = event->AsGestureEvent();
     44     View* gesture_target = FindTargetForGestureEvent(view, *gesture);
     45     root->ConvertEventToTarget(gesture_target, gesture);
     46     return gesture_target;
     47   }
     48 
     49   NOTREACHED() << "ViewTargeter does not yet support this event type.";
     50   return NULL;
     51 }
     52 
     53 ui::EventTarget* ViewTargeter::FindNextBestTarget(
     54     ui::EventTarget* previous_target,
     55     ui::Event* event) {
     56   if (!previous_target)
     57     return NULL;
     58 
     59   if (event->IsGestureEvent()) {
     60     ui::GestureEvent* gesture = event->AsGestureEvent();
     61     ui::EventTarget* next_target =
     62         FindNextBestTargetForGestureEvent(previous_target, *gesture);
     63     previous_target->ConvertEventToTarget(next_target, gesture);
     64     return next_target;
     65   }
     66 
     67   return previous_target->GetParentTarget();
     68 }
     69 
     70 bool ViewTargeter::SubtreeCanAcceptEvent(
     71     ui::EventTarget* target,
     72     const ui::LocatedEvent& event) const {
     73   NOTREACHED();
     74   return false;
     75 }
     76 
     77 bool ViewTargeter::EventLocationInsideBounds(
     78     ui::EventTarget* target,
     79     const ui::LocatedEvent& event) const {
     80   NOTREACHED();
     81   return false;
     82 }
     83 
     84 View* ViewTargeter::FindTargetForKeyEvent(View* root, const ui::KeyEvent& key) {
     85   if (root->GetFocusManager())
     86     return root->GetFocusManager()->GetFocusedView();
     87   return NULL;
     88 }
     89 
     90 View* ViewTargeter::FindTargetForScrollEvent(View* root,
     91                                              const ui::ScrollEvent& scroll) {
     92   gfx::Rect rect(scroll.location(), gfx::Size(1, 1));
     93   return root->GetEffectiveViewTargeter()->TargetForRect(root, rect);
     94 }
     95 
     96 View* ViewTargeter::FindTargetForGestureEvent(View* root,
     97                                               const ui::GestureEvent& gesture) {
     98   // TODO(tdanderson): The only code path that performs targeting for gestures
     99   //                   uses the ViewTargeter installed on the RootView (i.e.,
    100   //                   a RootViewTargeter). Provide a default implementation
    101   //                   here if we need to be able to perform gesture targeting
    102   //                   starting at an arbitrary node in a Views tree.
    103   NOTREACHED();
    104   return NULL;
    105 }
    106 
    107 ui::EventTarget* ViewTargeter::FindNextBestTargetForGestureEvent(
    108     ui::EventTarget* previous_target,
    109     const ui::GestureEvent& gesture) {
    110   NOTREACHED();
    111   return NULL;
    112 }
    113 
    114 }  // namespace views
    115