Yahoo! UI Library

 /**
 * The AutoComplete control provides the front-end logic for text-entry suggestion and
 * completion functionality.
 *
 * @module autocomplete
 * @requires yahoo, dom, event, datasource
 * @optional animation, connection, get
 * @namespace YAHOO.widget
 * @title AutoComplete Widget
 */

/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * The AutoComplete class provides the customizable functionality of a plug-and-play DHTML
 * auto completion widget.  Some key features:
 * <ul>
 * <li>Navigate with up/down arrow keys and/or mouse to pick a selection</li>
 * <li>The drop down container can "roll down" or "fly out" via configurable
 * animation</li>
 * <li>UI look-and-feel customizable through CSS, including container
 * attributes, borders, position, fonts, etc</li>
 * </ul>
 *
 * @class AutoComplete
 * @constructor
 * @param elInput {HTMLElement} DOM element reference of an input field.
 * @param elInput {String} String ID of an input field.
 * @param elContainer {HTMLElement} DOM element reference of an existing DIV.
 * @param elContainer {String} String ID of an existing DIV.
 * @param oDataSource {YAHOO.widget.DataSource} DataSource instance.
 * @param oConfigs {Object} (optional) Object literal of configuration params.
 */
YAHOO.widget.AutoComplete = function(elInput,elContainer,oDataSource,oConfigs) {
    if(elInput && elContainer && oDataSource) {
        // Validate DataSource
        if(oDataSource instanceof YAHOO.widget.DataSource) {
            this.dataSource = oDataSource;
        }
        else {
            YAHOO.log("Could not instantiate AutoComplete due to an invalid DataSource", "error", this.toString());
            return;
        }

        // Validate input element
        if(YAHOO.util.Dom.inDocument(elInput)) {
            if(YAHOO.lang.isString(elInput)) {
                    this._sName = "instance" + YAHOO.widget.AutoComplete._nIndex + " " + elInput;
                    this._elTextbox = document.getElementById(elInput);
            }
            else {
                this._sName = (elInput.id) ?
                    "instance" + YAHOO.widget.AutoComplete._nIndex + " " + elInput.id:
                    "instance" + YAHOO.widget.AutoComplete._nIndex;
                this._elTextbox = elInput;
            }
            YAHOO.util.Dom.addClass(this._elTextbox, "yui-ac-input");
        }
        else {
            YAHOO.log("Could not instantiate AutoComplete due to an invalid input element", "error", this.toString());
            return;
        }

        // Validate container element
        if(YAHOO.util.Dom.inDocument(elContainer)) {
            if(YAHOO.lang.isString(elContainer)) {
                    this._elContainer = document.getElementById(elContainer);
            }
            else {
                this._elContainer = elContainer;
            }
            if(this._elContainer.style.display == "none") {
                YAHOO.log("The container may not display properly if display is set to \"none\" in CSS", "warn", this.toString());
            }
            
            // For skinning
            var elParent = this._elContainer.parentNode;
            var elTag = elParent.tagName.toLowerCase();
            if(elTag == "div") {
                YAHOO.util.Dom.addClass(elParent, "yui-ac");
            }
            else {
                YAHOO.log("Could not find the wrapper element for skinning", "warn", this.toString());
            }
        }
        else {
            YAHOO.log("Could not instantiate AutoComplete due to an invalid container element", "error", this.toString());
            return;
        }

        // Set any config params passed in to override defaults
        if(oConfigs && (oConfigs.constructor == Object)) {
            for(var sConfig in oConfigs) {
                if(sConfig) {
                    this[sConfig] = oConfigs[sConfig];
                }
            }
        }

        // Initialization sequence
        this._initContainer();
        this._initProps();
        this._initList();
        this._initContainerHelpers();

        // Set up events
        var oSelf = this;
        var elTextbox = this._elTextbox;
        // Events are actually for the content module within the container
        var elContent = this._elContent;

        // Dom events
        YAHOO.util.Event.addListener(elTextbox,"keyup",oSelf._onTextboxKeyUp,oSelf);
        YAHOO.util.Event.addListener(elTextbox,"keydown",oSelf._onTextboxKeyDown,oSelf);
        YAHOO.util.Event.addListener(elTextbox,"focus",oSelf._onTextboxFocus,oSelf);
        YAHOO.util.Event.addListener(elTextbox,"blur",oSelf._onTextboxBlur,oSelf);
        YAHOO.util.Event.addListener(elContent,"mouseover",oSelf._onContainerMouseover,oSelf);
        YAHOO.util.Event.addListener(elContent,"mouseout",oSelf._onContainerMouseout,oSelf);
        YAHOO.util.Event.addListener(elContent,"scroll",oSelf._onContainerScroll,oSelf);
        YAHOO.util.Event.addListener(elContent,"resize",oSelf._onContainerResize,oSelf);
        YAHOO.util.Event.addListener(elTextbox,"keypress",oSelf._onTextboxKeyPress,oSelf);
        YAHOO.util.Event.addListener(window,"unload",oSelf._onWindowUnload,oSelf);

