ui/views/view_targeter.h

   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 namespace internal {
  25 class RootView;
  26 }  // namespace internal
  27
  28 class View;
  29 class ViewTargeterDelegate;
  30
  31 // A ViewTargeter is installed on a View that wishes to use the custom
  32 // hit-testing or event-targeting behaviour defined by |delegate|.
  33 class VIEWS_EXPORT ViewTargeter : public ui::EventTargeter {
  34  public:
  35   explicit ViewTargeter(ViewTargeterDelegate* delegate);
  36   ~ViewTargeter() override;
  37
  38   // A call-through to DoesIntersectRect() on |delegate_|.
  39   bool DoesIntersectRect(const View* target, const gfx::Rect& rect) const;
  40
  41   // A call-through to TargetForRect() on |delegate_|.
  42   View* TargetForRect(View* root, const gfx::Rect& rect) const;
  43
  44  protected:
  45   // ui::EventTargeter:
  46   ui::EventTarget* FindTargetForEvent(ui::EventTarget* root,
  47                                       ui::Event* event) override;
  48   ui::EventTarget* FindNextBestTarget(ui::EventTarget* previous_target,
  49                                       ui::Event* event) override;
  50
  51  private:
  52   View* FindTargetForKeyEvent(View* root, const ui::KeyEvent& key);
  53   View* FindTargetForScrollEvent(View* root, const ui::ScrollEvent& scroll);
  54
  55   virtual View* FindTargetForGestureEvent(View* root,
  56                                           const ui::GestureEvent& gesture);
  57   virtual ui::EventTarget* FindNextBestTargetForGestureEvent(
  58       ui::EventTarget* previous_target,
  59       const ui::GestureEvent& gesture);
  60
  61   // ViewTargeter does not own the |delegate_|, but |delegate_| must
  62   // outlive the targeter.
  63   ViewTargeterDelegate* delegate_;
  64
  65   DISALLOW_COPY_AND_ASSIGN(ViewTargeter);
  66 };
  67
  68 }  // namespace views
  69
  70 #endif  // UI_VIEWS_VIEW_TARGETER_H_