How does the Android Lockscreen get the Coverart?

Question

I know that I need to use a broadcast Receiver to get the currently playing song. But how do I Get the cover art of this explicit song? On the lockscreen it also works with Spotify or Google Music .. so no local Files are involved?

I am not able to find any clues on the extras of my receiving intent?

Answer 1

The lock screen utilizes a RemoteController, which allows you to listen to any apps that publish music controls via a RemoteControlClient.

Note that RemoteController was only made public in Android 4.4 and is not available prior to that. Unfortunately, there is no standardized broadcasts that fulfill this same role.