MapView unusable in a RecyclerView

[Nodjo]

Contrary to a View within an Activity, which is only attached and detached once, Views within RecyclerView items may be attached/detached repeatedly, see RecyclerView.Adapter.onViewAttachedToWindow and RecyclerView.Adapter.onViewDetachedFromWindow.

The MapView does not handle the View lifecycle properly, basically what is undone in onDetachedFromWindow is not done in onAttachedToWindow so it can effectively be attached only once.

A workaround for this issue is to call setHasTransientState(true) on the recycler's item view that contains the mapView. Doing this will prevent the RecyclerView from attempting to reuse the view

[spyhunter99]

This is a known issue and gets posted here frequently. Glad you found a solution! If we were to make changes to the map view, what should we change?

[Nodjo]

MapView.java implements onDetachedFromWindow but not onAttachedFromWindow. What's currently destroyed in onDetachedFromWindow should be initialized in onAttachedToWindow so that the view can go through a lifecycle where it's detached then attached again. Like onStart/onStop or onResume/onPause for an Activity.

[spyhunter99]

well the issue is that stuff is currently destroyed in onDetached that cannot be recreated. It's more like we need a pause/resume mechanism, however that's not part of the View or ViewGroup lifecycle.

setHasTransientState requires API 16 or newer. I'm adding this to the samples now to provide clarification and to the javadocs. This seems to be the only simple solution currently.