stream-chat-android-ui-components/src/main/kotlin/io/getstream/chat/android/ui/feature/gallery/AttachmentMediaActivity.kt (1)

66-97: Fix lifecycle safety: add finish() after invalid input, null-check URL before player creation, and preserve play state on resume

Line 77-81: onCreate() returns without finish() after validation fails, allowing onStart() to proceed with invalid data. Add finish() after showPlaybackError().

Line 92: onStart() directly passes nullable url to Uri.parse(url) without null checking. This will crash if inputs were invalid but onCreate() didn't finish. Add a null guard or capture url before use.

Line 108: onStop() hard-codes autoPlay = false, losing the actual play state. When resuming, the player always resumes paused. Capture player?.playWhenReady before pausing in onPause() instead.

Proposed diff

     if ((type.isNullOrEmpty() && mimeType.isNullOrEmpty()) || url.isNullOrEmpty()) {
         logger.e { "This file can't be displayed. The TYPE or the URL are null" }
         showPlaybackError()
+        finish()
         return
     }

 override fun onStart() {
     super.onStart()
     // (Re)create player when returning to foreground.
+    val mediaUrl = url ?: return
     player = createPlayer()
         .apply {
-            setMediaItem(MediaItem.fromUri(Uri.parse(url)), savedPlaybackPosition)
+            setMediaItem(MediaItem.fromUri(Uri.parse(mediaUrl)), savedPlaybackPosition)
             prepare()
             playWhenReady = autoPlay
         }
         .also(::setupPlayerView)
 }

 override fun onPause() {
     super.onPause()
+    // Capture whether we should resume playing before pause() flips playWhenReady to false.
+    autoPlay = player?.playWhenReady == true
     player?.pause()
 }

 override fun onStop() {
     super.onStop()
     // Save playback position and release player to free wake lock.
     savedPlaybackPosition = player?.currentPosition ?: 0L
-    autoPlay = false
+    binding.playerView.player = null
+    binding.controls.player = null
     player?.release()
     player = null
 }

stream-chat-android-compose/src/main/java/io/getstream/chat/android/compose/ui/attachments/preview/MediaGalleryPreviewScreen.kt (1)

551-610: Add bounds check and clear stale media when assetUrl is missing

1. Line 563 accesses attachments[currentPage] without checking bounds. Since LaunchedEffect depends only on (currentPage, player) and not attachments, if the attachments list shrinks while currentPage remains the same, this causes an IndexOutOfBoundsException.

2. When attachment.isVideo() is true but assetUrl is null (lines 565–576), the player retains the previous media item. The video page then renders with stale content that may not match the current page.

3. The onPlaybackError callback captured in DisposableEffect (line 29) is not wrapped with rememberUpdatedState, so if the callback changes, the lifecycle observer retains a stale reference.

Proposed fixes

+    val onPlaybackErrorState = rememberUpdatedState(onPlaybackError)

     LaunchedEffect(currentPage, player) {
         player?.let { activePlayer ->
             activePlayer.pause() // Pause the player when the page changes
+            if (currentPage !in attachments.indices) return@LaunchedEffect
             val attachment = attachments[currentPage]
             // Prepare the player with the media item if it's a video.
             if (attachment.isVideo()) {
                 attachment.assetUrl?.let { assetUrl ->
                     // Restore playback position if returning to the same page after app resume.
                     val startPosition = savedPlaybackState
                         ?.takeIf { (savedPage, _) => savedPage == currentPage }
                         ?.second
                         ?: 0L
                     savedPlaybackState = null
                     activePlayer.setMediaItem(MediaItem.fromUri(assetUrl), startPosition)
                     activePlayer.prepare()
-                }
+                } ?: run {
+                    // Prevent playing previous page's media
+                    activePlayer.stop()
+                    activePlayer.clearMediaItems()
+                }
             }
         }
     }

     DisposableEffect(lifecycleOwner, previewMode) {
         val observer = LifecycleEventObserver { _, event ->
             when (event) {
                 Lifecycle.Event.ON_START -> {
                     if (!previewMode && player == null) {
                         player = createPlayer(
                             context = context,
                             onBuffering = { isBuffering -> showBuffering = isBuffering },
-                            onPlaybackError = onPlaybackError,
+                            onPlaybackError = onPlaybackErrorState.value,
                         )
                     }
                 }

stream-chat-android-ui-components/src/main/kotlin/io/getstream/chat/android/ui/feature/gallery/AttachmentMediaActivity.kt (1)

66-98: Add finish() call in onCreate() when invalid inputs detected to prevent crash in onStart().

The issue is valid. The url property is nullable (String?), and when it's null, onCreate() returns after calling showPlaybackError() without invoking finish(). Since binding is already initialized before this validation check, the safety check in onStart() (if (!::binding.isInitialized) return) won't prevent execution. When the activity resumes, onStart() will attempt to pass the null url to Uri.parse(url), risking a crash or undefined behavior.

The proposed fix is correct:

• Add finish() in onCreate() after showPlaybackError() to terminate the activity lifecycle
• Add defensive null check in onStart() as a safety measure

The androidx.media3 API (Player.setMediaItem() and Player.release()) is available in the configured version.