Add smooth animation to voice messages play progress (#7698)

* Add linear animation to voice message playback progress

Instead of animating the small `progress` value changes, calculate an animation for the range `maxProgress - progress`, with a linear interpolator so it's completely smooth. Previously, the progress was updated in 'steps' that were quite noticeable.

features/messages/api/src/main/kotlin/io/element/android/features/messages/api/timeline/voicemessages/composer/VoiceMessageComposerStatePreviewParam.kt

@@ -39,5 +39,6 @@ fun aVoiceMessagePreviewState() = VoiceMessageState.Preview(
     showCursor = false,
     playbackProgress = 0f,
     time = 10.seconds,
+    duration = 10.seconds,
     waveform = WaveFormSamples.realisticWaveForm,
 )

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

@@ -142,6 +142,9 @@ fun TimelineItemVoiceView(
             modifier = Modifier
                 .weight(1f)
                 .height(34.dp),
+            isPlaying = state.isPlaying,
+            durationMs = state.durationMs,
+            playbackSpeed = state.playbackSpeed,
             seekEnabled = !isTalkbackActive(),
             onSeek = { state.eventSink(VoiceMessageEvent.Seek(it)) },
         )

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/voicemessages/composer/DefaultVoiceMessageComposerPresenter.kt

@@ -245,12 +245,16 @@ class DefaultVoiceMessageComposerPresenter(
         val playerTime by remember(playerState, recorderState) { derivedStateOf { displayTime(playerState, recorderState) } }
         val waveform by remember(recorderState) { derivedStateOf { recorderState.finishedWaveform() } }
 
+        val recorderDuration = (recorderState as VoiceRecorderState.Finished).duration
+        val duration = playerState.durationMs?.milliseconds ?: recorderDuration
+
         return VoiceMessageState.Preview(
             isSending = isSending,
             isPlaying = playerState.isPlaying,
             showCursor = showCursor,
             playbackProgress = playerState.progress,
             time = playerTime,
+            duration = duration,
             waveform = waveform,
         )
     }

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/voicemessages/composer/VoiceMessageComposerPlayer.kt

@@ -63,6 +63,7 @@ class VoiceMessageComposerPlayer(
             playState = it.playState,
             currentPosition = it.currentPosition,
             progress = calcProgress(it),
+            durationMs = if (it.playState != PlayState.Stopped) it.duration else null,
         )
     }.distinctUntilChanged()
 
@@ -183,17 +184,20 @@ class VoiceMessageComposerPlayer(
      * @property playState Whether this player is currently playing. See [PlayState].
      * @property currentPosition The elapsed time of this player in milliseconds.
      * @property progress The progress of this player between 0 and 1.
+     * @property durationMs The player-reported duration in milliseconds, when known and the player is not stopped.
      */
     data class State(
         val playState: PlayState,
         val currentPosition: Long,
         val progress: Float,
+        val durationMs: Long?,
     ) {
         companion object {
             val Initial = State(
                 playState = PlayState.Stopped,
                 currentPosition = 0L,
                 progress = 0f,
+                durationMs = null,
             )
         }
 

features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/voicemessages/composer/DefaultVoiceMessageComposerPresenterTest.kt

@@ -103,6 +103,7 @@ class DefaultVoiceMessageComposerPresenterTest {
 
     companion object {
         private val RECORDING_DURATION = 1.seconds
+        private val PLAYER_DURATION = 10.seconds
         private val FIRST_LEVEL_DURATION = 500.milliseconds
         private val RECORDING_STATE = VoiceMessageState.Recording(RECORDING_DURATION, listOf(0.1f, 0.2f).toImmutableList())
         private val FIRST_RECORDING_STATE = VoiceMessageState.Recording(FIRST_LEVEL_DURATION, listOf(0.1f).toImmutableList())
@@ -266,6 +267,7 @@ class DefaultVoiceMessageComposerPresenterTest {
 
