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 "ui/events/event_targeter.h"
   9 #include "ui/views/views_export.h"
  10
  11 namespace views {
  12
  13 class View;
  14 class ViewTargeterDelegate;
  15
  16 // Contains the logic used to determine the View to which an
  17 // event should be dispatched. A ViewTargeter (or one of its
  18 // derived classes) is installed on a View to specify the
  19 // targeting behaviour to be used for the subtree rooted at
  20 // that View.
  21 class VIEWS_EXPORT ViewTargeter : public ui::EventTargeter {
  22  public:
  23   explicit ViewTargeter(ViewTargeterDelegate* delegate);
  24   virtual ~ViewTargeter();
  25
  26   // A call-through to DoesIntersectRect() on |delegate_|.
  27   bool DoesIntersectRect(const View* target, const gfx::Rect& rect) const;
  28
  29  protected:
  30   // Returns the location of |event| represented as a rect. If |event| is
  31   // a gesture event, its bounding box is returned. Otherwise, a 1x1 rect
  32   // having its origin at the location of |event| is returned.
  33   gfx::RectF BoundsForEvent(const ui::LocatedEvent& event) const;
  34
  35   // ui::EventTargeter:
  36   virtual ui::EventTarget* FindTargetForEvent(ui::EventTarget* root,
  37                                               ui::Event* event) OVERRIDE;
  38   virtual ui::EventTarget* FindNextBestTarget(ui::EventTarget* previous_target,
  39                                               ui::Event* event) OVERRIDE;
  40   virtual bool SubtreeCanAcceptEvent(
  41       ui::EventTarget* target,
  42       const ui::LocatedEvent& event) const OVERRIDE;
  43   virtual bool EventLocationInsideBounds(
  44       ui::EventTarget* target,
  45       const ui::LocatedEvent& event) const OVERRIDE;
  46
  47  private:
  48   View* FindTargetForKeyEvent(View* view, const ui::KeyEvent& key);
  49
  50   // ViewTargeter does not own the |delegate_|, but |delegate_| must
  51   // outlive the targeter.
  52   ViewTargeterDelegate* delegate_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(ViewTargeter);
  55 };
  56
  57 }  // namespace views
  58
  59 #endif  // UI_VIEWS_VIEW_TARGETER_H_