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_DELEGATE_H_ 6#define UI_VIEWS_VIEW_TARGETER_DELEGATE_H_ 7 8#include "base/macros.h" 9#include "ui/views/views_export.h" 10 11namespace gfx { 12class Rect; 13} 14 15namespace views { 16class View; 17 18// Defines the default behaviour for hit-testing and event-targeting against a 19// View using a rectangular region representing an event's location. Views 20// wishing to define custom hit-testing or event-targeting behaviour do so by 21// extending ViewTargeterDelegate and then installing a ViewTargeter on 22// themselves. 23class VIEWS_EXPORT ViewTargeterDelegate { 24 public: 25 ViewTargeterDelegate() {} 26 virtual ~ViewTargeterDelegate() {} 27 28 // Returns true if the bounds of |target| intersects |rect|, where |rect| 29 // is in the local coodinate space of |target|. Overrides of this method by 30 // a View subclass should enforce DCHECK_EQ(this, target). 31 virtual bool DoesIntersectRect(const View* target, 32 const gfx::Rect& rect) const; 33 34 // If point-based targeting should be used, return the deepest visible 35 // descendant of |root| that contains the center point of |rect|. 36 // If rect-based targeting (i.e., fuzzing) should be used, return the 37 // closest visible descendant of |root| having at least kRectTargetOverlap of 38 // its area covered by |rect|. If no such descendant exists, return the 39 // deepest visible descendant of |root| that contains the center point of 40 // |rect|. See http://goo.gl/3Jp2BD for more information about rect-based 41 // targeting. 42 virtual View* TargetForRect(View* root, const gfx::Rect& rect); 43 44 private: 45 DISALLOW_COPY_AND_ASSIGN(ViewTargeterDelegate); 46}; 47 48} // namespace views 49 50#endif // UI_VIEWS_VIEW_TARGETER_DELEGATE_H_ 51