Add variable playback speed feature for voice messages

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/event/TimelineItemVoiceView.kt

@@ -8,6 +8,8 @@
 package io.element.android.features.messages.impl.timeline.components.event
 
 import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
@@ -16,6 +18,7 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.IconButtonDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
@@ -109,19 +112,30 @@ fun TimelineItemVoiceView(
             }
         }
         Spacer(Modifier.width(8.dp))
-        Text(
-            text = state.time,
-            color = ElementTheme.colors.textSecondary,
-            style = ElementTheme.typography.fontBodySmMedium,
-            maxLines = 1,
-            overflow = TextOverflow.Ellipsis,
-        )
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(2.dp),
+        ) {
+            PlaybackSpeedButton(
+                speed = state.playbackSpeed,
+                onClick = { state.eventSink(VoiceMessageEvents.ChangePlaybackSpeed) },
+            )
+            Text(
+                text = state.time,
+                color = ElementTheme.colors.textSecondary,
+                style = ElementTheme.typography.fontBodySmMedium,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
         Spacer(Modifier.width(8.dp))
         WaveformPlaybackView(
             showCursor = state.showCursor,
             playbackProgress = state.progress,
             waveform = content.waveform,
-            modifier = Modifier.height(34.dp),
+            modifier = Modifier
+                .weight(1f)
+                .height(34.dp),
             seekEnabled = !isTalkbackActive(),
             onSeek = { state.eventSink(VoiceMessageEvents.Seek(it)) },
         )
@@ -172,6 +186,36 @@ private fun RetryButton(
     }
 }
 
+@Composable
+private fun PlaybackSpeedButton(
+    speed: Float,
+    onClick: () -> Unit,
+) {
+    val speedText = when (speed) {
+        0.5f -> "0.5×"
+        1.0f -> "1×"
+        1.5f -> "1.5×"
+        2.0f -> "2×"
+        else -> "${speed}×"
+    }
+    androidx.compose.foundation.layout.Box(
+        modifier = Modifier
+            .background(
+                color = ElementTheme.colors.bgCanvasDefault,
+                shape = RoundedCornerShape(12.dp)
+            )
+            .padding(horizontal = 8.dp, vertical = 4.dp)
+            .clickable(onClick = onClick),
+        contentAlignment = Alignment.Center,
+    ) {
+        Text(
+            text = speedText,
+            color = ElementTheme.colors.iconSecondary,
+            style = ElementTheme.typography.fontBodyXsMedium,
+        )
+    }
+}
+
 @Composable
 private fun ControlIcon(
     imageVector: ImageVector,
@@ -295,3 +339,14 @@ internal fun ProgressButtonPreview() = ElementPreview {
         ProgressButton(displayImmediately = false)
     }
 }
+
+@PreviewsDayNight
+@Composable
+internal fun PlaybackSpeedButtonPreview() = ElementPreview {
+    Row {
+        PlaybackSpeedButton(speed = 0.5f, onClick = {})
+        PlaybackSpeedButton(speed = 1.0f, onClick = {})
+        PlaybackSpeedButton(speed = 1.5f, onClick = {})
+        PlaybackSpeedButton(speed = 2.0f, onClick = {})
+    }
+}

libraries/mediaplayer/api/src/main/kotlin/io/element/android/libraries/mediaplayer/api/MediaPlayer.kt

@@ -46,6 +46,12 @@ interface MediaPlayer : AutoCloseable {
      */
     fun seekTo(positionMs: Long)
 
+    /**
+     * Sets the playback speed.
+     * @param speed The playback speed (e.g., 0.5f for half speed, 1.0f for normal, 2.0f for double speed)
+     */
+    fun setPlaybackSpeed(speed: Float)
+
     /**
      * Releases any resources associated with this player.
      */

libraries/mediaplayer/impl/src/main/kotlin/io/element/android/libraries/mediaplayer/impl/DefaultMediaPlayer.kt

@@ -160,6 +160,10 @@ class DefaultMediaPlayer(
         }
     }
 
+    override fun setPlaybackSpeed(speed: Float) {
+        player.setPlaybackSpeed(speed)
+    }
+
     override fun close() {
         player.release()
     }

libraries/mediaplayer/impl/src/main/kotlin/io/element/android/libraries/mediaplayer/impl/SimplePlayer.kt

@@ -33,6 +33,7 @@ interface SimplePlayer {
     fun isPlaying(): Boolean
     fun pause()
     fun seekTo(positionMs: Long)
+    fun setPlaybackSpeed(speed: Float)
     fun release()
     interface Listener {
         fun onIsPlayingChanged(isPlaying: Boolean)
@@ -87,5 +88,9 @@ class DefaultSimplePlayer(
 
     override fun seekTo(positionMs: Long) = p.seekTo(positionMs)
 
