location.flyTo extents, tests, and documentation

[cityremade]

Spotted behaviour:

Onload: selected location has a geojson catchment which is turned off

zoom to feature bounds flies to the point - location extent is a point at this time - as expected

Catchment is displayed from checkbox

zoom to feature bounds flies to the extent of the catchment - as expected

Catchment is hidden from checkbox

zoom to feature bounds still flies to the extent of the catchment - surprising

This means that once a geojson catchment is displayed it alters location extent and its visibility doesn't update location extent anymore.

When catchment is an mvt_clone it doesn't change location extent - zoom to feature bounds flies to the point at all times, regardless of initial value for display flag - again surprising. Should fly to mvt clone extent.

Is this the desired behaviour?

[dbauszus-glx]

MVT_clones are about to be retired due to a multitude of issues.

Can I get a JSON location to replicate the issue with the location.flyTo() method?

[dbauszus-glx]

The get extents part should be split from the flyTo method so that this can be tested and documented.

At the core of this method is the ability to get features and calculate their total extent. You can not get features from an MVT source. The features are tiles which doesn't give you the total extent of tiles not loaded.

It is theoretically possible to calculate the extent from a query but this would require an array of mapp-layer objects and not just ol-layer objects.

[dbauszus-glx]

The issue to resolve the layer extent must be completed first. #1473