ReaderActivity: Fix transition crash on Android 8 (#6542)

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

@@ -30,6 +30,7 @@ import android.view.animation.AnimationUtils
 import android.widget.FrameLayout
 import android.widget.Toast
 import androidx.core.graphics.ColorUtils
+import androidx.core.transition.addListener
 import androidx.core.view.WindowCompat
 import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.WindowInsetsControllerCompat
@@ -609,7 +610,14 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
         val newViewer = ReadingModeType.toViewer(presenter.getMangaReadingMode(), this)
 
         updateCropBordersShortcut()
-        setOrientation(presenter.getMangaOrientationType())
+        if (window.sharedElementEnterTransition is MaterialContainerTransform) {
+            // Wait until transition is complete to avoid crash on API 26
+            window.sharedElementEnterTransition.addListener(
+                onEnd = { setOrientation(presenter.getMangaOrientationType()) }
+            )
+        } else {
+            setOrientation(presenter.getMangaOrientationType())
+        }
 
         // Destroy previous viewer if there was one
         if (prevViewer != null) {