Allow Data URLs in offlineRegionDefinitions styleURL

[mariusvn]

Is your feature request related to a problem? Please describe.
The offline region definition require an URL to define the style of the downloaded data. This makes the download of custom style generated on the fly impossible.

Describe the solution you'd like
Would be nice to allow raw json or data URL that contains a style definition.

Describe alternatives you've considered
As i said before, I tried with the data URLs in the style URL but it doesn't seems like the URL parser parse it.

Additional context
MapLibre gives me this message followed by the content of the styleURL: [HTTP] Unable to parse resourceUrl

[boldtrn]

Yes, I think we should allow to pass a Style.Builder to the offline regions.

[mariusvn]

yeah that would be even better

[louwers]

This is apparently working on iOS (using a file:// URL), but not on Android. This error is coming from here:

maplibre-native/platform/android/MapLibreAndroid/src/main/java/org/maplibre/android/module/http/HttpRequestImpl.java

Line 65 in d15de92

HttpLogger.log(Log.ERROR, String.format("[HTTP] Unable to parse resourceUrl %s", resourceUrl));

So apparently this hits the 'HTTP file source' instead of the 'Local File Source' implementation. Maybe fixing this is as easy as changing

maplibre-native/src/mbgl/storage/http_file_source.hpp

Lines 17 to 19 in d15de92

	bool canRequest(const Resource& resource) const override {
	return resource.hasLoadingMethod(Resource::LoadingMethod::Network);
	}

to return false when the URL scheme of the requested resource is file://, i.e. the inverse of

maplibre-native/platform/default/src/mbgl/storage/local_file_source.cpp

Lines 15 to 17 in d15de92

	bool acceptsURL(const std::string& url) {
	return 0 == url.rfind(mbgl::util::FILE_PROTOCOL, 0);
	}

[ccannell]

Interested in a fix. This is a blocker for an app I'm writing for a client.

[mariusvn]

it may be an error that came with android 13 new storage restrictions