/**
 * @class Ext.form.field.ComboBox
 * @extends Ext.form.field.Picker
 *
 * A combobox control with support for autocomplete, remote loading, and many other features.
 *
 * A ComboBox is like a combination of a traditional HTML text `<input>` field and a `<select>`
 * field; the user is able to type freely into the field, and/or pick values from a dropdown selection
 * list. The user can input any value by default, even if it does not appear in the selection list;
 * to prevent free-form values and restrict them to items in the list, set {@link #forceSelection} to `true`.
 *
 * The selection list's options are populated from any {@link Ext.data.Store}, including remote
 * stores. The data items in the store are mapped to each option's displayed text and backing value via
 * the {@link #valueField} and {@link #displayField} configurations, respectively.
 *
 * If your store is not remote, i.e. it depends only on local data and is loaded up front, you should be
 * sure to set the {@link #queryMode} to `'local'`, as this will improve responsiveness for the user.
 *
 * {@img Ext.form.ComboBox/Ext.form.ComboBox.png Ext.form.ComboBox component}
 *
 * ## Example usage:
 *
 *     // The data store containing the list of states
 *     var states = Ext.create('Ext.data.Store', {
 *         fields: ['abbr', 'name'],
 *         data : [
 *             {"abbr":"AL", "name":"Alabama"},
 *             {"abbr":"AK", "name":"Alaska"},
 *             {"abbr":"AZ", "name":"Arizona"}
 *             //...
 *         ]
 *     });
 *
 *     // Create the combo box, attached to the states data store
 *     Ext.create('Ext.form.ComboBox', {
 *         fieldLabel: 'Choose State',
 *         store: states,
 *         queryMode: 'local',
 *         displayField: 'name',
 *         valueField: 'abbr',
 *         renderTo: Ext.getBody()
 *     });
 *
 * ## Events
 *
 * To do something when something in ComboBox is selected, configure the select event:
 *
 *     var cb = Ext.create('Ext.form.ComboBox', {
 *         // all of your config options
 *         listeners:{
 *              scope: yourScope,
 *              'select': yourFunction
 *         }
 *     });
 *
 *     // Alternatively, you can assign events after the object is created:
 *     var cb = new Ext.form.field.ComboBox(yourOptions);
 *     cb.on('select', yourFunction, yourScope);
 *
 * ## Multiple Selection
 *
 * ComboBox also allows selection of multiple items from the list; to enable multi-selection set the
 * {@link #multiSelect} config to `true`.
 *
 * @constructor
 * Create a new ComboBox.
 * @param {Object} config Configuration options
 * @xtype combo
 * @docauthor Jason Johnston <jason@sencha.com>
 */
Ext.define('Ext.form.field.ComboBox', {
    extend:'Ext.form.field.Picker',
    requires: ['Ext.util.DelayedTask', 'Ext.EventObject', 'Ext.view.BoundList', 'Ext.view.BoundListKeyNav', 'Ext.data.StoreManager'],
    alternateClassName: 'Ext.form.ComboBox',
    alias: ['widget.combobox', 'widget.combo'],

    /**
     * @cfg {String} triggerCls
     * An additional CSS class used to style the trigger button. The trigger will always get the
     * {@link #triggerBaseCls} by default and <tt>triggerCls</tt> will be <b>appended</b> if specified.
     * Defaults to 'x-form-arrow-trigger' for ComboBox.
     */
    triggerCls: Ext.baseCSSPrefix + 'form-arrow-trigger',

    /**
     * @cfg {Ext.data.Store/Array} store The data source to which this combo is bound (defaults to <tt>undefined</tt>).
     * Acceptable values for this property are:
     * <div class="mdetail-params"><ul>
     * <li><b>any {@link Ext.data.Store Store} subclass</b></li>
     * <li><b>an Array</b> : Arrays will be converted to a {@link Ext.data.Store} internally,
     * automatically generating {@link Ext.data.Field#name field names} to work with all data components.
     * <div class="mdetail-params"><ul>
     * <li><b>1-dimensional array</b> : (e.g., <tt>['Foo','Bar']</tt>)<div class="sub-desc">
     * A 1-dimensional array will automatically be expanded (each array item will be used for both the combo
     * {@link #valueField} and {@link #displayField})</div></li>
     * <li><b>2-dimensional array</b> : (e.g., <tt>[['f','Foo'],['b','Bar']]</tt>)<div class="sub-desc">
     * For a multi-dimensional array, the value in index 0 of each item will be assumed to be the combo
     * {@link #valueField}, while the value at index 1 is assumed to be the combo {@link #displayField}.
     * </div></li></ul></div></li></ul></div>
     * <p>See also <tt>{@link #queryMode}</tt>.</p>
     */