        // Custom events
        this.textboxFocusEvent = new YAHOO.util.CustomEvent("textboxFocus", this);
        this.textboxKeyEvent = new YAHOO.util.CustomEvent("textboxKey", this);
        this.dataRequestEvent = new YAHOO.util.CustomEvent("dataRequest", this);
        this.dataReturnEvent = new YAHOO.util.CustomEvent("dataReturn", this);
        this.dataErrorEvent = new YAHOO.util.CustomEvent("dataError", this);
        this.containerExpandEvent = new YAHOO.util.CustomEvent("containerExpand", this);
        this.typeAheadEvent = new YAHOO.util.CustomEvent("typeAhead", this);
        this.itemMouseOverEvent = new YAHOO.util.CustomEvent("itemMouseOver", this);
        this.itemMouseOutEvent = new YAHOO.util.CustomEvent("itemMouseOut", this);
        this.itemArrowToEvent = new YAHOO.util.CustomEvent("itemArrowTo", this);
        this.itemArrowFromEvent = new YAHOO.util.CustomEvent("itemArrowFrom", this);
        this.itemSelectEvent = new YAHOO.util.CustomEvent("itemSelect", this);
        this.unmatchedItemSelectEvent = new YAHOO.util.CustomEvent("unmatchedItemSelect", this);
        this.selectionEnforceEvent = new YAHOO.util.CustomEvent("selectionEnforce", this);
        this.containerCollapseEvent = new YAHOO.util.CustomEvent("containerCollapse", this);
        this.textboxBlurEvent = new YAHOO.util.CustomEvent("textboxBlur", this);
        
        // Finish up
        elTextbox.setAttribute("autocomplete","off");
        YAHOO.widget.AutoComplete._nIndex++;
        YAHOO.log("AutoComplete initialized","info",this.toString());
    }
    // Required arguments were not found
    else {
        YAHOO.log("Could not instantiate AutoComplete due invalid arguments", "error", this.toString());
    }
};

/////////////////////////////////////////////////////////////////////////////
//
// Public member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * The DataSource object that encapsulates the data used for auto completion.
 * This object should be an inherited object from YAHOO.widget.DataSource.
 *
 * @property dataSource
 * @type YAHOO.widget.DataSource
 */
YAHOO.widget.AutoComplete.prototype.dataSource = null;

/**
 * Number of characters that must be entered before querying for results. A negative value
 * effectively turns off the widget. A value of 0 allows queries of null or empty string
 * values.
 *
 * @property minQueryLength
 * @type Number
 * @default 1
 */
YAHOO.widget.AutoComplete.prototype.minQueryLength = 1;

/**
 * Maximum number of results to display in results container.
 *
 * @property maxResultsDisplayed
 * @type Number
 * @default 10
 */
YAHOO.widget.AutoComplete.prototype.maxResultsDisplayed = 10;

/**
 * Number of seconds to delay before submitting a query request.  If a query
 * request is received before a previous one has completed its delay, the
 * previous request is cancelled and the new request is set to the delay.
 * Implementers should take care when setting this value very low (i.e., less
 * than 0.2) with low latency DataSources and the typeAhead feature enabled, as
 * fast typers may see unexpected behavior.
 *
 * @property queryDelay
 * @type Number
 * @default 0.2
 */
YAHOO.widget.AutoComplete.prototype.queryDelay = 0.2;

/**
 * Class name of a highlighted item within results container.
 *
 * @property highlightClassName
 * @type String
 * @default "yui-ac-highlight"
 */
YAHOO.widget.AutoComplete.prototype.highlightClassName = "yui-ac-highlight";

/**
 * Class name of a pre-highlighted item within results container.
 *
 * @property prehighlightClassName
 * @type String
 */
YAHOO.widget.AutoComplete.prototype.prehighlightClassName = null;

