API: container Tooltip.js (YUI Library)

# Yahoo! UI Library

### Container 2.8.1

Yahoo! UI Library > container > Tooltip.js (source view)
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    (function () {

        /**
        * Tooltip is an implementation of Overlay that behaves like an OS tooltip,
        * displaying when the user mouses over a particular element, and
        * disappearing on mouse out.
        * @namespace YAHOO.widget
        * @class Tooltip
        * @extends YAHOO.widget.Overlay
        * @constructor
        * @param {String} el The element ID representing the Tooltip <em>OR</em>
        * @param {HTMLElement} el The element representing the Tooltip
        * @param {Object} userConfig The configuration object literal containing
        * the configuration that should be set for this Overlay. See configuration
        * documentation for more details.
        */
        YAHOO.widget.Tooltip = function (el, userConfig) {
            YAHOO.widget.Tooltip.superclass.constructor.call(this, el, userConfig);
        };

        var Lang = YAHOO.lang,
            Event = YAHOO.util.Event,
            CustomEvent = YAHOO.util.CustomEvent,
            Dom = YAHOO.util.Dom,
            Tooltip = YAHOO.widget.Tooltip,
            UA = YAHOO.env.ua,
            bIEQuirks = (UA.ie && (UA.ie <= 6 || document.compatMode == "BackCompat")),

            m_oShadowTemplate,

            /**
            * Constant representing the Tooltip's configuration properties
            * @property DEFAULT_CONFIG
            * @private
            * @final
            * @type Object
            */
            DEFAULT_CONFIG = {

                "PREVENT_OVERLAP": {
                    key: "preventoverlap",
                    value: true,
                    validator: Lang.isBoolean,
                    supercedes: ["x", "y", "xy"]
                },

                "SHOW_DELAY": {
                    key: "showdelay",
                    value: 200,
                    validator: Lang.isNumber
                },

                "AUTO_DISMISS_DELAY": {
                    key: "autodismissdelay",
                    value: 5000,
                    validator: Lang.isNumber
                },

                "HIDE_DELAY": {
                    key: "hidedelay",
                    value: 250,
                    validator: Lang.isNumber
                },

                "TEXT": {
                    key: "text",
                    suppressEvent: true
                },

                "CONTAINER": {
                    key: "container"
                },

                "DISABLED": {
                    key: "disabled",
                    value: false,
                    suppressEvent: true
                },

                "XY_OFFSET": {
                    key: "xyoffset",
                    value: [0, 25],
                    suppressEvent: true
                }
            },

            /**
            * Constant representing the name of the Tooltip's events
            * @property EVENT_TYPES
            * @private
            * @final
            * @type Object
            */
            EVENT_TYPES = {
                "CONTEXT_MOUSE_OVER": "contextMouseOver",
                "CONTEXT_MOUSE_OUT": "contextMouseOut",
                "CONTEXT_TRIGGER": "contextTrigger"
            };

        /**
        * Constant representing the Tooltip CSS class
        * @property YAHOO.widget.Tooltip.CSS_TOOLTIP
        * @static
        * @final
        * @type String
        */
        Tooltip.CSS_TOOLTIP = "yui-tt";

        function restoreOriginalWidth(sOriginalWidth, sForcedWidth) {

            var oConfig = this.cfg,
                sCurrentWidth = oConfig.getProperty("width");

            if (sCurrentWidth == sForcedWidth) {
                oConfig.setProperty("width", sOriginalWidth);
            }
        }

        /*
            changeContent event handler that sets a Tooltip instance's "width"
            configuration property to the value of its root HTML
            elements's offsetWidth if a specific width has not been set.
        */

        function setWidthToOffsetWidth(p_sType, p_aArgs) {

            if ("_originalWidth" in this) {
                restoreOriginalWidth.call(this, this._originalWidth, this._forcedWidth);
            }

            var oBody = document.body,
                oConfig = this.cfg,
                sOriginalWidth = oConfig.getProperty("width"),
                sNewWidth,
                oClone;

            if ((!sOriginalWidth || sOriginalWidth == "auto") &&
                (oConfig.getProperty("container") != oBody ||
                oConfig.getProperty("x") >= Dom.getViewportWidth() ||
                oConfig.getProperty("y") >= Dom.getViewportHeight())) {

                oClone = this.element.cloneNode(true);
                oClone.style.visibility = "hidden";
                oClone.style.top = "0px";
                oClone.style.left = "0px";

                oBody.appendChild(oClone);

                sNewWidth = (oClone.offsetWidth + "px");

                oBody.removeChild(oClone);
                oClone = null;

                oConfig.setProperty("width", sNewWidth);
                oConfig.refireEvent("xy");

                this._originalWidth = sOriginalWidth || "";
                this._forcedWidth = sNewWidth;
            }
        }

