force-graph
Version:
2D force-directed graph rendered on HTML5 canvas
84 lines (73 loc) • 2.4 kB
HTML
<head>
<style> body { margin: 0; } </style>
<script src="//cdn.jsdelivr.net/npm/force-graph"></script>
<!--<script src="../../dist/force-graph.js"></script>-->
</head>
<body>
<div id="graph"></div>
<script>
// Random tree
const N = 80;
const gData = {
nodes: [...Array(N).keys()].map(i => ({ id: i })),
links: [...Array(N).keys()]
.filter(id => id)
.map(id => ({
source: id,
target: Math.round(Math.random() * (id-1))
}))
};
// cross-link node objects
gData.links.forEach(link => {
const a = gData.nodes[link.source];
const b = gData.nodes[link.target];
!a.neighbors && (a.neighbors = []);
!b.neighbors && (b.neighbors = []);
a.neighbors.push(b);
b.neighbors.push(a);
!a.links && (a.links = []);
!b.links && (b.links = []);
a.links.push(link);
b.links.push(link);
});
const NODE_R = 8;
const highlightNodes = new Set();
const highlightLinks = new Set();
let hoverNode = null;
const elem = document.getElementById('graph');
new ForceGraph(elem)
.graphData(gData)
.nodeRelSize(NODE_R)
.onNodeHover(node => {
highlightNodes.clear();
highlightLinks.clear();
if (node) {
highlightNodes.add(node);
node.neighbors.forEach(neighbor => highlightNodes.add(neighbor));
node.links.forEach(link => highlightLinks.add(link));
}
hoverNode = node || null;
})
.onLinkHover(link => {
highlightNodes.clear();
highlightLinks.clear();
if (link) {
highlightLinks.add(link);
highlightNodes.add(link.source);
highlightNodes.add(link.target);
}
})
.autoPauseRedraw(false) // keep redrawing after engine has stopped
.linkWidth(link => highlightLinks.has(link) ? 5 : 1)
.linkDirectionalParticles(4)
.linkDirectionalParticleWidth(link => highlightLinks.has(link) ? 4 : 0)
.nodeCanvasObjectMode(node => highlightNodes.has(node) ? 'before' : undefined)
.nodeCanvasObject((node, ctx) => {
// add ring just for highlighted nodes
ctx.beginPath();
ctx.arc(node.x, node.y, NODE_R * 1.4, 0, 2 * Math.PI, false);
ctx.fillStyle = node === hoverNode ? 'red' : 'orange';
ctx.fill();
});
</script>
</body>