<!DOCTYPE html>
<html>
<head>
<title>Force-Directed Layout (Dynamic)</title>
<script type="text/javascript" src="../../d3.js"></script>
<script type="text/javascript" src="../../d3.geom.js"></script>
<script type="text/javascript" src="../../d3.layout.js"></script>
<style type="text/css">
rect {
fill: #fff;
}
.node {
fill: #000;
}
.cursor {
fill: none;
stroke: brown;
pointer-events: none;
}
.link {
stroke: #999;
}
</style>
</head>
<body>
<div id="chart"></div>
<script type="text/javascript">
var w = 960,
h = 500,
fill = d3.scale.category20(),
nodes = [],
links = [];
var vis = d3.select("#chart").append("svg:svg")
.attr("width", w)
.attr("height", h);
vis.append("svg:rect")
.attr("width", w)
.attr("height", h);
var force = d3.layout.force()
.distance(30)
.nodes(nodes)
.links(links)
.size([w, h]);
var cursor = vis.append("svg:circle")
.attr("r", 30)
.attr("transform", "translate(-100,-100)")
.attr("class", "cursor");
force.on("tick", function() {
vis.selectAll("line.link")
.attr("x1", function(d) { return d.source.x; })
.attr("y1", function(d) { return d.source.y; })
.attr("x2", function(d) { return d.target.x; })
.attr("y2", function(d) { return d.target.y; });
vis.selectAll("circle.node")
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
});
vis.on("mousemove", function() {
cursor.attr("transform", "translate(" + d3.svg.mouse(this) + ")");
});
vis.on("mousedown", function() {
var point = d3.svg.mouse(this),
node = {x: point[0], y: point[1]},
n = nodes.push(node);
// add links to any nearby nodes
nodes.forEach(function(target) {
var x = target.x - node.x,
y = target.y - node.y;
if (Math.sqrt(x * x + y * y) < 30) {
links.push({source: node, target: target});
}
});
restart();
});
restart();
function restart() {
force.start();
vis.selectAll("line.link")
.data(links)
.enter().insert("svg:line", "circle.node")
.attr("class", "link")
.attr("x1", function(d) { return d.source.x; })
.attr("y1", function(d) { return d.source.y; })
.attr("x2", function(d) { return d.target.x; })
.attr("y2", function(d) { return d.target.y; });
vis.selectAll("circle.node")
.data(nodes)
.enter().insert("svg:circle", "circle.cursor")
.attr("class", "node")
.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; })
.attr("r", 4.5)
.call(force.drag);
}
</script>
</body>
</html>