extjs4.1 复选框 联动菜单

var treeStore = Ext.create('Ext.data.TreeStore', {
			root : {
				expanded : true,
				children : [{
							text : "detention",
							leaf : true
						}, {
							text : "homework",
							expanded : true,
							checked : false,
							children : [{
										text : "book report",
										checked : false,
										expanded : true,
										children : [{
													text : "buy lottery tickets",
													checked : false,
													expanded : true,
													leaf : true
												}, {
													text : "buy lottery tickets3",
													checked : false,
													expanded : true,
													leaf : true
												}]
									}, {
										text : "alegrbra",
										checked : false,
										expanded : true,
										leaf : false,
										children : [{
													text : "buy lottery tickets2",
													checked : false,
													leaf : true
												}, {
													text : "buy lottery tickets3",
													checked : false,
													expanded : true,
													leaf : true
												}]
									}]
						}, {
							text : "buy lottery tickets",
							leaf : true
						}]
			}
		});

var treePanel = Ext.create('Ext.tree.Panel', {
	width : 200,
	height : 250,
	store : treeStore,
	rootVisible : false,
	checked : true,
	defaults : {
		checked : false
	}
});

treePanel.on('checkchange', function(record, checked) {
			if (checked) {
				record.bubble(function(parentNode) {
								parentNode.set('checked', true);
						});
				record.cascadeBy(function(node) {
							node.set('checked', true);
						});
			} else {
				record.cascadeBy(function(node) {
							node.set('checked', false);
						});
				record.bubble(function(parentNode) {
							if ('Root' != parentNode.get('text')) {
								
								var flag = true;
								for (var i = 0; i < parentNode.childNodes.length; i++) {
									var child = parentNode.childNodes[i];
									if (child.get('checked')) {
										flag = false;
										continue;
									}
								}
								if (flag) {
									parentNode.set('checked', false);
								}
							}
						});
			}
		}, treePanel);

var win = Ext.widget('window', {
			title : '修改客服权限',
			closeAction : 'hide',
			width : 400,
			height : 300,
			layout : 'fit',
			resizable : true,
			modal : true,
			buttonAlign : 'center',
			items : treePanel,
			listeners : {
				'beforehide' : function() {
					fromForm.getForm().reset();
				}
			},
			buttons : [{
						text : '修改',
						id : 'update_btn',
						handler : function() {
							addOrUpdateAction('update');
						}
					}, {
						text : '关闭',
						handler : function() {
							win.hide();
						}
					}]
		});