Allow for switching between emoji categories using swipe left/right (#1488)

app/build.gradle.kts

@@ -107,6 +107,7 @@ dependencies {
     implementation("androidx.core:core-ktx:1.16.0")
     implementation("androidx.recyclerview:recyclerview:1.4.0")
     implementation("androidx.autofill:autofill:1.1.0")
+    implementation("androidx.viewpager2:viewpager2:1.1.0")
 
     // kotlin
     implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.8.1")

app/src/main/java/helium314/keyboard/keyboard/KeyboardSwitcher.java

@@ -479,7 +479,6 @@ public final class KeyboardSwitcher implements KeyboardState.SwitchActions {
         if (mKeyboardViewWrapper.getOneHandedModeEnabled() == enabled) {
             return;
         }
-        mEmojiPalettesView.clearKeyboardCache();
         final Settings settings = Settings.getInstance();
         mKeyboardViewWrapper.setOneHandedModeEnabled(enabled);
         mKeyboardViewWrapper.setOneHandedGravity(settings.getCurrent().mOneHandedModeGravity);
@@ -645,6 +644,12 @@ public final class KeyboardSwitcher implements KeyboardState.SwitchActions {
         }
     }
 
+    public void trimMemory() {
+        if (mEmojiPalettesView != null) {
+            mEmojiPalettesView.clearKeyboardCache();
+        }
+    }
+
     @SuppressLint("InflateParams")
     public View onCreateInputView(@NonNull Context displayContext, final boolean isHardwareAcceleratedDrawingEnabled) {
         if (mKeyboardView != null) {

app/src/main/java/helium314/keyboard/keyboard/emoji/EmojiCategory.java

@@ -261,20 +261,6 @@ final class EmojiCategory {
         return 0;
     }
 
-    // Returns the view pager's page position for the categoryId
-    public int getPagerPageIdFromCategoryAndPageId(final int categoryId, final int categoryPageId) {
-        int sum = 0;
-        for (int i = 0; i < mShownCategories.size(); ++i) {
-            final CategoryProperties props = mShownCategories.get(i);
-            if (props.mCategoryId == categoryId) {
-                return sum + categoryPageId;
-            }
-            sum += props.getPageCount();
-        }
-        Log.w(TAG, "categoryId not found: " + categoryId);
-        return 0;
-    }
-
     public int getRecentTabId() {
         return getTabIdFromCategoryId(EmojiCategory.ID_RECENTS);
     }
@@ -285,11 +271,11 @@ final class EmojiCategory {
     }
 
     // Returns a keyboard from the recycler view's adapter position.
-    public DynamicGridKeyboard getKeyboardFromAdapterPosition(final int position) {
+    public DynamicGridKeyboard getKeyboardFromAdapterPosition(int categoryId, final int position) {
-        if (position >= 0 && position < getCurrentCategoryPageCount()) {
+        if (position >= 0 && position < getCategoryPageCount(categoryId)) {
-            return getKeyboard(mCurrentCategoryId, position);
+            return getKeyboard(categoryId, position);
         }
-        Log.w(TAG, "invalid position for categoryId : " + mCurrentCategoryId);
+        Log.w(TAG, "invalid position for categoryId : " + categoryId);
         return null;
     }
 

app/src/main/java/helium314/keyboard/keyboard/emoji/EmojiLayoutParams.kt

@@ -8,7 +8,7 @@ package helium314.keyboard.keyboard.emoji
 import android.content.res.Resources
 import android.view.View
 import android.widget.LinearLayout
-import androidx.recyclerview.widget.RecyclerView
+import androidx.viewpager2.widget.ViewPager2
 import helium314.keyboard.keyboard.internal.KeyboardParams
 import helium314.keyboard.latin.R
 import helium314.keyboard.latin.settings.Settings
@@ -47,7 +47,7 @@ internal class EmojiLayoutParams(res: Resources) {
         emojiKeyboardHeight = emojiListHeight - emojiCategoryPageIdViewHeight - emojiListBottomMargin
     }
 
