Drag & Zoom (Canvas)

Community Help
1

Hi,

I was wondering if https://observablehq.com/@d3/drag-zoom would be feasible with canvas only.

See https://observablehq.com/d/5dd9d53be3c6738c. Would it be possible to add some condition to use d3.drag or d3.zoom depending on the position of the event?

Thanks for the ideas.

2

It should be. You’d need to implement drag.subject for Canvas, as shown here:

Per the d3-drag README, if the returned subject is null or undefined, no drag gesture is started. This means the d3-zoom behavior can then handle the event to initiate zooming.

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3

Thanks. I will try this.

Meanwhile I made something related (what I wanted to do in reality) -> https://observablehq.com/@severo/drag-zoom-svg-rescaled

4

OK, I’ve been able to implement it with Canvas -> https://observablehq.com/@severo/drag-zoom-canvas

Thanks @mbostock for the help, and @Fil for your explanations (d3-drag and d3-zoom - Mystery Bug)

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