    /**
     * @cfg {Boolean} multiSelect
     * If set to <tt>true</tt>, allows the combo field to hold more than one value at a time, and allows selecting
     * multiple items from the dropdown list. The combo's text field will show all selected values separated by
     * the {@link #delimiter}. (Defaults to <tt>false</tt>.)
     */
    multiSelect: false,

    /**
     * @cfg {String} delimiter
     * The character(s) used to separate the {@link #displayField display values} of multiple selected items
     * when <tt>{@link #multiSelect} = true</tt>. Defaults to <tt>', '</tt>.
     */
    delimiter: ', ',

    /**
     * @cfg {String} displayField The underlying {@link Ext.data.Field#name data field name} to bind to this
     * ComboBox (defaults to 'text').
     * <p>See also <tt>{@link #valueField}</tt>.</p>
     */
    displayField: 'text',

    /**
     * @cfg {String} valueField
     * @required
     * The underlying {@link Ext.data.Field#name data value name} to bind to this ComboBox (defaults to match
     * the value of the {@link #displayField} config).
     * <p><b>Note</b>: use of a <tt>valueField</tt> requires the user to make a selection in order for a value to be
     * mapped. See also <tt>{@link #displayField}</tt>.</p>
     */

    /**
     * @cfg {String} triggerAction The action to execute when the trigger is clicked.
     * <div class="mdetail-params"><ul>
     * <li><b><tt>'all'</tt></b> : <b>Default</b>
     * <p class="sub-desc">{@link #doQuery run the query} specified by the <tt>{@link #allQuery}</tt> config option</p></li>
     * <li><b><tt>'query'</tt></b> :
     * <p class="sub-desc">{@link #doQuery run the query} using the {@link Ext.form.field.Base#getRawValue raw value}.</p></li>
     * </ul></div>
     * <p>See also <code>{@link #queryParam}</code>.</p>
     */
    triggerAction: 'all',

    /**
     * @cfg {String} allQuery The text query to send to the server to return all records for the list
     * with no filtering (defaults to '')
     */
    allQuery: '',

    /**
     * @cfg {String} queryParam Name of the query ({@link Ext.data.proxy.Proxy#extraParam extraParam} name for the store)
     * as it will be passed on the querystring (defaults to <tt>'query'</tt>). If explicitly set to a falsey value it will
     * not be send.
     */
    queryParam: 'query',

    /**
     * @cfg {String} queryMode
     * The mode for queries. Acceptable values are:
     * <div class="mdetail-params"><ul>
     * <li><b><tt>'remote'</tt></b> : <b>Default</b>
     * <p class="sub-desc">Automatically loads the <tt>{@link #store}</tt> the <b>first</b> time the trigger
     * is clicked. If you do not want the store to be automatically loaded the first time the trigger is
     * clicked, set to <tt>'local'</tt> and manually load the store.  To force a requery of the store
     * <b>every</b> time the trigger is clicked see <tt>{@link #lastQuery}</tt>.</p></li>
     * <li><b><tt>'local'</tt></b> :
     * <p class="sub-desc">ComboBox loads local data</p>
     * <pre><code>
var combo = new Ext.form.field.ComboBox({
    renderTo: document.body,
    queryMode: 'local',
    store: new Ext.data.ArrayStore({
        id: 0,
        fields: [
            'myId',  // numeric value is the key
            'displayText'
        ],
        data: [[1, 'item1'], [2, 'item2']]  // data is local
    }),
    valueField: 'myId',
    displayField: 'displayText',
    triggerAction: 'all'
});
     * </code></pre></li>
     * </ul></div>
     */
    queryMode: 'remote',

    queryCaching: true,

    /**
     * @cfg {Number} pageSize If greater than <tt>0</tt>, a {@link Ext.toolbar.Paging} is displayed in the
     * footer of the dropdown list and the {@link #doQuery filter queries} will execute with page start and
     * {@link Ext.toolbar.Paging#pageSize limit} parameters. Only applies when <tt>{@link #queryMode} = 'remote'</tt>
     * (defaults to <tt>0</tt>).
     */
    pageSize: 0,