        // "onDOMReady" that renders the ToolTip

        function onDOMReady(p_sType, p_aArgs, p_oObject) {
            this.render(p_oObject);
        }

        //  "init" event handler that automatically renders the Tooltip

        function onInit() {
            Event.onDOMReady(onDOMReady, this.cfg.getProperty("container"), this);
        }

        YAHOO.extend(Tooltip, YAHOO.widget.Overlay, {

            /**
            * The Tooltip initialization method. This method is automatically
            * called by the constructor. A Tooltip is automatically rendered by
            * the init method, and it also is set to be invisible by default,
            * and constrained to viewport by default as well.
            * @method init
            * @param {String} el The element ID representing the Tooltip <em>OR</em>
            * @param {HTMLElement} el The element representing the Tooltip
            * @param {Object} userConfig The configuration object literal
            * containing the configuration that should be set for this Tooltip.
            * See configuration documentation for more details.
            */
            init: function (el, userConfig) {

                this.logger = new YAHOO.widget.LogWriter(this.toString());

                Tooltip.superclass.init.call(this, el);

                this.beforeInitEvent.fire(Tooltip);

                Dom.addClass(this.element, Tooltip.CSS_TOOLTIP);

                if (userConfig) {
                    this.cfg.applyConfig(userConfig, true);
                }

                this.cfg.queueProperty("visible", false);
                this.cfg.queueProperty("constraintoviewport", true);

                this.setBody("");

                this.subscribe("changeContent", setWidthToOffsetWidth);
                this.subscribe("init", onInit);
                this.subscribe("render", this.onRender);

                this.initEvent.fire(Tooltip);
            },

            /**
            * Initializes the custom events for Tooltip
            * @method initEvents
            */
            initEvents: function () {

                Tooltip.superclass.initEvents.call(this);
                var SIGNATURE = CustomEvent.LIST;

                /**
                * CustomEvent fired when user mouses over a context element. Returning false from
                * a subscriber to this event will prevent the tooltip from being displayed for
                * the current context element.
                *
                * @event contextMouseOverEvent
                * @param {HTMLElement} context The context element which the user just moused over
                * @param {DOMEvent} e The DOM event object, associated with the mouse over
                */
                this.contextMouseOverEvent = this.createEvent(EVENT_TYPES.CONTEXT_MOUSE_OVER);
                this.contextMouseOverEvent.signature = SIGNATURE;

                /**
                * CustomEvent fired when the user mouses out of a context element.
                *
                * @event contextMouseOutEvent
                * @param {HTMLElement} context The context element which the user just moused out of
                * @param {DOMEvent} e The DOM event object, associated with the mouse out
                */
                this.contextMouseOutEvent = this.createEvent(EVENT_TYPES.CONTEXT_MOUSE_OUT);
                this.contextMouseOutEvent.signature = SIGNATURE;

                /**
                * CustomEvent fired just before the tooltip is displayed for the current context.
                * <p>
                *  You can subscribe to this event if you need to set up the text for the
                *  tooltip based on the context element for which it is about to be displayed.
                * </p>
                * <p>This event differs from the beforeShow event in following respects:</p>
                * <ol>
                *   <li>
                *    When moving from one context element to another, if the tooltip is not
                *    hidden (the <code>hidedelay</code> is not reached), the beforeShow and Show events will not
                *    be fired when the tooltip is displayed for the new context since it is already visible.
                *    However the contextTrigger event is always fired before displaying the tooltip for
                *    a new context.
                *   </li>
                *   <li>
                *    The trigger event provides access to the context element, allowing you to
                *    set the text of the tooltip based on context element for which the tooltip is
                *    triggered.
                *   </li>
                * </ol>
                * <p>
                *  It is not possible to prevent the tooltip from being displayed
                *  using this event. You can use the contextMouseOverEvent if you need to prevent
                *  the tooltip from being displayed.
                * </p>
                * @event contextTriggerEvent
                * @param {HTMLElement} context The context element for which the tooltip is triggered
                */
                this.contextTriggerEvent = this.createEvent(EVENT_TYPES.CONTEXT_TRIGGER);
                this.contextTriggerEvent.signature = SIGNATURE;
            },

