Add NavigationMapRoute above road layers

[ericrwolfe]

The Android Maps SDK didn't used to expose the sourceLayerIdentifier, which meant that layer IDs were hardcoded in the traffic plugin (fixed) and for the route line.

This can cause the route line to appear in the wrong place if the current style doesn't have a ROUTE_BELOW_LAYER where we expect it.

We should update the NavigationMapRoute and place the route line either above the topmost map layer that isn't a symbol layer as is done on iOS, or above the topmost layer with source = roads.

cc @danesfeder @bsudekum

[danesfeder]

update the NavigationMapRoute and place the route line either above the topmost map layer that isn't a symbol layer as is done on iOS, or above the topmost layer with source = roads

@tobrun is there a reliable way to do this?

I'm looking at https://github.com/mapbox/mapbox-plugins-android/blob/master/plugin-traffic/src/main/java/com/mapbox/mapboxsdk/plugins/traffic/TrafficPlugin.java#L198 wondering if that's a viable solution (you mention it might not always be accurate).

[tobrun]

@tobrun is there a reliable way to do this?
I'm looking at https://github.com/mapbox/mapbox-plugins-android/blob/master/plugin-traffic/src/main/java/com/mapbox/mapboxsdk/plugins/traffic/TrafficPlugin.java#L198 wondering if that's a viable solution (you mention it might not always be accurate).

Afaik this is the only way for now, I would be nice if we could add this kind of functionality to core instead of writing it on the binding side.

[danesfeder]

@ericrwolfe

@cammace baked the same logic from the traffic plugin:
https://github.com/mapbox/mapbox-plugins-android/blob/master/plugin-traffic/src/main/java/com/mapbox/mapboxsdk/plugins/traffic/TrafficPlugin.java#L198

into the NavigationMapRoute:
https://github.com/mapbox/mapbox-navigation-android/blob/master/libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/route/NavigationMapRoute.java#L517

I'm wondering if we saw this issue with that one style because I kept our normal "route below" layer set:
https://github.com/mapbox/mapbox-navigation-android/blob/master/libandroid-navigation-ui/src/main/java/com/mapbox/services/android/navigation/ui/v5/NavigationView.java#L369

So the logic to look through the layers was never hit.

[ericrwolfe]

Yeah, I think this might be due to the ROUTE_BELOW_LAYER code. We should remove that and instead make sure that the NaivgationMapRoute code is hit.

[danesfeder]

Closed with #590