-    fun setEmojiListProperties(vp: RecyclerView) {
+    fun setEmojiListProperties(vp: ViewPager2) {
         val lp = vp.layoutParams as LinearLayout.LayoutParams
         lp.height = emojiKeyboardHeight
         lp.bottomMargin = emojiListBottomMargin

app/src/main/java/helium314/keyboard/keyboard/emoji/EmojiPalettesAdapter.java

@@ -12,156 +12,32 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
-import helium314.keyboard.keyboard.Key;
 import helium314.keyboard.keyboard.Keyboard;
-import helium314.keyboard.keyboard.KeyboardView;
 import helium314.keyboard.latin.R;
 
 import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;
-import helium314.keyboard.latin.settings.Settings;
 
 final class EmojiPalettesAdapter extends RecyclerView.Adapter<EmojiPalettesAdapter.ViewHolder>{
     private static final String TAG = EmojiPalettesAdapter.class.getSimpleName();
     private static final boolean DEBUG_PAGER = false;
 
+    private final int mCategoryId;
     private final OnKeyEventListener mListener;
-    private final DynamicGridKeyboard mRecentsKeyboard;
-    private final SparseArray<EmojiPageKeyboardView> mActiveKeyboardViews = new SparseArray<>();
     private final EmojiCategory mEmojiCategory;
-    private int mActivePosition = 0;
 
-    public EmojiPalettesAdapter(final EmojiCategory emojiCategory,
+    public EmojiPalettesAdapter(final EmojiCategory emojiCategory, int categoryId, final OnKeyEventListener listener) {
-            final OnKeyEventListener listener) {
         mEmojiCategory = emojiCategory;
+        mCategoryId = categoryId;
         mListener = listener;
-        mRecentsKeyboard = mEmojiCategory.getKeyboard(EmojiCategory.ID_RECENTS, 0);
     }
 
