Customize inertia values from drag pan

[jinkwon]

mapbox-gl-js version:
Latest version

Steps to Trigger Behavior

No steps. :)

Expected Behavior

There is no way to customize velocity value.
https://github.com/mapbox/mapbox-gl-js/blob/master/src/ui/handler/drag_pan.js#L153

Actual Behavior

I need options to configure velocity value.

[peterqliu]

drag pan is set at a velocity such that the map position under the mouse stays constant throughout the panning motion. How would you propose a configurable velocity would work? Or do you mean the velocity after mouseup/touchend?

[mourner]

I guess we want these const values exposed as options. E.g. Leaflet allows their customization.

[jinkwon]

@mourner That's what I wanted. 👍

[1ec5]

Relatedly, on iOS, we abandoned these options in favor of a default inertial pan that lasts about one second regardless of the strength of the gesture (mapbox/mapbox-gl-native#1266), plus a decelerationRate option (mapbox/mapbox-gl-native#5504). The default was chosen for consistency with scroll views on that platform. It would be nice to be able to tailor the internal panning for touch devices (#949) differently than when using a mouse on a desktop platform.

[jinkwon]

Is there any working progress?

[mourner]

@jinkwon not at this moment, but we'd of course welcome a pull request.

[jinkwon]

@mourner OK. ;)

[ansis]

This was implemented a while back in #8887

[dimaShin]

Hi guys.
Thanks for this feature.
Unfortunately, it seems broken now.
The original implementation of the DragPan enable method had a check to ignore calls when already enabled. However, later this check was removed. This means that any call will rewrite the inertia options. I'm facing this behaviour with the draw library.

@ansis , Github blames you :)