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 ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_
6#define ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_
7
8#include "ash/ash_export.h"
9#include "base/basictypes.h"
10#include "base/memory/scoped_ptr.h"
11#include "ui/events/event.h"
12
13namespace aura {
14class Window;
15class WindowDelegate;
16}
17
18namespace ash {
19
20// Provides functions for handling drag events inside and outside the root
21// window where drag is started. This internally sets up a capture window for
22// tracking drag events outside the root window where drag is initiated.
23// ash/wm/coordinate_conversion.h is used internally and only X11 environment
24// is supported for now.
25class ASH_EXPORT DragDropTracker {
26 public:
27  DragDropTracker(aura::Window* context_root,
28                  aura::WindowDelegate* delegate);
29  ~DragDropTracker();
30
31  aura::Window* capture_window() { return capture_window_.get(); }
32
33  // Tells our |capture_window_| to take capture. This is not done right at
34  // creation to give the caller a chance to perform any operations needed
35  // before the capture is transfered.
36  void TakeCapture();
37
38  // Gets the target located at |event| in the coordinates of the active root
39  // window.
40  aura::Window* GetTarget(const ui::LocatedEvent& event);
41
42  // Converts the locations of |event| in the coordinates of the active root
43  // window to the ones in |target|'s coordinates.
44  // Caller takes ownership of the returned object.
45  ui::LocatedEvent* ConvertEvent(aura::Window* target,
46                                 const ui::LocatedEvent& event);
47
48 private:
49  // A window for capturing drag events while dragging.
50  scoped_ptr<aura::Window> capture_window_;
51
52  DISALLOW_COPY_AND_ASSIGN(DragDropTracker);
53};
54
55}  // namespace ash
56
57#endif  // ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_
58