1// Copyright (c) 2012 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_WM_PUBLIC_DRAG_DROP_DELEGATE_H_
6#define UI_WM_PUBLIC_DRAG_DROP_DELEGATE_H_
7
8#include "ui/aura/aura_export.h"
9
10namespace ui {
11class DropTargetEvent;
12}
13
14namespace aura {
15class Window;
16namespace client {
17
18// Delegate interface for drag and drop actions on aura::Window.
19class AURA_EXPORT DragDropDelegate {
20 public:
21  // OnDragEntered is invoked when the mouse enters this window during a drag &
22  // drop session. This is immediately followed by an invocation of
23  // OnDragUpdated, and eventually one of OnDragExited or OnPerformDrop.
24  virtual void OnDragEntered(const ui::DropTargetEvent& event) = 0;
25
26  // Invoked during a drag and drop session while the mouse is over the window.
27  // This should return a bitmask of the DragDropTypes::DragOperation supported
28  // based on the location of the event. Return 0 to indicate the drop should
29  // not be accepted.
30  virtual int OnDragUpdated(const ui::DropTargetEvent& event) = 0;
31
32  // Invoked during a drag and drop session when the mouse exits the window, or
33  // when the drag session was canceled and the mouse was over the window.
34  virtual void OnDragExited() = 0;
35
36  // Invoked during a drag and drop session when OnDragUpdated returns a valid
37  // operation and the user release the mouse.
38  virtual int OnPerformDrop(const ui::DropTargetEvent& event) = 0;
39
40 protected:
41  virtual ~DragDropDelegate() {}
42};
43
44AURA_EXPORT void SetDragDropDelegate(Window* window,
45                                     DragDropDelegate* delegate);
46AURA_EXPORT DragDropDelegate* GetDragDropDelegate(Window* window);
47
48}  // namespace client
49}  // namespace aura
50
51#endif  // UI_WM_PUBLIC_DRAG_DROP_DELEGATE_H_
52