Avoid unnecessary transition setup in reader if not transitioning

app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaController.kt

@@ -891,15 +891,20 @@ class MangaController :
 
     private fun openChapter(chapter: Chapter, sharedElement: View? = null) {
         val activity = activity ?: return
-        val intent = ReaderActivity.newIntent(activity, presenter.manga, chapter)
         activity.apply {
+            val intent = ReaderActivity.newIntent(activity, presenter.manga, chapter)
             if (sharedElement != null && Build.VERSION.SDK_INT != Build.VERSION_CODES.O) {
                 val activityOptions = ActivityOptions.makeSceneTransitionAnimation(
                     activity,
                     sharedElement,
                     ReaderActivity.SHARED_ELEMENT_NAME
                 )
-                startActivity(intent, activityOptions.toBundle())
+                startActivity(
+                    intent.apply {
+                        putExtra(ReaderActivity.EXTRA_IS_TRANSITION, true)
+                    },
+                    activityOptions.toBundle(),
+                )
             } else {
                 startActivity(intent)
             }

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt

@@ -43,6 +43,7 @@ import com.google.android.material.slider.Slider
 import com.google.android.material.transition.platform.MaterialContainerTransform
 import com.google.android.material.transition.platform.MaterialContainerTransformSharedElementCallback
 import dev.chrisbanes.insetter.applyInsetter
+import eu.kanade.tachiyomi.BuildConfig
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.database.models.Chapter
 import eu.kanade.tachiyomi.data.database.models.Manga
@@ -110,6 +111,7 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
         private const val ENABLED_BUTTON_IMAGE_ALPHA = 255
         private const val DISABLED_BUTTON_IMAGE_ALPHA = 64
 
+        const val EXTRA_IS_TRANSITION = "${BuildConfig.APPLICATION_ID}.READER_IS_TRANSITION"
         const val SHARED_ELEMENT_NAME = "reader_shared_element_root"
     }
 
@@ -158,15 +160,17 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
         applyAppTheme(preferences)
 
         // Setup shared element transitions
-        window.requestFeature(Window.FEATURE_ACTIVITY_TRANSITIONS)
-        findViewById<View>(android.R.id.content)?.let { contentView ->
-            contentView.transitionName = SHARED_ELEMENT_NAME
-            setEnterSharedElementCallback(MaterialContainerTransformSharedElementCallback())
-            window.sharedElementEnterTransition = buildContainerTransform(true)
-            window.sharedElementReturnTransition = buildContainerTransform(false)
-
-            // Postpone custom transition until manga ready
-            postponeEnterTransition()
+        if (intent.extras?.getBoolean(EXTRA_IS_TRANSITION) == true) {
+            window.requestFeature(Window.FEATURE_ACTIVITY_TRANSITIONS)
+            findViewById<View>(android.R.id.content)?.let { contentView ->
+                contentView.transitionName = SHARED_ELEMENT_NAME
+                setEnterSharedElementCallback(MaterialContainerTransformSharedElementCallback())
+                window.sharedElementEnterTransition = buildContainerTransform(true)
+                window.sharedElementReturnTransition = buildContainerTransform(false)
+
+                // Postpone custom transition until manga ready
+                postponeEnterTransition()
+            }
         }
 
         super.onCreate(savedInstanceState)