Reputation: 957
I am using the d3.behavior.zoom to implement panning and zooming on a tree layout, but it is exhibiting a behavior I would describe as bouncing or numeric instability. When you start to drag, the display will inexplicably jump around until it just disappears. The code looks like this:
var svg = target.append ("g");
...
svg.call (d3.behavior.zoom()
.translate ([0, 0])
.scale (1.0)
.scaleExtent([0.5, 2.0])
.on("zoom", function() {
svg.attr("transform","translate(" + d3.event.translate[0] + "," + d3.event.translate[1] + ") scale(" + d3.event.scale + ")");
})
);
Is there a better way to set the transformation that doesn't cause this type of interference?
Upvotes: 27
Views: 7520
Reputation: 1334
This answer is a tweaked version of @Bretton Wade's answer using D3.js
v4.
var svg = target.append ("g");
var child = svg.append ("g");
...
svg.call (d3.zoom()
.on("zoom", function() {
child.attr("transform", d3.event.transform);
})
);
...
child.append("line")...
Upvotes: 1
Reputation: 957
After looking a bit more closely, the instability is coming from the svg element's transformation being applied to the mouse location during movement. The solution I ended up with is to insert another "g" element between the one with the zoom behavior and the element content specifically to receive the zoom/pan transformation:
var svg = target.append ("g");
var child = svg.append ("g");
...
svg.call (d3.behavior.zoom()
.translate ([0, 0])
.scale (1.0)
.scaleExtent([0.5, 2.0])
.on("zoom", function() {
child.attr("transform","translate(" + d3.event.translate[0] + "," + d3.event.translate[1] + ") scale(" + d3.event.scale + ")");
})
);
...
child.append("line")...
Upvotes: 55