/**
 * Query delimiter. A single character separator for multiple delimited
 * selections. Multiple delimiter characteres may be defined as an array of
 * strings. A null value or empty string indicates that query results cannot
 * be delimited. This feature is not recommended if you need forceSelection to
 * be true.
 *
 * @property delimChar
 * @type String | String[]
 */
YAHOO.widget.AutoComplete.prototype.delimChar = null;

/**
 * Whether or not the first item in results container should be automatically highlighted
 * on expand.
 *
 * @property autoHighlight
 * @type Boolean
 * @default true
 */
YAHOO.widget.AutoComplete.prototype.autoHighlight = true;

/**
 * Whether or not the input field should be automatically updated
 * with the first query result as the user types, auto-selecting the substring
 * that the user has not typed.
 *
 * @property typeAhead
 * @type Boolean
 * @default false
 */
YAHOO.widget.AutoComplete.prototype.typeAhead = false;

/**
 * Whether or not to animate the expansion/collapse of the results container in the
 * horizontal direction.
 *
 * @property animHoriz
 * @type Boolean
 * @default false
 */
YAHOO.widget.AutoComplete.prototype.animHoriz = false;

/**
 * Whether or not to animate the expansion/collapse of the results container in the
 * vertical direction.
 *
 * @property animVert
 * @type Boolean
 * @default true
 */
YAHOO.widget.AutoComplete.prototype.animVert = true;

/**
 * Speed of container expand/collapse animation, in seconds..
 *
 * @property animSpeed
 * @type Number
 * @default 0.3
 */
YAHOO.widget.AutoComplete.prototype.animSpeed = 0.3;

/**
 * Whether or not to force the user's selection to match one of the query
 * results. Enabling this feature essentially transforms the input field into a
 * &lt;select&gt; field. This feature is not recommended with delimiter character(s)
 * defined.
 *
 * @property forceSelection
 * @type Boolean
 * @default false
 */
YAHOO.widget.AutoComplete.prototype.forceSelection = false;

/**
 * Whether or not to allow browsers to cache user-typed input in the input
 * field. Disabling this feature will prevent the widget from setting the
 * autocomplete="off" on the input field. When autocomplete="off"
 * and users click the back button after form submission, user-typed input can
 * be prefilled by the browser from its cache. This caching of user input may
 * not be desired for sensitive data, such as credit card numbers, in which
 * case, implementers should consider setting allowBrowserAutocomplete to false.
 *
 * @property allowBrowserAutocomplete
 * @type Boolean
 * @default true
 */
YAHOO.widget.AutoComplete.prototype.allowBrowserAutocomplete = true;

/**
 * Whether or not the results container should always be displayed.
 * Enabling this feature displays the container when the widget is instantiated
 * and prevents the toggling of the container to a collapsed state.
 *
 * @property alwaysShowContainer
 * @type Boolean
 * @default false
 */
YAHOO.widget.AutoComplete.prototype.alwaysShowContainer = false;

/**
 * Whether or not to use an iFrame to layer over Windows form elements in
 * IE. Set to true only when the results container will be on top of a
 * &lt;select&gt; field in IE and thus exposed to the IE z-index bug (i.e.,
 * 5.5 < IE < 7).
 *
 * @property useIFrame
 * @type Boolean
 * @default false
 */
YAHOO.widget.AutoComplete.prototype.useIFrame = false;

/**
 * Whether or not the results container should have a shadow.
 *
 * @property useShadow
 * @type Boolean
 * @default false
 */
YAHOO.widget.AutoComplete.prototype.useShadow = false;

/////////////////////////////////////////////////////////////////////////////
//
// Public methods
//
/////////////////////////////////////////////////////////////////////////////

 /**
 * Public accessor to the unique name of the AutoComplete instance.
 *
 * @method toString
 * @return {String} Unique name of the AutoComplete instance.
 */
YAHOO.widget.AutoComplete.prototype.toString = function() {
    return "AutoComplete " + this._sName;
};

 /**
 * Returns true if container is in an expanded state, false otherwise.
 *
 * @method isContainerOpen
 * @return {Boolean} Returns true if container is in an expanded state, false otherwise.
 */
YAHOO.widget.AutoComplete.prototype.isContainerOpen = function() {
    return this._bContainerOpen;
};

/**
 * Public accessor to the internal array of DOM &lt;li&gt; elements that
 * display query results within the results container.
 *
 * @method getListItems
 * @return {HTMLElement[]} Array of &lt;li&gt; elements within the results container.
 */
YAHOO.widget.AutoComplete.prototype.getListItems = function() {
    return this._aListItems;
};

