<!-- Copyright 2013 The Polymer Authors. All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. --> <!-- /** * @module Polymer Elements */ --> <!-- /** * The polymer-selection element is used to manage selection state. It has no * visual appearance and is typically used in conjuneciton with another element. * For example, <a href="polymer-selector.html">polymer-selector</a> * use a polymer-selection to manage selection. * * To mark an item as selected, call the select(item) method on * polymer-selection. Notice that the item itself is an argument to this method. * The polymer-selection element manages selection state for any given set of * items. When an item is selected, the `polymer-select` event is fired. * The attribute "multi" indicates if multiple items can be selected at once. * * Example: * * <polymer-element name="selection-example"> * <template> * <style> * ::-webkit-distributed(> .selected) { * font-weight: bold; * font-style: italic; * } * </style> * <ul on-tap="{{itemTapAction}}"> * <content></content> * </ul> * <polymer-selection id="selection" multi on-polymer-select="{{selectAction}}"></polymer-selection> * </template> * <script> * Polymer('selection-example', { * itemTapAction: function(e) { * this.$.selection.select(e.target); * }, * selectAction: function(e, detail) { * detail.item.classList.toggle('selected', detail.isSelected); * } * }); * </script> * </polymer-element> * * <selection-example> * <li>Red</li> * <li>Green</li> * <li>Blue</li> * </selection-example> * * @class polymer-selection */ /** * Fired when an item's selection state is changed. This event is fired both * when an item is selected or deselected. The `isSelected` detail property * contains the selection state. * * @event polymer-select * @param {Object} detail * @param {boolean} detail.isSelected true for selection and false for deselection * @param {Object} detail.item the item element */ --> <link rel="import" href="../polymer/polymer.html"> <polymer-element name="polymer-selection" attributes="multi"> <template> <style> :host { display: none !important; } </style> </template> <script> Polymer('polymer-selection', { /** * If true, multiple selections are allowed. * * @attribute multi * @type boolean * @default false */ multi: false, ready: function() { this.clear(); }, clear: function() { this.selection = []; }, /** * Retrieves the selected item(s). * @method getSelection * @returns Returns the selected item(s). If the multi property is true, * getSelection will return an array, otherwise it will return * the selected item or undefined if there is no selection. */ getSelection: function() { return this.multi ? this.selection : this.selection[0]; }, /** * Indicates if a given item is selected. * @method isSelected * @param {any} item The item whose selection state should be checked. * @returns Returns true if `item` is selected. */ isSelected: function(item) { return this.selection.indexOf(item) >= 0; }, setItemSelected: function(item, isSelected) { if (item !== undefined && item !== null) { if (isSelected) { this.selection.push(item); } else { var i = this.selection.indexOf(item); if (i >= 0) { this.selection.splice(i, 1); } } this.fire("polymer-select", {isSelected: isSelected, item: item}); } }, /** * Set the selection state for a given `item`. If the multi property * is true, then the selected state of `item` will be toggled; otherwise * the `item` will be selected. * @method select * @param {any} item: The item to select. */ select: function(item) { if (this.multi) { this.toggle(item); } else if (this.getSelection() !== item) { this.setItemSelected(this.getSelection(), false); this.setItemSelected(item, true); } }, /** * Toggles the selection state for `item`. * @method toggle * @param {any} item: The item to toggle. */ toggle: function(item) { this.setItemSelected(item, !this.isSelected(item)); } }); </script> </polymer-element>