Remember the last position of emoji and sticker picker as you swap between them.

app/src/main/java/org/thoughtcrime/securesms/components/emoji/EmojiKeyboardProvider.java

@@ -39,6 +39,7 @@ public class EmojiKeyboardProvider implements MediaKeyboardProvider,
   private final EmojiEventListener   emojiEventListener;
 
   private Controller controller;
+  private int        currentPosition;
 
   public EmojiKeyboardProvider(@NonNull Context context, @Nullable EmojiEventListener emojiEventListener) {
     this.context            = context;
@@ -66,11 +67,18 @@ public class EmojiKeyboardProvider implements MediaKeyboardProvider,
 
     models.add(recentModel);
     models.addAll(EmojiPages.DISPLAY_PAGES);
+
+    currentPosition = recentModel.getEmoji().size() > 0 ? 0 : 1;
   }
 
   @Override
   public void requestPresentation(@NonNull Presenter presenter, boolean isSoloProvider) {
-    presenter.present(this, emojiPagerAdapter, this, this, null, null, recentModel.getEmoji().size() > 0 ? 0 : 1);
+    presenter.present(this, emojiPagerAdapter, this, this, null, null, currentPosition);
+  }
+
+  @Override
+  public void setCurrentPosition(int currentPosition) {
+    this.currentPosition = currentPosition;
   }
 
   @Override

app/src/main/java/org/thoughtcrime/securesms/components/emoji/MediaKeyboard.java

@@ -212,6 +212,7 @@ public class MediaKeyboard extends FrameLayout implements InputView,
       public void onPageSelected(int i) {
         categoryTabAdapter.setActivePosition(i);
         categoryTabs.smoothScrollToPosition(i);
+        providers[providerIndex].setCurrentPosition(i);
       }
 
       @Override

app/src/main/java/org/thoughtcrime/securesms/components/emoji/MediaKeyboardProvider.java

@@ -14,6 +14,7 @@ public interface MediaKeyboardProvider {
   /** @return True if the click was handled with provider-specific logic, otherwise false */
   void requestPresentation(@NonNull Presenter presenter, boolean isSoloProvider);
   void setController(@Nullable Controller controller);
+  void setCurrentPosition(int currentPosition);
 
   interface BackspaceObserver {
     void onBackspaceClicked();

app/src/main/java/org/thoughtcrime/securesms/stickers/StickerKeyboardProvider.java

@@ -37,6 +37,7 @@ public final class StickerKeyboardProvider implements MediaKeyboardProvider,
                                                 MediaKeyboardProvider.AddObserver,
                                                 StickerKeyboardPageFragment.EventListener
 {
+  private static final int UNSET = -1;
 
   private final Context              context;
   private final StickerEventListener eventListener;
@@ -47,6 +48,7 @@ public final class StickerKeyboardProvider implements MediaKeyboardProvider,
   private Presenter                presenter;
   private boolean                  isSoloProvider;
   private StickerKeyboardViewModel viewModel;
+  private int                      currentPosition;
 
   public StickerKeyboardProvider(@NonNull FragmentActivity activity,
                                  @NonNull StickerEventListener eventListener)
@@ -55,6 +57,7 @@ public final class StickerKeyboardProvider implements MediaKeyboardProvider,
     this.eventListener    = eventListener;
     this.pagerAdapter     = new StickerPagerAdapter(activity.getSupportFragmentManager(), this);
     this.stickerThrottler = new Throttler(100);
+    this.currentPosition  = UNSET;
 
     initViewModel(activity);
   }
@@ -76,7 +79,7 @@ public final class StickerKeyboardProvider implements MediaKeyboardProvider,
     PackListResult result = viewModel.getPacks().getValue();
 
     if (result != null) {
-      present(presenter, result, true);
+      present(presenter, result, false);
     }
   }
 
@@ -109,6 +112,11 @@ public final class StickerKeyboardProvider implements MediaKeyboardProvider,
     }
   }
 
+  @Override
+  public void setCurrentPosition(int currentPosition) {
+    this.currentPosition = currentPosition;
+  }
+
   private void initViewModel(@NonNull FragmentActivity activity) {
     StickerKeyboardRepository repository = new StickerKeyboardRepository(DatabaseFactory.getStickerDatabase(activity));
     viewModel = ViewModelProviders.of(activity, new StickerKeyboardViewModel.Factory(activity.getApplication(), repository)).get(StickerKeyboardViewModel.class);
@@ -133,9 +141,9 @@ public final class StickerKeyboardProvider implements MediaKeyboardProvider,
       return;
     }
 
-    int startingIndex = presenter.getCurrentPosition();
+    int startingIndex = currentPosition;
 
-    if (calculateStartingIndex) {
+    if (calculateStartingIndex || startingIndex == UNSET) {
       startingIndex = !result.hasRecents() && result.getPacks().size() > 0 ? 1 : 0;
     }