cc #2041

Is there are progress here?
Can't see a quick way to adjust the zoom speed for the mouse wheel. It is really slow.

As a quick hack one can adjust manually the hardcoded normalisation factor in
plotly.min.js:

var r=-e.deltaY;if(isFinite(r)||(r=e.wheelDelta/10),isFinite(r)){var n,i=Math.exp(-Math.min(Math.max(r,-20),20)/200),...

I replaced /200 by /10.

If using in Javascript, I solved this by overtaking the wheel event (capture phase) and emitted my own event with modified deltaY. This works on cartesian plots, I did not check others.

function handler(event)
{
      if (!event.isTrusted) return;
      event.stopPropagation();
      var newEv = new WheelEvent('wheel', {
        clientX: event.clientX,
        clientY:event.clientY, 
        deltaY:event.deltaY*2,
      });
      event.target.dispatchEvent(newEv);
}

If using in Javascript, I solved this by overtaking the wheel event (capture phase) and emitted my own event with modified deltaY. This works on cartesian plots, I did not check others.

function handler(event)
{
      if (!event.isTrusted) return;
      event.stopPropagation();
      var newEv = new WheelEvent('wheel', {
        clientX: event.clientX,
        clientY:event.clientY, 
        deltaY:event.deltaY*2,
      });
      event.target.dispatchEvent(newEv);
}

What is the element that you attached the 'handler'? I tried on 'document' and plot element and does not work....

I attached it to plot element but on wheel event in capture mode.

Thank you! I've missed the 'capture mode' from the initial post. Now it worked.

What's the 'capture mode' you guys talking about? Could you share the script of this part, please?

Use the same element, Plotly.react is called on. So if you initialize plot with Plotly.react(plotEl, data, layout, options) you should do something like this:
plotEl.addEventListener('wheel', handler, true);

The last true, means capture events. For explanation on capture events, search for "event bubbling capturing"

capture events

Thanks a lot, @mitja-p. I'm using angular-plotly.js, based on your suggestion, I did it this way, and it works now. (in case somebody using angular-plotly.js needs it in the future. )

<plotly-plot *ngIf="isPlotDataReady" [data]="graph.data" [layout]="graph.layout">
...

ngAfterViewInit() {
this.elementRef.nativeElement.addEventListener('wheel', this.handler, true);
}

public handler(event: any) {
console.log(event.deltaY);
if (!event.isTrusted) return;
event.stopPropagation();
var newEv = new WheelEvent('wheel', {
clientX: event.clientX,
clientY: event.clientY,
deltaY: event.deltaY / 20,
view: window,
bubbles: true,
cancelable: true
});

event.target.dispatchEvent(newEv);

}