Network Annotation with Collision Detection

Using collision detection with network visualization labels

This demonstrates how to use d3-annotation() with bboxCollide to procedurally place node labels. After using the nodes data to create a network visualization of the Les Miserables play, we filter the nodes to leave out the side characters and pass that array to d3-annotation. We then create a second forceSimulation, this time using the size of the notes as the property in our bounding box collision detection, to move the labels out of each others' way.

d3-annotation by Susie Lu.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <link href='https://fonts.googleapis.com/css?family=Lato:300,900' rel='stylesheet' type='text/css'>

<style>

:root {
      --annotation-color: #e91e56;
    }
     body{
        background-color: whitesmoke;
     }

svg {
        background-color: white;
        font-family: 'Lato';
        overflow: visible;
     }

line {
       stroke:#e3e3e3;
     }

.editable .annotation-subject, .editable .annotation-textbox {
       cursor: move;
     }

.line {
        fill: none;
        stroke: black;
        stroke-width: 1px;
      }

.annotation path {
        stroke: var(--annotation-color);
        fill: rgba(0,0,0,0);
      }

.annotation path.connector-arrow{
        fill: var(--annotation-color);
      }

.annotation text {
        fill: var(--annotation-color);
      }

.annotation-title {
        font-weight: bold;
      }

.annotation .annotation-subject circle.handle {
        display: none;
      }

.annotation-note-bg {
        fill: rgba(255, 255, 255, 0);
      }

circle.handle {
        stroke-dasharray: 5;
        stroke: grey;
        fill: rgba(255, 255, 255, 0);
        cursor: move;

stroke-opacity: .4;
      }

circle.handle.highlight {
        stroke-opacity: 1;
      }

.annotation.major {
        font-weight: 900;
        font-size: 1em;
      }

.annotation-note-label tspan {
        text-anchor: middle;
      }

</style>
</head>
<body>
    <svg width=1000 height=650></svg>
    <script src="https://d3js.org/d3.v4.js"></script>
    <script src="bboxCollide.js"></script>
    <script src="https://cdn.jsdelivr.net/gh/susielu/d3-annotation/d3-annotation.js"></script>

var svg = d3.select("svg"),
        width = +svg.attr("width"),
        height = +svg.attr("height");
        
    var color = d3.scaleOrdinal(d3.schemeCategory20)
      .range(["#e91e56", "#00965f", "#00bcd4", "#3f51b5", "#9c27b0", "#ff5722", "#cddc39", "#607d8b", "#8bc34a"]);
    var simulation = d3.forceSimulation()
        .force("link", d3.forceLink().id( d => d.id ))
        .force("charge", d3.forceManyBody().strength(-80))
        .force("center", d3.forceCenter(width / 2, height / 2));
    d3.json("miserables.json", function(error, graph) {

if (error) throw error;
      var link = svg.append("g")
          .attr("class", "links")
        .selectAll("line")
        .data(graph.links)
        .enter().append("line")
          .attr("stroke-width", d => Math.sqrt(d.value));

var node = svg.append("g")
          .attr("class", "nodes")
        .selectAll("circle")
        .data(graph.nodes)
        .enter().append("circle")
          .attr("r", d => d.type === "major" ? 9 : 3)
          .style("fill", d => d3.hsl(color(d.group)).darker())
          .style("fill-opacity", d => d.type === "other" ? 0.5 : 1)

node.append("title")
          .text(d => d.id);

window.collide = d3.bboxCollide((a) => {
        return [[a.offsetCornerX - 5, a.offsetCornerY - 10],[a.offsetCornerX + a.width + 5, a.offsetCornerY + a.height+ 5]]
      })
     .strength(0.5)
     .iterations(1)

window.yScale = d3.scaleLinear()

simulation
          .nodes(graph.nodes)
          .on("tick", ticked)
          .on("end", function() {

const noteBoxes = makeAnnotations.collection().noteNodes

window.labelForce = d3.forceSimulation(noteBoxes)
              .force("x", d3.forceX(a => a.positionX).strength(a => Math.max(0.25, Math.min(3, Math.abs(a.x - a.positionX) / 20))))
              .force("y", d3.forceY(a => a.positionY).strength(a => Math.max(0.25, Math.min(3, Math.abs(a.x - a.positionX) / 20))))
             .force("collision", window.collide)
              .alpha(0.5)
              .on('tick', d => {
                  makeAnnotations.annotations()
                  .forEach((d, i) => {
                    const match = noteBoxes[i]	
                          d.dx = match.x - match.positionX
                          d.dy = match.y - match.positionY
                  })
                
                  makeAnnotations.update()
              })
            
          })
      const nonOtherNodes = graph.nodes
        .filter(d => d.type !== "other")

simulation.force("link")
          .links(graph.links);
      function ticked() {
        link
            .attr("x1", d => d.source.x)
            .attr("y1", d => d.source.y)
            .attr("x2", d => d.target.x)
            .attr("y2", d => d.target.y);
        node
            .attr("cx", d => d.x)
            .attr("cy", d => d.y);

makeAnnotations.annotations()
          .forEach((d, i) => {
            d.position = nonOtherNodes[i]
          })
      }

window.makeAnnotations = d3.annotation()
        .type(d3.annotationLabel)
        .annotations(nonOtherNodes
        .map((d,i) => {
          return {
            data: {x: d.x, y: d.y, group: d.group},
            note: { label: d.id,
              align: "middle",
              orientation: "fixed" },
            connector: { type: "elbow"},
            className: d.type
          }
        }))
        .accessors({ x: d => d.x , y: d => d.y})

svg.append("g")
        .attr("class", "annotation-test")
        .call(makeAnnotations)

svg.selectAll(".annotation-note text")
        .style("fill", d => color(d.data.group))

svg.selectAll(".annotation-connector > path")
        .style("stroke", (d,i) => color(d.data.group))
      
    });
    </script>
</body>
</html>

Updated missing url https://cdn.rawgit.com/susielu/d3-annotation/master/d3-annotation.js to https://cdn.jsdelivr.net/gh/susielu/d3-annotation/d3-annotation.js

https://d3js.org/d3.v4.js

https://cdn.rawgit.com/susielu/d3-annotation/master/d3-annotation.js