7372754 by wboykinm

index.html

<!DOCTYPE html>
<meta charset="utf-8">
<style>

rect {
  fill: none;
  pointer-events: all;
}

.feature {
  fill: #ccc;
  cursor: pointer;
}

.feature.active {
  fill: orange;
}

.mesh {
  fill: none;
  stroke: #fff;
  stroke-width: .5px;
  stroke-linejoin: round;
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>

var width = 960,
    height = 500,
    active;

var projection = d3.geo.mercator()
    .scale(10000)
    .translate([width / 2, height / 2]);

var path = d3.geo.path()
    .projection(projection);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

svg.append("rect")
    .attr("width", width)
    .attr("height", height)
    .on("click", reset);

var g = svg.append("g");

d3.json("/d/4090846/us.json", function(error, us) {
  g.selectAll("path")
      .data(topojson.feature(us, us.objects.states).features)
    .enter().append("path")
      .attr("d", path)
      .attr("class", "feature")
      .on("click", click);

  g.append("path")
      .datum(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; }))
      .attr("class", "mesh")
      .attr("d", path);
});

function click(d) {
  if (active === d) return reset();
  g.selectAll(".active").classed("active", false);
  d3.select(this).classed("active", active = d);

  var b = path.bounds(d);
  g.transition().duration(750).attr("transform",
      "translate(" + projection.translate() + ")"
      + "scale(" + .95 / Math.max((b[1][0] - b[0][0]) / width, (b[1][1] - b[0][1]) / height) + ")"
      + "translate(" + -(b[1][0] + b[0][0]) / 2 + "," + -(b[1][1] + b[0][1]) / 2 + ")");
}

function reset() {
  g.selectAll(".active").classed("active", active = false);
  g.transition().duration(750).attr("transform", "");
}

</script>