MainActivityMediaSession.kt

gistfile1.kt

class MainActivity : AppCompatActivity() {

    private var mediaServiceBinder: MediaService.PlayerServiceBinder? = null
    private var mediaController: MediaControllerCompat? = null
    private var callback: MediaControllerCompat.Callback? = null
    private var serviceConnection: ServiceConnection? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        callback = object : MediaControllerCompat.Callback() {
            override fun onPlaybackStateChanged(state: PlaybackStateCompat?) {
                state?.let {
                    val playing = state.state == PlaybackStateCompat.STATE_PLAYING
                    playButton.isEnabled = !playing
                    pauseButton.isEnabled = playing
                    stopButton.isEnabled = playing
                }
            }
        }

        serviceConnection = object : ServiceConnection {

            override fun onServiceConnected(className: ComponentName?, service: IBinder?) {
                mediaServiceBinder = service as MediaService.PlayerServiceBinder
                try {
                    mediaController = MediaControllerCompat(this@MainActivity,
                            mediaServiceBinder?.getMediaSessionToken()!!)
                    mediaController?.registerCallback(callback as MediaControllerCompat.Callback)
                    callback?.onPlaybackStateChanged(mediaController?.playbackState)
                } catch (e: RemoteException) {
                    mediaController = null
                }
            }

            override fun onServiceDisconnected(className: ComponentName?) {
                mediaServiceBinder = null
                if (mediaController != null) {
                    mediaController?.unregisterCallback(callback as MediaControllerCompat.Callback)
                    mediaController = null
                }
            }
        }

        bindService(Intent(this, MediaService::class.java), serviceConnection, Context.BIND_AUTO_CREATE)

        previousButton.setOnClickListener { previousTrack() }
        playButton.setOnClickListener { playTrack() }
        stopButton.setOnClickListener { stopPlaying() }
        pauseButton.setOnClickListener { pausePlaying() }
        nextButton.setOnClickListener { nextTrack() }
    }

    private fun nextTrack() {
        mediaController?.let {
            it.transportControls.skipToNext()
            outputTextView.append("next track ${mediaController?.metadata?.description?.title} was chosen...\n")
            buttonChangeColor(BUTTON_NEXT)
        }
    }

    private fun pausePlaying() {
        mediaController?.let {
            it.transportControls.pause()
            outputTextView.append("track ${mediaController?.metadata?.description?.title} was paused...\n")
            buttonChangeColor(BUTTON_PAUSE)
        }
    }

    private fun stopPlaying() {
        mediaController?.let {
            it.transportControls.stop()
            outputTextView.append("track ${mediaController?.metadata?.description?.title} was stopped...\n")
            buttonChangeColor(BUTTON_STOP)
        }
    }

    private fun playTrack() {
        mediaController?.let {
            it.transportControls.play()
            outputTextView.append("track ${mediaController?.metadata?.description?.title} is playing...\n")
            buttonChangeColor(BUTTON_PLAY)
        }
    }

    private fun previousTrack() {
        mediaController?.let {
            it.transportControls.skipToPrevious()
            outputTextView.append("previous track ${mediaController?.metadata?.description?.title} was chosen...\n")
            buttonChangeColor(BUTTON_PREVIOUS)
        }
    }

    fun buttonChangeColor(typeButton: Int) {
        pauseButton.setBackgroundResource(android.R.drawable.btn_default)
        playButton.setBackgroundResource(android.R.drawable.btn_default)
        stopButton.setBackgroundResource(android.R.drawable.btn_default)
        nextButton.setBackgroundResource(android.R.drawable.btn_default)
        previousButton.setBackgroundResource(android.R.drawable.btn_default)
        when (typeButton) {
            BUTTON_PLAY ->  playButton.setBackgroundResource(R.color.colorButtonClick)
            BUTTON_PAUSE ->  pauseButton.setBackgroundResource(R.color.colorButtonClick)
            BUTTON_STOP ->  stopButton.setBackgroundResource(R.color.colorButtonClick)
            BUTTON_NEXT ->  nextButton.setBackgroundResource(R.color.colorButtonClick)
            BUTTON_PREVIOUS ->  previousButton.setBackgroundResource(R.color.colorButtonClick)
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        mediaServiceBinder = null
        if (mediaController != null) {
            mediaController?.unregisterCallback(callback as MediaControllerCompat.Callback)
            mediaController = null
        }
        unbindService(serviceConnection)
    }

    companion object {

        private const val BUTTON_PLAY = 1
        private const val BUTTON_STOP = 2
        private const val BUTTON_PAUSE = 3
        private const val BUTTON_NEXT = 4
        private const val BUTTON_PREVIOUS = 5
    }
}