Autoplay the next voice message if it is the next timeline item. (#6089)

ElementX/Sources/Services/MediaPlayer/MediaPlayerProvider.swift

@@ -6,11 +6,14 @@
 // Please see LICENSE files in the repository root for full details.
 //
 
+import AVFoundation
 import Foundation
 
 class MediaPlayerProvider: MediaPlayerProviderProtocol {
     private lazy var audioPlayer = AudioPlayer()
     private var audioPlayerStates: [String: AudioPlayerState] = [:]
+    /// Held onto for the duration of the playback, an unowned player is silent.
+    private var soundEffectPlayer: AVAudioPlayer?
     
     var player: AudioPlayerProtocol {
         audioPlayer
@@ -55,6 +58,17 @@ class MediaPlayerProvider: MediaPlayerProviderProtocol {
         }
     }
     
+    /// Doesn't configure an audio session, so that it can be used alongside any existing player or session.
+    func play(soundEffect: SoundEffect) {
+        do {
+            let player = try AVAudioPlayer(contentsOf: soundEffect.fileURL)
+            soundEffectPlayer = player
+            player.play()
+        } catch {
+            MXLog.error("Failed playing the sound effect: \(error)")
+        }
+    }
+    
     // MARK: - Private
     
     private func audioPlayerStateID(for identifier: AudioPlayerStateIdentifier) -> String? {

ElementX/Sources/Services/MediaPlayer/MediaPlayerProviderProtocol.swift

@@ -8,6 +8,17 @@
 
 import Foundation
 
+enum SoundEffect {
+    /// A short, light blip.
+    case tink
+    
+    var fileURL: URL {
+        switch self {
+        case .tink: URL.systemSoundsDirectory.appending(component: "Tink.caf")
+        }
+    }
+}
+
 protocol MediaPlayerProviderProtocol {
     var player: AudioPlayerProtocol { get }
     
@@ -15,6 +26,10 @@ protocol MediaPlayerProviderProtocol {
     func register(audioPlayerState: AudioPlayerState)
     func unregister(audioPlayerState: AudioPlayerState)
     func detachAllStates(except exception: AudioPlayerState?) async
+    
+    /// Plays a short sound on top of whatever is already playing. It goes through the app's own
+    /// audio session, so unlike the sounds built into iOS it is heard in silent mode too.
+    func play(soundEffect: SoundEffect)
 }
 
 // sourcery: AutoMockable