Return Last SnapTo Feature

[fmg-lydonchandra]

Is your feature request related to a problem? Please describe.
ol.interaction.Snap to return last snapTo feature.
see https://stackoverflow.com/questions/32194030/how-to-get-feature-which-is-snaped-by-ol-interaction-snap

Describe the solution you'd like
ol.interaction.Snap to return last snapTo feature alongside existing result object

return {
            vertex: closestVertex,
            vertexPixel: [
              Math.round(vertexPixel[0]),
              Math.round(vertexPixel[1]),
            ],
            feature: closestFeature,
          };

[mike-000]

As you suggested in Stack Overflow you can use forEachFeatureAtPixel. That could be done in a condition function for any interaction, as well as drawstart and drawend, and done using only documented API methods as in https://codesandbox.io/s/draw-and-modify-features-forked-enrgqv?file=/main.js If the Snap interaction was constructed with features: snapFeatures instead of source: snapSource just replace snapSource.getFeatures().includes with snapFeatures.getArray().includes.

[ahocevar]

I think the best way to add an API for getting information about what was snapped would be a new Snap event, dispatched by the Snap interaction, in its handleEvent function when there is a result. The event could have the desired vertex, vertexPixel and feature properties.

[fmg-lydonchandra]

hi @ahocevar & @mike-000 feedback / review please, #14676

[fmg-lydonchandra]

hi @ahocevar , PR re-review please #14676

[fmg-lydonchandra]

hi @ahocevar , PR re-review please #14676