-    public void flushPendingRecentKeys() {
-        mRecentsKeyboard.flushPendingRecentKeys();
-        final KeyboardView recentKeyboardView =
-                mActiveKeyboardViews.get(mEmojiCategory.getRecentTabId());
-        if (recentKeyboardView != null) {
-            recentKeyboardView.invalidateAllKeys();
-        }
-    }
-
-    public void addRecentKey(final Key key) {
-        if (Settings.getValues().mIncognitoModeEnabled) {
-            // We do not want to log recent keys while being in incognito
-            return;
-        }
-        if (mEmojiCategory.isInRecentTab()) {
-            mRecentsKeyboard.addPendingKey(key);
-            return;
-        }
-        mRecentsKeyboard.addKeyFirst(key);
-        final KeyboardView recentKeyboardView =
-                mActiveKeyboardViews.get(mEmojiCategory.getRecentTabId());
-        if (recentKeyboardView != null) {
-            recentKeyboardView.invalidateAllKeys();
-        }
-    }
-
-    public void onPageScrolled() {
-        releaseCurrentKey(false /* withKeyRegistering */);
-    }
-
-    public void releaseCurrentKey(final boolean withKeyRegistering) {
-        // Make sure the delayed key-down event (highlight effect and haptic feedback) will be
-        // canceled.
-        final EmojiPageKeyboardView currentKeyboardView =
-                mActiveKeyboardViews.get(mActivePosition);
-        if (currentKeyboardView == null) {
-            return;
-        }
-        currentKeyboardView.releaseCurrentKey(withKeyRegistering);
-    }
-
-/*
-    @Override
-    public Object instantiateItem(final ViewGroup container, final int position) {
-        if (DEBUG_PAGER) {
-            Log.d(TAG, "instantiate item: " + position);
-        }
-        final EmojiPageKeyboardView oldKeyboardView = mActiveKeyboardViews.get(position);
-        if (oldKeyboardView != null) {
-            oldKeyboardView.deallocateMemory();
-            // This may be redundant but wanted to be safer..
-            mActiveKeyboardViews.remove(position);
-        }
-        final Keyboard keyboard =
-                mEmojiCategory.getKeyboardFromPagePosition(position);
-        final LayoutInflater inflater = LayoutInflater.from(container.getContext());
-        final EmojiPageKeyboardView keyboardView = (EmojiPageKeyboardView) inflater.inflate(
-                R.layout.emoji_keyboard_page, container, false);
-        keyboardView.setKeyboard(keyboard);
-        keyboardView.setOnKeyEventListener(mListener);
-        container.addView(keyboardView);
-        mActiveKeyboardViews.put(position, keyboardView);
-        return keyboardView;
-    }
-
-    @Override
-    public void setPrimaryItem(final ViewGroup container, final int position,
-            final Object object) {
-        if (mActivePosition == position) {
-            return;
-        }
-        final EmojiPageKeyboardView oldKeyboardView = mActiveKeyboardViews.get(mActivePosition);
-        if (oldKeyboardView != null) {
-            oldKeyboardView.releaseCurrentKey(false);
-            oldKeyboardView.deallocateMemory();
-        }
-        mActivePosition = position;
-    }
-
-    @Override
-    public boolean isViewFromObject(final View view, final Object object) {
-        return view == object;
-    }
-
-    @Override
-    public void destroyItem(final ViewGroup container, final int position,
-            final Object object) {
-        if (DEBUG_PAGER) {
-            Log.d(TAG, "destroy item: " + position + ", " + object.getClass().getSimpleName());
-        }
-        final EmojiPageKeyboardView keyboardView = mActiveKeyboardViews.get(position);
-        if (keyboardView != null) {
-            keyboardView.deallocateMemory();
-            mActiveKeyboardViews.remove(position);
-        }
-        if (object instanceof View) {
-            container.removeView((View)object);
-        } else {
-            Log.w(TAG, "Warning!!! Emoji palette may be leaking. " + object);
-        }
-    }
-*/
-
     @NonNull
     @Override
     public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
-        /*if (DEBUG_PAGER) {
-            Log.d(TAG, "instantiate item: " + viewType);
-        }
-        final EmojiPageKeyboardView oldKeyboardView = mActiveKeyboardViews.get(viewType);
-        if (oldKeyboardView != null) {
-            oldKeyboardView.deallocateMemory();
-            // This may be redundant but wanted to be safer..
-            mActiveKeyboardViews.remove(viewType);
-        }
-        final Keyboard keyboard =
-                mEmojiCategory.getKeyboardFromPagePosition(parent.getVerticalScrollbarPosition());*/
         final LayoutInflater inflater = LayoutInflater.from(parent.getContext());
         final EmojiPageKeyboardView keyboardView = (EmojiPageKeyboardView)inflater.inflate(
                 R.layout.emoji_keyboard_page, parent, false);
-        /*keyboardView.setKeyboard(keyboard);
-        keyboardView.setOnKeyEventListener(mListener);
-        parent.addView(keyboardView);
-        mActiveKeyboardViews.put(parent.getVerticalScrollbarPosition(), keyboardView);*/
         return new ViewHolder(keyboardView);
     }
 
@@ -170,33 +46,22 @@ final class EmojiPalettesAdapter extends RecyclerView.Adapter<EmojiPalettesAdapt
         if (DEBUG_PAGER) {
             Log.d(TAG, "instantiate item: " + position);
         }
-        final EmojiPageKeyboardView oldKeyboardView = mActiveKeyboardViews.get(position);
+
-        if (oldKeyboardView != null) {
-            oldKeyboardView.deallocateMemory();
-            // This may be redundant but wanted to be safer..
-            mActiveKeyboardViews.remove(position);
-        }
         final Keyboard keyboard =
-                mEmojiCategory.getKeyboardFromAdapterPosition(position);
+                mEmojiCategory.getKeyboardFromAdapterPosition(mCategoryId, position);
         holder.getKeyboardView().setKeyboard(keyboard);
         holder.getKeyboardView().setOnKeyEventListener(mListener);
-        //parent.addView(keyboardView);
+    }
-        mActiveKeyboardViews.put(position, holder.getKeyboardView());
 