    /**
     * @cfg {Number} queryDelay The length of time in milliseconds to delay between the start of typing and
     * sending the query to filter the dropdown list (defaults to <tt>500</tt> if <tt>{@link #queryMode} = 'remote'</tt>
     * or <tt>10</tt> if <tt>{@link #queryMode} = 'local'</tt>)
     */

    /**
     * @cfg {Number} minChars The minimum number of characters the user must type before autocomplete and
     * {@link #typeAhead} activate (defaults to <tt>4</tt> if <tt>{@link #queryMode} = 'remote'</tt> or <tt>0</tt> if
     * <tt>{@link #queryMode} = 'local'</tt>, does not apply if <tt>{@link Ext.form.field.Trigger#editable editable} = false</tt>).
     */

    /**
     * @cfg {Boolean} autoSelect <tt>true</tt> to automatically highlight the first result gathered by the data store
     * in the dropdown list when it is opened. (Defaults to <tt>true</tt>). A false value would cause nothing in the
     * list to be highlighted automatically, so the user would have to manually highlight an item before pressing
     * the enter or {@link #selectOnTab tab} key to select it (unless the value of ({@link #typeAhead}) were true),
     * or use the mouse to select a value.
     */
    autoSelect: true,

    /**
     * @cfg {Boolean} typeAhead <tt>true</tt> to populate and autoselect the remainder of the text being
     * typed after a configurable delay ({@link #typeAheadDelay}) if it matches a known value (defaults
     * to <tt>false</tt>)
     */
    typeAhead: false,

    /**
     * @cfg {Number} typeAheadDelay The length of time in milliseconds to wait until the typeahead text is displayed
     * if <tt>{@link #typeAhead} = true</tt> (defaults to <tt>250</tt>)
     */
    typeAheadDelay: 250,

    /**
     * @cfg {Boolean} selectOnTab
     * Whether the Tab key should select the currently highlighted item. Defaults to <tt>true</tt>.
     */
    selectOnTab: true,

    /**
     * @cfg {Boolean} forceSelection <tt>true</tt> to restrict the selected value to one of the values in the list,
     * <tt>false</tt> to allow the user to set arbitrary text into the field (defaults to <tt>false</tt>)
     */
    forceSelection: false,

    /**
     * @cfg {String} valueNotFoundText When using a name/value combo, if the value passed to setValue is not found in
     * the store, valueNotFoundText will be displayed as the field text if defined (defaults to undefined). If this
     * default text is used, it means there is no value set and no validation will occur on this field.
     */

    /**
     * The value of the match string used to filter the store. Delete this property to force a requery.
     * Example use:
     * <pre><code>
var combo = new Ext.form.field.ComboBox({
    ...
    queryMode: 'remote',
    listeners: {
        // delete the previous query in the beforequery event or set
        // combo.lastQuery = null (this will reload the store the next time it expands)
        beforequery: function(qe){
            delete qe.combo.lastQuery;
        }
    }
});
     * </code></pre>
     * To make sure the filter in the store is not cleared the first time the ComboBox trigger is used
     * configure the combo with <tt>lastQuery=''</tt>. Example use:
     * <pre><code>
var combo = new Ext.form.field.ComboBox({
    ...
    queryMode: 'local',
    triggerAction: 'all',
    lastQuery: ''
});
     * </code></pre>
     * @property lastQuery
     * @type String
     */

    /**
     * @cfg {Object} defaultListConfig
     * Set of options that will be used as defaults for the user-configured {@link #listConfig} object.
     */
    defaultListConfig: {
        emptyText: '',
        loadingText: 'Loading...',
        loadingHeight: 70,
        minWidth: 70,
        maxHeight: 300,
        shadow: 'sides'
    },

    /**
     * @cfg {Mixed} transform
     * The id, DOM node or {@link Ext.core.Element} of an existing HTML <tt>&lt;select&gt;</tt> element to
     * convert into a ComboBox. The target select's options will be used to build the options in the ComboBox
     * dropdown; a configured {@link #store} will take precedence over this.
     */

