MotionLayout - MainActivity

MainActivity.kt

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        title = getString(R.string.app_name)

        setupVideo()
    }
    
    
    override fun onPause() {
        super.onPause()
        if (currentPlaybackState == MainActivityViewModel.VideoPlaybackState.PLAYING)  {
            video_player.pause()
        }
    }

    override fun onStart() {
        super.onStart()
        if (currentPlaybackState == MainActivityViewModel.VideoPlaybackState.PLAYING) {
            video_player.ensureSurface()
            video_player.showControls()
            attachVideoListeners()
        }
    }

    private fun setupVideo() {
        // Set the video URL
        video_player.videoUrl = viewModel.videoUrl

        viewModel.playbackState.observe(this, Observer { playbackState ->
            if (playbackState != currentPlaybackState) {
                invalidateOptionsMenu() // update the play/stop icon in the options menu.

                currentPlaybackState = playbackState

                when (currentPlaybackState) {
                    MainActivityViewModel.VideoPlaybackState.PLAYING -> {
                        playVideo()
                    }
                    else -> {
                        stopVideo()
                    }
                }
            }

            updateVideoLayout()
        })

        viewModel.layoutState.observe(this, Observer { layoutState ->
            if (layoutState != currentLayoutState) {
                currentLayoutState = layoutState
                updateVideoLayout()
            }
        })
    }

    private fun updateVideoLayout() {
        val isFullscreen = (currentLayoutState == MainActivityViewModel.VideoLayoutState.FULLSCREEN)

        if (isFullscreen && resources.configuration.orientation != Configuration.ORIENTATION_LANDSCAPE) {
            requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE
        } else if (!isFullscreen && resources.configuration.orientation != Configuration.ORIENTATION_PORTRAIT) {
            requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT
        }

        video_player.setFullScreenMode(isFullscreen)
        video_player.setPreserveAspectRatio(isFullscreen)

        val videoState = Pair(currentPlaybackState, currentLayoutState)

        val newState = when (videoState) {
            Pair(MainActivityViewModel.VideoPlaybackState.PLAYING, MainActivityViewModel.VideoLayoutState.FULLSCREEN) -> R.id.video_state_fullscreen
            Pair(MainActivityViewModel.VideoPlaybackState.PLAYING, MainActivityViewModel.VideoLayoutState.PIP) -> R.id.video_state_pip_playing
            Pair(MainActivityViewModel.VideoPlaybackState.STOPPED, MainActivityViewModel.VideoLayoutState.PIP) -> R.id.video_state_pip_stopped
            Pair(MainActivityViewModel.VideoPlaybackState.PLAYING, MainActivityViewModel.VideoLayoutState.EMBEDDED) -> R.id.video_state_embedded_playing
            else -> R.id.video_state_embedded_stopped
        }

        if (activity_container.currentState != newState) {
            activity_container.transitionToState(newState)
        }
    }

    private fun playVideo() {
        video_player.play()
       attachVideoListeners()
    }

    private fun stopVideo() {
        if (video_player.isPlaying) {
            video_player.stop()
            video_player.setVideoListener(null)
        }
    }
    
    private fun attachVideoListeners() {
        video_player.setVideoListener(videoPlayerCallbacks)
    }
}