Implement snapshot feature in maps API

[mar-v-in]

The current implementation of the maps API lacks support for the snapshot() functionality.

https://github.com/microg/GmsCore/blob/master/play-services-maps-core-mapbox/src/main/kotlin/org/microg/gms/maps/mapbox/GoogleMap.kt#L483

This is a requirement for location sharing in Signal messenger.

[khao-soi]

Is there an easy way to test this function? Last night I tried to implement this method, but I lack experience in kotlin and android development.

[mar-v-in]

You can try out most maps features (including the snapshot feature) in the maps api demo app: https://github.com/googlemaps/android-samples/releases/tag/v1.6.0

[khao-soi]

So, I tried a few things here. When I connect my phone (LOS + microG) and attach the debugger to its com.google.android.gms process it doesn't seem to hit any breakpoint.
When I create a virtual device (Nexus 6 for no specific reason) based on the Android 10.0 microG Image and start the maps demo app I get "Maps SDK for Android Demos (Kotlin) won't run without Google Play Services". Self-Check has everything besides Phonesky and GSF.

Any ideas?

[mar-v-in]

For using microG in Android Emulator, check https://github.com/microg/GmsCore/wiki/Development-Tools#using-the-emulator

For debugging apps that use Maps API, you need to attach the debugger to the app using Maps, not com.google.android.gms.

[fynngodau]

Snapshots are now implemented:

GmsCore/play-services-maps-core-mapbox/src/main/kotlin/org/microg/gms/maps/mapbox/GoogleMap.kt

Lines 477 to 500 in d56b6a0

	override fun snapshot(callback: ISnapshotReadyCallback, bitmap: IObjectWrapper?) {
	val map = map
	if (map == null) {
	// Snapshot cannot be taken
	Log.e(TAG, "snapshot could not be taken because map is null")
	runOnMainLooper { callback.onBitmapWrappedReady(ObjectWrapper.wrap(null)) }
	} else {
	if (!isStarted) {
	Log.w(TAG, "Caller did not call onStart() before taking snapshot. Calling onStart() now, for snapshot not to fail.")
	// Snapshots fail silently if onStart had not been called. This is the case with Signal.
	onStart()
	isStarted = true
	}
	Log.d(TAG, "taking snapshot now")
	map.snapshot {
	runOnMainLooper {
	Log.d(TAG, "snapshot ready, providing to application")
	callback.onBitmapWrappedReady(ObjectWrapper.wrap(it))
	}
	}
	}
	}

Re. sharing locations in Signal (signalapp/Signal-Android#12723), the next blocker is #1960.