/**
 * @class Ext.grid.CheckboxSelectionModel
 * @extends Ext.grid.RowSelectionModel
 * A custom selection model that renders a column of checkboxes that can be toggled to select or deselect rows.
 * @constructor
 * @param {Object} config The configuration options
 */
Ext.grid.CheckboxSelectionModel = Ext.extend(Ext.grid.RowSelectionModel, {

    
/**
     * @cfg {Boolean} checkOnly true if rows can only be selected by clicking on the
     * checkbox column (defaults to false).
     */
    
/**
     * @cfg {String} header Any valid text or HTML fragment to display in the header cell for the
     * checkbox column.  Defaults to:

     * '<div class="x-grid3-hd-checker">&#160;</div>'
     * 
     * The default CSS class of 'x-grid3-hd-checker' displays a checkbox in the header
     * and provides support for automatic check all/none behavior on header click. This string
     * can be replaced by any valid HTML fragment, including a simple text string (e.g.,
     * 'Select Rows'), but the automatic check all/none behavior will only work if the
     * 'x-grid3-hd-checker' class is supplied.
     */
    header: '
 
',
    
/**
     * @cfg {Number} width The default width in pixels of the checkbox column (defaults to 20).
     */
    width: 20,
    
/**
     * @cfg {Boolean} sortable true if the checkbox column is sortable (defaults to
     * false).
     */
    sortable: false,

    // private
    menuDisabled:true,
    fixed:true,
    dataIndex: '',
    id: 'checker',

    constructor: function(){
        Ext.grid.CheckboxSelectionModel.superclass.constructor.apply(this, arguments);

        if(this.checkOnly){
            this.handleMouseDown = Ext.emptyFn;
        }
    },

    // private
    initEvents : function(){
        Ext.grid.CheckboxSelectionModel.superclass.initEvents.call(this);
        this.grid.on('render', function(){
            var view = this.grid.getView();
            view.mainBody.on('mousedown', this.onMouseDown, this);
            Ext.fly(view.innerHd).on('mousedown', this.onHdMouseDown, this);

        }, this);
    },

    // private
    onMouseDown : function(e, t){
        if(e.button === 0 && t.className == 'x-grid3-row-checker'){ // Only fire if left-click
            e.stopEvent();
            var row = e.getTarget('.x-grid3-row');
            if(row){
                var index = row.rowIndex;
                if(this.isSelected(index)){
                    this.deselectRow(index);
                }else{
                    this.selectRow(index, true);
                }
            }
        }
    },

    // private
    onHdMouseDown : function(e, t){
        if(t.className == 'x-grid3-hd-checker'){
            e.stopEvent();
            var hd = Ext.fly(t.parentNode);
            var isChecked = hd.hasClass('x-grid3-hd-checker-on');
            if(isChecked){
                hd.removeClass('x-grid3-hd-checker-on');
                this.clearSelections();
            }else{
                hd.addClass('x-grid3-hd-checker-on');
                this.selectAll();
            }
        }
    },

    // private
    renderer : function(v, p, record){
        return '
 
';
    }
});