SkyWayでAndroidで音声の出力先を切り替える

skywayを使っていて、Androidでつまづいたのですが、GalaxyS5・Android6.0でとりあえず動いたのでメモ

enum class AudioOutput{
    Speaker,
    Call
}

fun setAudioOutput(type:AudioOutput?){
    val audioManager = context.getSystemService(Context.AUDIO_SERVICE) as? AudioManager
    val mediaPlayer = MediaPlayer()

    // MODE_IN_COMMUNICATION: In communication audio mode. An audio/video chat or VoIP call is established.
    audioManager?.mode = AudioManager.MODE_IN_COMMUNICATION

    type?.let{
        // Adjust output for Speakerphone.
        audioManager?.isSpeakerphoneOn = when(it){
            AudioOutput.Call -> false
            AudioOutput.Speaker -> true
        }
    } ?: run{
        if(this.isHeadsetOn()){
            audioManager?.isSpeakerphoneOn = false
        }else{
            audioManager?.isSpeakerphoneOn = true
        }
    }

    mediaPlayer.setAudioStreamType(AudioManager.MODE_IN_COMMUNICATION)
}

fun isHeadsetOn(): Boolean {
    val audioManager = context.getSystemService(Context.AUDIO_SERVICE) as AudioManager
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
        return audioManager.isWiredHeadsetOn() || audioManager.isBluetoothA2dpOn()
    } else {
        val devices = audioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS)
        for (i in devices.indices) {
            val device = devices[i]
            if (device.type === AudioDeviceInfo.TYPE_WIRED_HEADPHONES
                    || device.type === AudioDeviceInfo.TYPE_BLUETOOTH_A2DP
                    || device.type === AudioDeviceInfo.TYPE_BLUETOOTH_SCO) {
                return true
            }
        }
    }
    return false
}