Improve conversation open speed.

app/src/main/java/org/thoughtcrime/securesms/components/voice/VoiceNoteMediaController.java

@@ -16,6 +16,7 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.DefaultLifecycleObserver;
+import androidx.lifecycle.Lifecycle;
 import androidx.lifecycle.LifecycleOwner;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
@@ -33,9 +34,9 @@ import java.util.Optional;
 
 /**
  * Encapsulates control of voice note playback from an Activity component.
- *
+ * <p>
  * This class assumes that it will be created within the scope of Activity#onCreate
- *
+ * <p>
  * The workhorse of this repository is the ProgressEventHandler, which will supply a
  * steady stream of update events to the set callback.
  */
@@ -54,15 +55,17 @@ public class VoiceNoteMediaController implements DefaultLifecycleObserver {
   private MutableLiveData<VoiceNotePlaybackState>       voiceNotePlaybackState = new MutableLiveData<>(VoiceNotePlaybackState.NONE);
   private LiveData<Optional<VoiceNotePlayerView.State>> voiceNotePlayerViewState;
   private VoiceNoteProximityWakeLockManager             voiceNoteProximityWakeLockManager;
+  private boolean                                       isMediaBrowserCreationPostponed;
 
   private final MediaControllerCompatCallback mediaControllerCompatCallback = new MediaControllerCompatCallback();
 
   public VoiceNoteMediaController(@NonNull FragmentActivity activity) {
+    this(activity, false);
+  }
+
+  public VoiceNoteMediaController(@NonNull FragmentActivity activity, boolean postponeMediaBrowserCreation) {
     this.activity                        = activity;
-    this.mediaBrowser = new MediaBrowserCompat(activity,
+    this.isMediaBrowserCreationPostponed = postponeMediaBrowserCreation;
-                                               new ComponentName(activity, VoiceNotePlaybackService.class),
-                                               new ConnectionCallback(),
-                                               null);
 
     activity.getLifecycle().addObserver(this);
 
@@ -95,6 +98,17 @@ public class VoiceNoteMediaController implements DefaultLifecycleObserver {
     });
   }
 
+  public void ensureMediaBrowser() {
+    if (mediaBrowser != null) {
+      return;
+    }
+
+    mediaBrowser = new MediaBrowserCompat(activity,
+                                          new ComponentName(activity, VoiceNotePlaybackService.class),
+                                          new ConnectionCallback(),
+                                          null);
+  }
+
   public LiveData<VoiceNotePlaybackState> getVoiceNotePlaybackState() {
     return voiceNotePlaybackState;
   }
@@ -103,8 +117,22 @@ public class VoiceNoteMediaController implements DefaultLifecycleObserver {
     return voiceNotePlayerViewState;
   }
 
+  public void finishPostpone() {
+    isMediaBrowserCreationPostponed = false;
+    if (activity != null && mediaBrowser == null && activity.getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.RESUMED)) {
+      ensureMediaBrowser();
+      mediaBrowser.disconnect();
+      mediaBrowser.connect();
+    }
+  }
+
   @Override
   public void onResume(@NonNull LifecycleOwner owner) {
+    if (mediaBrowser == null && isMediaBrowserCreationPostponed) {
+      return;
+    }
+
+    ensureMediaBrowser();
     mediaBrowser.disconnect();
     mediaBrowser.connect();
   }
@@ -117,8 +145,10 @@ public class VoiceNoteMediaController implements DefaultLifecycleObserver {
       MediaControllerCompat.getMediaController(activity).unregisterCallback(mediaControllerCompatCallback);
     }
 
+    if (mediaBrowser != null) {
       mediaBrowser.disconnect();
     }
+  }
 
   @Override
   public void onDestroy(@NonNull LifecycleOwner owner) {

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationActivity.kt

@@ -16,9 +16,11 @@ import org.thoughtcrime.securesms.components.reminder.ReminderView
 import org.thoughtcrime.securesms.components.settings.app.subscription.DonationPaymentComponent
 import org.thoughtcrime.securesms.components.settings.app.subscription.StripeRepository
 import org.thoughtcrime.securesms.recipients.Recipient
+import org.thoughtcrime.securesms.util.Debouncer
 import org.thoughtcrime.securesms.util.DynamicNoActionBarTheme
 import org.thoughtcrime.securesms.util.DynamicTheme
 import org.thoughtcrime.securesms.util.views.Stub
+import java.util.concurrent.TimeUnit
 
 open class ConversationActivity : PassphraseRequiredActivity(), ConversationParentFragment.Callback, DonationPaymentComponent {
 
@@ -26,6 +28,7 @@ open class ConversationActivity : PassphraseRequiredActivity(), ConversationPare
     private const val STATE_WATERMARK = "share_data_watermark"
   }
 
+  private val transitionDebouncer: Debouncer = Debouncer(150, TimeUnit.MILLISECONDS)
   private lateinit var fragment: ConversationParentFragment
   private var shareDataTimestamp: Long = -1L
 
@@ -35,6 +38,8 @@ open class ConversationActivity : PassphraseRequiredActivity(), ConversationPare
   }
 
   override fun onCreate(savedInstanceState: Bundle?, ready: Boolean) {
+    supportPostponeEnterTransition()
+    transitionDebouncer.publish { supportStartPostponedEnterTransition() }
     window.requestFeature(Window.FEATURE_ACTIVITY_TRANSITIONS)
 
     if (savedInstanceState != null) {
@@ -51,6 +56,11 @@ open class ConversationActivity : PassphraseRequiredActivity(), ConversationPare
     }
   }
 
+  override fun onDestroy() {
+    super.onDestroy()
+    transitionDebouncer.clear()
+  }
+
   override fun onSaveInstanceState(outState: Bundle) {
     super.onSaveInstanceState(outState)
     outState.putLong(STATE_WATERMARK, shareDataTimestamp)

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationFragment.java

@@ -746,6 +746,7 @@ public class ConversationFragment extends LoggingFragment implements Multiselect
             startupStopwatch.split("first-render");
             startupStopwatch.stop(TAG);
             SignalLocalMetrics.ConversationOpen.onRenderFinished();
+            listener.onFirstRender();
           });
         }
       });
@@ -1480,6 +1481,7 @@ public class ConversationFragment extends LoggingFragment implements Multiselect
                            @NonNull ConversationReactionOverlay.OnHideListener onHideListener);
     void    onCursorChanged();
     void    onMessageWithErrorClicked(@NonNull MessageRecord messageRecord);
+    void    onFirstRender();
     void    onVoiceNotePause(@NonNull Uri uri);
     void    onVoiceNotePlay(@NonNull Uri uri, long messageId, double progress);
     void    onVoiceNoteResume(@NonNull Uri uri, long messageId);

app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationParentFragment.java

@@ -512,7 +512,7 @@ public class ConversationParentFragment extends Fragment
       return;
     }
 
-    voiceNoteMediaController = new VoiceNoteMediaController(requireActivity());
+    voiceNoteMediaController = new VoiceNoteMediaController(requireActivity(), true);
     voiceRecorderWakeLock    = new VoiceRecorderWakeLock(requireActivity());
 
     // TODO [alex] LargeScreenSupport -- Should be removed once we move to multi-pane layout.
@@ -4040,6 +4040,12 @@ public class ConversationParentFragment extends Fragment
     }
   }
 
+  @Override
+  public void onFirstRender() {
+    requireActivity().supportStartPostponedEnterTransition();
+    voiceNoteMediaController.finishPostpone();
+  }
+
   @Override
   public void onVoiceNotePause(@NonNull Uri uri) {
     voiceNoteMediaController.pausePlayback(uri);