基于jQuery与Bootstrap实现DOM面板拖拽交换位置

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<html>
<head>
	<meta charset="utf-8">
	<title>jQuery 拖拽交换元素的位置</title>
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<!-- 引入 Bootstrap -->
	<!-- 新 Bootstrap 核心 CSS 文件 -->
	<link href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="external nofollow" rel="stylesheet">
	<link rel="stylesheet" type="text/css" href="../css/exchange-position.css" rel="external nofollow" />
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</head>
<body>
	<div class="container" style="padding-top: 20px;">
		<div class="row" id="panelsBox">
			<div class="col-md-4 column" data-index="1">
				<div class="panel panel-success">
					<div class="panel-heading">
						<h3 class="panel-title">
							Panel title
						</h3>
					</div>
					<div class="panel-body">
						Panel content
					</div>
					<div class="panel-footer">
						Panel footer
					</div>
				</div>
			</div>
			<div class="col-md-4 column" data-index="2">
				<div class="panel panel-info">
					<div class="panel-heading">
						<h3 class="panel-title">
							Panel title
						</h3>
					</div>
					<div class="panel-body">
						Panel content
					</div>
					<div class="panel-footer">
						Panel footer
					</div>
				</div>
			</div>
			<div class="col-md-4 column" data-index="3">
				<div class="panel panel-danger">
					<div class="panel-heading">
						<h3 class="panel-title">
							Panel title
						</h3>
					</div>
					<div class="panel-body">
						Panel content
					</div>
					<div class="panel-footer">
						Panel footer
					</div>
				</div>
			</div>
		</div>
		
	</div>
</body>
</html>

#panelsBox>div>.panel{
	position: relative;
}

/**
 * 拖拽面板 到某个面板的位置，交换两个面板位置
 * 若没有到任意一个面板位置，则被拖拽面板回原位置
 */
$(function(){
	//1.监听 mousedown 事件
	$("#panelsBox").on('mousedown','.panel',function(e){
		var target_index = $(this).parent().attr("data-index");		//被拖动面板元素位置
		var targetX = e.pageX - parseInt($(this).css("left"));
		var targetY = e.pageY - parseInt($(this).css("top"));
		$(this).fadeTo(20, 0.5);				//点击后开始拖动并透明
		$(this).css("z-index",100);				//设置优先展示
		
		//2.监听当前被拖拽的面板的移动事件：鼠标移动到何处，相应面板的css控制显示到何处
		$(this).mousemove(function(e){
			var x = e.pageX - targetX;				//移动时根据鼠标位置计算面板元素左上角的相对位置
			var y = e.pageY - targetY;
			$(this).css({top:y,left:x});			//设置面板元素新位置
		}).mouseup(function(e){
			//3.监听鼠标松开事件：交换面板元素，并将父级data-index换为原来的值
			$(this).fadeTo("fast", 1);				//停止移动并恢复成不透明
			$(this).css("z-index",0);				//展示优先级降低
			//鼠标松开对应的面板元素的父div对应data-index
			var exchangeElem = $(document.elementFromPoint(e.pageX,e.pageY)).parents(".panel");
			
			if(exchangeElem.length > 0){
				var exchange_index = $(exchangeElem[0]).parent("div").attr("data-index");
				var device_id_target = $(exchangeElem[0]).parent("div").attr("data-device-id");
				device_id_target = device_id_target == undefined?"":device_id_target;
				if(target_index != exchange_index){
					//交换面板元素
					$("#panelsBox").children("div[data-index=" + target_index + "]").empty().append(exchangeElem[0]);
					$("#panelsBox").children("div[data-index=" + exchange_index + "]").empty().append(this);
					$("#panelsBox").children("div[data-index=" + exchange_index + "]").children(".panel").css({'top':"0px",'left':"0px",'z-index':0});
					//交换data-index
					$("#deviceList").children("div[data-index=" + target_index + "]")
						attr("data-index",exchange_index);
					$(document.elementFromPoint(e.pageX,e.pageY)).parents(".panel").parent()
						.attr("data-index",target_index);
				}else{
					//返回原位置
					$(this).css({'top':"0px",'left':"0px",'z-index':0});
				}
				
			}else{
				//返回原位置
				$(this).css({'top':"0px",'left':"0px",'z-index':0});
			}
		});
	});
});