closePublication method
Close the currently open publication and its related reader or playback ressources.
Implementation
@override
Future<void> closePublication() async {
await methodChannel.invokeMethod<void>('closePublication');
// Reset the lazy-stream fields so the next getter access creates a fresh
// subscription and fires onListen on native before the next book's widget
// mounts. The native side clears its event buffers in the same call, so no
// stale locator or status from this publication will be replayed.
_onTextLocatorChanged = null;
_onReaderStatusChanged = null;
_onNarrationSyncChanged = null;
}