扩展了 jquery 的插件 easy drag (转载 木野狐)

<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>-->/**
*?EasyDrag?1.3?-?Drag?&?Drop?jQuery?Plug-in
*
*?For?usage?instructions?please?visit?http://fromvega.com
*
*?Copyright?(c)?2007?fromvega
*/

(function($){

????//?to?track?if?the?mouse?button?is?pressed
????var?isMouseDown????=?false;

????//?to?track?the?current?element?being?dragged
????var?currentElement?=?null;

????//?callback?holders
????var?dropCallbacks?=?{};
????var?dragCallbacks?=?{};

????//?global?position?records
????var?lastMouseX;
????var?lastMouseY;
????var?lastElemTop;
????var?lastElemLeft;

????//?returns?the?mouse?(cursor)?current?position
????$.getMousePosition?=?function(e){
????????var?posx?=?0;
????????var?posy?=?0;

????????if?(!e)?var?e?=?window.event;

????????if?(e.pageX?||?e.pageY)?{
????????????posx?=?e.pageX;
????????????posy?=?e.pageY;
????????}
????????else?if?(e.clientX?||?e.clientY)?{
????????????posx?=?e.clientX?+?document.body.scrollLeft?+?document.documentElement.scrollLeft;
????????????posy?=?e.clientY?+?document.body.scrollTop??+?document.documentElement.scrollTop;
????????}

????????return?{?'x':?posx,?'y':?posy?};
????}

????//?updates?the?position?of?the?current?element?being?dragged
????$.updatePosition?=?function(e)?{
????????var?pos?=?$.getMousePosition(e);

????????var?spanX?=?(pos.x?-?lastMouseX);
????????var?spanY?=?(pos.y?-?lastMouseY);

????????$(currentElement).css("top",??(lastElemTop?+?spanY));
????????$(currentElement).css("left",?(lastElemLeft?+?spanX));
????}

????//?when?the?mouse?is?moved?while?the?mouse?button?is?pressed
????$(document).mousemove(function(e){
????????if(isMouseDown){
????????????//?update?the?position?and?call?the?registered?function
????????????$.updatePosition(e);
????????????if(dragCallbacks[currentElement.id]?!=?undefined){
????????????????dragCallbacks[currentElement.id](e);
????????????}

????????????return?false;
????????}
????});

????//?when?the?mouse?button?is?released
????$(document).mouseup(function(e){
????????if(isMouseDown){
????????????isMouseDown?=?false;
????????????if(dropCallbacks[currentElement.id]?!=?undefined){
????????????????dropCallbacks[currentElement.id](e);
????????????}
????????????return?false;
????????}
????});

????//?register?the?function?to?be?called?while?an?element?is?being?dragged
????$.fn.ondrag?=?function(callback){
????????return?this.each(function(){
????????????dragCallbacks[this.id]?=?callback;
????????});
????}

????//?register?the?function?to?be?called?when?an?element?is?dropped
????$.fn.ondrop?=?function(callback){
????????return?this.each(function(){
????????????dropCallbacks[this.id]?=?callback;
????????});
????}

????//?set?an?element?as?draggable?-?allowBubbling?enables/disables?event?bubbling
????$.fn.easydrag?=?function(allowBubbling,?handle_ids){

????????return?this.each(function(){

????????????//?if?no?id?is?defined?assign?a?unique?one
????????????if(undefined?==?this.id)?this.id?=?'easydrag'+time();

????????????if?(handle_ids)?{
????????????????//?修改鼠标光标为移动的形状
????????????????for?(var?i=0;?i<handle_ids.length;?i++)?{
????????????????????$("#"?+?handle_ids[i]).css("cursor",?"move");
????????????????}
????????????}?else?{
????????????????$(this).css("cursor",?"move");
????????????}
????????????
????????????//?when?an?element?receives?a?mouse?press
????????????$(this).mousedown(function(e){
????????????????if?(handle_ids)?{
????????????????????//?判断是否是在拖动某个?handle
????????????????????var?srcElement;
????????????????????if?(e)
????????????????????????srcElement?=?e.srcElement;
????????????????????else
????????????????????????srcElement?=?window.event.srcElement;
????????????????????
????????????????????var?exists?=?false;
????????????????????if?(srcElement.id?!=?undefined)?{
????????????????????????for?(var?i=0;?i<handle_ids.length;?i++)?{
????????????????????????????if?(handle_ids[i]?==?srcElement.id)?{
????????????????????????????????exists?=?true;
????????????????????????????????break;
????????????????????????????}
????????????????????????}
????????????????????}
????????????????????if?(!exists)
????????????????????????return?false;
????????????????}
????????????????//?set?it?as?absolute?positioned
????????????????$(this).css("position",?"absolute");

????????????????//?set?z-index
????????????????$(this).css("z-index",?"10000");

????????????????//?update?track?variables
????????????????isMouseDown????=?true;
????????????????currentElement?=?this;

????????????????//?retrieve?positioning?properties
????????????????var?pos????=?$.getMousePosition(e);
????????????????lastMouseX?=?pos.x;
????????????????lastMouseY?=?pos.y;

????????????????lastElemTop??=?this.offsetTop;
????????????????lastElemLeft?=?this.offsetLeft;

????????????????$.updatePosition(e);

????????????????return?allowBubbling???true?:?false;
????????????});
????????});
????}

})(jQuery);
调用代码：
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>-->????win.easydrag(false,?['oDragHandle_'?+?id]);
?
????//?自定义的拖放后处理，记录目标移动到的新位置
????win.ondrop(function(){
????????//?save?position?info
????????notesData[id].x?=?parseInt(win.css("left"));
????????notesData[id].y?=?parseInt(win.css("top"));
????});

转载地址：http://www.cnblogs.com/RChen/archive/2007/09/20/easydrag.html