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 CHROME_BROWSER_COMMAND_UPDATER_H_ 6 #define CHROME_BROWSER_COMMAND_UPDATER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/containers/hash_tables.h" 10 #include "ui/base/window_open_disposition.h" 11 12 class CommandObserver; 13 class CommandUpdaterDelegate; 14 15 //////////////////////////////////////////////////////////////////////////////// 16 // 17 // CommandUpdater class 18 // 19 // This object manages the enabled state of a set of commands. Observers 20 // register to listen to changes in this state so they can update their 21 // presentation. 22 // 23 class CommandUpdater { 24 public: 25 // Create a CommandUpdater with |delegate| to handle the execution of specific 26 // commands. 27 explicit CommandUpdater(CommandUpdaterDelegate* delegate); 28 ~CommandUpdater(); 29 30 // Returns true if the specified command ID is supported. 31 bool SupportsCommand(int id) const; 32 33 // Returns true if the specified command ID is enabled. The command ID must be 34 // supported by this updater. 35 bool IsCommandEnabled(int id) const; 36 37 // Performs the action associated with this command ID using CURRENT_TAB 38 // disposition. 39 // Returns true if the command was executed (i.e. it is supported and is 40 // enabled). 41 bool ExecuteCommand(int id); 42 43 // Performs the action associated with this command ID using the given 44 // disposition. 45 // Returns true if the command was executed (i.e. it is supported and is 46 // enabled). 47 bool ExecuteCommandWithDisposition(int id, WindowOpenDisposition disposition); 48 49 // Adds an observer to the state of a particular command. If the command does 50 // not exist, it is created, initialized to false. 51 void AddCommandObserver(int id, CommandObserver* observer); 52 53 // Removes an observer to the state of a particular command. 54 void RemoveCommandObserver(int id, CommandObserver* observer); 55 56 // Removes |observer| for all commands on which it's registered. 57 void RemoveCommandObserver(CommandObserver* observer); 58 59 // Notify all observers of a particular command that the command has been 60 // enabled or disabled. If the command does not exist, it is created and 61 // initialized to |state|. This function is very lightweight if the command 62 // state has not changed. 63 void UpdateCommandEnabled(int id, bool state); 64 65 private: 66 // A piece of data about a command - whether or not it is enabled, and a list 67 // of objects that observe the enabled state of this command. 68 class Command; 69 70 // Get a Command node for a given command ID, creating an entry if it doesn't 71 // exist if desired. 72 Command* GetCommand(int id, bool create); 73 74 // The delegate is responsible for executing commands. 75 CommandUpdaterDelegate* delegate_; 76 77 // This is a map of command IDs to states and observer lists 78 typedef base::hash_map<int, Command*> CommandMap; 79 CommandMap commands_; 80 81 DISALLOW_COPY_AND_ASSIGN(CommandUpdater); 82 }; 83 84 #endif // CHROME_BROWSER_COMMAND_UPDATER_H_ 85