/**
 * Public accessor to the data held in an &lt;li&gt; element of the
 * results container.
 *
 * @method getListItemData
 * @return {Object | Object[]} Object or array of result data or null
 */
YAHOO.widget.AutoComplete.prototype.getListItemData = function(oListItem) {
    if(oListItem._oResultData) {
        return oListItem._oResultData;
    }
    else {
        return false;
    }
};

/**
 * Sets HTML markup for the results container header. This markup will be
 * inserted within a &lt;div&gt; tag with a class of "yui-ac-hd".
 *
 * @method setHeader
 * @param sHeader {String} HTML markup for results container header.
 */
YAHOO.widget.AutoComplete.prototype.setHeader = function(sHeader) {
    if(this._elHeader) {
        var elHeader = this._elHeader;
        if(sHeader) {
            elHeader.innerHTML = sHeader;
            elHeader.style.display = "block";
        }
        else {
            elHeader.innerHTML = "";
            elHeader.style.display = "none";
        }
    }
};

/**
 * Sets HTML markup for the results container footer. This markup will be
 * inserted within a &lt;div&gt; tag with a class of "yui-ac-ft".
 *
 * @method setFooter
 * @param sFooter {String} HTML markup for results container footer.
 */
YAHOO.widget.AutoComplete.prototype.setFooter = function(sFooter) {
    if(this._elFooter) {
        var elFooter = this._elFooter;
        if(sFooter) {
                elFooter.innerHTML = sFooter;
                elFooter.style.display = "block";
        }
        else {
            elFooter.innerHTML = "";
            elFooter.style.display = "none";
        }
    }
};

/**
 * Sets HTML markup for the results container body. This markup will be
 * inserted within a &lt;div&gt; tag with a class of "yui-ac-bd".
 *
 * @method setBody
 * @param sBody {String} HTML markup for results container body.
 */
YAHOO.widget.AutoComplete.prototype.setBody = function(sBody) {
    if(this._elBody) {
        var elBody = this._elBody;
        if(sBody) {
                elBody.innerHTML = sBody;
                elBody.style.display = "block";
                elBody.style.display = "block";
        }
        else {
            elBody.innerHTML = "";
            elBody.style.display = "none";
        }
        this._maxResultsDisplayed = 0;
    }
};

/**
 * Overridable method that converts a result item object into HTML markup
 * for display. Return data values are accessible via the oResultItem object,
 * and the key return value will always be oResultItem[0]. Markup will be
 * displayed within &lt;li&gt; element tags in the container.
 *
 * @method formatResult
 * @param oResultItem {Object} Result item representing one query result. Data is held in an array.
 * @param sQuery {String} The current query string.
 * @return {String} HTML markup of formatted result data.
 */
YAHOO.widget.AutoComplete.prototype.formatResult = function(oResultItem, sQuery) {
    var sResult = oResultItem[0];
    if(sResult) {
        return sResult;
    }
    else {
        return "";
    }
};

/**
 * Overridable method called before container expands allows implementers to access data
 * and DOM elements.
 *
 * @method doBeforeExpandContainer
 * @param elTextbox {HTMLElement} The text input box.
 * @param elContainer {HTMLElement} The container element.
 * @param sQuery {String} The query string.
 * @param aResults {Object[]}  An array of query results.
 * @return {Boolean} Return true to continue expanding container, false to cancel the expand.
 */
YAHOO.widget.AutoComplete.prototype.doBeforeExpandContainer = function(elTextbox, elContainer, sQuery, aResults) {
    return true;
};

/**
 * Makes query request to the DataSource.
 *
 * @method sendQuery
 * @param sQuery {String} Query string.
 */
YAHOO.widget.AutoComplete.prototype.sendQuery = function(sQuery) {
    this._sendQuery(sQuery);
};

/**
 * Overridable method gives implementers access to the query before it gets sent.
 *
 * @method doBeforeSendQuery
 * @param sQuery {String} Query string.
 * @return {String} Query string.
 */
YAHOO.widget.AutoComplete.prototype.doBeforeSendQuery = function(sQuery) {
    return sQuery;
};

/**
 * Nulls out the entire AutoComplete instance and related objects, removes attached
 * event listeners, and clears out DOM elements inside the container. After
 * calling this method, the instance reference should be expliclitly nulled by
 * implementer, as in myDataTable = null. Use with caution!
 *
 * @method destroy
 */
YAHOO.widget.AutoComplete.prototype.destroy = function() {
    var instanceName = this.toString();
    var elInput = this._elTextbox;
    var elContainer = this._elContainer;