            /**
            * Initializes the class's configurable properties which can be
            * changed using the Overlay's Config object (cfg).
            * @method initDefaultConfig
            */
            initDefaultConfig: function () {

                Tooltip.superclass.initDefaultConfig.call(this);

                /**
                * Specifies whether the Tooltip should be kept from overlapping
                * its context element.
                * @config preventoverlap
                * @type Boolean
                * @default true
                */
                this.cfg.addProperty(DEFAULT_CONFIG.PREVENT_OVERLAP.key, {
                    value: DEFAULT_CONFIG.PREVENT_OVERLAP.value,
                    validator: DEFAULT_CONFIG.PREVENT_OVERLAP.validator,
                    supercedes: DEFAULT_CONFIG.PREVENT_OVERLAP.supercedes
                });

                /**
                * The number of milliseconds to wait before showing a Tooltip
                * on mouseover.
                * @config showdelay
                * @type Number
                * @default 200
                */
                this.cfg.addProperty(DEFAULT_CONFIG.SHOW_DELAY.key, {
                    handler: this.configShowDelay,
                    value: 200,
                    validator: DEFAULT_CONFIG.SHOW_DELAY.validator
                });

                /**
                * The number of milliseconds to wait before automatically
                * dismissing a Tooltip after the mouse has been resting on the
                * context element.
                * @config autodismissdelay
                * @type Number
                * @default 5000
                */
                this.cfg.addProperty(DEFAULT_CONFIG.AUTO_DISMISS_DELAY.key, {
                    handler: this.configAutoDismissDelay,
                    value: DEFAULT_CONFIG.AUTO_DISMISS_DELAY.value,
                    validator: DEFAULT_CONFIG.AUTO_DISMISS_DELAY.validator
                });

                /**
                * The number of milliseconds to wait before hiding a Tooltip
                * after mouseout.
                * @config hidedelay
                * @type Number
                * @default 250
                */
                this.cfg.addProperty(DEFAULT_CONFIG.HIDE_DELAY.key, {
                    handler: this.configHideDelay,
                    value: DEFAULT_CONFIG.HIDE_DELAY.value,
                    validator: DEFAULT_CONFIG.HIDE_DELAY.validator
                });

                /**
                * Specifies the Tooltip's text.
                * @config text
                * @type String
                * @default null
                */
                this.cfg.addProperty(DEFAULT_CONFIG.TEXT.key, {
                    handler: this.configText,
                    suppressEvent: DEFAULT_CONFIG.TEXT.suppressEvent
                });

                /**
                * Specifies the container element that the Tooltip's markup
                * should be rendered into.
                * @config container
                * @type HTMLElement/String
                * @default document.body
                */
                this.cfg.addProperty(DEFAULT_CONFIG.CONTAINER.key, {
                    handler: this.configContainer,
                    value: document.body
                });

                /**
                * Specifies whether or not the tooltip is disabled. Disabled tooltips
                * will not be displayed. If the tooltip is driven by the title attribute
                * of the context element, the title attribute will still be removed for
                * disabled tooltips, to prevent default tooltip behavior.
                *
                * @config disabled
                * @type Boolean
                * @default false
                */
                this.cfg.addProperty(DEFAULT_CONFIG.DISABLED.key, {
                    handler: this.configContainer,
                    value: DEFAULT_CONFIG.DISABLED.value,
                    supressEvent: DEFAULT_CONFIG.DISABLED.suppressEvent
                });

                /**
                * Specifies the XY offset from the mouse position, where the tooltip should be displayed, specified
                * as a 2 element array (e.g. [10, 20]);
                *
                * @config xyoffset
                * @type Array
                * @default [0, 25]
                */
                this.cfg.addProperty(DEFAULT_CONFIG.XY_OFFSET.key, {
                    value: DEFAULT_CONFIG.XY_OFFSET.value.concat(),
                    supressEvent: DEFAULT_CONFIG.XY_OFFSET.suppressEvent
                });

                /**
                * Specifies the element or elements that the Tooltip should be
                * anchored to on mouseover.
                * @config context
                * @type HTMLElement[]/String[]
                * @default null
                */