-        /*if (mActivePosition == position) {
+    @Override
-            return;
+    public void onViewDetachedFromWindow(@NonNull ViewHolder holder) {
-        }
+        holder.getKeyboardView().releaseCurrentKey(false);
-        final EmojiPageKeyboardView oldKeyboardView = mActiveKeyboardViews.get(mActivePosition);
+        holder.getKeyboardView().deallocateMemory();
-        if (oldKeyboardView != null) {
-            oldKeyboardView.releaseCurrentKey(false);
-            oldKeyboardView.deallocateMemory();
-        }
-        mActivePosition = position;*/
     }
 
     @Override
     public int getItemCount() {
-        return mEmojiCategory.getCurrentCategoryPageCount();
+        return mEmojiCategory.getCategoryPageCount(mCategoryId);
     }
 
     static class ViewHolder extends RecyclerView.ViewHolder {
@@ -210,7 +75,6 @@ final class EmojiPalettesAdapter extends RecyclerView.Adapter<EmojiPalettesAdapt
         public EmojiPageKeyboardView getKeyboardView() {
             return customView;
         }
-
     }
 }
 

app/src/main/java/helium314/keyboard/keyboard/emoji/EmojiPalettesView.java

@@ -11,6 +11,7 @@ import android.content.Context;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
 import android.util.AttributeSet;
+import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.inputmethod.EditorInfo;
@@ -20,6 +21,7 @@ import android.widget.LinearLayout;
 import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
+import androidx.viewpager2.widget.ViewPager2;
 import helium314.keyboard.keyboard.Key;
 import helium314.keyboard.keyboard.Keyboard;
 import helium314.keyboard.keyboard.KeyboardActionListener;
@@ -41,8 +43,6 @@ import helium314.keyboard.latin.settings.Settings;
 import helium314.keyboard.latin.settings.SettingsValues;
 import helium314.keyboard.latin.utils.ResourceUtils;
 
-import org.jetbrains.annotations.NotNull;
-
 import static helium314.keyboard.latin.common.Constants.NOT_A_COORDINATE;
 