             val finalState = awaitItem()
             assertThat(finalState.voiceMessageState).isEqualTo(aPreviewState())
+            assertThat((finalState.voiceMessageState as VoiceMessageState.Preview).duration).isEqualTo(RECORDING_DURATION)
             startRecordResult.assertions().isCalledOnce()
             stopRecordResult.assertions().isCalledOnce().with(value(false))
             deleteRecordingResult.assertions().isNeverCalled()
@@ -302,6 +304,7 @@ class DefaultVoiceMessageComposerPresenterTest {
             awaitItem().eventSink(VoiceMessageComposerEvent.PlayerEvent(VoiceMessagePlayerEvent.Play))
             val finalState = awaitItem().also {
                 assertThat(it.voiceMessageState).isEqualTo(aPlayingState())
+                assertThat((it.voiceMessageState as VoiceMessageState.Preview).duration).isEqualTo(PLAYER_DURATION)
             }
             startRecordResult.assertions().isCalledOnce()
             stopRecordResult.assertions().isCalledOnce().with(value(false))
@@ -338,17 +341,30 @@ class DefaultVoiceMessageComposerPresenterTest {
             awaitItem().eventSink(VoiceMessageComposerEvent.RecorderEvent(VoiceMessageRecorderEvent.Stop))
             awaitItem().eventSink(VoiceMessageComposerEvent.PlayerEvent(VoiceMessagePlayerEvent.Seek(0.5f)))
             awaitItem().apply {
-                assertThat(voiceMessageState).isEqualTo(aPreviewState(playbackProgress = 0.5f, time = 0.seconds, showCursor = true))
+                assertThat(voiceMessageState).isEqualTo(
+                    aPreviewState(playbackProgress = 0.5f, time = 0.seconds, showCursor = true)
+                )
             }
             awaitItem().apply {
-                assertThat(voiceMessageState).isEqualTo(aPreviewState(playbackProgress = 0.5f, time = 5.seconds, showCursor = true))
+                assertThat(voiceMessageState).isEqualTo(
+                    aPreviewState(playbackProgress = 0.5f, time = 0.seconds, showCursor = true, duration = PLAYER_DURATION)
+                )
+            }
+            awaitItem().apply {
+                assertThat(voiceMessageState).isEqualTo(
+                    aPreviewState(playbackProgress = 0.5f, time = 5.seconds, showCursor = true, duration = PLAYER_DURATION)
+                )
                 eventSink(VoiceMessageComposerEvent.PlayerEvent(VoiceMessagePlayerEvent.Seek(0.2f)))
             }
             awaitItem().apply {
-                assertThat(voiceMessageState).isEqualTo(aPreviewState(playbackProgress = 0.2f, time = 5.seconds, showCursor = true))
+                assertThat(voiceMessageState).isEqualTo(
+                    aPreviewState(playbackProgress = 0.2f, time = 5.seconds, showCursor = true, duration = PLAYER_DURATION)
+                )
             }
             val finalState = awaitItem().apply {
-                assertThat(voiceMessageState).isEqualTo(aPreviewState(playbackProgress = 0.2f, time = 2.seconds, showCursor = true))
+                assertThat(voiceMessageState).isEqualTo(
+                    aPreviewState(playbackProgress = 0.2f, time = 2.seconds, showCursor = true, duration = PLAYER_DURATION)
+                )
             }
 
             testPauseAndDestroy(finalState)
@@ -827,6 +843,7 @@ class DefaultVoiceMessageComposerPresenterTest {
         playbackProgress: Float = 0f,
         isSending: Boolean = false,
         time: Duration = RECORDING_DURATION,
+        duration: Duration = RECORDING_DURATION,
         showCursor: Boolean = false,
         waveform: List<Float> = voiceRecorder.waveform,
     ) = VoiceMessageState.Preview(
@@ -834,6 +851,7 @@ class DefaultVoiceMessageComposerPresenterTest {
         playbackProgress = playbackProgress,
         isSending = isSending,
         time = time,
+        duration = duration,
         showCursor = showCursor,
         waveform = waveform.toImmutableList(),
     )
@@ -844,6 +862,7 @@ class DefaultVoiceMessageComposerPresenterTest {
             playbackProgress = 0.1f,
             showCursor = true,
             time = RECORDING_DURATION,
+            duration = PLAYER_DURATION,
         )
 
     private fun aPausedState() =