1// Copyright (c) 2011 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_COCOA_COMMAND_OBSERVER_BRIDGE 6#define CHROME_BROWSER_UI_COCOA_COMMAND_OBSERVER_BRIDGE 7 8#import <Cocoa/Cocoa.h> 9 10#include "base/compiler_specific.h" 11#include "chrome/browser/command_observer.h" 12 13@protocol CommandObserverProtocol; 14 15class CommandUpdater; 16 17// A C++ bridge class that handles listening for updates to commands and 18// passing them back to an object that supports the protocol delcared below. 19// The observer will create one of these bridges, call ObserveCommand() on the 20// command ids it cares about, and then wait for update notifications, 21// delivered via -enabledStateChangedForCommand:enabled:. Destroying this 22// bridge will handle automatically unregistering for updates, so there's no 23// need to do that manually. 24 25class CommandObserverBridge : public CommandObserver { 26 public: 27 CommandObserverBridge(id<CommandObserverProtocol> observer, 28 CommandUpdater* commands); 29 virtual ~CommandObserverBridge(); 30 31 // Register for updates about |command|. 32 void ObserveCommand(int command); 33 34 protected: 35 // Overridden from CommandObserver 36 virtual void EnabledStateChangedForCommand(int command, 37 bool enabled) OVERRIDE; 38 39 private: 40 id<CommandObserverProtocol> observer_; // weak, owns me 41 CommandUpdater* commands_; // weak 42}; 43 44// Implemented by the observing Objective-C object, called when there is a 45// state change for the given command. 46@protocol CommandObserverProtocol 47- (void)enabledStateChangedForCommand:(NSInteger)command enabled:(BOOL)enabled; 48@end 49 50#endif // CHROME_BROWSER_UI_COCOA_COMMAND_OBSERVER_BRIDGE 51