add originalEvent on user-initiated scroll zoomend and moveend #1975

[stepankuzmin]

originalEvent is missing on zoomend and moveend user-initiated scroll events. This PR adds _lastWheelEvent as originalEvent to zoomend and moveend events.

See #1975 for more info.

Launch Checklist

• write tests for all new functionality
• manually test the debug page

[jfirebaugh]

Can you say more about why you need this? I'm thinking that (in conjunction with supporting changes, see #3290 (comment) and #6047 (comment)) we should remove originalEvent from secondary events like zoomend and moveend, reserving it for events like mousedown and mouseup that correspond 1-to-1 with a DOM event.

Hearing more about what people are using originalEvent for will help me evaluate whether I'm on track with these plans.

[stepankuzmin]

Thanks for the reply! The main point is to detect if an *end event was initiated by a user. Consider using Mapbox GL JS in a Reactive application as an example. Using the set of *end event handlers, in that case, seems more logical than using single move event handler with debouncing.

[jfirebaugh]

Thanks! Will merge for now and consider future approach in #6047.