 /**
@@ -58,20 +58,132 @@ import static helium314.keyboard.latin.common.Constants.NOT_A_COORDINATE;
  */
 public final class EmojiPalettesView extends LinearLayout
         implements View.OnClickListener, OnKeyEventListener {
+    private static final class PagerViewHolder extends RecyclerView.ViewHolder {
+        private long mCategoryId;
+
+        private PagerViewHolder(View itemView) {
+            super(itemView);
+        }
+    }
+
+    private final class PagerAdapter extends RecyclerView.Adapter<PagerViewHolder> {
+        private boolean mInitialized;
+
+        private PagerAdapter() {
+            setHasStableIds(true);
+        }
+
+        @Override
+        public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView) {
+            recyclerView.setItemViewCacheSize(mEmojiCategory.getShownCategories().size());
+        }
+
+        @NonNull
+        @Override
+        public PagerViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+            var view = LayoutInflater.from(parent.getContext()).inflate(R.layout.emoji_category_view, parent, false);
+            var viewHolder = new PagerViewHolder(view);
+            var emojiRecyclerView = getRecyclerView(view);
+
+            emojiRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
+                @Override
+                public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
+                    super.onScrollStateChanged(recyclerView, newState);
+                    // Ignore this message. Only want the actual page selected.
+                }
+
+                @Override
+                public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
+                    updateState(recyclerView, viewHolder);
+                }
+            });
+
+            emojiRecyclerView.setPersistentDrawingCache(PERSISTENT_NO_CACHE);
+            return viewHolder;
+        }
+
+        @Override
+        public void onBindViewHolder(PagerViewHolder holder, int position) {
+            holder.mCategoryId = getItemId(position);
+            var recyclerView = getRecyclerView(holder.itemView);
+            recyclerView.setAdapter(new EmojiPalettesAdapter(mEmojiCategory, (int) holder.mCategoryId,
+                                                                  EmojiPalettesView.this));
+
+            if (! mInitialized) {
+                recyclerView.scrollToPosition(mEmojiCategory.getCurrentCategoryPageId());
+                mInitialized = true;
+            }
+        }
+
+        @Override
+        public int getItemCount() {
+            return mEmojiCategory.getShownCategories().size();
+        }
+
+        @Override
+        public void onViewAttachedToWindow(PagerViewHolder holder) {
+            if (mPager.getScrollState() == ViewPager2.SCROLL_STATE_DRAGGING // swipe
+                            || holder.getBindingAdapterPosition() == mPager.getCurrentItem() // tab
+            ) {
+                setCurrentCategoryId((int) getItemId(holder.getBindingAdapterPosition()), false);
+                updateState(getRecyclerView(holder.itemView), holder);
+            }
+        }
+
+        @Override
+        public void onViewDetachedFromWindow(PagerViewHolder holder) {
+            if (holder.mCategoryId == EmojiCategory.ID_RECENTS) {
+                // Needs to save pending updates for recent keys when we get out of the recents
+                // category because we don't want to move the recent emojis around while the user
+                // is in the recents category.
+                getRecentsKeyboard().flushPendingRecentKeys();
+                getRecyclerView(holder.itemView).getAdapter().notifyDataSetChanged();
+            }
+        }
+
+        @Override
+        public long getItemId(int position) {
+            return mEmojiCategory.getShownCategories().get(position).mCategoryId;
+        }
+
+        private static RecyclerView getRecyclerView(View view) {
+            return view.findViewById(R.id.emoji_keyboard_list);
+        }
+
+        private void updateState(@NonNull RecyclerView recyclerView, PagerViewHolder viewHolder) {
+            if (viewHolder.mCategoryId != mEmojiCategory.getCurrentCategoryId()) {
+                return;
+            }
+
+            final int offset = recyclerView.computeVerticalScrollOffset();
+            final int extent = recyclerView.computeVerticalScrollExtent();
+            final int range = recyclerView.computeVerticalScrollRange();
+            final float percentage = offset / (float) (range - extent);
+
+            final int currentCategorySize = mEmojiCategory.getCurrentCategoryPageCount();
+            final int a = (int) (percentage * currentCategorySize);
+            final float b = percentage * currentCategorySize - a;
+            mEmojiCategoryPageIndicatorView.setCategoryPageId(currentCategorySize, a, b);
+
+            LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
+            final int firstCompleteVisibleBoard = layoutManager.findFirstCompletelyVisibleItemPosition();
+            final int firstVisibleBoard = layoutManager.findFirstVisibleItemPosition();
+            mEmojiCategory.setCurrentCategoryPageId(
+                    firstCompleteVisibleBoard > 0 ? firstCompleteVisibleBoard : firstVisibleBoard);
+        }
+    }
+
     private boolean initialized = false;
     private final Colors mColors;
-    private EmojiPalettesAdapter mEmojiPalettesAdapter;
     private final EmojiLayoutParams mEmojiLayoutParams;
-    private final LinearLayoutManager mEmojiLayoutManager;
 
     private LinearLayout mTabStrip;
-    private RecyclerView mEmojiRecyclerView;
     private EmojiCategoryPageIndicatorView mEmojiCategoryPageIndicatorView;
 
     private KeyboardActionListener mKeyboardActionListener = KeyboardActionListener.EMPTY_LISTENER;
 
     private final EmojiCategory mEmojiCategory;
-
+    private ViewPager2 mPager;
 
     public EmojiPalettesView(final Context context, final AttributeSet attrs) {
         this(context, attrs, R.attr.emojiPalettesViewStyle);
@@ -91,7 +203,6 @@ public final class EmojiPalettesView extends LinearLayout
                 R.styleable.EmojiPalettesView, defStyle, R.style.EmojiPalettesView);
         mEmojiCategory = new EmojiCategory(context, layoutSet, emojiPalettesViewAttr);
         emojiPalettesViewAttr.recycle();
-        mEmojiLayoutManager = new LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false);
         setFitsSystemWindows(true);
     }
 
