Simple live waveform implementation.

libraries/voicerecorder/api/src/main/kotlin/io/element/android/libraries/voicerecorder/api/VoiceRecorderState.kt

@@ -29,9 +29,9 @@ sealed class VoiceRecorderState {
      * The recorder is currently recording.
      *
      * @property elapsedTime The elapsed time since the recording started.
-     * @property level The current audio level of the recording as a fraction of 1.
+     * @property levels The current audio levels of the recording as a fraction of 1.
      */
-    data class Recording(val elapsedTime: Duration, val level: Float) : VoiceRecorderState()
+    data class Recording(val elapsedTime: Duration, val levels: List<Float>) : VoiceRecorderState()
 
     /**
      * The recorder has finished recording.

libraries/voicerecorder/impl/src/main/kotlin/io/element/android/libraries/voicerecorder/impl/VoiceRecorderImpl.kt

@@ -96,13 +96,13 @@ class VoiceRecorderImpl @Inject constructor(
                 when (audio) {
                     is Audio.Data -> {
                         val audioLevel = audioLevelCalculator.calculateAudioLevel(audio.buffer)
-                        _state.emit(VoiceRecorderState.Recording(elapsedTime, audioLevel))
                         levels.add(audioLevel)
+                        _state.emit(VoiceRecorderState.Recording(elapsedTime, levels))
                         encoder.encode(audio.buffer, audio.readSize)
                     }
                     is Audio.Error -> {
                         Timber.e("Voice message error: code=${audio.audioRecordErrorCode}")
-                        _state.emit(VoiceRecorderState.Recording(elapsedTime, 0.0f))
+                        _state.emit(VoiceRecorderState.Recording(elapsedTime, listOf()))
                     }
                 }
             }