                /**
                * String representing the width of the Tooltip.  <em>Please note:
                * </em> As of version 2.3 if either no value or a value of "auto"
                * is specified, and the Toolip's "container" configuration property
                * is set to something other than <code>document.body</code> or
                * its "context" element resides outside the immediately visible
                * portion of the document, the width of the Tooltip will be
                * calculated based on the offsetWidth of its root HTML and set just
                * before it is made visible.  The original value will be
                * restored when the Tooltip is hidden. This ensures the Tooltip is
                * rendered at a usable width.  For more information see
                * YUILibrary bug #1685496 and YUILibrary
                * bug #1735423.
                * @config width
                * @type String
                * @default null
                */

            },

            // BEGIN BUILT-IN PROPERTY EVENT HANDLERS //

            /**
            * The default event handler fired when the "text" property is changed.
            * @method configText
            * @param {String} type The CustomEvent type (usually the property name)
            * @param {Object[]} args The CustomEvent arguments. For configuration
            * handlers, args[0] will equal the newly applied value for the property.
            * @param {Object} obj The scope object. For configuration handlers,
            * this will usually equal the owner.
            */
            configText: function (type, args, obj) {
                var text = args[0];
                if (text) {
                    this.setBody(text);
                }
            },

            /**
            * The default event handler fired when the "container" property
            * is changed.
            * @method configContainer
            * @param {String} type The CustomEvent type (usually the property name)
            * @param {Object[]} args The CustomEvent arguments. For
            * configuration handlers, args[0] will equal the newly applied value
            * for the property.
            * @param {Object} obj The scope object. For configuration handlers,
            * this will usually equal the owner.
            */
            configContainer: function (type, args, obj) {
                var container = args[0];

                if (typeof container == 'string') {
                    this.cfg.setProperty("container", document.getElementById(container), true);
                }
            },

            /**
            * @method _removeEventListeners
            * @description Removes all of the DOM event handlers from the HTML
            *  element(s) that trigger the display of the tooltip.
            * @protected
            */
            _removeEventListeners: function () {

                var aElements = this._context,
                    nElements,
                    oElement,
                    i;

                if (aElements) {
                    nElements = aElements.length;
                    if (nElements > 0) {
                        i = nElements - 1;
                        do {
                            oElement = aElements[i];
                            Event.removeListener(oElement, "mouseover", this.onContextMouseOver);
                            Event.removeListener(oElement, "mousemove", this.onContextMouseMove);
                            Event.removeListener(oElement, "mouseout", this.onContextMouseOut);
                        }
                        while (i--);
                    }
                }
            },

            /**
            * The default event handler fired when the "context" property
            * is changed.
            * @method configContext
            * @param {String} type The CustomEvent type (usually the property name)
            * @param {Object[]} args The CustomEvent arguments. For configuration
            * handlers, args[0] will equal the newly applied value for the property.
            * @param {Object} obj The scope object. For configuration handlers,
            * this will usually equal the owner.
            */
            configContext: function (type, args, obj) {

                var context = args[0],
                    aElements,
                    nElements,
                    oElement,
                    i;

                if (context) {

                    // Normalize parameter into an array
                    if (! (context instanceof Array)) {
                        if (typeof context == "string") {
                            this.cfg.setProperty("context", [document.getElementById(context)], true);
                        } else { // Assuming this is an element
                            this.cfg.setProperty("context", [context], true);
                        }
                        context = this.cfg.getProperty("context");
                    }

                    // Remove any existing mouseover/mouseout listeners
                    this._removeEventListeners();

                    // Add mouseover/mouseout listeners to context elements
                    this._context = context;

                    aElements = this._context;

                    if (aElements) {
                        nElements = aElements.length;
                        if (nElements > 0) {
                            i = nElements - 1;
                            do {
                                oElement = aElements[i];
                                Event.on(oElement, "mouseover", this.onContextMouseOver, this);
                                Event.on(oElement, "mousemove", this.onContextMouseMove, this);
                                Event.on(oElement, "mouseout", this.onContextMouseOut, this);
                            }
                            while (i--);
                        }
                    }
                }
            },

            // END BUILT-IN PROPERTY EVENT HANDLERS //

            // BEGIN BUILT-IN DOM EVENT HANDLERS //

            /**
            * The default event handler fired when the user moves the mouse while
            * over the context element.
            * @method onContextMouseMove
            * @param {DOMEvent} e The current DOM event
            * @param {Object} obj The object argument
            */
            onContextMouseMove: function (e, obj) {
                obj.pageX = Event.getPageX(e);
                obj.pageY = Event.getPageY(e);
            },