@@ -129,47 +240,14 @@ public final class EmojiPalettesView extends LinearLayout
         for (final EmojiCategory.CategoryProperties properties : mEmojiCategory.getShownCategories()) {
             addTab(mTabStrip, properties.mCategoryId);
         }
-        mEmojiPalettesAdapter = new EmojiPalettesAdapter(mEmojiCategory, this);
-
-        mEmojiRecyclerView = findViewById(R.id.emoji_keyboard_list);
-        mEmojiRecyclerView.setLayoutManager(mEmojiLayoutManager);
-        mEmojiRecyclerView.setAdapter(mEmojiPalettesAdapter);
-        mEmojiRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
-            @Override
-            public void onScrollStateChanged(@NonNull @NotNull RecyclerView recyclerView, int newState) {
-                super.onScrollStateChanged(recyclerView, newState);
-                // Ignore this message. Only want the actual page selected.
-            }
-
-            @Override
-            public void onScrolled(@NonNull @NotNull RecyclerView recyclerView, int dx, int dy) {
-                super.onScrolled(recyclerView, dx, dy);
-                mEmojiPalettesAdapter.onPageScrolled();
-
-                final int offset = recyclerView.computeVerticalScrollOffset();
-                final int extent = recyclerView.computeVerticalScrollExtent();
-                final int range = recyclerView.computeVerticalScrollRange();
-                final float percentage = offset / (float) (range - extent);
-
-                final int currentCategorySize = mEmojiCategory.getCurrentCategoryPageCount();
-                final int a = (int) (percentage * currentCategorySize);
-                final float b = percentage * currentCategorySize - a;
-                mEmojiCategoryPageIndicatorView.setCategoryPageId(currentCategorySize, a, b);
-
-                final int firstCompleteVisibleBoard = mEmojiLayoutManager.findFirstCompletelyVisibleItemPosition();
-                final int firstVisibleBoard = mEmojiLayoutManager.findFirstVisibleItemPosition();
-                mEmojiCategory.setCurrentCategoryPageId(
-                        firstCompleteVisibleBoard > 0 ? firstCompleteVisibleBoard : firstVisibleBoard);
-            }
-        });
-
-        mEmojiRecyclerView.setPersistentDrawingCache(PERSISTENT_NO_CACHE);
-        mEmojiLayoutParams.setEmojiListProperties(mEmojiRecyclerView);
 
+        mPager = findViewById(R.id.emoji_pager);
+        mPager.setAdapter(new PagerAdapter());
+        mEmojiLayoutParams.setEmojiListProperties(mPager);
         mEmojiCategoryPageIndicatorView = findViewById(R.id.emoji_category_page_id_view);
         mEmojiLayoutParams.setCategoryPageIdViewProperties(mEmojiCategoryPageIndicatorView);
 
-        setCurrentCategoryAndPageId(mEmojiCategory.getCurrentCategoryId(), mEmojiCategory.getCurrentCategoryPageId(), true);
+        setCurrentCategoryId(mEmojiCategory.getCurrentCategoryId(), true);
 
