Programmatic zoom intiated while the user is making a gesture causes the zoom callback to be invoked with the sourceEvent from the preceding user action, rather than an undefined sourceEvent.
I think this is because there is an active Gesture on the element and the following line does not update the event to null or undefined:
The example notebook tries to perform a programmatic zoom once for every user-initiated zoom, but because the programmatic zoomed callback is invoked with a trusted sourceEvent, this results in infinite recursion.
First noticed here (which now implements a workaround)
Programmatic zoom intiated while the user is making a gesture causes the
zoomcallback to be invoked with the sourceEvent from the preceding user action, rather than an undefined sourceEvent.I think this is because there is an active Gesture on the element and the following line does not update the event to null or undefined:
https://github.com/d3/d3-zoom/blob/23016d4ac35dd3f85d7696afbc77eb05036faa57/src/zoom.js#L192
which is called indirectly from
https://github.com/d3/d3-zoom/blob/main/src/zoom.js#L85
with an
undefinedevent.Example: https://observablehq.com/d/11402b3301150892 (see console for stack overflow)
The example notebook tries to perform a programmatic zoom once for every user-initiated zoom, but because the programmatic
zoomedcallback is invoked with a trusted sourceEvent, this results in infinite recursion.First noticed here (which now implements a workaround)