JSFiddle - React, Tailwind, and code Playground

by Anand Rathod

HTML

<p>Drag shapes around.</p> 
        <div id="holder"></div> 
        <p id="copy">Demo of <a href="http://raphaeljs.com/">Raphaël</a>—JavaScript Vector Library</p>

CSS

body {
    background: #333;
    color: #fff;
    font: 300 100.1% "Helvetica Neue", Helvetica, "Arial Unicode MS", Arial, sans-serif;
}
#holder {
    height: 480px;
    left: 50%;
    margin: -240px 0 0 -320px;
    position: absolute;
    top: 50%;
    width: 640px;
}
#copy {
    bottom: 0;
    font: 300 .7em "Helvetica Neue", Helvetica, "Arial Unicode MS", Arial, sans-serif;
    position: absolute;
    right: 1em;
    text-align: right;
}
#copy a {
    color: #fff;
}
            #holder {
                -moz-border-radius: 10px;
                -webkit-border-radius: 10px;
                border: solid 1px #333;
            }
            p {
                text-align: center;
            }

JavaScript

Raphael.fn.connection = function (obj1, obj2, line, bg) {
    if (obj1.line && obj1.from && obj1.to) {
        line = obj1;
        obj1 = line.from;
        obj2 = line.to;
    }
    var bb1 = obj1.getBBox(),
        bb2 = obj2.getBBox(),
        p = [{x: bb1.x + bb1.width / 2, y: bb1.y - 1},
        {x: bb1.x + bb1.width / 2, y: bb1.y + bb1.height + 1},
        {x: bb1.x - 1, y: bb1.y + bb1.height / 2},
        {x: bb1.x + bb1.width + 1, y: bb1.y + bb1.height / 2},
        {x: bb2.x + bb2.width / 2, y: bb2.y - 1},
        {x: bb2.x + bb2.width / 2, y: bb2.y + bb2.height + 1},
        {x: bb2.x - 1, y: bb2.y + bb2.height / 2},
        {x: bb2.x + bb2.width + 1, y: bb2.y + bb2.height / 2}],
        d = {}, dis = [];
    for (var i = 0; i < 4; i++) {
        for (var j = 4; j < 8; j++) {
            var dx = Math.abs(p[i].x - p[j].x),
                dy = Math.abs(p[i].y - p[j].y);
            if ((i == j - 4) || (((i != 3 && j != 6) || p[i].x < p[j].x) && ((i != 2 && j != 7) || p[i].x > p[j].x) && ((i != 0 && j != 5) || p[i].y > p[j].y) && ((i != 1 && j != 4) || p[i].y < p[j].y))) {
                dis.push(dx + dy);
                d[dis[dis.length - 1]] = [i, j];
            }
        }
    }
    if (dis.length == 0) {
        var res = [0, 4];
    } else {
        res = d[Math.min.apply(Math, dis)];
    }
    var x1 = p[res[0]].x,
        y1 = p[res[0]].y,
        x4 = p[res[1]].x,
        y4 = p[res[1]].y;
    dx = Math.max(Math.abs(x1 - x4) / 2, 10);
    dy = Math.max(Math.abs(y1 - y4) / 2, 10);
    var x2 = [x1, x1, x1 - dx, x1 + dx][res[0]].toFixed(3),
        y2 = [y1 - dy, y1 + dy, y1, y1][res[0]].toFixed(3),
        x3 = [0, 0, 0, 0, x4, x4, x4 - dx, x4 + dx][res[1]].toFixed(3),
        y3 = [0, 0, 0, 0, y1 + dy, y1 - dy, y4, y4][res[1]].toFixed(3);
    var path = ["M", x1.toFixed(3), y1.toFixed(3), "C", x2, y2, x3, y3, x4.toFixed(3), y4.toFixed(3)].join(",");
    if (line && line.line) {
        line.bg && line.bg.attr({path: path});
       ...