Integrate MapboxMap class

[tobrun]

Copies GoogleMap implementation as indicated by @bleege in #2616 (comment).
This will boil down to applying composition/delegation to our current MapView class.
This is the first step towards making the project more modular and testable.

[tobrun]

I have been trying to migrate the whole MapView class to a separate MapboxMap class. This refactor seems a bit big to handle at once. Will granularly move code and start with integrating MapboxMap as a facade interface.

[tobrun]

Current progress can be viewed here:
https://github.com/mapbox/mapbox-gl-native/tree/3145-Mapbox-class-refactor

[tobrun]

@bleege @zugaldia
Would love some 👀 on progress above.

Let me explain the why, what changed and whats needs to be done to finish this:

Why

The gist behind the MapboxMap class is having morepartity with Google and more simple feature activities in testapp but most importantly this will allow our code to be more testable because we can test against an non Android SDK component and we can stub out the actual Views eg. MapView.

What changed

• MapboxMap is a facade like implementation of the old MapView.
• Old MapView methods are hidden due to package visibility
• Expose different methods names for Android is inconsistent about “zoom” versus “zoomLevel” #3327 and "LatLngZoom" & "Coordinate": do they mean the same thing? #3309
• MapboxMap can be retrieved using the getAsyncMap() from getMapAsync for Android like in Google maps #2042
• Feature activities are using MapFragment for better readability/simplicity

What needs to happen to finish

• actual code needs to migrate from MapView into MapboxMap (current just facading)
• feature activity for an Activity hosting a MapView (non fragment approach)
• write tests on the new architecture
• correctly composes different classes in getMapAsync method
• correctly refactor annotations to use MapboxMap instead of MapView

Direct links to the classes

• MapboxMap
• MapView
• getMapAsync example in a feature Activity

[bleege]

@tobrun It looks like the whole refactor is done in 1 commit ( 0dcc5b3 )... is this accurate?

[tobrun]

@bleege yeah, I shouldn't have rebased before pushing

[bleege]

@tobrun NP... just wanted to make sure I was looking at all the changes.

It looks like the TestApp has been refactored to only use MapFragment. We'll still need some examples that use MapView too. Many developers don't use Fragments and we don't want to give the incorrect impression that they have to use Fragments.

[tobrun]

As discussed with @bleege and @zugaldia. We are going for full backwards compatibility for next release (no need for version bump needed for convention semver). More relevant information and discussion points will be added to related PR so we have one place to do discussion and follow up.