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_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_
6#define UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_
7
8#include <string>
9
10#include "base/memory/weak_ptr.h"
11#include "base/strings/string16.h"
12#include "base/time/time.h"
13#include "ui/views/background.h"
14#include "ui/views/controls/button/label_button.h"
15
16namespace views {
17
18class MenuButtonListener;
19
20////////////////////////////////////////////////////////////////////////////////
21//
22// MenuButton
23//
24//  A button that shows a menu when the left mouse button is pushed
25//
26////////////////////////////////////////////////////////////////////////////////
27class VIEWS_EXPORT MenuButton : public LabelButton {
28 public:
29  // A scoped lock for keeping the MenuButton in STATE_PRESSED e.g., while a
30  // menu is running. These are cumulative.
31  class VIEWS_EXPORT PressedLock {
32   public:
33    explicit PressedLock(MenuButton* menu_button);
34    ~PressedLock();
35
36   private:
37    base::WeakPtr<MenuButton> menu_button_;
38
39    DISALLOW_COPY_AND_ASSIGN(PressedLock);
40  };
41
42  static const char kViewClassName[];
43
44  // How much padding to put on the left and right of the menu marker.
45  static const int kMenuMarkerPaddingLeft;
46  static const int kMenuMarkerPaddingRight;
47
48  // Create a Button.
49  MenuButton(ButtonListener* listener,
50             const base::string16& text,
51             MenuButtonListener* menu_button_listener,
52             bool show_menu_marker);
53  virtual ~MenuButton();
54
55  bool show_menu_marker() const { return show_menu_marker_; }
56  void set_menu_marker(const gfx::ImageSkia* menu_marker) {
57    menu_marker_ = menu_marker;
58  }
59  const gfx::ImageSkia* menu_marker() const { return menu_marker_; }
60
61  const gfx::Point& menu_offset() const { return menu_offset_; }
62  void set_menu_offset(int x, int y) { menu_offset_.SetPoint(x, y); }
63
64  // Activate the button (called when the button is pressed).
65  virtual bool Activate();
66
67  // Overridden from View:
68  virtual gfx::Size GetPreferredSize() const OVERRIDE;
69  virtual const char* GetClassName() const OVERRIDE;
70  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
71  virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
72  virtual void OnMouseReleased(const ui::MouseEvent& event) OVERRIDE;
73  virtual void OnMouseEntered(const ui::MouseEvent& event) OVERRIDE;
74  virtual void OnMouseExited(const ui::MouseEvent& event) OVERRIDE;
75  virtual void OnMouseMoved(const ui::MouseEvent& event) OVERRIDE;
76  virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
77  virtual bool OnKeyPressed(const ui::KeyEvent& event) OVERRIDE;
78  virtual bool OnKeyReleased(const ui::KeyEvent& event) OVERRIDE;
79  virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
80
81 protected:
82  // Paint the menu marker image.
83  void PaintMenuMarker(gfx::Canvas* canvas);
84
85  // Overridden from LabelButton:
86  virtual gfx::Rect GetChildAreaBounds() OVERRIDE;
87
88  // Offset of the associated menu position.
89  gfx::Point menu_offset_;
90
91 private:
92  friend class PressedLock;
93
94  // Increment/decrement the number of "pressed" locks this button has, and
95  // set the state accordingly.
96  void IncrementPressedLocked();
97  void DecrementPressedLocked();
98
99  // Compute the maximum X coordinate for the current screen. MenuButtons
100  // use this to make sure a menu is never shown off screen.
101  int GetMaximumScreenXCoordinate();
102
103  // We use a time object in order to keep track of when the menu was closed.
104  // The time is used for simulating menu behavior for the menu button; that
105  // is, if the menu is shown and the button is pressed, we need to close the
106  // menu. There is no clean way to get the second click event because the
107  // menu is displayed using a modal loop and, unlike regular menus in Windows,
108  // the button is not part of the displayed menu.
109  base::TimeTicks menu_closed_time_;
110
111  // Our listener. Not owned.
112  MenuButtonListener* listener_;
113
114  // Whether or not we're showing a drop marker.
115  bool show_menu_marker_;
116
117  // The down arrow used to differentiate the menu button from normal buttons.
118  const gfx::ImageSkia* menu_marker_;
119
120  // If non-null the destuctor sets this to true. This is set while the menu is
121  // showing and used to detect if the menu was deleted while running.
122  bool* destroyed_flag_;
123
124  // The current number of "pressed" locks this button has.
125  int pressed_lock_count_;
126
127  base::WeakPtrFactory<MenuButton> weak_factory_;
128
129  DISALLOW_COPY_AND_ASSIGN(MenuButton);
130};
131
132}  // namespace views
133
134#endif  // UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_
135