Key of the vector basemap whose style last LANDED on the map — the style the map holds —, or
null when it holds none (no basemap yet, or a raster one, applied over an empty style).
_activeKey cannot answer that: it is set as soon as a switch is requested, while the style
asked for may still be downloading. The two differ for exactly that long, and
_sharesLandedStyle (registry.ts) relies on their being equal to recognise a switch between
two basemaps that share a style — the one case where asking the engine for the style again
gets no answer at all.
Key of the vector basemap whose style last LANDED on the map — the style the map holds —, or
nullwhen it holds none (no basemap yet, or a raster one, applied over an empty style)._activeKeycannot answer that: it is set as soon as a switch is requested, while the style asked for may still be downloading. The two differ for exactly that long, and_sharesLandedStyle(registry.ts) relies on their being equal to recognise a switch between two basemaps that share a style — the one case where asking the engine for the style again gets no answer at all.