    /**
     * @cfg {Object} listConfig
     * <p>An optional set of configuration properties that will be passed to the {@link Ext.view.BoundList}'s
     * constructor. Any configuration that is valid for BoundList can be included. Some of the more useful
     * ones are:</p>
     * <ul>
     *     <li>{@link Ext.view.BoundList#cls} - defaults to empty</li>
     *     <li>{@link Ext.view.BoundList#emptyText} - defaults to empty string</li>
     *     <li>{@link Ext.view.BoundList#getInnerTpl} - defaults to the template defined in BoundList</li>
     *     <li>{@link Ext.view.BoundList#itemSelector} - defaults to the value defined in BoundList</li>
     *     <li>{@link Ext.view.BoundList#loadingText} - defaults to <tt>'Loading...'</tt></li>
     *     <li>{@link Ext.view.BoundList#minWidth} - defaults to <tt>70</tt></li>
     *     <li>{@link Ext.view.BoundList#maxWidth} - defaults to <tt>undefined</tt></li>
     *     <li>{@link Ext.view.BoundList#maxHeight} - defaults to <tt>300</tt></li>
     *     <li>{@link Ext.view.BoundList#resizable} - defaults to <tt>false</tt></li>
     *     <li>{@link Ext.view.BoundList#shadow} - defaults to <tt>'sides'</tt></li>
     *     <li>{@link Ext.view.BoundList#width} - defaults to <tt>undefined</tt> (automatically set to the width
     *         of the ComboBox field if {@link #matchFieldWidth} is true)</li>
     * </ul>
     */

    //private
    ignoreSelection: 0,

    initComponent: function() {
        var me = this,
            isDefined = Ext.isDefined,
            store = me.store,
            transform = me.transform,
            transformSelect, isLocalMode;

        //<debug>
        if (!store && !transform) {
            Ext.Error.raise('Either a valid store, or a HTML select to transform, must be configured on the combo.');
        }
        if (me.typeAhead && me.multiSelect) {
            Ext.Error.raise('typeAhead and multiSelect are mutually exclusive options -- please remove one of them.');
        }
        if (me.typeAhead && !me.editable) {
            Ext.Error.raise('If typeAhead is enabled the combo must be editable: true -- please change one of those settings.');
        }
        if (me.selectOnFocus && !me.editable) {
            Ext.Error.raise('If selectOnFocus is enabled the combo must be editable: true -- please change one of those settings.');
        }
        //</debug>

        this.addEvents(
            // TODO need beforeselect?

            /**
             * @event beforequery
             * Fires before all queries are processed. Return false to cancel the query or set the queryEvent's
             * cancel property to true.
             * @param {Object} queryEvent An object that has these properties:<ul>
             * <li><code>combo</code> : Ext.form.field.ComboBox <div class="sub-desc">This combo box</div></li>
             * <li><code>query</code> : String <div class="sub-desc">The query string</div></li>
             * <li><code>forceAll</code> : Boolean <div class="sub-desc">True to force "all" query</div></li>
             * <li><code>cancel</code> : Boolean <div class="sub-desc">Set to true to cancel the query</div></li>
             * </ul>
             */
            'beforequery',

            /*
             * @event select
             * Fires when at least one list item is selected.
             * @param {Ext.form.field.ComboBox} combo This combo box
             * @param {Array} records The selected records
             */
            'select'
        );

        // Build store from 'transform' HTML select element's options
        if (!store && transform) {
            transformSelect = Ext.getDom(transform);
            if (transformSelect) {
                store = Ext.Array.map(Ext.Array.from(transformSelect.options), function(option) {
                    return [option.value, option.text];
                });
                if (!me.name) {
                    me.name = transformSelect.name;
                }
                if (!('value' in me)) {
                    me.value = transformSelect.value;
                }
            }
        }

        me.bindStore(store, true);
        store = me.store;
        if (store.autoCreated) {
            me.queryMode = 'local';
            me.valueField = me.displayField = 'field1';
            if (!store.expanded) {
                me.displayField = 'field2';
            }
        }


        if (!isDefined(me.valueField)) {
            me.valueField = me.displayField;
        }

        isLocalMode = me.queryMode === 'local';
        if (!isDefined(me.queryDelay)) {
            me.queryDelay = isLocalMode ? 10 : 500;
        }
        if (!isDefined(me.minChars)) {
            me.minChars = isLocalMode ? 0 : 4;
        }