         mEmojiCategoryPageIndicatorView.setColors(mColors.get(ColorType.EMOJI_CATEGORY_SELECTED), mColors.get(ColorType.STRIP_BACKGROUND));
         initialized = true;
@@ -187,7 +265,7 @@ public final class EmojiPalettesView extends LinearLayout
             AudioAndHapticFeedbackManager.getInstance().performHapticAndAudioFeedback(KeyCode.NOT_SPECIFIED, this);
             final int categoryId = ((Long) tag).intValue();
             if (categoryId != mEmojiCategory.getCurrentCategoryId()) {
-                setCurrentCategoryAndPageId(categoryId, 0, false);
+                setCurrentCategoryId(categoryId, false);
                 updateEmojiCategoryPageIdView();
             }
         }
@@ -212,7 +290,7 @@ public final class EmojiPalettesView extends LinearLayout
      */
     @Override
     public void onReleaseKey(final Key key) {
-        mEmojiPalettesAdapter.addRecentKey(key);
+        addRecentKey(key);
         final int code = key.getCode();
         if (code == KeyCode.MULTIPLE_CODE_POINTS) {
             mKeyboardActionListener.onTextInput(key.getOutputText());
@@ -237,13 +315,22 @@ public final class EmojiPalettesView extends LinearLayout
         setupBottomRowKeyboard(editorInfo, keyboardActionListener);
         final KeyDrawParams params = new KeyDrawParams();
         params.updateParams(mEmojiLayoutParams.getBottomRowKeyboardHeight(), keyVisualAttr);
-        if (mEmojiRecyclerView.getAdapter() == null) {
-            mEmojiRecyclerView.setAdapter(mEmojiPalettesAdapter);
-            setCurrentCategoryAndPageId(mEmojiCategory.getCurrentCategoryId(), mEmojiCategory.getCurrentCategoryPageId(), true);
-        }
         setupSidePadding();
     }
 
+    private void addRecentKey(final Key key) {
+        if (Settings.getValues().mIncognitoModeEnabled) {
+            // We do not want to log recent keys while being in incognito
+            return;
+        }
+        if (mEmojiCategory.isInRecentTab()) {
+            getRecentsKeyboard().addPendingKey(key);
+            return;
+        }
+        getRecentsKeyboard().addKeyFirst(key);
+        mPager.getAdapter().notifyItemChanged(mEmojiCategory.getRecentTabId());
+    }
+
     private void setupBottomRowKeyboard(final EditorInfo editorInfo, final KeyboardActionListener keyboardActionListener) {
         MainKeyboardView keyboardView = findViewById(R.id.bottom_row_keyboard);
         keyboardView.setKeyboardActionListener(keyboardActionListener);
@@ -263,11 +350,11 @@ public final class EmojiPalettesView extends LinearLayout
         final float rightPadding =  keyboardAttr.getFraction(R.styleable.Keyboard_keyboardRightPadding,
                 keyboardWidth, keyboardWidth, 0f) * sv.mSidePaddingScale;
         keyboardAttr.recycle();
-        mEmojiRecyclerView.setPadding(
+        mPager.setPadding(
                 (int) leftPadding,
-                mEmojiRecyclerView.getPaddingTop(),
+                mPager.getPaddingTop(),
                 (int) rightPadding,
-                mEmojiRecyclerView.getPaddingBottom()
+                mPager.getPaddingBottom()
         );
         mEmojiCategoryPageIndicatorView.setPadding(
                 (int) leftPadding,
@@ -280,9 +367,11 @@ public final class EmojiPalettesView extends LinearLayout
 
     public void stopEmojiPalettes() {
         if (!initialized) return;
-        mEmojiPalettesAdapter.releaseCurrentKey(true);
+        getRecentsKeyboard().flushPendingRecentKeys();
-        mEmojiPalettesAdapter.flushPendingRecentKeys();
+    }
-        mEmojiRecyclerView.setAdapter(null);
+
+    private DynamicGridKeyboard getRecentsKeyboard() {
+        return mEmojiCategory.getKeyboard(EmojiCategory.ID_RECENTS, 0);
     }
 
     public void setKeyboardActionListener(final KeyboardActionListener listener) {
@@ -298,22 +387,15 @@ public final class EmojiPalettesView extends LinearLayout
                 mEmojiCategory.getCurrentCategoryPageId(), 0.0f);
     }
 