            /**
            * The default event handler fired when the user mouses over the
            * context element.
            * @method onContextMouseOver
            * @param {DOMEvent} e The current DOM event
            * @param {Object} obj The object argument
            */
            onContextMouseOver: function (e, obj) {
                var context = this;

                if (context.title) {
                    obj._tempTitle = context.title;
                    context.title = "";
                }

                // Fire first, to honor disabled set in the listner
                if (obj.fireEvent("contextMouseOver", context, e) !== false
                        && !obj.cfg.getProperty("disabled")) {

                    // Stop the tooltip from being hidden (set on last mouseout)
                    if (obj.hideProcId) {
                        clearTimeout(obj.hideProcId);
                        obj.logger.log("Clearing hide timer: " + obj.hideProcId, "time");
                        obj.hideProcId = null;
                    }

                    Event.on(context, "mousemove", obj.onContextMouseMove, obj);

                    /**
                    * The unique process ID associated with the thread responsible
                    * for showing the Tooltip.
                    * @type int
                    */
                    obj.showProcId = obj.doShow(e, context);
                    obj.logger.log("Setting show tooltip timeout: " + obj.showProcId, "time");
                }
            },

            /**
            * The default event handler fired when the user mouses out of
            * the context element.
            * @method onContextMouseOut
            * @param {DOMEvent} e The current DOM event
            * @param {Object} obj The object argument
            */
            onContextMouseOut: function (e, obj) {
                var el = this;

                if (obj._tempTitle) {
                    el.title = obj._tempTitle;
                    obj._tempTitle = null;
                }

                if (obj.showProcId) {
                    clearTimeout(obj.showProcId);
                    obj.logger.log("Clearing show timer: " + obj.showProcId, "time");
                    obj.showProcId = null;
                }

                if (obj.hideProcId) {
                    clearTimeout(obj.hideProcId);
                    obj.logger.log("Clearing hide timer: " + obj.hideProcId, "time");
                    obj.hideProcId = null;
                }

                obj.fireEvent("contextMouseOut", el, e);

                obj.hideProcId = setTimeout(function () {
                    obj.hide();
                }, obj.cfg.getProperty("hidedelay"));
            },

            // END BUILT-IN DOM EVENT HANDLERS //

            /**
            * Processes the showing of the Tooltip by setting the timeout delay
            * and offset of the Tooltip.
            * @method doShow
            * @param {DOMEvent} e The current DOM event
            * @param {HTMLElement} context The current context element
            * @return {Number} The process ID of the timeout function associated
            * with doShow
            */
            doShow: function (e, context) {

                var offset = this.cfg.getProperty("xyoffset"),
                    xOffset = offset[0],
                    yOffset = offset[1],
                    me = this;

                if (UA.opera && context.tagName &&
                    context.tagName.toUpperCase() == "A") {
                    yOffset += 12;
                }

                return setTimeout(function () {

                    var txt = me.cfg.getProperty("text");

                    // title does not over-ride text
                    if (me._tempTitle && (txt === "" || YAHOO.lang.isUndefined(txt) || YAHOO.lang.isNull(txt))) {
                        me.setBody(me._tempTitle);
                    } else {
                        me.cfg.refireEvent("text");
                    }

                    me.logger.log("Show tooltip", "time");
                    me.moveTo(me.pageX + xOffset, me.pageY + yOffset);

                    if (me.cfg.getProperty("preventoverlap")) {
                        me.preventOverlap(me.pageX, me.pageY);
                    }

                    Event.removeListener(context, "mousemove", me.onContextMouseMove);

                    me.contextTriggerEvent.fire(context);

                    me.show();

                    me.hideProcId = me.doHide();
                    me.logger.log("Hide tooltip time active: " + me.hideProcId, "time");

                }, this.cfg.getProperty("showdelay"));
            },

            /**
            * Sets the timeout for the auto-dismiss delay, which by default is 5
            * seconds, meaning that a tooltip will automatically dismiss itself
            * after 5 seconds of being displayed.
            * @method doHide
            */
            doHide: function () {

                var me = this;

                me.logger.log("Setting hide tooltip timeout", "time");

                return setTimeout(function () {

                    me.logger.log("Hide tooltip", "time");
                    me.hide();

                }, this.cfg.getProperty("autodismissdelay"));