    // Unhook custom events
    this.textboxFocusEvent.unsubscribeAll();
    this.textboxKeyEvent.unsubscribeAll();
    this.dataRequestEvent.unsubscribeAll();
    this.dataReturnEvent.unsubscribeAll();
    this.dataErrorEvent.unsubscribeAll();
    this.containerExpandEvent.unsubscribeAll();
    this.typeAheadEvent.unsubscribeAll();
    this.itemMouseOverEvent.unsubscribeAll();
    this.itemMouseOutEvent.unsubscribeAll();
    this.itemArrowToEvent.unsubscribeAll();
    this.itemArrowFromEvent.unsubscribeAll();
    this.itemSelectEvent.unsubscribeAll();
    this.unmatchedItemSelectEvent.unsubscribeAll();
    this.selectionEnforceEvent.unsubscribeAll();
    this.containerCollapseEvent.unsubscribeAll();
    this.textboxBlurEvent.unsubscribeAll();

    // Unhook DOM events
    YAHOO.util.Event.purgeElement(elInput, true);
    YAHOO.util.Event.purgeElement(elContainer, true);

    // Remove DOM elements
    elContainer.innerHTML = "";

    // Null out objects
    for(var key in this) {
        if(YAHOO.lang.hasOwnProperty(this, key)) {
            this[key] = null;
        }
    }

    YAHOO.log("AutoComplete instance destroyed: " + instanceName);
};

/////////////////////////////////////////////////////////////////////////////
//
// Public events
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Fired when the input field receives focus.
 *
 * @event textboxFocusEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 */
YAHOO.widget.AutoComplete.prototype.textboxFocusEvent = null;

/**
 * Fired when the input field receives key input.
 *
 * @event textboxKeyEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param nKeycode {Number} The keycode number.
 */
YAHOO.widget.AutoComplete.prototype.textboxKeyEvent = null;

/**
 * Fired when the AutoComplete instance makes a query to the DataSource.
 * 
 * @event dataRequestEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param sQuery {String} The query string.
 */
YAHOO.widget.AutoComplete.prototype.dataRequestEvent = null;

/**
 * Fired when the AutoComplete instance receives query results from the data
 * source.
 *
 * @event dataReturnEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param sQuery {String} The query string.
 * @param aResults {Object[]} Results array.
 */
YAHOO.widget.AutoComplete.prototype.dataReturnEvent = null;

/**
 * Fired when the AutoComplete instance does not receive query results from the
 * DataSource due to an error.
 *
 * @event dataErrorEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param sQuery {String} The query string.
 */
YAHOO.widget.AutoComplete.prototype.dataErrorEvent = null;

/**
 * Fired when the results container is expanded.
 *
 * @event containerExpandEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 */
YAHOO.widget.AutoComplete.prototype.containerExpandEvent = null;

/**
 * Fired when the input field has been prefilled by the type-ahead
 * feature. 
 *
 * @event typeAheadEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param sQuery {String} The query string.
 * @param sPrefill {String} The prefill string.
 */
YAHOO.widget.AutoComplete.prototype.typeAheadEvent = null;

/**
 * Fired when result item has been moused over.
 *
 * @event itemMouseOverEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param elItem {HTMLElement} The &lt;li&gt element item moused to.
 */
YAHOO.widget.AutoComplete.prototype.itemMouseOverEvent = null;

/**
 * Fired when result item has been moused out.
 *
 * @event itemMouseOutEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param elItem {HTMLElement} The &lt;li&gt; element item moused from.
 */
YAHOO.widget.AutoComplete.prototype.itemMouseOutEvent = null;

/**
 * Fired when result item has been arrowed to. 
 *
 * @event itemArrowToEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param elItem {HTMLElement} The &lt;li&gt; element item arrowed to.
 */
YAHOO.widget.AutoComplete.prototype.itemArrowToEvent = null;

/**
 * Fired when result item has been arrowed away from.
 *
 * @event itemArrowFromEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param elItem {HTMLElement} The &lt;li&gt; element item arrowed from.
 */
YAHOO.widget.AutoComplete.prototype.itemArrowFromEvent = null;

/**
 * Fired when an item is selected via mouse click, ENTER key, or TAB key.
 *
 * @event itemSelectEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @param elItem {HTMLElement} The selected &lt;li&gt; element item.
 * @param oData {Object} The data returned for the item, either as an object,
 * or mapped from the schema into an array.
 */
YAHOO.widget.AutoComplete.prototype.itemSelectEvent = null;

