We use a Player instance to start casting. We use that Player instance to pause Casting, seek Cast, play Cast, get callbacks about the state of playback on the Cast device. etc.
After restarting the app and reconnecting the Cast Session, how does this get “reconnected” to a Player Instance? That original Player instance that was used to start playback no longer exists.
If a Player has the same Source or playlist of Sources loaded (individually identified by the media URL), the player will handle it as the same session and connect to the existing playback of the cast receiver. If the Player has a different Source or playlist of Sources and casting is started, it will override the existing session on the cast receiver.
This also works when creating a new Player and new Sources as the media URL is used as an identifier.
Does this answer your question or is there any follow up question I can help you with?