            },

            /**
            * Fired when the Tooltip is moved, this event handler is used to
            * prevent the Tooltip from overlapping with its context element.
            * @method preventOverlay
            * @param {Number} pageX The x coordinate position of the mouse pointer
            * @param {Number} pageY The y coordinate position of the mouse pointer
            */
            preventOverlap: function (pageX, pageY) {

                var height = this.element.offsetHeight,
                    mousePoint = new YAHOO.util.Point(pageX, pageY),
                    elementRegion = Dom.getRegion(this.element);

                elementRegion.top -= 5;
                elementRegion.left -= 5;
                elementRegion.right += 5;
                elementRegion.bottom += 5;

                this.logger.log("context " + elementRegion, "ttip");
                this.logger.log("mouse " + mousePoint, "ttip");

                if (elementRegion.contains(mousePoint)) {
                    this.logger.log("OVERLAP", "warn");
                    this.cfg.setProperty("y", (pageY - height - 5));
                }
            },

            /**
            * @method onRender
            * @description "render" event handler for the Tooltip.
            * @param {String} p_sType String representing the name of the event
            * that was fired.
            * @param {Array} p_aArgs Array of arguments sent when the event
            * was fired.
            */
            onRender: function (p_sType, p_aArgs) {

                function sizeShadow() {

                    var oElement = this.element,
                        oShadow = this.underlay;

                    if (oShadow) {
                        oShadow.style.width = (oElement.offsetWidth + 6) + "px";
                        oShadow.style.height = (oElement.offsetHeight + 1) + "px";
                    }

                }

                function addShadowVisibleClass() {
                    Dom.addClass(this.underlay, "yui-tt-shadow-visible");

                    if (UA.ie) {
                        this.forceUnderlayRedraw();
                    }
                }

                function removeShadowVisibleClass() {
                    Dom.removeClass(this.underlay, "yui-tt-shadow-visible");
                }

                function createShadow() {

                    var oShadow = this.underlay,
                        oElement,
                        Module,
                        nIE,
                        me;

                    if (!oShadow) {

                        oElement = this.element;
                        Module = YAHOO.widget.Module;
                        nIE = UA.ie;
                        me = this;

                        if (!m_oShadowTemplate) {
                            m_oShadowTemplate = document.createElement("div");
                            m_oShadowTemplate.className = "yui-tt-shadow";
                        }

                        oShadow = m_oShadowTemplate.cloneNode(false);

                        oElement.appendChild(oShadow);

                        this.underlay = oShadow;

                        // Backward compatibility, even though it's probably
                        // intended to be "private", it isn't marked as such in the api docs
                        this._shadow = this.underlay;

                        addShadowVisibleClass.call(this);

                        this.subscribe("beforeShow", addShadowVisibleClass);
                        this.subscribe("hide", removeShadowVisibleClass);

                        if (bIEQuirks) {
                            window.setTimeout(function () {
                                sizeShadow.call(me);
                            }, 0);

                            this.cfg.subscribeToConfigEvent("width", sizeShadow);
                            this.cfg.subscribeToConfigEvent("height", sizeShadow);
                            this.subscribe("changeContent", sizeShadow);

                            Module.textResizeEvent.subscribe(sizeShadow, this, true);
                            this.subscribe("destroy", function () {
                                Module.textResizeEvent.unsubscribe(sizeShadow, this);
                            });
                        }
                    }
                }

                function onBeforeShow() {
                    createShadow.call(this);
                    this.unsubscribe("beforeShow", onBeforeShow);
                }

                if (this.cfg.getProperty("visible")) {
                    createShadow.call(this);
                } else {
                    this.subscribe("beforeShow", onBeforeShow);
                }

            },

            /**
             * Forces the underlay element to be repainted, through the application/removal
             * of a yui-force-redraw class to the underlay element.
             *
             * @method forceUnderlayRedraw
             */
            forceUnderlayRedraw : function() {
                var tt = this;
                Dom.addClass(tt.underlay, "yui-force-redraw");
                setTimeout(function() {Dom.removeClass(tt.underlay, "yui-force-redraw");}, 0);
            },

            /**
            * Removes the Tooltip element from the DOM and sets all child
            * elements to null.
            * @method destroy
            */
            destroy: function () {

                // Remove any existing mouseover/mouseout listeners
                this._removeEventListeners();

                Tooltip.superclass.destroy.call(this);

            },

            /**
            * Returns a string representation of the object.
            * @method toString
            * @return {String} The string representation of the Tooltip
            */
            toString: function () {
                return "Tooltip " + this.id;
            }

        });

    }());

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