/**
 * Fired when a user selection does not match any of the displayed result items.
 *
 * @event unmatchedItemSelectEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 */
YAHOO.widget.AutoComplete.prototype.unmatchedItemSelectEvent = null;

/**
 * Fired if forceSelection is enabled and the user's input has been cleared
 * because it did not match one of the returned query results.
 *
 * @event selectionEnforceEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 */
YAHOO.widget.AutoComplete.prototype.selectionEnforceEvent = null;

/**
 * Fired when the results container is collapsed.
 *
 * @event containerCollapseEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 */
YAHOO.widget.AutoComplete.prototype.containerCollapseEvent = null;

/**
 * Fired when the input field loses focus.
 *
 * @event textboxBlurEvent
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 */
YAHOO.widget.AutoComplete.prototype.textboxBlurEvent = null;

/////////////////////////////////////////////////////////////////////////////
//
// Private member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Internal class variable to index multiple AutoComplete instances.
 *
 * @property _nIndex
 * @type Number
 * @default 0
 * @private
 */
YAHOO.widget.AutoComplete._nIndex = 0;

/**
 * Name of AutoComplete instance.
 *
 * @property _sName
 * @type String
 * @private
 */
YAHOO.widget.AutoComplete.prototype._sName = null;

/**
 * Text input field DOM element.
 *
 * @property _elTextbox
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elTextbox = null;

/**
 * Container DOM element.
 *
 * @property _elContainer
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elContainer = null;

/**
 * Reference to content element within container element.
 *
 * @property _elContent
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elContent = null;

/**
 * Reference to header element within content element.
 *
 * @property _elHeader
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elHeader = null;

/**
 * Reference to body element within content element.
 *
 * @property _elBody
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elBody = null;

/**
 * Reference to footer element within content element.
 *
 * @property _elFooter
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elFooter = null;

/**
 * Reference to shadow element within container element.
 *
 * @property _elShadow
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elShadow = null;

/**
 * Reference to iframe element within container element.
 *
 * @property _elIFrame
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._elIFrame = null;

/**
 * Whether or not the input field is currently in focus. If query results come back
 * but the user has already moved on, do not proceed with auto complete behavior.
 *
 * @property _bFocused
 * @type Boolean
 * @private
 */
YAHOO.widget.AutoComplete.prototype._bFocused = true;

/**
 * Animation instance for container expand/collapse.
 *
 * @property _oAnim
 * @type Boolean
 * @private
 */
YAHOO.widget.AutoComplete.prototype._oAnim = null;

/**
 * Whether or not the results container is currently open.
 *
 * @property _bContainerOpen
 * @type Boolean
 * @private
 */
YAHOO.widget.AutoComplete.prototype._bContainerOpen = false;

/**
 * Whether or not the mouse is currently over the results
 * container. This is necessary in order to prevent clicks on container items
 * from being text input field blur events.
 *
 * @property _bOverContainer
 * @type Boolean
 * @private
 */
YAHOO.widget.AutoComplete.prototype._bOverContainer = false;

/**
 * Array of &lt;li&gt; elements references that contain query results within the
 * results container.
 *
 * @property _aListItems
 * @type HTMLElement[]
 * @private
 */
YAHOO.widget.AutoComplete.prototype._aListItems = null;

/**
 * Number of &lt;li&gt; elements currently displayed in results container.
 *
 * @property _nDisplayedItems
 * @type Number
 * @private
 */
YAHOO.widget.AutoComplete.prototype._nDisplayedItems = 0;

/**
 * Internal count of &lt;li&gt; elements displayed and hidden in results container.
 *
 * @property _maxResultsDisplayed
 * @type Number
 * @private
 */
YAHOO.widget.AutoComplete.prototype._maxResultsDisplayed = 0;

/**
 * Current query string
 *
 * @property _sCurQuery
 * @type String
 * @private
 */
YAHOO.widget.AutoComplete.prototype._sCurQuery = null;

/**
 * Past queries this session (for saving delimited queries).
 *
 * @property _sSavedQuery
 * @type String
 * @private
 */
YAHOO.widget.AutoComplete.prototype._sSavedQuery = null;

/**
 * Pointer to the currently highlighted &lt;li&gt; element in the container.
 *
 * @property _oCurItem
 * @type HTMLElement
 * @private
 */
YAHOO.widget.AutoComplete.prototype._oCurItem = null;

