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mbostock/.block

Last active February 9, 2016 01:58
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Multitouch
Raw
.block
license: gpl-3.0
Raw
README.md

A demonstration of handling multitouch events using D3. Requires a touch-supporting browser, such as iOS Safari.

Raw
index.html
<!DOCTYPE html>
<meta charset="utf-8">
<meta name="viewport" content="initial-scale=1,maximum-scale=1">
<style>
html,
body {
height: 100%;
}
body {
margin: 0;
}
svg {
display: block;
overflow: hidden;
width: 100%;
height: 100%;
}
</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>
var color = d3.scale.category10();
var svg = d3.select("body").append("svg")
.attr("width", innerWidth)
.attr("height", innerHeight);
var circle = svg.selectAll("circle.touch");
d3.select("body")
.on("touchstart", touch)
.on("touchmove", touch)
.on("touchend", touch);
function touch() {
d3.event.preventDefault();
circle = circle
.data(d3.touches(svg.node()), function(d) { return d.identifier; });
circle.exit()
.attr("class", null)
.transition()
.attr("r", 1e-6)
.remove();
circle.enter().append("circle")
.attr("class", "touch")
.attr("r", 1e-6)
.style("fill", function(d) { return color(d.identifier); })
.transition()
.duration(500)
.ease("elastic")
.attr("r", 48);
circle
.attr("cx", function(d) { return d[0]; })
.attr("cy", function(d) { return d[1]; });
}
</script>
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