block by mbostock 35964711079355050ff1

Zoom vs. Click

Full Screen

This example demonstrates how to disambiguate a click from a zoom gesture using d3.event.defaultPrevented. Click and drag to pan, mousewheel to zoom, or click the background to briefly highlight it.

index.html

<!DOCTYPE html>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<style>

html,
body {
  height: 100%;
  margin: 0;
  overflow: hidden;
}

svg {
  position: absolute;
}

rect {
  fill: white;
}

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

var width = self.frameElement ? 960 : innerWidth,
    height = self.frameElement ? 500 : innerHeight;

var data = d3.range(20).map(function() { return [Math.random() * width, Math.random() * height]; });

var color = d3.scale.category10();

var zoom = d3.behavior.zoom()
    .on("zoom", zoomed);

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

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

g.append("rect")
    .attr("width", width)
    .attr("height", height)
    .on("click", clicked);

var view = g.append("g")
    .attr("class", "view");

view.selectAll("circle")
    .data(data)
  .enter().append("circle")
    .attr("transform", function(d) { return "translate(" + d + ")"; })
    .attr("r", 32)
    .style("fill", function(d, i) { return color(i); });

function zoomed() {
  view.attr("transform", "translate(" + d3.event.translate + ") scale(" + d3.event.scale + ")");
}

function clicked(d, i) {
  if (d3.event.defaultPrevented) return; // zoomed

  d3.select(this).transition()
      .style("fill", "black")
    .transition()
      .style("fill", "white");
}

function nozoom() {
  d3.event.preventDefault();
}

</script>