refactor: update playback parameters API to return success status and handle state synchronization in UI

Author: madebymozart

samples/powerplay/src/main/cpp/PowerPlayJNI.cpp

@@ -423,13 +423,13 @@ Java_com_google_oboe_samples_powerplay_engine_PowerPlayAudioPlayer_removeSampleS
 /**
  * Native (JNI) implementation of PowerPlayAudioPlayer.setPlaybackParametersNative()
  */
-JNIEXPORT void JNICALL
+JNIEXPORT jboolean JNICALL
 Java_com_google_oboe_samples_powerplay_engine_PowerPlayAudioPlayer_setPlaybackParametersNative(
         JNIEnv *env,
         jobject,
         jfloat speed,
         jfloat pitch) {
-    player.setPlaybackParameters(speed, pitch);
+    return player.setPlaybackParameters(speed, pitch);
 }
 
 #ifdef __cplusplus

samples/powerplay/src/main/cpp/PowerPlayMultiPlayer.cpp

@@ -353,9 +353,7 @@ bool PowerPlayMultiPlayer::removeSampleSource(int32_t index) {
     return true;
 }
 
-void PowerPlayMultiPlayer::setPlaybackParameters(float speed, float pitch) {
-    mPlaybackSpeed = speed;
-    mPlaybackPitch = pitch;
+bool PowerPlayMultiPlayer::setPlaybackParameters(float speed, float pitch) {
     if (mAudioStream) {
         oboe::PlaybackParameters params = {
             oboe::FallbackMode::Default,
@@ -367,6 +365,10 @@ void PowerPlayMultiPlayer::setPlaybackParameters(float speed, float pitch) {
         if (result != oboe::Result::OK) {
             __android_log_print(ANDROID_LOG_ERROR, "PowerPlayMultiPlayer",
                                 "setPlaybackParameters failed: %s", oboe::convertToText(result));
+            return false;
         }
     }
+    mPlaybackSpeed = speed;
+    mPlaybackPitch = pitch;
+    return true;
 }

samples/powerplay/src/main/cpp/PowerPlayMultiPlayer.h

@@ -60,7 +60,7 @@ class PowerPlayMultiPlayer : public iolib::SimpleMultiPlayer {
 
     bool removeSampleSource(int32_t index);
 
-    void setPlaybackParameters(float speed, float pitch);
+    bool setPlaybackParameters(float speed, float pitch);
 
 private:
     class MyPresentationCallback : public oboe::AudioStreamPresentationCallback {

samples/powerplay/src/main/kotlin/com/google/oboe/samples/powerplay/MainActivity.kt

@@ -743,12 +743,18 @@ class MainActivity : ComponentActivity() {
                     playbackSpeed = playbackSpeed,
                     playbackPitch = playbackPitch,
                     onSpeedChange = {
-                        playbackSpeed = it
-                        player.setPlaybackParameters(playbackSpeed, playbackPitch)
+                        val success = player.setPlaybackParameters(it, playbackPitch)
+                        if (success) {
+                            playbackSpeed = it
+                        }
+                        success
                     },
                     onPitchChange = {
-                        playbackPitch = it
-                        player.setPlaybackParameters(playbackSpeed, playbackPitch)
+                        val success = player.setPlaybackParameters(playbackSpeed, it)
+                        if (success) {
+                            playbackPitch = it
+                        }
+                        success
                     },
                     fileSampleRate = currentTrack?.wavInfo?.sampleRate ?: 48000,
                     onDismiss = { showBottomSheet = false }
@@ -859,8 +865,8 @@ class MainActivity : ComponentActivity() {
         onSliderPositionChange: (Float) -> Unit,
         playbackSpeed: Float,
         playbackPitch: Float,
-        onSpeedChange: (Float) -> Unit,
-        onPitchChange: (Float) -> Unit,
+        onSpeedChange: (Float) -> Boolean,
+        onPitchChange: (Float) -> Boolean,
         fileSampleRate: Int,
         onDismiss: () -> Unit
     ) {
@@ -869,6 +875,12 @@ class MainActivity : ComponentActivity() {
         val actualFrames = remember { mutableIntStateOf(0) }
         var isModified by remember { mutableStateOf(playbackSpeed != 1.0f || playbackPitch != 1.0f) }
 
+        var localSpeed by remember { mutableFloatStateOf(playbackSpeed) }
+        var localPitch by remember { mutableFloatStateOf(playbackPitch) }
+
+        LaunchedEffect(playbackSpeed) { localSpeed = playbackSpeed }
+        LaunchedEffect(playbackPitch) { localPitch = playbackPitch }
+
         Column(
             modifier = Modifier
                 .fillMaxWidth()
@@ -993,9 +1005,15 @@ class MainActivity : ComponentActivity() {
                 color = if (canUseSpeed) Color.Unspecified else Color.Gray
             )
             Slider(
-                value = playbackSpeed,
-                onValueChange = onSpeedChange,
+                value = localSpeed,
+                onValueChange = {
+                    localSpeed = it
+                    onSpeedChange(it)
+                },
                 onValueChangeFinished = {
+                    if (localSpeed != playbackSpeed) {
+                        localSpeed = playbackSpeed
+                    }
                     isModified = (playbackSpeed != 1.0f || playbackPitch != 1.0f)
                 },
                 valueRange = 0.5f..2.0f,
@@ -1015,9 +1033,15 @@ class MainActivity : ComponentActivity() {
                 color = if (canUsePitch) Color.Unspecified else Color.Gray
             )
             Slider(
-                value = playbackPitch,
-                onValueChange = onPitchChange,
+                value = localPitch,
+                onValueChange = {
+                    localPitch = it
+                    onPitchChange(it)
+                },
                 onValueChangeFinished = {
+                    if (localPitch != playbackPitch) {
+                        localPitch = playbackPitch
+                    }
                     isModified = (playbackSpeed != 1.0f || playbackPitch != 1.0f)
                 },
                 valueRange = 0.5f..2.0f,

samples/powerplay/src/main/kotlin/com/google/oboe/samples/powerplay/engine/PowerPlayAudioPlayer.kt

@@ -66,7 +66,7 @@ class PowerPlayAudioPlayer() : DefaultLifecycleObserver {
     fun setLooping(index: Int, looping: Boolean) = setLoopingNative(index, looping)
     fun teardownAudioStream() = teardownAudioStreamNative()
     fun unloadAssets() = unloadAssetsNative()
-    fun setPlaybackParameters(speed: Float, pitch: Float) = setPlaybackParametersNative(speed, pitch)
+    fun setPlaybackParameters(speed: Float, pitch: Float): Boolean = setPlaybackParametersNative(speed, pitch)
 
     /**
      * Loads a file from assets into memory and returns its WAV properties.
@@ -259,7 +259,7 @@ class PowerPlayAudioPlayer() : DefaultLifecycleObserver {
     private external fun getDurationMillisNative(index: Int): Long
     private external fun getWavFileInfoNative(wavBytes: ByteArray): IntArray
     private external fun removeSampleSourceNative(index: Int): Boolean
-    private external fun setPlaybackParametersNative(speed: Float, pitch: Float)
+    private external fun setPlaybackParametersNative(speed: Float, pitch: Float): Boolean
 
     /**
      * Companion