Trigger pending transition at right time for video gifs.

app/src/main/java/org/thoughtcrime/securesms/mediasend/VideoEditorFragment.java

@@ -93,6 +93,22 @@ public class VideoEditorFragment extends Fragment implements VideoEditorHud.Even
     player.setVideoSource(slide, true);
 
     if (slide.isVideoGif()) {
+      player.setPlayerCallback(new VideoPlayer.PlayerCallback() {
+        @Override
+        public void onPlaying() {
+          controller.onPlayerReady();
+        }
+
+        @Override
+        public void onStopped() {
+          // Do nothing.
+        }
+
+        @Override
+        public void onError() {
+          controller.onPlayerError();
+        }
+      });
       player.hideControls();
       player.loopForever();
     } else if (MediaConstraints.isVideoTranscodeAvailable()) {

app/src/main/java/org/thoughtcrime/securesms/mediasend/v2/gif/MediaReviewGifPageFragment.kt

@@ -0,0 +1,65 @@
+package org.thoughtcrime.securesms.mediasend.v2.gif
+
+import android.net.Uri
+import android.os.Bundle
+import android.view.View
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
+import org.thoughtcrime.securesms.R
+import org.thoughtcrime.securesms.mediasend.MediaSendGifFragment
+import org.thoughtcrime.securesms.mediasend.v2.HudCommand
+import org.thoughtcrime.securesms.mediasend.v2.MediaSelectionViewModel
+
+private const val GIF_TAG = "media.send.gif.fragment"
+
+/**
+ * Fragment which ensures we fire off ResumeEntryTransition when viewing a non-video gif.
+ */
+class MediaReviewGifPageFragment : Fragment(R.layout.fragment_container) {
+
+  private lateinit var mediaSendGifFragment: MediaSendGifFragment
+
+  private val sharedViewModel: MediaSelectionViewModel by viewModels(ownerProducer = { requireActivity() })
+
+  override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+    mediaSendGifFragment = ensureGifFragment()
+    sharedViewModel.sendCommand(HudCommand.ResumeEntryTransition)
+  }
+
+  private fun ensureGifFragment(): MediaSendGifFragment {
+    val fragmentInManager: MediaSendGifFragment? = childFragmentManager.findFragmentByTag(GIF_TAG) as? MediaSendGifFragment
+
+    return if (fragmentInManager != null) {
+      sharedViewModel.sendCommand(HudCommand.ResumeEntryTransition)
+      fragmentInManager
+    } else {
+      val mediaSendGifFragment = MediaSendGifFragment.newInstance(
+        requireUri()
+      )
+
+      childFragmentManager.beginTransaction()
+        .replace(
+          R.id.fragment_container,
+          mediaSendGifFragment,
+          GIF_TAG
+        )
+        .commitAllowingStateLoss()
+
+      mediaSendGifFragment
+    }
+  }
+
+  private fun requireUri(): Uri = requireNotNull(requireArguments().getParcelable(ARG_URI))
+
+  companion object {
+    private const val ARG_URI = "arg.uri"
+
+    fun newInstance(uri: Uri): Fragment {
+      return MediaReviewGifPageFragment().apply {
+        arguments = Bundle().apply {
+          putParcelable(ARG_URI, uri)
+        }
+      }
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/mediasend/v2/review/MediaReviewFragmentPagerAdapter.kt

@@ -6,6 +6,7 @@ import androidx.recyclerview.widget.RecyclerView
 import androidx.viewpager2.adapter.FragmentStateAdapter
 import org.thoughtcrime.securesms.mediasend.Media
 import org.thoughtcrime.securesms.mediasend.MediaSendGifFragment
+import org.thoughtcrime.securesms.mediasend.v2.gif.MediaReviewGifPageFragment
 import org.thoughtcrime.securesms.mediasend.v2.images.MediaReviewImagePageFragment
 import org.thoughtcrime.securesms.mediasend.v2.videos.MediaReviewVideoPageFragment
 import org.thoughtcrime.securesms.util.MediaUtil
@@ -43,7 +44,7 @@ class MediaReviewFragmentPagerAdapter(fragment: Fragment) : FragmentStateAdapter
     val mediaItem: Media = mediaList[position]
 
     return when {
-      MediaUtil.isGif(mediaItem.mimeType) -> MediaSendGifFragment.newInstance(mediaItem.uri)
+      MediaUtil.isGif(mediaItem.mimeType) -> MediaReviewGifPageFragment.newInstance(mediaItem.uri)
       MediaUtil.isImageType(mediaItem.mimeType) -> MediaReviewImagePageFragment.newInstance(mediaItem.uri)
       MediaUtil.isVideoType(mediaItem.mimeType) -> MediaReviewVideoPageFragment.newInstance(mediaItem.uri, mediaItem.isVideoGif)
       else -> {