Skip to content

Instantly share code, notes, and snippets.

@Fil
Last active May 10, 2017 09:44
Show Gist options
  • Save Fil/652458d1831e41de6efe1d453152131b to your computer and use it in GitHub Desktop.
Save Fil/652458d1831e41de6efe1d453152131b to your computer and use it in GitHub Desktop.
Zoom to Bounding Box II d3v4
license: gpl-3.0
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.background {
fill: none;
pointer-events: all;
}
.feature {
fill: #ccc;
cursor: pointer;
}
.feature.active {
fill: red;
}
.mesh {
fill: none;
stroke: #fff;
stroke-linecap: round;
stroke-linejoin: round;
}
</style>
<body>
<script src="//d3js.org/d3.v4.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>
var width = 960,
height = 500,
active = d3.select(null);
var projection = d3.geoAlbersUsa()
.scale(1000)
.translate([width / 2, height / 2]);
var zoom = d3.zoom()
.on("zoom", zoomed);
var initialTransform = d3.zoomIdentity
.translate(0,0)
.scale(1);
var path = d3.geoPath()
.projection(projection);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.on("click", stopped, true);
svg.append("rect")
.attr("class", "background")
.attr("width", width)
.attr("height", height)
.on("click", reset);
var g = svg.append("g");
svg
.call(zoom) // delete this line to disable free zooming
.call(zoom.transform, initialTransform);
d3.json("https://gist.githubusercontent.com/mbostock/4090846/raw/d534aba169207548a8a3d670c9c2cc719ff05c47/us.json", function(error, us) {
if (error) throw error;
g.selectAll("path")
.data(topojson.feature(us, us.objects.states).features)
.enter().append("path")
.attr("d", path)
.attr("class", "feature")
.on("click", clicked);
g.append("path")
.datum(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; }))
.attr("class", "mesh")
.attr("d", path);
});
function clicked(d) {
if (active.node() === this) return reset();
active.classed("active", false);
active = d3.select(this).classed("active", true);
var bounds = path.bounds(d),
dx = bounds[1][0] - bounds[0][0],
dy = bounds[1][1] - bounds[0][1],
x = (bounds[0][0] + bounds[1][0]) / 2,
y = (bounds[0][1] + bounds[1][1]) / 2,
scale = Math.max(1, Math.min(8, 0.9 / Math.max(dx / width, dy / height))),
translate = [width / 2 - scale * x, height / 2 - scale * y];
var transform = d3.zoomIdentity
.translate(translate[0], translate[1])
.scale(scale);
svg.transition()
.duration(750)
.call(zoom.transform, transform);
}
function reset() {
active.classed("active", false);
active = d3.select(null);
svg.transition()
.duration(750)
.call(zoom.transform, initialTransform);
}
function zoomed() {
var transform = d3.event.transform;
g.style("stroke-width", 1.5 / transform.k + "px");
g.attr("transform", transform);
}
// If the drag behavior prevents the default click,
// also stop propagation so we don’t click-to-zoom.
function stopped() {
if (d3.event.defaultPrevented) d3.event.stopPropagation();
}
</script>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment