michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: 
michael@0: /**
michael@0:  * Command Updater
michael@0:  */
michael@0: var CommandUpdater = {
michael@0:   /**
michael@0:    * Gets a controller that can handle a particular command.
michael@0:    * @param   command
michael@0:    *          A command to locate a controller for, preferring controllers that
michael@0:    *          show the command as enabled.
michael@0:    * @returns In this order of precedence:
michael@0:    *            - the first controller supporting the specified command
michael@0:    *              associated with the focused element that advertises the
michael@0:    *              command as ENABLED
michael@0:    *            - the first controller supporting the specified command
michael@0:    *              associated with the global window that advertises the
michael@0:    *              command as ENABLED
michael@0:    *            - the first controller supporting the specified command
michael@0:    *              associated with the focused element
michael@0:    *            - the first controller supporting the specified command
michael@0:    *              associated with the global window
michael@0:    */
michael@0:   _getControllerForCommand: function(command) {
michael@0:     try {
michael@0:       var controller = top.document.commandDispatcher.getControllerForCommand(command);
michael@0:       if (controller && controller.isCommandEnabled(command))
michael@0:         return controller;
michael@0:     }
michael@0:     catch(e) {
michael@0:     }
michael@0:     var controllerCount = window.controllers.getControllerCount();
michael@0:     for (var i = 0; i < controllerCount; ++i) {
michael@0:       var current = window.controllers.getControllerAt(i);
michael@0:       try {
michael@0:         if (current.supportsCommand(command) && current.isCommandEnabled(command))
michael@0:           return current;
michael@0:       }
michael@0:       catch (e) {
michael@0:       }
michael@0:     }
michael@0:     return controller || window.controllers.getControllerForCommand(command);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Updates the state of a XUL <command> element for the specified command
michael@0:    * depending on its state.
michael@0:    * @param   command
michael@0:    *          The name of the command to update the XUL <command> element for
michael@0:    */
michael@0:   updateCommand: function(command) {
michael@0:     var enabled = false;
michael@0:     try {
michael@0:       var controller = this._getControllerForCommand(command);
michael@0:       if (controller) {
michael@0:         enabled = controller.isCommandEnabled(command);
michael@0:       }
michael@0:     }
michael@0:     catch(ex) { }
michael@0: 
michael@0:     this.enableCommand(command, enabled);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Updates the state of a XUL <command> element for the specified command
michael@0:    * depending on its state.
michael@0:    * @param   command
michael@0:    *          The name of the command to update the XUL <command> element for
michael@0:    */
michael@0:   updateCommands: function(_commands) {
michael@0:     var commands = _commands.split(",");
michael@0:     for (var command in commands) {
michael@0:       this.updateCommand(commands[command]);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Enables or disables a XUL <command> element.
michael@0:    * @param   command
michael@0:    *          The name of the command to enable or disable
michael@0:    * @param   enabled
michael@0:    *          true if the command should be enabled, false otherwise.
michael@0:    */
michael@0:   enableCommand: function(command, enabled) {
michael@0:     var element = document.getElementById(command);
michael@0:     if (!element)
michael@0:       return;
michael@0:     if (enabled)
michael@0:       element.removeAttribute("disabled");
michael@0:     else
michael@0:       element.setAttribute("disabled", "true");
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Performs the action associated with a specified command using the most
michael@0:    * relevant controller.
michael@0:    * @param   command
michael@0:    *          The command to perform.
michael@0:    */
michael@0:   doCommand: function(command) {
michael@0:     var controller = this._getControllerForCommand(command);
michael@0:     if (!controller)
michael@0:       return;
michael@0:     controller.doCommand(command);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Changes the label attribute for the specified command.
michael@0:    * @param   command
michael@0:    *          The command to update.
michael@0:    * @param   labelAttribute
michael@0:    *          The label value to use.
michael@0:    */
michael@0:   setMenuValue: function(command, labelAttribute) {
michael@0:     var commandNode = top.document.getElementById(command);
michael@0:     if (commandNode)
michael@0:     {
michael@0:       var label = commandNode.getAttribute(labelAttribute);
michael@0:       if ( label )
michael@0:         commandNode.setAttribute('label', label);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Changes the accesskey attribute for the specified command.
michael@0:    * @param   command
michael@0:    *          The command to update.
michael@0:    * @param   valueAttribute
michael@0:    *          The value attribute to use.
michael@0:    */
michael@0:   setAccessKey: function(command, valueAttribute) {
michael@0:     var commandNode = top.document.getElementById(command);
michael@0:     if (commandNode)
michael@0:     {
michael@0:       var value = commandNode.getAttribute(valueAttribute);
michael@0:       if ( value )
michael@0:         commandNode.setAttribute('accesskey', value);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Inform all the controllers attached to a node that an event has occurred
michael@0:    * (e.g. the tree controllers need to be informed of blur events so that they can change some of the
michael@0:    * menu items back to their default values)
michael@0:    * @param   node
michael@0:    *          The node receiving the event
michael@0:    * @param   event
michael@0:    *          The event.
michael@0:    */
michael@0:   onEvent: function(node, event) {
michael@0:     var numControllers = node.controllers.getControllerCount();
michael@0:     var controller;
michael@0: 
michael@0:     for ( var controllerIndex = 0; controllerIndex < numControllers; controllerIndex++ )
michael@0:     {
michael@0:       controller = node.controllers.getControllerAt(controllerIndex);
michael@0:       if ( controller )
michael@0:         controller.onEvent(event);
michael@0:     }
michael@0:   }
michael@0: };