/**
 * Whether or not an item has been selected since the container was populated
 * with results. Reset to false by _populateList, and set to true when item is
 * selected.
 *
 * @property _bItemSelected
 * @type Boolean
 * @private
 */
YAHOO.widget.AutoComplete.prototype._bItemSelected = false;

/**
 * Key code of the last key pressed in textbox.
 *
 * @property _nKeyCode
 * @type Number
 * @private
 */
YAHOO.widget.AutoComplete.prototype._nKeyCode = null;

/**
 * Delay timeout ID.
 *
 * @property _nDelayID
 * @type Number
 * @private
 */
YAHOO.widget.AutoComplete.prototype._nDelayID = -1;

/**
 * Src to iFrame used when useIFrame = true. Supports implementations over SSL
 * as well.
 *
 * @property _iFrameSrc
 * @type String
 * @private
 */
YAHOO.widget.AutoComplete.prototype._iFrameSrc = "javascript:false;";

/**
 * For users typing via certain IMEs, queries must be triggered by intervals,
 * since key events yet supported across all browsers for all IMEs.
 *
 * @property _queryInterval
 * @type Object
 * @private
 */
YAHOO.widget.AutoComplete.prototype._queryInterval = null;

/**
 * Internal tracker to last known textbox value, used to determine whether or not
 * to trigger a query via interval for certain IME users.
 *
 * @event _sLastTextboxValue
 * @type String
 * @private
 */
YAHOO.widget.AutoComplete.prototype._sLastTextboxValue = null;

/////////////////////////////////////////////////////////////////////////////
//
// Private methods
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Updates and validates latest public config properties.
 *
 * @method __initProps
 * @private
 */
YAHOO.widget.AutoComplete.prototype._initProps = function() {
    // Correct any invalid values
    var minQueryLength = this.minQueryLength;
    if(!YAHOO.lang.isNumber(minQueryLength)) {
        this.minQueryLength = 1;
    }
    var maxResultsDisplayed = this.maxResultsDisplayed;
    if(!YAHOO.lang.isNumber(maxResultsDisplayed) || (maxResultsDisplayed < 1)) {
        this.maxResultsDisplayed = 10;
    }
    var queryDelay = this.queryDelay;
    if(!YAHOO.lang.isNumber(queryDelay) || (queryDelay < 0)) {
        this.queryDelay = 0.2;
    }
    var delimChar = this.delimChar;
    if(YAHOO.lang.isString(delimChar) && (delimChar.length > 0)) {
        this.delimChar = [delimChar];
    }
    else if(!YAHOO.lang.isArray(delimChar)) {
        this.delimChar = null;
    }
    var animSpeed = this.animSpeed;
    if((this.animHoriz || this.animVert) && YAHOO.util.Anim) {
        if(!YAHOO.lang.isNumber(animSpeed) || (animSpeed < 0)) {
            this.animSpeed = 0.3;
        }
        if(!this._oAnim ) {
            this._oAnim = new YAHOO.util.Anim(this._elContent, {}, this.animSpeed);
        }
        else {
            this._oAnim.duration = this.animSpeed;
        }
    }
    if(this.forceSelection && delimChar) {
        YAHOO.log("The forceSelection feature has been enabled with delimChar defined.","warn", this.toString());
    }
};

/**
 * Initializes the results container helpers if they are enabled and do
 * not exist
 *
 * @method _initContainerHelpers
 * @private
 */
YAHOO.widget.AutoComplete.prototype._initContainerHelpers = function() {
    if(this.useShadow && !this._elShadow) {
        var elShadow = document.createElement("div");
        elShadow.className = "yui-ac-shadow";
        this._elShadow = this._elContainer.appendChild(elShadow);
    }
    if(this.useIFrame && !this._elIFrame) {
        var elIFrame = document.createElement("iframe");
        elIFrame.src = this._iFrameSrc;
        elIFrame.frameBorder = 0;
        elIFrame.scrolling = "no";
        elIFrame.style.position = "absolute";
        elIFrame.style.width = "100%";
        elIFrame.style.height = "100%";
        elIFrame.tabIndex = -1;
        this._elIFrame = this._elContainer.appendChild(elIFrame);
    }
};