        if (!me.displayTpl) {
            me.displayTpl = Ext.create('Ext.XTemplate',
                '<tpl for=".">' +
                    '{[typeof values === "string" ? values : values.' + me.displayField + ']}' +
                    '<tpl if="xindex < xcount">' + me.delimiter + '</tpl>' +
                '</tpl>'
            );
        } else if (Ext.isString(me.displayTpl)) {
            me.displayTpl = Ext.create('Ext.XTemplate', me.displayTpl);
        }

        me.callParent();

        me.doQueryTask = Ext.create('Ext.util.DelayedTask', me.doRawQuery, me);

        // store has already been loaded, setValue
        if (me.store.getCount() > 0) {
            me.setValue(me.value);
        }

        // render in place of 'transform' select
        if (transformSelect) {
            me.render(transformSelect.parentNode, transformSelect);
            Ext.removeNode(transformSelect);
            delete me.renderTo;
        }
    },

    beforeBlur: function() {
        var me = this;
        me.doQueryTask.cancel();
        if (me.forceSelection) {
            me.assertValue();
        } else {
            me.collapse();
        }
    },

    // private
    assertValue: function() {
        var me = this,
            value = me.getRawValue(),
            rec;

        if (me.multiSelect) {
            // For multiselect, check that the current displayed value matches the current
            // selection, if it does not then revert to the most recent selection.
            if (value !== me.getDisplayValue()) {
                me.setValue(me.lastSelection);
            }
        } else {
            // For single-select, match the displayed value to a record and select it,
            // if it does not match a record then revert to the most recent selection.
            rec = me.findRecordByDisplay(value);
            if (rec) {
                me.select(rec);
            } else {
                me.setValue(me.lastSelection);
            }
        }
        me.collapse();
    },

    onTypeAhead: function() {
        var me = this,
            displayField = me.displayField,
            record = me.store.findRecord(displayField, me.getRawValue()),
            boundList = me.getPicker(),
            newValue, len, selStart;

        if (record) {
            newValue = record.get(displayField);
            len = newValue.length;
            selStart = me.getRawValue().length;

            boundList.highlightItem(boundList.getNode(record));

            if (selStart !== 0 && selStart !== len) {
                me.setRawValue(newValue);
                me.selectText(selStart, newValue.length);
            }
        }
    },

    // invoked when a different store is bound to this combo
    // than the original
    resetToDefault: function() {

    },

    bindStore: function(store, initial) {
        var me = this,
            oldStore = me.store;

        // this code directly accesses this.picker, bc invoking getPicker
        // would create it when we may be preping to destroy it
        if (oldStore && !initial) {
            if (oldStore !== store && oldStore.autoDestroy) {
                oldStore.destroy();
            } else {
                oldStore.un({
                    scope: me,
                    load: me.onLoad,
                    exception: me.collapse
                });
            }
            if (!store) {
                me.store = null;
                if (me.picker) {
                    me.picker.bindStore(null);
                }
            }
        }
        if (store) {
            if (!initial) {
                me.resetToDefault();
            }

            me.store = Ext.data.StoreManager.lookup(store);
            me.store.on({
                scope: me,
                load: me.onLoad,
                exception: me.collapse
            });

            if (me.picker) {
                me.picker.bindStore(store);
            }
        }
    },

    onLoad: function() {
        var me = this,
            value = me.value;

        me.syncSelection();
        if (me.picker && !me.picker.getSelectionModel().hasSelection()) {
            me.doAutoSelect();
        }
    },

    /**
     * @private
     * Execute the query with the raw contents within the textfield.
     */
    doRawQuery: function() {
        this.doQuery(this.getRawValue());
    },

    /**
     * Executes a query to filter the dropdown list. Fires the {@link #beforequery} event prior to performing the
     * query allowing the query action to be canceled if needed.
     * @param {String} queryString The SQL query to execute
     * @param {Boolean} forceAll <tt>true</tt> to force the query to execute even if there are currently fewer
     * characters in the field than the minimum specified by the <tt>{@link #minChars}</tt> config option.  It
     * also clears any filter previously saved in the current store (defaults to <tt>false</tt>)
     * @return {Boolean} true if the query was permitted to run, false if it was cancelled by a {@link #beforequery} handler.
     */
    doQuery: function(queryString, forceAll) {
        queryString = queryString || '';

