OfflineRegion setObserver in Android

[tcolligan-ap]

Platform: Android
Mapbox SDK version: 4.1

Currently the OfflineRegion class has a setObserver method that allows devs to determine the status of an offline region, primarily for while it is being downloaded.

However there is no way to remove the observer from the OfflineRegion object instance. Passing in null looks like it will cause a crash based on the source. A way to remove the observer would be nice.

[zugaldia]

@tcolligan-ap Agreed, this is an API that would be good to add. Passing a null value would be the intended way to remove the observer but right now the method signature for public void setObserver(@NonNull final OfflineRegionObserver observer) won't let you.

Probably we could just add a new removeObserver() method that simply does a private native void setOfflineRegionObserver(null) call.

[Guardiola31337]

make observer param nulllable, resetting observer is valid (eg. when download finished downloading)

☝️ landed in #8919 and it's available in version 5.1.0.
There is an example in OfflineActivity.java.

Closing here because it's already solved.

Thanks @tcolligan-ap for your report. Feel free to open new tickets if you find any other issues 😉

cc/ @zugaldia