Prevent shared element animation when we're not on the initial media.

app/src/main/java/org/thoughtcrime/securesms/mediapreview/MediaPreviewV2Activity.kt

@@ -25,6 +25,9 @@ class MediaPreviewV2Activity : PassphraseRequiredActivity(), VoiceNoteMediaContr
 
   private val viewModel: MediaPreviewV2ViewModel by viewModels()
   private val lifecycleDisposable = LifecycleDisposable()
+  private val args by lazy {
+    MediaIntentFactory.requireArguments(intent.extras!!)
+  }
 
   private lateinit var transitionImageView: ImageView
 
@@ -34,8 +37,6 @@ class MediaPreviewV2Activity : PassphraseRequiredActivity(), VoiceNoteMediaContr
   }
 
   override fun onCreate(savedInstanceState: Bundle?, ready: Boolean) {
-    val args = MediaIntentFactory.requireArguments(intent.extras!!)
-
     if (MediaPreviewCache.drawable != null) {
       val originalCorners = ShapeAppearanceModel.Builder()
         .setTopLeftCornerSize(args.sharedElementArgs.topLeft)
@@ -122,6 +123,14 @@ class MediaPreviewV2Activity : PassphraseRequiredActivity(), VoiceNoteMediaContr
     MediaPreviewCache.drawable = null
   }
 
+  override fun finishAfterTransition() {
+    if (viewModel.shouldFinishAfterTransition(args.initialMediaUri)) {
+      super.finishAfterTransition()
+    } else {
+      super.finish()
+    }
+  }
+
   companion object {
     private const val FRAGMENT_TAG = "media_preview_fragment_v2"
     const val SHARED_ELEMENT_TRANSITION_NAME = "thumb"

app/src/main/java/org/thoughtcrime/securesms/mediapreview/MediaPreviewV2ViewModel.kt

@@ -2,6 +2,7 @@ package org.thoughtcrime.securesms.mediapreview
 
 import android.content.Context
 import android.content.Intent
+import android.net.Uri
 import androidx.lifecycle.ViewModel
 import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers
 import io.reactivex.rxjava3.core.Completable
@@ -31,6 +32,10 @@ class MediaPreviewV2ViewModel : ViewModel() {
     store.update { it.copy(isInSharedAnimation = isInSharedAnimation) }
   }
 
+  fun shouldFinishAfterTransition(initialMediaUri: Uri): Boolean {
+    return currentPosition in store.state.mediaRecords.indices && store.state.mediaRecords[currentPosition].toMedia()?.uri == initialMediaUri
+  }
+
   fun fetchAttachments(context: Context, startingAttachmentId: AttachmentId, threadId: Long, sorting: MediaTable.Sorting, forceRefresh: Boolean = false) {
     if (store.state.loadState == MediaPreviewV2State.LoadState.INIT || forceRefresh) {
       disposables += store.update(repository.getAttachments(context, startingAttachmentId, threadId, sorting)) { result: MediaPreviewRepository.Result, oldState: MediaPreviewV2State ->