        // store in object and pass by reference in 'beforequery'
        // so that client code can modify values.
        var me = this,
            qe = {
                query: queryString,
                forceAll: forceAll,
                combo: me,
                cancel: false
            },
            store = me.store,
            isLocalMode = me.queryMode === 'local';

        if (me.fireEvent('beforequery', qe) === false || qe.cancel) {
            return false;
        }

        // get back out possibly modified values
        queryString = qe.query;
        forceAll = qe.forceAll;

        // query permitted to run
        if (forceAll || (queryString.length >= me.minChars)) {
            // expand before starting query so LoadMask can position itself correctly
            me.expand();

            // make sure they aren't querying the same thing
            if (!me.queryCaching || me.lastQuery !== queryString) {
                me.lastQuery = queryString;
                store.clearFilter(!forceAll);
                if (isLocalMode) {
                    if (!forceAll) {
                        store.filter(me.displayField, queryString);
                    }
                } else {
                    store.load({
                        params: me.getParams(queryString)
                    });
                }
            }

            // Clear current selection if it does not match the current value in the field
            if (me.getRawValue() !== me.getDisplayValue()) {
                me.ignoreSelection++;
                me.picker.getSelectionModel().deselectAll();
                me.ignoreSelection--;
            }

            if (isLocalMode) {
                me.doAutoSelect();
            }
            if (me.typeAhead) {
                me.doTypeAhead();
            }
        }
        return true;
    },

    // private
    getParams: function(queryString) {
        var p = {},
            pageSize = this.pageSize,
            param = this.queryParam;
            
        if (param) {
            p[param] = queryString;
        }
        
        if (pageSize) {
            p.start = 0;
            p.limit = pageSize;
        }
        return p;
    },

    /**
     * @private
     * If the autoSelect config is true, and the picker is open, highlights the first item.
     */
    doAutoSelect: function() {
        var me = this,
            picker = me.picker,
            lastSelected, itemNode;
        if (picker && me.autoSelect && me.store.getCount() > 0) {
            // Highlight the last selected item and scroll it into view
            lastSelected = picker.getSelectionModel().lastSelected;
            itemNode = picker.getNode(lastSelected || 0);
            if (itemNode) {
                picker.highlightItem(itemNode);
                picker.listEl.scrollChildIntoView(itemNode, false);
            }
        }
    },

    doTypeAhead: function() {
        if (!this.typeAheadTask) {
            this.typeAheadTask = Ext.create('Ext.util.DelayedTask', this.onTypeAhead, this);
        }
        if (this.lastKey != Ext.EventObject.BACKSPACE && this.lastKey != Ext.EventObject.DELETE) {
            this.typeAheadTask.delay(this.typeAheadDelay);
        }
    },

    onTriggerClick: function() {
        var me = this;
        if (!me.readOnly && !me.disabled) {
            if (me.isExpanded) {
                me.collapse();
            } else {
                me.onFocus({});
                if (me.triggerAction === 'all') {
                    me.doQuery(me.allQuery, true);
                } else {
                    me.doQuery(me.getRawValue());
                }
            }
            me.inputEl.focus();
        }
    },


    // store the last key and doQuery if relevant
    onKeyUp: function(e, t) {
        var me = this,
            key = e.getKey();

        if (!me.readOnly && !me.disabled && me.editable) {
            me.lastKey = key;
            // we put this in a task so that we can cancel it if a user is
            // in and out before the queryDelay elapses

            // perform query w/ any normal key or backspace or delete
            if (!e.isSpecialKey() || key == e.BACKSPACE || key == e.DELETE) {
                me.doQueryTask.delay(me.queryDelay);
            }
        }
        
        if (me.enableKeyEvents) {
            me.callParent(arguments);
        }
    },

    initEvents: function() {
        var me = this;
        me.callParent();

