ui/base/accelerators/accelerator.h

   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_base_export.h"
  18 #include "ui/events/event_constants.h"
  19 #include "ui/events/keycodes/keyboard_codes.h"
  20
  21 namespace ui {
  22
  23 class 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.
  27 class UI_BASE_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   bool IsRepeat() const;
  58
  59   // Returns a string with the localized shortcut if any.
  60   base::string16 GetShortcutText() const;
  61
  62   void set_platform_accelerator(scoped_ptr<PlatformAccelerator> p) {
  63     platform_accelerator_ = p.Pass();
  64   }
  65
  66   // This class keeps ownership of the returned object.
  67   const PlatformAccelerator* platform_accelerator() const {
  68     return platform_accelerator_.get();
  69   }
  70
  71   void set_is_repeat(bool is_repeat) { is_repeat_ = is_repeat; }
  72
  73  protected:
  74   // The keycode (VK_...).
  75   KeyboardCode key_code_;
  76
  77   // The event type (usually ui::ET_KEY_PRESSED).
  78   EventType type_;
  79
  80   // The state of the Shift/Ctrl/Alt keys.
  81   int modifiers_;
  82
  83   // True if the accelerator is created for an auto repeated key event.
  84   bool is_repeat_;
  85
  86   // Stores platform specific data. May be NULL.
  87   scoped_ptr<PlatformAccelerator> platform_accelerator_;
  88 };
  89
  90 // An interface that classes that want to register for keyboard accelerators
  91 // should implement.
  92 class UI_BASE_EXPORT AcceleratorTarget {
  93  public:
  94   // Should return true if the accelerator was processed.
  95   virtual bool AcceleratorPressed(const Accelerator& accelerator) = 0;
  96
  97   // Should return true if the target can handle the accelerator events. The
  98   // AcceleratorPressed method is invoked only for targets for which
  99   // CanHandleAccelerators returns true.
 100   virtual bool CanHandleAccelerators() const = 0;
 101
 102  protected:
 103   virtual ~AcceleratorTarget() {}
 104 };
 105
 106 // Since accelerator code is one of the few things that can't be cross platform
 107 // in the chrome UI, separate out just the GetAcceleratorForCommandId() from
 108 // the menu delegates.
 109 class AcceleratorProvider {
 110  public:
 111   // Gets the accelerator for the specified command id. Returns true if the
 112   // command id has a valid accelerator, false otherwise.
 113   virtual bool GetAcceleratorForCommandId(int command_id,
 114                                           ui::Accelerator* accelerator) = 0;
 115
 116  protected:
 117   virtual ~AcceleratorProvider() {}
 118 };
 119
 120 }  // namespace ui
 121
 122 #endif  // UI_BASE_ACCELERATORS_ACCELERATOR_H_