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 CHROME_BROWSER_UI_VIEWS_FRAME_MINIMIZE_BUTTON_METRICS_WIN_H_
6#define CHROME_BROWSER_UI_VIEWS_FRAME_MINIMIZE_BUTTON_METRICS_WIN_H_
7
8#include <windows.h>
9
10#include "base/basictypes.h"
11
12// Class that implements obtaining the X coordinate of the native minimize
13// button for the native frame on Windows.
14// This is a separate class because obtaining it is somewhat tricky and this
15// code is shared between BrowserDesktopWindowTreeHostWin and BrowserFrameWin.
16class MinimizeButtonMetrics {
17 public:
18  MinimizeButtonMetrics();
19  ~MinimizeButtonMetrics();
20
21  void Init(HWND hwnd);
22
23  // Obtain the X offset of the native minimize button. Since Windows can lie
24  // to us if we call this at the wrong moment, this might come from a cached
25  // value rather than read when called.
26  int GetMinimizeButtonOffsetX() const;
27
28  // Must be called when hwnd_ is activated to update the minimize button
29  // position cache.
30  void OnHWNDActivated();
31
32 private:
33  // Gets the value for GetMinimizeButtonOffsetX(), caching if found.
34  int GetAndCacheMinimizeButtonOffsetX() const;
35
36  HWND hwnd_;
37
38  // Cached offset of the minimize button. If RTL this is the location of the
39  // minimize button, if LTR this is the offset from the right edge of the
40  // client area to the minimize button.
41  mutable int cached_minimize_button_x_delta_;
42
43  // Static cache of |cached_minimize_button_x_delta_|.
44  static int last_cached_minimize_button_x_delta_;
45
46  // Has OnHWNDActivated() been invoked?
47  bool was_activated_;
48
49  DISALLOW_COPY_AND_ASSIGN(MinimizeButtonMetrics);
50};
51
52#endif  // CHROME_BROWSER_UI_VIEWS_FRAME_MINIMIZE_BUTTON_METRICS_WIN_H_
53