Resolves once the map reports its style — and the style's sources — loaded.
Resolves at once when it already is. Otherwise it listens on STYLE_READY_EVENTS,
re-tests isStyleLoaded() on each emission, and detaches from all three when it holds. It
never rejects and has no deadline: a map whose style never loads can build nothing anyway,
and a timeout would only turn that into a second, later failure.
Resolves once the map reports its style — and the style's sources — loaded.
Resolves at once when it already is. Otherwise it listens on STYLE_READY_EVENTS, re-tests
isStyleLoaded()on each emission, and detaches from all three when it holds. It never rejects and has no deadline: a map whose style never loads can build nothing anyway, and a timeout would only turn that into a second, later failure.