/*!
 * Ext JS Library 3.0.0
 * Copyright(c) 2006-2009 Ext JS, LLC
 * licensing@extjs.com
 * http://www.extjs.com/license
 */
/**

 * @class Ext.ListView.Sorter

 * @extends Ext.util.Observable

 * <p>Supporting Class for Ext.ListView.</p>

 * @constructor

 * @param {Object} config

 */

Ext.ListView.Sorter = Ext.extend(Ext.util.Observable, {

    /**

     * @cfg {Array} sortClasses

     * The CSS classes applied to a header when it is sorted. (defaults to <tt>["sort-asc", "sort-desc"]</tt>)

     */

    sortClasses : ["sort-asc", "sort-desc"],



    constructor: function(config){

        Ext.apply(this, config);

        Ext.ListView.Sorter.superclass.constructor.call(this);

    },



    init : function(listView){

        this.view = listView;

        listView.on('render', this.initEvents, this);

    },



    initEvents : function(view){

        view.mon(view.innerHd, 'click', this.onHdClick, this);

        view.innerHd.setStyle('cursor', 'pointer');

        view.mon(view.store, 'datachanged', this.updateSortState, this);

        this.updateSortState.defer(10, this, [view.store]);

    },



    updateSortState : function(store){

        var state = store.getSortState();

        if(!state){

            return;

        }

        this.sortState = state;

        var cs = this.view.columns, sortColumn = -1;

        for(var i = 0, len = cs.length; i < len; i++){

            if(cs[i].dataIndex == state.field){

                sortColumn = i;

                break;

            }

        }

        if(sortColumn != -1){

            var sortDir = state.direction;

            this.updateSortIcon(sortColumn, sortDir);

        }

    },



    updateSortIcon : function(col, dir){

        var sc = this.sortClasses;

        var hds = this.view.innerHd.select('em').removeClass(sc);

        hds.item(col).addClass(sc[dir == "DESC" ? 1 : 0]);

    },



    onHdClick : function(e){

        var hd = e.getTarget('em', 3);

        if(hd && !this.view.disableHeaders){

            var index = this.view.findHeaderIndex(hd);

            this.view.store.sort(this.view.columns[index].dataIndex);

        }

    }

});