PlayPauseButton_1.kt

@Composable
fun PlayPauseButton(modifier: Modifier = Modifier) {
    val controller = PlayerControllerAmbient.current

    val isPlaying by controller.isPlaying.collectAsState()
    val playbackState by controller.playbackState.collectAsState()

    IconButton(
        onClick = { controller.playPause() },
        modifier = Modifier + modifier
    ) {
        if (isPlaying) {
            Icon(Icons.Filled.Pause)
        } else {
            when (playbackState) {
                ExoPlayer.STATE_ENDED -> {
                    Icon(Icons.Filled.Restore)
                }
                ExoPlayer.STATE_BUFFERING -> {
                    CircularProgressIndicator()
                }
                else -> {
                    Icon(Icons.Filled.PlayArrow)
                }
            }
        }
    }
}