-    private void setCurrentCategoryAndPageId(final int categoryId, final int categoryPageId, final boolean force) {
+    private void setCurrentCategoryId(final int categoryId, final boolean initial) {
         final int oldCategoryId = mEmojiCategory.getCurrentCategoryId();
-        final int oldCategoryPageId = mEmojiCategory.getCurrentCategoryPageId();
+        if (initial || oldCategoryId != categoryId) {
-
-        if (oldCategoryId == EmojiCategory.ID_RECENTS && categoryId != EmojiCategory.ID_RECENTS) {
-            // Needs to save pending updates for recent keys when we get out of the recents
-            // category because we don't want to move the recent emojis around while the user
-            // is in the recents category.
-            mEmojiPalettesAdapter.flushPendingRecentKeys();
-        }
-
-        if (force || oldCategoryId != categoryId || oldCategoryPageId != categoryPageId) {
             mEmojiCategory.setCurrentCategoryId(categoryId);
-            mEmojiCategory.setCurrentCategoryPageId(categoryPageId);
+
-            mEmojiPalettesAdapter.notifyDataSetChanged();
+            if (mPager.getScrollState() != ViewPager2.SCROLL_STATE_DRAGGING) {
-            mEmojiRecyclerView.scrollToPosition(categoryPageId);
+                // Not swiping
+                mPager.setCurrentItem(mEmojiCategory.getTabIdFromCategoryId(
+                                mEmojiCategory.getCurrentCategoryId()), ! initial);
             }
 
             final View old = mTabStrip.findViewWithTag((long) oldCategoryId);
@@ -324,8 +406,14 @@ public final class EmojiPalettesView extends LinearLayout
             if (current instanceof ImageView)
                 Settings.getValues().mColors.setColor((ImageView) current, ColorType.EMOJI_CATEGORY_SELECTED);
         }
+    }
 
     public void clearKeyboardCache() {
+        if (!initialized) {
+            return;
+        }
+
         mEmojiCategory.clearKeyboardCache();
+        mPager.getAdapter().notifyDataSetChanged();
     }
 }

app/src/main/java/helium314/keyboard/latin/LatinIME.java

@@ -2022,8 +2022,10 @@ public class LatinIME extends InputMethodService implements
     public void onTrimMemory(int level) {
         super.onTrimMemory(level);
         switch (level) {
-            case TRIM_MEMORY_RUNNING_LOW, TRIM_MEMORY_RUNNING_CRITICAL, TRIM_MEMORY_COMPLETE ->
+            case TRIM_MEMORY_RUNNING_LOW, TRIM_MEMORY_RUNNING_CRITICAL, TRIM_MEMORY_COMPLETE -> {
                 KeyboardLayoutSet.onSystemLocaleChanged(); // clears caches, nothing else
+                mKeyboardSwitcher.trimMemory();
+            }
             // deallocateMemory always called on hiding, and should not be called when showing
         }
     }

app/src/main/res/layout/emoji_category_view.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright (C) 2013 The Android Open Source Project
+    modified
+    SPDX-License-Identifier: Apache-2.0 AND GPL-3.0-only
+-->
+
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+        xmlns:app="http://schemas.android.com/apk/res-auto"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:background="@android:color/transparent"
+        style="?attr/emojiPalettesViewStyle">
+    <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/emoji_keyboard_list"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+            android:orientation="vertical" />
+</FrameLayout>

app/src/main/res/layout/emoji_palettes_view.xml

@@ -15,11 +15,10 @@
     android:background="@android:color/transparent"
     style="?attr/emojiPalettesViewStyle"
 >
-    <androidx.recyclerview.widget.RecyclerView
+    <androidx.viewpager2.widget.ViewPager2
-        android:id="@+id/emoji_keyboard_list"
+        android:id="@+id/emoji_pager"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content"
+        android:layout_height="wrap_content" />
-        android:orientation="vertical" />
     <helium314.keyboard.keyboard.emoji.EmojiCategoryPageIndicatorView
         android:id="@+id/emoji_category_page_id_view"
         android:layout_width="match_parent"