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Last active February 9, 2016 01:16
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click-to-center via transform
license: gpl-3.0
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.background {
fill: none;
pointer-events: all;
}
#states {
fill: #aaa;
}
#states .active {
fill: orange;
}
#state-borders {
fill: none;
stroke: #fff;
stroke-width: 1.5px;
stroke-linejoin: round;
stroke-linecap: round;
pointer-events: none;
}
</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,
centered;
var projection = d3.geo.albersUsa()
.scale(1070)
.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("class", "background")
.attr("width", width)
.attr("height", height)
.on("click", clicked);
var g = svg.append("g");
d3.json("/mbostock/raw/4090846/us.json", function(error, us) {
if (error) throw error;
g.append("g")
.attr("id", "states")
.selectAll("path")
.data(topojson.feature(us, us.objects.states).features)
.enter().append("path")
.attr("d", path)
.on("click", clicked);
g.append("path")
.datum(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; }))
.attr("id", "state-borders")
.attr("d", path);
});
function clicked(d) {
var x = 0,
y = 0;
// If the click was on the centered state or the background, re-center.
// Otherwise, center the clicked-on state.
if (!d || centered === d) {
centered = null;
} else {
var centroid = path.centroid(d);
x = width / 2 - centroid[0];
y = height / 2 - centroid[1];
centered = d;
}
// Transition to the new transform.
g.transition()
.duration(750)
.attr("transform", "translate(" + x + "," + y + ")");
}
</script>
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