/**
 * @class Ext.grid.header.DragZone
 * @extends Ext.dd.DragZone
 * @private
 */
Ext.define('Ext.grid.header.DragZone', {
    extend: 'Ext.dd.DragZone',
    colHeaderCls: Ext.baseCSSPrefix + 'column-header',
    maxProxyWidth: 120,

    constructor: function(headerCt) {
        this.headerCt = headerCt;
        this.ddGroup =  this.getDDGroup();
        this.callParent([headerCt.el]);
        this.proxy.el.addCls(Ext.baseCSSPrefix + 'grid-col-dd');
    },

    getDDGroup: function() {
        return 'header-dd-zone-' + this.headerCt.up('[scrollerOwner]').id;
    },

    getDragData: function(e) {
        var header = e.getTarget('.'+this.colHeaderCls),
            headerCmp;

        if (header) {
            headerCmp = Ext.getCmp(header.id);
            if (!this.headerCt.dragging && headerCmp.draggable && !(headerCmp.isOnLeftEdge(e) || headerCmp.isOnRightEdge(e))) {
                var ddel = document.createElement('div');
                ddel.innerHTML = Ext.getCmp(header.id).text;
                return {
                    ddel: ddel,
                    header: headerCmp
                };
            }
        }
        return false;
    },

    onBeforeDrag: function() {
        return !(this.headerCt.dragging || this.disabled);
    },

    onInitDrag: function() {
        this.headerCt.dragging = true;
        this.callParent(arguments);
    },

    onDragDrop: function() {
        this.headerCt.dragging = false;
        this.callParent(arguments);
    },

    afterRepair: function() {
        this.callParent();
        this.headerCt.dragging = false;
    },

    getRepairXY: function() {
        return this.dragData.header.el.getXY();
    },
    
    disable: function() {
        this.disabled = true;
    },
    
    enable: function() {
        this.disabled = false;
    }
});