jsPlumb连线库入门

官网演示：https://jsplumbtoolkit.com/demo/flowchart/dom.html
例子：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style type="text/css">
.item {
    width: 100px;
    height: 100px;
    border: 1px solid purple;
    position: absolute;
}
#div1 {
    left: 100px;
    top: 100px;
}
#div2 {
    left: 200px;
    top: 500px;
}
#div3 {
    left: 500px;
    top: 100px;
}
#div4 {
    left: 400px;
    top: 400px;
}
</style>
<script src="dom.jsPlumb-1.7.2-min.js"></script>
</head>
<body>
<div class="item" id="div1"></div>
<div class="item" id="div2"></div>
<div class="item" id="div3"></div>
<div class="item" id="div4"></div>
</body>
<script type="text/javascript">
jsPlumb.ready(function() {
    //jsPlumb.connect({source: "div1", target: "div2", detachable: false});
    //jsPlumb.draggable($(".item"));
    //jsPlumb.draggable(jsPlumb.getSelector(".item"));
    //$(".item").draggable();
    //var greyEndpointOptions = {
    //    endpoint: "Rectangle",
    //    paintStyle: { 25, height: 21, fillStyle: "#666"},
    //    isSource: true,
    //    connectorStyle: {strokeStyle: "#666"},
    //    isTarget: true
    //};
    //jsPlumb.addEndpoint("div1", {anchor: "Bottom"}, greyEndpointOptions);
    //jsPlumb.addEndpoint("div2", {anchor: "Top"}, greyEndpointOptions);
    
    var endpointOptions = {
        isSource: true,
        isTarget: true,
        //endpoint: ["Dot", {radius: 30}],
        endpoint: ["Rectangle", { 20, height: 10}],
        style: {fillStyle: "blue"},
        //connector: ["Bezier", {curviness: 175}],
        //connector: "Straight",
        connector: "Flowchart",
        connectorStyle: {lineWidth: 20, strokeStyle: "blue"},
        scope: "blueline",
        dragAllowedWhenFull: false,
        paintStyle: {lineWidth: 25, strokeStyle: "cyan"}
    };
    var div1Endpoint = jsPlumb.addEndpoint("div1", {anchor: "TopCenter"}, endpointOptions);
    var div2Endpoint = jsPlumb.addEndpoint("div2", {anchor: "BottomCenter"}, endpointOptions);

    var sourceEndpoint = {isSource: true, endpoint: ["Dot", {radius: 50}]};
    var targetEndpoint = {endpoint: ["Rectangle", { 10, height: 10}]};
    jsPlumb.addEndpoint("div3", sourceEndpoint);
    jsPlumb.makeTarget("div4", targetEndpoint);
});
</script>
</html>