Store voice player playback index in a datastore.

libraries/voiceplayer/impl/build.gradle.kts

@@ -26,10 +26,12 @@ dependencies {
     implementation(projects.libraries.di)
     implementation(projects.libraries.matrix.api)
     implementation(projects.libraries.mediaplayer.api)
+    implementation(projects.libraries.preferences.api)
     implementation(projects.libraries.uiUtils)
     implementation(projects.services.analytics.api)
 
     implementation(libs.androidx.annotationjvm)
+    implementation(libs.androidx.datastore.preferences)
     implementation(libs.coroutines.core)
 
     testCommonDependencies(libs)

libraries/voiceplayer/impl/src/main/kotlin/io/element/android/libraries/voiceplayer/impl/DefaultVoiceMessagePresenterFactory.kt

@@ -26,6 +26,7 @@ class DefaultVoiceMessagePresenterFactory(
     @SessionCoroutineScope
     private val sessionCoroutineScope: CoroutineScope,
     private val voiceMessagePlayerFactory: VoiceMessagePlayer.Factory,
+    private val voicePlayerStore: VoicePlayerStore,
 ) : VoiceMessagePresenterFactory {
     override fun createVoiceMessagePresenter(
         eventId: EventId?,
@@ -44,6 +45,7 @@ class DefaultVoiceMessagePresenterFactory(
         return VoiceMessagePresenter(
             analyticsService = analyticsService,
             sessionCoroutineScope = sessionCoroutineScope,
+            voicePlayerStore = voicePlayerStore,
             player = player,
             eventId = eventId,
             duration = duration,

libraries/voiceplayer/impl/src/main/kotlin/io/element/android/libraries/voiceplayer/impl/VoiceMessagePresenter.kt

@@ -9,12 +9,13 @@
 package io.element.android.libraries.voiceplayer.impl
 
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import io.element.android.libraries.architecture.AsyncData
 import io.element.android.libraries.architecture.Presenter
 import io.element.android.libraries.architecture.runUpdatingState
@@ -34,15 +35,16 @@ import kotlin.time.Duration.Companion.milliseconds
 class VoiceMessagePresenter(
     private val analyticsService: AnalyticsService,
     private val sessionCoroutineScope: CoroutineScope,
+    private val voicePlayerStore: VoicePlayerStore,
     private val player: VoiceMessagePlayer,
     private val eventId: EventId?,
     private val duration: Duration,
 ) : Presenter<VoiceMessageState> {
     private val play = mutableStateOf<AsyncData<Unit>>(AsyncData.Uninitialized)
-    private val playbackSpeedIndex = mutableIntStateOf(0)
 
     @Composable
     override fun present(): VoiceMessageState {
+        val localCoroutineScope = rememberCoroutineScope()
         val playerState by player.state.collectAsState(
             VoiceMessagePlayer.State(
                 isReady = false,
@@ -53,6 +55,12 @@ class VoiceMessagePresenter(
             )
         )
 
+        val playbackSpeedIndex by voicePlayerStore.playBackSpeedIndex().collectAsState(0)
+
+        LaunchedEffect(playbackSpeedIndex) {
+            player.setPlaybackSpeed(VoicePlayerConfig.availablePlaybackSpeeds[playbackSpeedIndex])
+        }
+
         val buttonType by remember {
             derivedStateOf {
                 when {
@@ -114,9 +122,10 @@ class VoiceMessagePresenter(
                 is VoiceMessageEvent.Seek -> {
                     player.seekTo((event.percentage * duration).toLong())
                 }
-                is VoiceMessageEvent.ChangePlaybackSpeed -> {
+                is VoiceMessageEvent.ChangePlaybackSpeed -> localCoroutineScope.launch {
-                    playbackSpeedIndex.intValue = (playbackSpeedIndex.intValue + 1) % VoicePlayerConfig.availablePlaybackSpeeds.size
+                    voicePlayerStore.setPlayBackSpeedIndex(
-                    player.setPlaybackSpeed(VoicePlayerConfig.availablePlaybackSpeeds[playbackSpeedIndex.intValue])
+                        (playbackSpeedIndex + 1) % VoicePlayerConfig.availablePlaybackSpeeds.size
+                    )
                 }
             }
         }
@@ -126,7 +135,7 @@ class VoiceMessagePresenter(
             progress = progress,
             time = time,
             showCursor = showCursor,
-            playbackSpeed = VoicePlayerConfig.availablePlaybackSpeeds[playbackSpeedIndex.intValue],
+            playbackSpeed = VoicePlayerConfig.availablePlaybackSpeeds[playbackSpeedIndex],
             eventSink = ::handleEvent,
         )
     }

