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 #ifndef UI_VIEWS_VIEW_TARGETER_H_
6 #define UI_VIEWS_VIEW_TARGETER_H_
7 
8 #include "base/macros.h"
9 #include "ui/events/event_targeter.h"
10 #include "ui/views/views_export.h"
11 
12 namespace gfx {
13 class Rect;
14 }  // namespace gfx
15 
16 namespace ui {
17 class GestureEvent;
18 class KeyEvent;
19 class ScrollEvent;
20 }  // namespace ui
21 
22 namespace views {
23 
24 class View;
25 class ViewTargeterDelegate;
26 
27 // A ViewTargeter is installed on a View that wishes to use the custom
28 // hit-testing or event-targeting behaviour defined by |delegate|.
29 class VIEWS_EXPORT ViewTargeter : public ui::EventTargeter {
30  public:
31   explicit ViewTargeter(ViewTargeterDelegate* delegate);
32   ~ViewTargeter() override;
33 
34   // A call-through to DoesIntersectRect() on |delegate_|.
35   bool DoesIntersectRect(const View* target, const gfx::Rect& rect) const;
36 
37   // A call-through to TargetForRect() on |delegate_|.
38   View* TargetForRect(View* root, const gfx::Rect& rect) const;
39 
40  protected:
41   // ui::EventTargeter:
42   ui::EventTarget* FindTargetForEvent(ui::EventTarget* root,
43                                       ui::Event* event) override;
44   ui::EventTarget* FindNextBestTarget(ui::EventTarget* previous_target,
45                                       ui::Event* event) override;
46 
47  private:
48   View* FindTargetForKeyEvent(View* root, const ui::KeyEvent& key);
49   View* FindTargetForScrollEvent(View* root, const ui::ScrollEvent& scroll);
50 
51   virtual View* FindTargetForGestureEvent(View* root,
52                                           const ui::GestureEvent& gesture);
53   virtual ui::EventTarget* FindNextBestTargetForGestureEvent(
54       ui::EventTarget* previous_target,
55       const ui::GestureEvent& gesture);
56 
57   // ViewTargeter does not own the |delegate_|, but |delegate_| must
58   // outlive the targeter.
59   ViewTargeterDelegate* delegate_;
60 
61   DISALLOW_COPY_AND_ASSIGN(ViewTargeter);
62 };
63 
64 }  // namespace views
65 
66 #endif  // UI_VIEWS_VIEW_TARGETER_H_
67