accelerator.h revision d0247b1b59f9c528cb6df88b4f2b9afaf80d181e 
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// This class describe a keyboard accelerator (or keyboard shortcut).
6// Keyboard accelerators are registered with the FocusManager.
7// It has a copy constructor and assignment operator so that it can be copied.
8// It also defines the < operator so that it can be used as a key in a std::map.
9//
10
11#ifndef UI_BASE_ACCELERATORS_ACCELERATOR_H_
12#define UI_BASE_ACCELERATORS_ACCELERATOR_H_
13
14#include "base/memory/scoped_ptr.h"
15#include "base/strings/string16.h"
16#include "ui/base/accelerators/platform_accelerator.h"
17#include "ui/base/ui_export.h"
18#include "ui/events/event_constants.h"
19#include "ui/events/keycodes/keyboard_codes.h"
20
21namespace ui {
22
23class PlatformAccelerator;
24
25// This is a cross-platform class for accelerator keys used in menus.
26// |platform_accelerator| should be used to store platform specific data.
27class UI_EXPORT Accelerator {
28 public:
29  Accelerator();
30  Accelerator(ui::KeyboardCode keycode, int modifiers);
31  Accelerator(const Accelerator& accelerator);
32  ~Accelerator();
33
34  Accelerator& operator=(const Accelerator& accelerator);
35
36  // Define the < operator so that the KeyboardShortcut can be used as a key in
37  // a std::map.
38  bool operator <(const Accelerator& rhs) const;
39
40  bool operator ==(const Accelerator& rhs) const;
41
42  bool operator !=(const Accelerator& rhs) const;
43
44  ui::KeyboardCode key_code() const { return key_code_; }
45
46  // Sets the event type if the accelerator should be processed on an event
47  // other than ui::ET_KEY_PRESSED.
48  void set_type(ui::EventType type) { type_ = type; }
49  ui::EventType type() const { return type_; }
50
51  int modifiers() const { return modifiers_; }
52
53  bool IsShiftDown() const;
54  bool IsCtrlDown() const;
55  bool IsAltDown() const;
56  bool IsCmdDown() const;
57
58  // Returns a string with the localized shortcut if any.
59  base::string16 GetShortcutText() const;
60
61  void set_platform_accelerator(scoped_ptr<PlatformAccelerator> p) {
62    platform_accelerator_ = p.Pass();
63  }
64
65  // This class keeps ownership of the returned object.
66  const PlatformAccelerator* platform_accelerator() const {
67    return platform_accelerator_.get();
68  }
69
70
71 protected:
72  // The keycode (VK_...).
73  KeyboardCode key_code_;
74
75  // The event type (usually ui::ET_KEY_PRESSED).
76  EventType type_;
77
78  // The state of the Shift/Ctrl/Alt keys.
79  int modifiers_;
80
81  // Stores platform specific data. May be NULL.
82  scoped_ptr<PlatformAccelerator> platform_accelerator_;
83};
84
85// An interface that classes that want to register for keyboard accelerators
86// should implement.
87class UI_EXPORT AcceleratorTarget {
88 public:
89  // Should return true if the accelerator was processed.
90  virtual bool AcceleratorPressed(const Accelerator& accelerator) = 0;
91
92  // Should return true if the target can handle the accelerator events. The
93  // AcceleratorPressed method is invoked only for targets for which
94  // CanHandleAccelerators returns true.
95  virtual bool CanHandleAccelerators() const = 0;
96
97 protected:
98  virtual ~AcceleratorTarget() {}
99};
100
101// Since accelerator code is one of the few things that can't be cross platform
102// in the chrome UI, separate out just the GetAcceleratorForCommandId() from
103// the menu delegates.
104class AcceleratorProvider {
105 public:
106  // Gets the accelerator for the specified command id. Returns true if the
107  // command id has a valid accelerator, false otherwise.
108  virtual bool GetAcceleratorForCommandId(int command_id,
109                                          ui::Accelerator* accelerator) = 0;
110
111 protected:
112  virtual ~AcceleratorProvider() {}
113};
114
115}  // namespace ui
116
117#endif  // UI_BASE_ACCELERATORS_ACCELERATOR_H_
118