access combotree function on datagrid editor

[iskandarkbr]

i've trie this methods for tree :

Code:

$.extend($.fn.tree.defaults.methods, {
		highlight: function(jq, target){
			return jq.each(function(){
				$(this).find('.tree-node-selected').removeClass('tree-node-selected');  /*isoft; original: .tree.node.hover*/
				$(target).addClass('tree-node-selected');
			})
		},
		navTree: function(jq){
			return jq.each(function(){
				var t = $(this);
				t.attr('tabindex',0);
				t.unbind('.tree').bind('keydown.tree', function(e){
					var curr = getCurr();
					if (!curr.length){return}
					if (e.keyCode == 40){	// down
						var li = getNext(curr);
						if (li.length){
							t.tree('highlight', li[0]);
							t.tree('scrollTo',li[0]);  /*isoft*/
						}
					} else if (e.keyCode == 38){	// up
						var li = getPrev(curr);
						if (li.length){
							t.tree('highlight', li[0]);
							t.tree('scrollTo',li[0]);	/*isoft*/						
						}
					} else if (e.keyCode == 13){
						t.tree('select', curr[0]);
					} else if (e.keyCode == 39){	// right
						if (!t.tree('isLeaf', curr[0])){
							t.tree('expand', curr[0]);
						}
					} else if (e.keyCode == 37){	// left
						if (!t.tree('isLeaf', curr[0])){
							t.tree('collapse', curr[0]);
						}
					}
					e.preventDefault();
				}).bind('mouseover.tree', function(e){
					var node = $(e.target).closest('div.tree-node');
					if (node.length){
						t.find('.tree-node-hover').each(function(){
							if (this != node[0]){
								$(this).removeClass('tree-node-hover');
							}
						})
					}
				});
				function getCurr(){
					var n = t.find('.tree-node-hover');
					if (!n.length){
						n = t.find('.tree-node-selected');
					}
					return n;
				}
				function getNext(curr){
					var n = $();
					var node = t.tree('getNode', curr[0]);
					if (t.tree('isLeaf', node.target)){
						n = curr.parent().next().children('div.tree-node');
						if (!n.length){
							var p = t.tree('getParent', curr[0]);
							if (p){
								n = $(p.target).parent().next().children('div.tree-node');
							}
						}
					} else {
						if (node.state == 'closed'){
							n = curr.parent().next().children('div.tree-node');
						} else {
							var cc = t.tree('getChildren', curr[0]);
							if (cc.length){
								n = $(cc[0].target);
							}
						}

					}
					return n;
				}
				function getPrev(curr){
					var n = curr.parent().prev().children('div.tree-node');
					if (n.length){
						var node = t.tree('getNode', n[0]);
						if (node.state == 'open'){
							var cc = t.tree('getChildren', node.target);
							if (cc.length){
								n = $(cc[cc.length-1].target);
							}
						}
					} else {
						var p = t.tree('getParent', curr[0]);
						if (p){
							n = $(p.target);
						}
					}
					return n;
				}
			})
		}
	});

now, i place combotree on my datagrid as editor, how to access above method for my cobotree's tree?