+    override fun setPlaybackSpeed(speed: Float) {
+        p.setPlaybackParameters(p.playbackParameters.withSpeed(speed))
+    }
+
     override fun release() = p.release()
 }

libraries/mediaplayer/impl/src/test/kotlin/io/element/android/libraries/mediaplayer/impl/FakeSimplePlayer.kt

@@ -19,6 +19,7 @@ class FakeSimplePlayer(
     private val isPlayingLambda: () -> Boolean = { lambdaError() },
     private val pauseLambda: () -> Unit = { lambdaError() },
     private val seekToLambda: (Long) -> Unit = { lambdaError() },
+    private val setPlaybackSpeedLambda: (Float) -> Unit = { lambdaError() },
     private val releaseLambda: () -> Unit = { lambdaError() },
 ) : SimplePlayer {
     private val listeners = mutableListOf<SimplePlayer.Listener>()
@@ -44,6 +45,7 @@ class FakeSimplePlayer(
     override fun isPlaying() = isPlayingLambda()
     override fun pause() = pauseLambda()
     override fun seekTo(positionMs: Long) = seekToLambda(positionMs)
+    override fun setPlaybackSpeed(speed: Float) = setPlaybackSpeedLambda(speed)
     override fun release() = releaseLambda()
 
     fun simulateIsPlayingChanged(isPlaying: Boolean) {

libraries/mediaplayer/test/src/main/kotlin/io/element/android/libraries/mediaplayer/test/FakeMediaPlayer.kt

@@ -95,6 +95,10 @@ class FakeMediaPlayer(
         }
     }
 
+    override fun setPlaybackSpeed(speed: Float) {
+        // no-op
+    }
+
     override fun close() {
         // no-op
     }

libraries/mediaviewer/impl/src/main/kotlin/io/element/android/libraries/mediaviewer/impl/gallery/ui/VoiceItemView.kt

@@ -9,7 +9,9 @@ package io.element.android.libraries.mediaviewer.impl.gallery.ui
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.combinedClickable
+import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
@@ -119,13 +121,22 @@ private fun VoiceInfoRow(
             VoiceMessageState.Button.Disabled -> PlayButton(onClick = {}, enabled = false)
         }
         Spacer(Modifier.width(8.dp))
-        Text(
-            text = if (state.progress > 0f) state.time else voice.mediaInfo.duration ?: state.time,
-            color = ElementTheme.colors.textSecondary,
-            style = ElementTheme.typography.fontBodyMdMedium,
-            maxLines = 1,
-            overflow = TextOverflow.Ellipsis,
-        )
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(2.dp),
+        ) {
+            PlaybackSpeedButton(
+                speed = state.playbackSpeed,
+                onClick = { state.eventSink(VoiceMessageEvents.ChangePlaybackSpeed) },
+            )
+            Text(
+                text = if (state.progress > 0f) state.time else voice.mediaInfo.duration ?: state.time,
+                color = ElementTheme.colors.textSecondary,
+                style = ElementTheme.typography.fontBodyMdMedium,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
         Spacer(modifier = Modifier.width(8.dp))
         WaveformPlaybackView(
             modifier = Modifier
@@ -223,6 +234,36 @@ private fun RetryButton(
     }
 }
 
+@Composable
+private fun PlaybackSpeedButton(
+    speed: Float,
+    onClick: () -> Unit,
+) {
+    val speedText = when (speed) {
+        0.5f -> "0.5×"
+        1.0f -> "1×"
+        1.5f -> "1.5×"
+        2.0f -> "2×"
+        else -> "${speed}×"
+    }
+    androidx.compose.foundation.layout.Box(
+        modifier = Modifier
+            .background(
+                color = ElementTheme.colors.bgCanvasDefault,
+                shape = RoundedCornerShape(12.dp)
+            )
+            .padding(horizontal = 8.dp, vertical = 4.dp)
+            .clickable(onClick = onClick),
+        contentAlignment = Alignment.Center,
+    ) {
+        Text(
+            text = speedText,
+            color = ElementTheme.colors.iconSecondary,
+            style = ElementTheme.typography.fontBodyXsMedium,
+        )
+    }
+}
+
 @Composable
 private fun ControlIcon(
     imageVector: ImageVector,
@@ -283,3 +324,14 @@ internal fun VoiceItemViewPlayPreview(
         onLongClick = {},
     )
 }
+
+@PreviewsDayNight
+@Composable
+internal fun PlaybackSpeedButtonPreview() = ElementPreview {
+    Row {
+        PlaybackSpeedButton(speed = 0.5f, onClick = {})
+        PlaybackSpeedButton(speed = 1.0f, onClick = {})
+        PlaybackSpeedButton(speed = 1.5f, onClick = {})
+        PlaybackSpeedButton(speed = 2.0f, onClick = {})
+    }
+}

libraries/voiceplayer/api/src/main/kotlin/io/element/android/libraries/voiceplayer/api/VoiceMessageEvents.kt

