fix: Timeout on setting same source twice (#1520)

# Description

When setting the same source twice for a player, the `onPrepared` event
was not sent on most platform implementations.
Also fixing listening and canceling event stream on Android multiple times.

packages/audioplayers/example/integration_test/lib_test.dart

@@ -21,6 +21,9 @@ void main() {
   final isAndroid = !kIsWeb && Platform.isAndroid;
   final isLinux = !kIsWeb && Platform.isLinux;
 
+  // FIXME(gustl22): Cannot reuse event channel with same id on Linux (flutter/flutter#126209)
+  var linuxPlayerCount = 0;
+
   final wavUrl1TestData = LibSourceTestData(
     source: UrlSource(wavUrl1),
     duration: const Duration(milliseconds: 451),
@@ -245,8 +248,7 @@ void main() {
     testWidgets('Emit platform log', (tester) async {
       final logCompleter = Completer<String>();
 
-      // FIXME(gustl22): Cannot reuse event channel with same id on Linux (flutter/flutter#126209)
-      final playerId = isLinux ? 'somePlayerId0' : 'somePlayerId';
+      final playerId = 'somePlayerId${isLinux ? linuxPlayerCount++ : ''}';
       final player = AudioPlayer(playerId: playerId);
       final onLogSub = player.onLog.listen(
         logCompleter.complete,
@@ -331,8 +333,7 @@ void main() {
     testWidgets('#create and #dispose', (tester) async {
       final platform = AudioplayersPlatformInterface.instance;
 
-      // FIXME(gustl22): Cannot reuse event channel with same id on Linux (flutter/flutter#126209)
-      final playerId = isLinux ? 'somePlayerId1' : 'somePlayerId';
+      final playerId = 'somePlayerId${isLinux ? linuxPlayerCount++ : ''}';
       await platform.create(playerId);
       await tester.pumpAndSettle();
       await platform.dispose(playerId);
@@ -353,8 +354,7 @@ void main() {
     testWidgets('#setSource #getPosition and #getDuration', (tester) async {
       final platform = AudioplayersPlatformInterface.instance;
 
-      // FIXME(gustl22): Cannot reuse event channel with same id on Linux (flutter/flutter#126209)
-      final playerId = isLinux ? 'somePlayerId2' : 'somePlayerId';
+      final playerId = 'somePlayerId${isLinux ? linuxPlayerCount++ : ''}';
       await platform.create(playerId);
 
       final preparedCompleter = Completer<void>();
@@ -392,10 +392,65 @@ void main() {
         await platform.dispose(playerId);
       }
     });
+
+    testWidgets('Set same source twice (#1520)', (tester) async {
+      final platform = AudioplayersPlatformInterface.instance;
+
+      final playerId = 'somePlayerId${isLinux ? linuxPlayerCount++ : ''}';
+      await platform.create(playerId);
+
+      final eventStream = platform.getEventStream(playerId);
+      for (var i = 0; i < 2; i++) {
+        final preparedCompleter = Completer<void>();
+        final onPreparedSub = eventStream
+            .where((event) => event.eventType == AudioEventType.prepared)
+            .map((event) => event.isPrepared!)
+            .listen(
+          (isPrepared) {
+            if (isPrepared) {
+              preparedCompleter.complete();
+            }
+          },
+          onError: preparedCompleter.completeError,
+        );
+        if (isLinux) {
+          // FIXME(gustl22): Linux needs additional pump (#1507)
+          await tester.pump();
+        }
+        await platform.setSourceUrl(
+          playerId,
+          (wavUrl1TestData.source as UrlSource).url,
+        );
+        await preparedCompleter.future.timeout(const Duration(seconds: 30));
+        await onPreparedSub.cancel();
+      }
+      if (!isLinux) {
+        // FIXME(gustl22): Linux not disposing properly (#1507)
+        await platform.dispose(playerId);
+      }
+    });
   });
 
   group('Platform event channel', () {
-    // TODO(gustl22): remove once https://github.com/flutter/flutter/issues/126209 is fixed
+    testWidgets('Listen and cancel twice', (tester) async {
+      final platform = AudioplayersPlatformInterface.instance;
+
+      final playerId = 'somePlayerId${isLinux ? linuxPlayerCount++ : ''}';
+      await platform.create(playerId);
+
+      final eventStream = platform.getEventStream(playerId);
+      for (var i = 0; i < 2; i++) {
+        final eventSub = eventStream.listen(null);
+        await eventSub.cancel();
+      }
+      if (!isLinux) {
+        // FIXME(gustl22): Linux not disposing properly (#1507)
+        await platform.dispose(playerId);
+      }
+    });
+
+    // TODO(gustl22): remove once https://github.com/flutter/flutter/issues/126209
+    // is fixed, as tests should cover the problem in flutter engine.
     testWidgets(
       'Reuse same platform event channel id',
       (tester) async {
@@ -425,8 +480,7 @@ void main() {
       final errorCompleter = Completer<Object>();
       final platform = AudioplayersPlatformInterface.instance;
 
-      // FIXME(gustl22): Cannot reuse event channel with same id on Linux (flutter/flutter#126209)
-      final playerId = isLinux ? 'somePlayerId3' : 'somePlayerId';
+      final playerId = 'somePlayerId${isLinux ? linuxPlayerCount++ : ''}';
       await platform.create(playerId);
 
       final eventStreamSub = platform

packages/audioplayers_android/android/src/main/kotlin/xyz/luan/audioplayers/AudioplayersPlugin.kt

@@ -353,7 +353,6 @@ class EventHandler(private val eventChannel: EventChannel) : EventChannel.Stream
 
     override fun onCancel(arguments: Any?) {
         eventSink = null
-        eventChannel.setStreamHandler(null)
     }
 
     fun success(method: String, arguments: Map<String, Any> = HashMap()) {
@@ -369,5 +368,6 @@ class EventHandler(private val eventChannel: EventChannel) : EventChannel.Stream
             it.endOfStream()
             onCancel(null)
         }
+        eventChannel.setStreamHandler(null)
     }
 }

packages/audioplayers_android/android/src/main/kotlin/xyz/luan/audioplayers/player/WrappedPlayer.kt

@@ -34,6 +34,8 @@ class WrappedPlayer internal constructor(
                     playing = false
                     player?.release()
                 }
+            } else {
+                ref.handlePrepared(this, true)
             }
         }
 

packages/audioplayers_linux/linux/audio_player.cc

@@ -72,6 +72,8 @@ void AudioPlayer::SetSourceUrl(std::string url) {
                 }
             }
         }
+    } else {
+        this->OnPrepared(true);
     }
 }
 

packages/audioplayers_web/lib/wrapped_player.dart

@@ -30,7 +30,13 @@ class WrappedPlayer {
 
   Future<void> setUrl(String url) async {
     if (_currentUrl == url) {
-      return; // nothing to do
+      eventStreamController.add(
+        const AudioEvent(
+          eventType: AudioEventType.prepared,
+          isPrepared: true,
+        ),
+      );
+      return;
     }
     _currentUrl = url;
 

packages/audioplayers_windows/windows/audio_player.cpp

@@ -69,6 +69,8 @@ void AudioPlayer::SetSourceUrl(std::string url) {
             // Forward errors to event stream, as this is called asynchronously
             this->OnError("WindowsAudioError", "Error setting url to '" + url + "'.", nullptr);
         }
+    } else {
+        OnPrepared(true);
     }
 }