Question

Android has with version (4+ ?) introduced offline maps where I can on the handset select an area to cache and then Google Maps downloads that map data on the handset.

As I got a comment: I want to use the data, that is already on my device (if the user has done the downloading for offline maps use before). And not open a new data connection to Google’s servers (e.g. because data charges would apply).

Can I use that map data from within my app – e.g. by sending the maps app an intent do show an area (perhaps with overlays)?
Or use even the map widget inside my app?

I am not talking about downloading some tiles from the Google servers into my app

Answer 1

Can I use that map data from within my app – e.g. by sending the maps app an intent do show an area (perhaps with overlays)?

Well, you can invoke a map application using ACTION_VIEW and a geo: Intent. Whether that will view some cached area depends on what map app the user uses and whether or not the user cached the area around your specified latitude and longitude.

Or use even the map widget inside my app?

While you can integrate a MapView in your app, it will not use this cached data. Partially, that is because the MapView code predates any of this caching stuff. Partially, that is because the cached data is owned by another process (the Maps app) and therefore is inaccessible to you.