        /*
         * Setup keyboard handling. If enableKeyEvents is true, we already have 
         * a listener on the inputEl for keyup, so don't create a second.
         */
        if (!me.enableKeyEvents) {
            me.mon(me.inputEl, 'keyup', me.onKeyUp, me);
        }
    },

    createPicker: function() {
        var me = this,
            picker,
            menuCls = Ext.baseCSSPrefix + 'menu',
            opts = Ext.apply({
                selModel: {
                    mode: me.multiSelect ? 'SIMPLE' : 'SINGLE'
                },
                floating: true,
                hidden: true,
                ownerCt: me.ownerCt,
                cls: me.el.up('.' + menuCls) ? menuCls : '',
                store: me.store,
                displayField: me.displayField,
                focusOnToFront: false,
                pageSize: me.pageSize
            }, me.listConfig, me.defaultListConfig);

        picker = me.picker = Ext.create('Ext.view.BoundList', opts);

        me.mon(picker, {
            itemclick: me.onItemClick,
            refresh: me.onListRefresh,
            scope: me
        });

        me.mon(picker.getSelectionModel(), {
            selectionChange: me.onListSelectionChange,
            scope: me
        });

        return picker;
    },

    onListRefresh: function() {
        this.alignPicker();
        this.syncSelection();
    },
    
    onItemClick: function(picker, record){
        /*
         * If we're doing single selection, the selection change events won't fire when
         * clicking on the selected element. Detect it here.
         */
        var me = this,
            lastSelection = me.lastSelection,
            valueField = me.valueField,
            selected;
        
        if (!me.multiSelect && lastSelection) {
            selected = lastSelection[0];
            if (record.get(valueField) === selected.get(valueField)) {
                me.collapse();
            }
        }   
    },

    onListSelectionChange: function(list, selectedRecords) {
        var me = this;
        // Only react to selection if it is not called from setValue, and if our list is
        // expanded (ignores changes to the selection model triggered elsewhere)
        if (!me.ignoreSelection && me.isExpanded) {
            if (!me.multiSelect) {
                Ext.defer(me.collapse, 1, me);
            }
            me.setValue(selectedRecords, false);
            if (selectedRecords.length > 0) {
                me.fireEvent('select', me, selectedRecords);
            }
            me.inputEl.focus();
        }
    },

    /**
     * @private
     * Enables the key nav for the BoundList when it is expanded.
     */
    onExpand: function() {
        var me = this,
            keyNav = me.listKeyNav,
            selectOnTab = me.selectOnTab,
            picker = me.getPicker();

        // Handle BoundList navigation from the input field. Insert a tab listener specially to enable selectOnTab.
        if (keyNav) {
            keyNav.enable();
        } else {
            keyNav = me.listKeyNav = Ext.create('Ext.view.BoundListKeyNav', this.inputEl, {
                boundList: picker,
                forceKeyDown: true,
                tab: function(e) {
                    if (selectOnTab) {
                        this.selectHighlighted(e);
                        me.triggerBlur();
                    }
                    // Tab key event is allowed to propagate to field
                    return true;
                }
            });
        }

        // While list is expanded, stop tab monitoring from Ext.form.field.Trigger so it doesn't short-circuit selectOnTab
        if (selectOnTab) {
            me.ignoreMonitorTab = true;
        }

        Ext.defer(keyNav.enable, 1, keyNav); //wait a bit so it doesn't react to the down arrow opening the picker
        me.inputEl.focus();
    },

    /**
     * @private
     * Disables the key nav for the BoundList when it is collapsed.
     */
    onCollapse: function() {
        var me = this,
            keyNav = me.listKeyNav;
        if (keyNav) {
            keyNav.disable();
            me.ignoreMonitorTab = false;
        }
    },

    /**
     * Selects an item by a {@link Ext.data.Model Model}, or by a key value.
     * @param r
     */
    select: function(r) {
        this.setValue(r, true);
    },

    /**
     * Find the record by searching for a specific field/value combination
     * Returns an Ext.data.Record or false
     * @private
     */
    findRecord: function(field, value) {
        var ds = this.store,
            idx = ds.findExact(field, value);
        return idx !== -1 ? ds.getAt(idx) : false;
    },
    findRecordByValue: function(value) {
        return this.findRecord(this.valueField, value);
    },
    findRecordByDisplay: function(value) {
        return this.findRecord(this.displayField, value);
    },

