ExoPlayer Short Tip 4: Playback Progression

Player.kt

class Player {

    interface ProgressionListener {

        val interval: Long

        fun progression(position: Long, duration: Long)
    }
    
     private inner class RunnableProgression(val progressionListener: ProgressionListener) : Runnable {

        override fun run() {
            if (player.duration >= 0) {
                progressionListener.progression(player.currentPosition.coerceAtMost(player.duration), player.duration)
            }
            handler.postDelayed(this, progressionListener.interval)
        }
    }
    
    private val handler = Handler()
    private val player: ExoPlayer = ExoPlayerFactory.newInstance(...)
    private val runnableProgressions = mutableListOf<RunnableProgression>()
    
    fun addProgressionListeners(vararg progressionListener: ProgressionListener) {
        progressionListener.forEach { runnableProgressions.add(RunnableProgression(it)) }
    }
    
    fun postRunnableProgressions() {
        runnableProgressions.forEach { handler.post(it) }
    }

    fun removeRunnableProgressions() {
        runnableProgressions.forEach { handler.removeCallbacks(it) }
    }
    
    override fun start() {
        ...
        postRunnableProgressions()
    }

    override fun pause() {
        ...
        removeRunnableProgressions()
    }

    override fun resume() {
        ...
        if (exoPlayer.playWhenReady) {
            postRunnableProgressions()
        }
    }

    override fun stop() {
        ...
        removeRunnableProgressions()
    }

    override fun release() {
        ...
        removeRunnableProgressions()
    }
}