Fix MediaPlayer Position Access Issue

[efstathiosntonas]

probably fixes #557

[hyochan]

@efstathiosntonas Thank you for your PR and this is really insightful 👀

Although the added isPlaying check prevents inaccurate event emissions, the current implementation still schedules mTask via mTimer, potentially utilizing system resources even when not playing.

I think the code should be changed as below to be more idealistic.

@ReactMethod
fun pausePlayer(promise: Promise) {
    ...
    mTimer?.cancel()  // Cancel TimerTask to prevent unnecessary resource usage.
    ...
}

@ReactMethod
fun resumePlayer(promise: Promise) {
    ...
    // Re-schedule TimerTask only upon resumption to ensure resource efficiency.
    mTimer = Timer()
    mTimer!!.schedule(mTask, 0, subsDurationMillis.toLong())
    ...
}

How do you think?

[efstathiosntonas]

@hyochan your knowledge in this is better than mine since I do not know kotlin/java, I'll do whatever you think best. I've just gave it a chance by checking if the player is already running.

can you give me a full example of the changes above, it's not quite clear what is the order.

[efstathiosntonas]

@hyochan I think we need to recreate the mTask inside the resumePlayer otherwise it will throw Task already scheduled or cancelled, what do you think?

something like this:

cancel timer on setOnPreparedListener:

 mediaPlayer!!.setOnPreparedListener { mp ->
                Log.d(tag, "mediaplayer prepared and start")
                mp.start()
                /**
                 * Set timer task to send event to RN.
                 */
                mTask = object : TimerTask() {
                    override fun run() {
                            val obj = Arguments.createMap()
                            obj.putInt("duration", mp.duration)
                            obj.putInt("currentPosition", mp.currentPosition)
                            sendEvent(reactContext, "rn-playback", obj)
                    }
                }

                mTimer?.cancel() // <---- cancel timer
                mTimer = Timer()
                mTimer!!.schedule(mTask, 0, subsDurationMillis.toLong())
                val resolvedPath = if (((path == "DEFAULT"))) "${reactContext.cacheDir}/$defaultFileName" else path
                promise.resolve(resolvedPath)
            }

cancel timer before resuming, start a new timer task on resumePlayer and cancel the timer after pausing the media player on pausePlayer function:

    @ReactMethod
    fun resumePlayer(promise: Promise) {
        if (mediaPlayer == null) {
            promise.reject("resume", "mediaPlayer is null on resume.")
            return
        }

        if (mediaPlayer!!.isPlaying) {
            promise.reject("resume", "mediaPlayer is already running.")
            return
        }

        try {
            mTimer?.cancel() // <---- cancel timer on resume
            
            mediaPlayer!!.seekTo(mediaPlayer!!.currentPosition)

            mTask = object : TimerTask() { // <---- create a new timer task
                override fun run() {
                    val obj = Arguments.createMap()
                    obj.putInt("duration", mediaPlayer!!.duration)
                    obj.putInt("currentPosition", mediaPlayer!!.currentPosition)
                    sendEvent(reactContext, "rn-playback", obj)
                }
            }
            mTimer = Timer()
            mTimer!!.schedule(mTask, 0, subsDurationMillis.toLong())
            mediaPlayer!!.start()
            promise.resolve("resume player")
        } catch (e: Exception) {
            Log.e(tag, "mediaPlayer resume: " + e.message)
            promise.reject("resume", e.message)
        }
    }

    @ReactMethod
    fun pausePlayer(promise: Promise) {
        if (mediaPlayer == null) {
            promise.reject("pausePlay", "mediaPlayer is null on pause.")
            return
        }

        try {
            mediaPlayer!!.pause()
            mTimer?.cancel() // <---- on pause cancel timer
            promise.resolve("pause player")
        } catch (e: Exception) {
            Log.e(tag, "pausePlay exception: " + e.message)
            promise.reject("pausePlay", e.message)
        }
    }

[efstathiosntonas]

@hyochan after applying the patch above I still get the crash, without the patch the amount of crashes was higher though 🤔

edit: I asked ChatGPT:

and:

[efstathiosntonas]

@hyochan I've wrapped it in a try/catch, at least it will silence the error and avoid crash. I really don't know what else to do with this one.

@@ -231,13 +233,19 @@ class RNAudioRecorderPlayerModule(private val reactContext: ReactApplicationCont
                  */
                 mTask = object : TimerTask() {
                     override fun run() {
-                        val obj = Arguments.createMap()
-                        obj.putInt("duration", mp.duration)
-                        obj.putInt("currentPosition", mp.currentPosition)
-                        sendEvent(reactContext, "rn-playback", obj)
+                       try {
+                           val obj = Arguments.createMap()
+                           obj.putInt("duration", mp.duration)
+                           obj.putInt("currentPosition", mp.currentPosition)
+                           sendEvent(reactContext, "rn-playback", obj)
+                       } catch (e: IllegalStateException) {
+                           // Handle the exception
+                           Log.e(tag, "MediaPlayer is not in a valid state", e)
+                       }
                     }
                 }

+                mTimer?.cancel()
                 mTimer = Timer()
                 mTimer!!.schedule(mTask, 0, subsDurationMillis.toLong())
                 val resolvedPath = if (((path == "DEFAULT"))) "${reactContext.cacheDir}/$defaultFileName" else path

[hyochan]

@hyochan I've wrapped it in a try/catch, at least it will silence the error and avoid crash. I really don't know what else to do with this one.

@@ -231,13 +233,19 @@ class RNAudioRecorderPlayerModule(private val reactContext: ReactApplicationCont
                  */
                 mTask = object : TimerTask() {
                     override fun run() {
-                        val obj = Arguments.createMap()
-                        obj.putInt("duration", mp.duration)
-                        obj.putInt("currentPosition", mp.currentPosition)
-                        sendEvent(reactContext, "rn-playback", obj)
+                       try {
+                           val obj = Arguments.createMap()
+                           obj.putInt("duration", mp.duration)
+                           obj.putInt("currentPosition", mp.currentPosition)
+                           sendEvent(reactContext, "rn-playback", obj)
+                       } catch (e: IllegalStateException) {
+                           // Handle the exception
+                           Log.e(tag, "MediaPlayer is not in a valid state", e)
+                       }
                     }
                 }

+                mTimer?.cancel()
                 mTimer = Timer()
                 mTimer!!.schedule(mTask, 0, subsDurationMillis.toLong())
                 val resolvedPath = if (((path == "DEFAULT"))) "${reactContext.cacheDir}/$defaultFileName" else path

I have managed to handle this in c5ef0f1. Let's see what happens 🤔

[efstathiosntonas]

thanks @hyochan, keep it up!