    /**
     * Sets the specified value(s) into the field. For each value, if a record is found in the {@link #store} that
     * matches based on the {@link #valueField}, then that record's {@link #displayField} will be displayed in the
     * field.  If no match is found, and the {@link #valueNotFoundText} config option is defined, then that will be
     * displayed as the default field text. Otherwise a blank value will be shown, although the value will still be set.
     * @param {String|Array} value The value(s) to be set. Can be either a single String or {@link Ext.data.Model},
     * or an Array of Strings or Models.
     * @return {Ext.form.field.Field} this
     */
    setValue: function(value, doSelect) {
        var me = this,
            valueNotFoundText = me.valueNotFoundText,
            inputEl = me.inputEl,
            i, len, record,
            models = [],
            displayTplData = [],
            processedValue = [];

        if (me.store.loading) {
            // Called while the Store is loading. Ensure it is processed by the onLoad method.
            me.value = value;
            return me;
        }

        // This method processes multi-values, so ensure value is an array.
        value = Ext.Array.from(value);

        // Loop through values
        for (i = 0, len = value.length; i < len; i++) {
            record = value[i];
            if (!record || !record.isModel) {
                record = me.findRecordByValue(record);
            }
            // record found, select it.
            if (record) {
                models.push(record);
                displayTplData.push(record.data);
                processedValue.push(record.get(me.valueField));
            }
            // record was not found, this could happen because
            // store is not loaded or they set a value not in the store
            else {
                // if valueNotFoundText is defined, display it, otherwise display nothing for this value
                if (Ext.isDefined(valueNotFoundText)) {
                    displayTplData.push(valueNotFoundText);
                }
                processedValue.push(value[i]);
            }
        }

        // Set the value of this field. If we are multiselecting, then that is an array.
        me.value = me.multiSelect ? processedValue : processedValue[0];
        if (!Ext.isDefined(me.value)) {
            me.value = null;
        }
        me.displayTplData = displayTplData; //store for getDisplayValue method
        me.lastSelection = me.valueModels = models;

        if (inputEl && me.emptyText && !Ext.isEmpty(value)) {
            inputEl.removeCls(me.emptyCls);
        }

        // Calculate raw value from the collection of Model data
        me.setRawValue(me.getDisplayValue());
        me.checkChange();

        if (doSelect !== false) {
            me.syncSelection();
        }
        me.applyEmptyText();

        return me;
    },

    /**
     * @private Generate the string value to be displayed in the text field for the currently stored value
     */
    getDisplayValue: function() {
        return this.displayTpl.apply(this.displayTplData);
    },

    getValue: function() {
        // If the user has not changed the raw field value since a value was selected from the list,
        // then return the structured value from the selection. If the raw field value is different
        // than what would be displayed due to selection, return that raw value.
        var me = this,
            picker = me.picker,
            rawValue = me.getRawValue(), //current value of text field
            value = me.value; //stored value from last selection or setValue() call

        if (me.getDisplayValue() !== rawValue) {
            value = rawValue;
            me.value = me.displayTplData = me.valueModels = null;
            if (picker) {
                me.ignoreSelection++;
                picker.getSelectionModel().deselectAll();
                me.ignoreSelection--;
            }
        }

        return value;
    },

    getSubmitValue: function() {
        return this.getValue();
    },

    isEqual: function(v1, v2) {
        var fromArray = Ext.Array.from,
            i, len;

        v1 = fromArray(v1);
        v2 = fromArray(v2);
        len = v1.length;

        if (len !== v2.length) {
            return false;
        }

        for(i = 0; i < len; i++) {
            if (v2[i] !== v1[i]) {
                return false;
            }
        }

        return true;
    },

    /**
     * Clears any value currently set in the ComboBox.
     */
    clearValue: function() {
        this.setValue([]);
    },

    /**
     * @private Synchronizes the selection in the picker to match the current value of the combobox.
     */
    syncSelection: function() {
        var me = this,
            ExtArray = Ext.Array,
            picker = me.picker,
            selection, selModel;
        if (picker) {
            // From the value, find the Models that are in the store's current data
            selection = [];
            ExtArray.forEach(me.valueModels || [], function(value) {
                if (value && value.isModel && me.store.indexOf(value) >= 0) {
                    selection.push(value);
                }
            });

            // Update the selection to match
            me.ignoreSelection++;
            selModel = picker.getSelectionModel();
            selModel.deselectAll();
            if (selection.length) {
                selModel.select(selection);
            }
            me.ignoreSelection--;
        }
    }
});