libraries/voiceplayer/impl/src/main/kotlin/io/element/android/libraries/voiceplayer/impl/VoicePlayerStore.kt

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2025 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.voiceplayer.impl
+
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.intPreferencesKey
+import dev.zacsweers.metro.AppScope
+import dev.zacsweers.metro.ContributesBinding
+import io.element.android.libraries.preferences.api.store.PreferenceDataStoreFactory
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+
+interface VoicePlayerStore {
+    suspend fun setPlayBackSpeedIndex(index: Int)
+    fun playBackSpeedIndex(): Flow<Int>
+}
+
+@ContributesBinding(AppScope::class)
+class PreferencesVoicePlayerStore(
+    preferenceDataStoreFactory: PreferenceDataStoreFactory,
+) : VoicePlayerStore {
+    private val store = preferenceDataStoreFactory.create("elementx_voice_player")
+    private val playbackSpeedIndex = intPreferencesKey("playback_speed_index")
+
+    override fun playBackSpeedIndex(): Flow<Int> {
+        return store.data.map { prefs ->
+            prefs[playbackSpeedIndex] ?: 0
+        }
+    }
+
+    override suspend fun setPlayBackSpeedIndex(index: Int) {
+        store.edit { prefs ->
+            prefs[playbackSpeedIndex] = index
+        }
+    }
+}

libraries/voiceplayer/impl/src/test/kotlin/io/element/android/libraries/voiceplayer/impl/InMemoryVoicePlayerStore.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2025 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.voiceplayer.impl
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+
+internal class InMemoryVoicePlayerStore(
+    defaultPlaybackSpeedIndex: Int = 0,
+) : VoicePlayerStore {
+    private val playBackSpeedIndex = MutableStateFlow(defaultPlaybackSpeedIndex)
+
+    override fun playBackSpeedIndex(): Flow<Int> {
+        return playBackSpeedIndex.asStateFlow()
+    }
+
+    override suspend fun setPlayBackSpeedIndex(index: Int) {
+        playBackSpeedIndex.emit(index)
+    }
+}

libraries/voiceplayer/impl/src/test/kotlin/io/element/android/libraries/voiceplayer/impl/VoiceMessagePresenterTest.kt

@@ -240,6 +240,7 @@ fun TestScope.createVoiceMessagePresenter(
     mediaPlayer: FakeMediaPlayer = FakeMediaPlayer(),
     voiceMessageMediaRepo: VoiceMessageMediaRepo = FakeVoiceMessageMediaRepo(),
     analyticsService: AnalyticsService = FakeAnalyticsService(),
+    voicePlayerStore: VoicePlayerStore = InMemoryVoicePlayerStore(),
     eventId: EventId? = EventId("\$anEventId"),
     filename: String = "filename doesn't really matter for a voice message",
     duration: Duration = 61_000.milliseconds,
@@ -257,6 +258,7 @@ fun TestScope.createVoiceMessagePresenter(
         mimeType = mimeType,
         filename = filename
     ),
+    voicePlayerStore = voicePlayerStore,
     eventId = eventId,
     duration = duration,
 )