menuitem.js

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Copyright 2007 Google Inc. All Rights Reserved.

/**
 * @fileoverview A class for representing items in menus.
 * @see goog.ui.Menu
 *
 */

goog.provide('goog.ui.MenuItem');

goog.require('goog.ui.Component.State');
goog.require('goog.ui.Control');
goog.require('goog.ui.ControlContent');
goog.require('goog.ui.MenuItemRenderer');
goog.require('goog.ui.registry');


/**
 * Class representing an item in a menu.
 *
 * @param {goog.ui.ControlContent} content Text caption or DOM structure to
 *     display as the content of the item (use to add icons or styling to
 *     menus).
 * @param {*} opt_model Data/model associated with the menu item.
 * @param {goog.dom.DomHelper} opt_domHelper Optional DOM helper used for
 *     document interactions.
 * @param {goog.ui.MenuItemRenderer} opt_renderer Optional renderer.
 * @constructor
 * @extends {goog.ui.Control}
 */
goog.ui.MenuItem = function(content, opt_model, opt_domHelper, opt_renderer) {
  goog.ui.Control.call(this, content, opt_renderer ||
      goog.ui.MenuItemRenderer.getInstance(), opt_domHelper);
  this.setValue(opt_model);
};
goog.inherits(goog.ui.MenuItem, goog.ui.Control);


// goog.ui.Component and goog.ui.Control implementation.


/**
 * Returns the value associated with the menu item.  The default implementation
 * returns the model object associated with the item (if any), or its caption.
 * @return {*} Value associated with the menu item, if any, or its caption.
 */
goog.ui.MenuItem.prototype.getValue = function() {
  var model = this.getModel();
  return model != null ? model : this.getCaption();
};


/**
 * Sets the value associated with the menu item.  The default implementation
 * stores the value as the model of the menu item.
 * @param {*} value Value to be associated with the menu item.
 */
goog.ui.MenuItem.prototype.setValue = function(value) {
  this.setModel(value);
};


/**
 * Sets the menu item to be selectable or not.  Set to true for menu items
 * that represent selectable options.
 * @param {boolean} selectable Whether the menu item is selectable.
 */
goog.ui.MenuItem.prototype.setSelectable = function(selectable) {
  this.setSupportedState(goog.ui.Component.State.SELECTED, selectable);
  if (this.isChecked() && !selectable) {
    this.setChecked(false);
  }

  var element = this.getElement();
  if (element) {
    this.renderer_.setSelectable(this, element, selectable);
  }
};


/**
 * Sets the menu item to be checkable or not.  Set to true for menu items
 * that represent checkable options.
 * @param {boolean} checkable Whether the menu item is checkable.
 */
goog.ui.MenuItem.prototype.setCheckable = function(checkable) {
  this.setSupportedState(goog.ui.Component.State.CHECKED, checkable);

  var element = this.getElement();
  if (element) {
    this.renderer_.setCheckable(this, element, checkable);
  }
};


// Register a decorator factory function for goog.ui.MenuItems.
goog.ui.registry.setDecoratorByClassName(goog.ui.MenuItemRenderer.CSS_CLASS,
    function() {
      // MenuItem defaults to using MenuItemRenderer.
      return new goog.ui.MenuItem(null);
    });