@@ -10,4 +10,5 @@ package io.element.android.libraries.voiceplayer.api
 sealed interface VoiceMessageEvents {
     data object PlayPause : VoiceMessageEvents
     data class Seek(val percentage: Float) : VoiceMessageEvents
+    data object ChangePlaybackSpeed : VoiceMessageEvents
 }

libraries/voiceplayer/api/src/main/kotlin/io/element/android/libraries/voiceplayer/api/VoiceMessageState.kt

@@ -12,6 +12,7 @@ data class VoiceMessageState(
     val progress: Float,
     val time: String,
     val showCursor: Boolean,
+    val playbackSpeed: Float,
     val eventSink: (event: VoiceMessageEvents) -> Unit,
 ) {
     enum class Button {

libraries/voiceplayer/api/src/main/kotlin/io/element/android/libraries/voiceplayer/api/VoiceMessageStateProvider.kt

@@ -47,10 +47,12 @@ fun aVoiceMessageState(
     progress: Float = 0f,
     time: String = "1:00",
     showCursor: Boolean = false,
+    playbackSpeed: Float = 1.0f,
 ) = VoiceMessageState(
     button = button,
     progress = progress,
     time = time,
     showCursor = showCursor,
+    playbackSpeed = playbackSpeed,
     eventSink = {},
 )

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

@@ -79,6 +79,13 @@ interface VoiceMessagePlayer {
      */
     fun seekTo(positionMs: Long)
 
+    /**
+     * Set the playback speed.
+     *
+     * @param speed The playback speed (e.g., 0.5f for half speed, 1.0f for normal, 2.0f for double speed)
+     */
+    fun setPlaybackSpeed(speed: Float)
+
     data class State(
         /**
          * Whether the player is ready to play.
@@ -218,6 +225,10 @@ class Factory(
         }
     }
 
+    override fun setPlaybackSpeed(speed: Float) {
+        mediaPlayer.setPlaybackSpeed(speed)
+    }
+
     private val MediaPlayer.State.isMyTrack: Boolean
         get() = if (eventId == null) false else this.mediaId == eventId.value
 

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

@@ -37,6 +37,9 @@ class VoiceMessagePresenter(
     private val duration: Duration,
 ) : Presenter<VoiceMessageState> {
     private val play = mutableStateOf<AsyncData<Unit>>(AsyncData.Uninitialized)
+    private val playbackSpeed = mutableStateOf(1.0f)
+
+    private val availablePlaybackSpeeds = listOf(0.5f, 1.0f, 1.5f, 2.0f)
 
     @Composable
     override fun present(): VoiceMessageState {
@@ -111,6 +114,13 @@ class VoiceMessagePresenter(
                 is VoiceMessageEvents.Seek -> {
                     player.seekTo((event.percentage * duration).toLong())
                 }
+                is VoiceMessageEvents.ChangePlaybackSpeed -> {
+                    val currentIndex = availablePlaybackSpeeds.indexOf(playbackSpeed.value)
+                    val nextIndex = (currentIndex + 1) % availablePlaybackSpeeds.size
+                    val newSpeed = availablePlaybackSpeeds[nextIndex]
+                    playbackSpeed.value = newSpeed
+                    player.setPlaybackSpeed(newSpeed)
+                }
             }
         }
 
@@ -119,6 +129,7 @@ class VoiceMessagePresenter(
             progress = progress,
             time = time,
             showCursor = showCursor,
+            playbackSpeed = playbackSpeed.value,
             eventSink = { eventSink(it) },
         )
     }

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

@@ -222,6 +222,40 @@ class VoiceMessagePresenterTest {
             }
         }
     }
+
+    @Test
+    fun `changing playback speed cycles through available speeds`() = runTest {
+        val presenter = createVoiceMessagePresenter(
+            duration = 10_000.milliseconds,
+        )
+        moleculeFlow(RecompositionMode.Immediate) {
+            presenter.present()
+        }.test {
+            val initialState = awaitItem().also {
+                assertThat(it.playbackSpeed).isEqualTo(1.0f)
+            }
+
+            initialState.eventSink(VoiceMessageEvents.ChangePlaybackSpeed)
+            awaitItem().also {
+                assertThat(it.playbackSpeed).isEqualTo(1.5f)
+            }
+
+            initialState.eventSink(VoiceMessageEvents.ChangePlaybackSpeed)
+            awaitItem().also {
+                assertThat(it.playbackSpeed).isEqualTo(2.0f)
+            }
+
+            initialState.eventSink(VoiceMessageEvents.ChangePlaybackSpeed)
+            awaitItem().also {
+                assertThat(it.playbackSpeed).isEqualTo(0.5f)
+            }
+
+            initialState.eventSink(VoiceMessageEvents.ChangePlaybackSpeed)
+            awaitItem().also {
+                assertThat(it.playbackSpeed).isEqualTo(1.0f)
+            }
+        }
+    }
 }
 
 fun TestScope.createVoiceMessagePresenter(