| license: mit |
Click to add nodes! Nodes near the cursor will be linked to the new node. Clicking an existing node will remove it.
This is an extension of this example, adding the capability of removing nodes by clicking them. This means that dragging is no longer supported.
forked from tgk's block: Add and remove nodes
forked from juzkev's block: Add and remove nodes
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <style> | |
| rect { | |
| fill: none; | |
| pointer-events: all; | |
| } | |
| .node { | |
| fill: #000; | |
| } | |
| .cursor { | |
| fill: none; | |
| stroke: brown; | |
| pointer-events: none; | |
| } | |
| .link { | |
| stroke: #999; | |
| } | |
| </style> | |
| <body> | |
| <script src="http://d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| var width = 960, | |
| height = 500; | |
| var fill = d3.schemeCategory20; | |
| var links = []; | |
| var nodes = [{}] | |
| var force = d3.forceSimulation() | |
| .nodes(nodes) // initialize with a single node | |
| .force("link", d3.forceLink(links).distance(200)) | |
| .force("charge", d3.forceManyBody().strength(-1000)) | |
| .force("x", d3.forceX()) | |
| .force("y", d3.forceY()) | |
| .alphaTarget(1) | |
| .on("tick", tick); | |
| var svg = d3.select("body").append("svg") | |
| .attr("width", width) | |
| .attr("height", height) | |
| .on("mousemove", mousemove) | |
| .on("mousedown", mousedownCanvas); | |
| svg.append("rect") | |
| .attr("width", width) | |
| .attr("height", height); | |
| var node = svg.selectAll(".node"), | |
| link = svg.selectAll(".link"); | |
| var cursor = svg.append("circle") | |
| .attr("r", 30) | |
| .attr("transform", "translate(-100,-100)") | |
| .attr("class", "cursor"); | |
| restart(); | |
| function mousemove() { | |
| cursor.attr("transform", "translate(" + d3.mouse(this) + ")"); | |
| } | |
| function mousedownCanvas() { | |
| console.log("mouseDownCanvas", this) | |
| var point = d3.mouse(this), | |
| node = {x: point[0], y: point[1]}; | |
| console.log("mouseDownCanvas", node) | |
| // add links to any nearby nodes | |
| nodes.forEach(function(target) { | |
| console.log("target", target) | |
| var x = target.x - node.x, | |
| y = target.y - node.y; | |
| if (Math.sqrt(x * x + y * y) < 30) { | |
| console.log("adding link", node, target) | |
| links.push({source: node, target: target}); | |
| } | |
| }); | |
| nodes.push(node); | |
| restart(); | |
| } | |
| function mousedownNode(d, i) { | |
| nodes.splice(i, 1); | |
| links = links.filter(function(l) { | |
| return l.source !== d && l.target !== d; | |
| }); | |
| d3.event.stopPropagation(); | |
| restart(); | |
| } | |
| function tick() { | |
| 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; }); | |
| node.attr("cx", function(d) { return d.x; }) | |
| .attr("cy", function(d) { return d.y; }); | |
| } | |
| function restart() { | |
| node = node.data(nodes, function(d) { return d.id}); | |
| node.exit() | |
| .remove(); | |
| node.enter().append("circle", ".cursor") | |
| .attr("class", "node") | |
| .attr("r", 5) | |
| .on("mousedown", mousedownNode) | |
| .merge(node); | |
| link = link.data(links, function(d) { return d.source.id + "-" + d.target.id; }); | |
| link.exit() | |
| .remove(); | |
| link.enter().append("line", ".node") | |
| .attr("class", "link") | |
| .merge(link); | |
| // Update and restart the simulation. | |
| force.nodes(nodes); | |
| force.force("link").links(links); | |
| force.alpha(1).restart(); | |
| } | |
| </script> |