MainActivity.kt

class MainActivity : AppCompatActivity() {

    private val viewModel: MainActivityViewModel by viewModels()

    private val videoPlayerCallbacks = object: ControlledVideoView.IVideoListener {
        override fun onPipToggleClicked() {
            viewModel.onPipToggled()
        }

        override fun onVideoCloseClicked() {
            viewModel.onVideoClosed()
        }

        override fun onVideoFullScreenClicked(isFullScreen: Boolean) {
            //isFullScreen = true means we're already in fullscreen,
            // so we want to turn it off and lock to portrait. And Vice Versa
            val orientationLock = when (isFullScreen) {
                true -> Configuration.ORIENTATION_PORTRAIT
                false -> Configuration.ORIENTATION_LANDSCAPE
            }

            viewModel.onOrientationForced(orientationLock)
        }
    }
}