base库插件---拖动

 1 /**
 2  * Created by Administrator on 2014/6/5 0005.  Base-drag 基于Base库的拖拽插件  tags为你要拖拽的元素参数， 数组形式传入
 3  */
 4 
 5 $().extend('drag', function () {
 6     var tags = arguments;
 7     for (var i = 0; i < this.elements.length; i ++) {
 8         addEvent(this.elements[i], 'mousedown', function (e) {
 9             if (trim(this.innerHTML).length == 0) e.preventDefault();
10             var _this = this;
11             var diffX = e.clientX - _this.offsetLeft;
12             var diffY = e.clientY - _this.offsetTop;
13 
14             //自定义拖拽区域
15             var flag = false;
16 
17             for (var i = 0; i < tags.length; i ++) {
18                 if (e.target == tags[i]) {
19                     flag = true;                    //只要有一个是true，就立刻返回
20                     break;
21                 }
22             }
23 
24             if (flag) {
25                 addEvent(document, 'mousemove', move);
26                 addEvent(document, 'mouseup', up);
27             } else {
28                 removeEvent(document, 'mousemove', move);
29                 removeEvent(document, 'mouseup', up);
30             }
31 
32             function move(e) {
33                 var left = e.clientX - diffX;
34                 var top = e.clientY - diffY;
35 
36                 if (left < 0) {
37                     left = 0;
38                 } else if (left <= getScroll().left) {
39                     left = getScroll().left;
40                 } else if (left > getInner().width + getScroll().left - _this.offsetWidth) {
41                     left = getInner().width + getScroll().left - _this.offsetWidth;
42                 }
43 
44                 if (top < 0) {
45                     top = 0;
46                 } else if (top <= getScroll().top) {
47                     top = getScroll().top;
48                 } else if (top > getInner().height + getScroll().top - _this.offsetHeight) {
49                     top = getInner().height + getScroll().top - _this.offsetHeight;
50                 }
51 
52                 _this.style.left = left + 'px';
53                 _this.style.top = top + 'px';
54 
55                 if (typeof _this.setCapture != 'undefined') {
56                     _this.setCapture();
57                 }
58             }
59 
60             function up() {
61                 removeEvent(document, 'mousemove', move);
62                 removeEvent(document, 'mouseup', up);
63                 if (typeof _this.releaseCapture != 'undefined') {
64                     _this.releaseCapture();
65                 }
66             }
67         });
68     }
69     return this;
70 });