LayerType
The imported-overlay model, shared by every renderer.
Only the final overlay draw is platform- or flavour-specific; the layer list, its storage and the import plumbing live in MapLayersManager. This is common code rather than Android's because the desktop app imports layers too — so uri is a plain string: an Android content://, a file:// under the app's own storage, or an http(s) network layer, parsed where it is used rather than by a platform URI type here.