/**
                             * The Popover Component
                             *
                             * @module aui-popover
                             */
                            
                            var StdMod = A.WidgetStdMod,
                            
                                getClassName = A.getClassName,
                            
                                CSS_ARROW = getClassName('arrow'),
                                CSS_POPOVER_BD = getClassName('popover-content'),
                                CSS_POPOVER_FT = getClassName('popover-footer'),
                                CSS_POPOVER_HD = getClassName('popover-title');
                            
                            /**
                             * A base class for Popover.
                             *
                             * Check the [live demo](http://alloyui.com/examples/popover/).
                             *
                             * @class A.Popover
                             * @extends Widget
                             * @uses A.WidgetCssClass, A.WidgetPosition, A.WidgetStdMod, A.WidgetToggle,
                             *     A.WidgetAutohide, A.WidgetToolbars, A.WidgetModality,
                             *     A.WidgetPositionAlign, A.WidgetPositionAlignSuggestion,
                             *     A.WidgetPositionConstrain, A.WidgetStack
                             * @param {Object} config Object literal specifying widget configuration
                             *     properties.
                             * @constructor
                             * @example
                            ```
                            <button id="myPopover" class="btn btn-primary">Click here to toggle the popover</button>
                            ```
                             * @example
                            ```
                            YUI().use(
                              'aui-popover',
                              function(Y) {
                                var trigger = Y.one('#myPopover');
                            
                                var popover = new Y.Popover(
                                  {
                                    align: {
                                      node: trigger,
                                      points:[Y.WidgetPositionAlign.BC, Y.WidgetPositionAlign.TC]
                                    },
                                    bodyContent: 'Body Content',
                                    headerContent: 'Header content',
                                    position: 'top'
                                  }
                                ).render();
                            
                                trigger.on(
                                  'click',
                                  function() {
                                    popover.set('visible', !popover.get('visible'));
                                  }
                                );
                              }
                            );
                            ```
                             */
                            A.Popover = A.Base.create('popover', A.Widget, [
                                A.WidgetCssClass,
                                A.WidgetPosition,
                                A.WidgetStdMod,
                                A.WidgetToggle,
                                A.WidgetAutohide,
                                A.WidgetToolbars,
                                A.WidgetModality,
                                A.WidgetPositionAlign,
                                A.WidgetPositionAlignSuggestion,
                                A.WidgetPositionConstrain,
                                A.WidgetStack,
                                A.WidgetTransition,
                                A.WidgetTrigger
                            ], {
                            
                                /**
                                 * Construction logic executed during Popover instantiation. Lifecycle.
                                 *
                                 * @method initializer
                                 * @protected
                                 */
                                initializer: function() {
                                    var instance = this;
                            
                                    A.after(instance._afterRenderBoxClassNames, instance, '_renderBoxClassNames');
                            
                                    this._resizeHandle = A.on('windowresize', A.bind(this._onResize, this));
                                },
                            
                                /**
                                 * Destructor lifecycle implementation for the `Popover` class.
                                 *
                                 * @method destructor
                                 * @protected
                                 */
                                destructor: function() {
                                    this._resizeHandle.detach();
                                },
                            
                                /**
                                 * Render the Popover component instance. Lifecycle.
                                 *
                                 * @method renderUI
                                 * @protected
                                 */
                                renderUI: function() {
                                    var instance = this,
                                        boundingBox = instance.get('boundingBox');
                            
                                    boundingBox.append(A.Popover.TEMPLATES.arrow);
                            
                                    instance.suggestAlignment();
                                },
                            
                                /**
                                 * Fire after `contentBox` class names changes.
                                 *
                                 * @method _afterRenderBoxClassNames
                                 * @param event
                                 * @protected
                                 */
                                _afterRenderBoxClassNames: function() {
                                    var instance = this,
                                        contentBox = instance.get('contentBox');
                            
                                    contentBox.removeClass(instance.getClassName('content'));
                                },
                            
                                /**
                                 * Fired after the window is resized.
                                 *
                                 * @method _onResize
                                 * @protected
                                 */
                                _onResize: function() {
                                    this.suggestAlignment();
                                },
                            
                                /**
                                 * Fire after `boundingBox` style changes.
                                 *
                                 * @method _uiSetVisible
                                 * @param val
                                 * @protected
                                 */
                                _uiSetVisible: function(val) {
                                    var instance = this,
                                        boundingBox = instance.get('boundingBox');
                            
                                    instance._widgetUiSetVisible(val);
                            
                                    boundingBox.setStyle('display', val ? 'block' : 'none');
                            
                                    if (val) {
                                        instance.suggestAlignment();
                                    }
                                },
                            
                                /**
                                 * Get templates from a widget extension.
                                 *
                                 * @method _getStdModTemplate
                                 * @param section
                                 * @protected
                                 */
                                _getStdModTemplate: function(section) {
                                    return A.Node.create(A.Popover.TEMPLATES[section], this._stdModNode.get('ownerDocument'));
                                },
                            
                                _widgetUiSetVisible: A.Widget.prototype._uiSetVisible
                            }, {
                                /**
                                 * Static property provides a string to identify the CSS prefix.
                                 *
                                 * @property CSS_PREFIX
                                 * @type String
                                 * @static
                                 */
                                CSS_PREFIX: getClassName('popover'),
                            
                                /**
                                 * Static property used to define the default attribute
                                 * configuration for the Popover.
                                 *
                                 * @property ATTRS
                                 * @type Object
                                 * @static
                                 */
                                ATTRS: {
                                    /**
                                     * DOM event to hide the tooltip.
                                     *
                                     * @attribute triggerToggleEvent
                                     * @default click
                                     * @type String
                                     */
                                    triggerToggleEvent: {
                                        value: 'click'
                                    }
                                },
                            
                                /**
                                 * Static property provides a set of reusable templates.
                                 *
                                 * @property TEMPLATES
                                 * @type Object
                                 * @static
                                 */
                                TEMPLATES: {
                                    header: '<div class="' + StdMod.SECTION_CLASS_NAMES[StdMod.HEADER] + ' ' + CSS_POPOVER_HD + '"></div>',
                                    body: '<div class="' + StdMod.SECTION_CLASS_NAMES[StdMod.BODY] + ' ' + CSS_POPOVER_BD + '"></div>',
                                    footer: '<div class="' + StdMod.SECTION_CLASS_NAMES[StdMod.FOOTER] + ' ' + CSS_POPOVER_FT + '"></div>',
                                    arrow: '<div class="' + CSS_ARROW + '"></div>'
                                }
                            });