1 // Copyright (c) 2013 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_EXTENSIONS_GLOBAL_SHORTCUT_LISTENER_H_ 6 #define CHROME_BROWSER_EXTENSIONS_GLOBAL_SHORTCUT_LISTENER_H_ 7 8 #include <map> 9 10 #include "base/basictypes.h" 11 #include "ui/events/keycodes/keyboard_codes.h" 12 13 namespace ui { 14 class Accelerator; 15 } 16 17 namespace extensions { 18 19 // Platform-neutral implementation of a class that keeps track of observers and 20 // monitors keystrokes. It relays messages to the appropriate observer when a 21 // global shortcut has been struck by the user. 22 class GlobalShortcutListener { 23 public: 24 class Observer { 25 public: 26 // Called when your global shortcut (|accelerator|) is struck. 27 virtual void OnKeyPressed(const ui::Accelerator& accelerator) = 0; 28 }; 29 30 virtual ~GlobalShortcutListener(); 31 32 static GlobalShortcutListener* GetInstance(); 33 34 // Register an observer for when a certain |accelerator| is struck. Returns 35 // true if register successfully, or false if 1) the specificied |accelerator| 36 // has been registered by another caller or other native applications, or 37 // 2) shortcut handling is suspended. 38 // 39 // Note that we do not support recognizing that an accelerator has been 40 // registered by another application on all platforms. This is a per-platform 41 // consideration. 42 bool RegisterAccelerator(const ui::Accelerator& accelerator, 43 Observer* observer); 44 45 // Stop listening for the given |accelerator|, does nothing if shortcut 46 // handling is suspended. 47 void UnregisterAccelerator(const ui::Accelerator& accelerator, 48 Observer* observer); 49 50 // Stop listening for all accelerators of the given |observer|, does nothing 51 // if shortcut handling is suspended. 52 void UnregisterAccelerators(Observer* observer); 53 54 // Suspend/Resume global shortcut handling. Note that when suspending, 55 // RegisterAccelerator/UnregisterAccelerator/UnregisterAccelerators are not 56 // allowed to be called until shortcut handling has been resumed. 57 void SetShortcutHandlingSuspended(bool suspended); 58 59 // Returns whether shortcut handling is currently suspended. 60 bool IsShortcutHandlingSuspended() const; 61 62 protected: 63 GlobalShortcutListener(); 64 65 // Called by platform specific implementations of this class whenever a key 66 // is struck. Only called for keys that have an observer registered. 67 void NotifyKeyPressed(const ui::Accelerator& accelerator); 68 69 private: 70 // The following methods are implemented by platform-specific implementations 71 // of this class. 72 // 73 // Start/StopListening are called when transitioning between zero and nonzero 74 // registered accelerators. StartListening will be called after 75 // RegisterAcceleratorImpl and StopListening will be called after 76 // UnregisterAcceleratorImpl. 77 // 78 // For RegisterAcceleratorImpl, implementations return false if registration 79 // did not complete successfully. 80 virtual void StartListening() = 0; 81 virtual void StopListening() = 0; 82 virtual bool RegisterAcceleratorImpl(const ui::Accelerator& accelerator) = 0; 83 virtual void UnregisterAcceleratorImpl( 84 const ui::Accelerator& accelerator) = 0; 85 86 // The map of accelerators that have been successfully registered as global 87 // shortcuts and their observer. 88 typedef std::map<ui::Accelerator, Observer*> AcceleratorMap; 89 AcceleratorMap accelerator_map_; 90 91 // Keeps track of whether shortcut handling is currently suspended. 92 bool shortcut_handling_suspended_; 93 94 DISALLOW_COPY_AND_ASSIGN(GlobalShortcutListener); 95 }; 96 97 } // namespace extensions 98 99 #endif // CHROME_BROWSER_EXTENSIONS_GLOBAL_SHORTCUT_LISTENER_H_ 100