/**
 * Initializes the results container once at object creation
 *
 * @method _initContainer
 * @private
 */
YAHOO.widget.AutoComplete.prototype._initContainer = function() {
    YAHOO.util.Dom.addClass(this._elContainer, "yui-ac-container");
    
    if(!this._elContent) {
        // The elContent div helps size the iframe and shadow properly
        var elContent = document.createElement("div");
        elContent.className = "yui-ac-content";
        elContent.style.display = "none";
        this._elContent = this._elContainer.appendChild(elContent);

        var elHeader = document.createElement("div");
        elHeader.className = "yui-ac-hd";
        elHeader.style.display = "none";
        this._elHeader = this._elContent.appendChild(elHeader);

        var elBody = document.createElement("div");
        elBody.className = "yui-ac-bd";
        this._elBody = this._elContent.appendChild(elBody);

        var elFooter = document.createElement("div");
        elFooter.className = "yui-ac-ft";
        elFooter.style.display = "none";
        this._elFooter = this._elContent.appendChild(elFooter);
    }
    else {
        YAHOO.log("Could not initialize the container","warn",this.toString());
    }
};

/**
 * Clears out contents of container body and creates up to
 * YAHOO.widget.AutoComplete#maxResultsDisplayed &lt;li&gt; elements in an
 * &lt;ul&gt; element.
 *
 * @method _initList
 * @private
 */
YAHOO.widget.AutoComplete.prototype._initList = function() {
    this._aListItems = [];
    while(this._elBody.hasChildNodes()) {
        var oldListItems = this.getListItems();
        if(oldListItems) {
            for(var oldi = oldListItems.length-1; oldi >= 0; oldi--) {
                oldListItems[oldi] = null;
            }
        }
        this._elBody.innerHTML = "";
    }

    var oList = document.createElement("ul");
    oList = this._elBody.appendChild(oList);
    for(var i=0; i<this.maxResultsDisplayed; i++) {
        var oItem = document.createElement("li");
        oItem = oList.appendChild(oItem);
        this._aListItems[i] = oItem;
        this._initListItem(oItem, i);
    }
    this._maxResultsDisplayed = this.maxResultsDisplayed;
};

/**
 * Initializes each &lt;li&gt; element in the container list.
 *
 * @method _initListItem
 * @param oItem {HTMLElement} The &lt;li&gt; DOM element.
 * @param nItemIndex {Number} The index of the element.
 * @private
 */
YAHOO.widget.AutoComplete.prototype._initListItem = function(oItem, nItemIndex) {
    var oSelf = this;
    oItem.style.display = "none";
    oItem._nItemIndex = nItemIndex;

    oItem.mouseover = oItem.mouseout = oItem.onclick = null;
    YAHOO.util.Event.addListener(oItem,"mouseover",oSelf._onItemMouseover,oSelf);
    YAHOO.util.Event.addListener(oItem,"mouseout",oSelf._onItemMouseout,oSelf);
    YAHOO.util.Event.addListener(oItem,"click",oSelf._onItemMouseclick,oSelf);
};

/**
 * Enables interval detection for  Korean IME support.
 *
 * @method _onIMEDetected
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @private
 */
YAHOO.widget.AutoComplete.prototype._onIMEDetected = function(oSelf) {
    oSelf._enableIntervalDetection();
};

/**
 * Enables query triggers based on text input detection by intervals (rather
 * than by key events).
 *
 * @method _enableIntervalDetection
 * @private
 */
YAHOO.widget.AutoComplete.prototype._enableIntervalDetection = function() {
    var currValue = this._elTextbox.value;
    var lastValue = this._sLastTextboxValue;
    if(currValue != lastValue) {
        this._sLastTextboxValue = currValue;
        this._sendQuery(currValue);
    }
};


/**
 * Cancels text input detection by intervals.
 *
 * @method _cancelIntervalDetection
 * @param oSelf {YAHOO.widget.AutoComplete} The AutoComplete instance.
 * @private
 */
YAHOO.widget.AutoComplete.prototype._cancelIntervalDetection = function(oSelf) {
    if(oSelf._queryInterval) {
        clearInterval(oSelf._queryInterval);
    }
};


/**
 * Whether or not key is functional or should be ignored. Note that the right
 * arrow key is NOT an ignored key since it triggers queries for certain intl
 * charsets.
 *
 * @method _isIgnoreKey
 * @param nKeycode {Number} Code of key pressed.
 * @return {Boolean} True if key should be ignored, false otherwise.
 * @private
 */
YAHOO.widget.AutoComplete.prototype._isIgnoreKey = function(nKeyCode) {
    if((nKeyCode == 9) || (nKeyCode == 13)  || // tab, enter
            (nKeyCode == 16) || (nKeyCode == 17) || // shift, ctl
            (nKeyCode >= 18 && nKeyCode <= 20) || // alt,pause/break,caps lock
            (nKeyCode == 27)