Add ability to remove or clear recent emojis

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

@@ -234,6 +234,24 @@ public Key(@Nullable final String label, @Nullable final String iconName, final
      */
     protected Key(@NonNull final Key key, @Nullable final PopupKeySpec[] popupKeys,
                 @Nullable final String labelHint, final int backgroundType) {
+        this(key, popupKeys, labelHint, backgroundType, key.getPopupKeysColumnNumber());
+    }
+
+    /**
+     * Copy constructor that overrides the number of popup key columns.
+     *
+     * <p>The source key may report zero columns (e.g. emoji recent keys restored from settings),
+     * which cannot lay out popup keys. Callers that assign popup keys can pass an explicit column
+     * count here instead of relying on the source key.</p>
+     *
+     * @param key the original key.
+     * @param popupKeys the popup keys that should be assigned to this key.
+     * @param labelHint the label hint that should be assigned to this key.
+     * @param backgroundType the background type that should be assigned to this key.
+     * @param popupKeysColumnNumber the number of columns to lay the popup keys out in.
+     */
+    protected Key(@NonNull final Key key, @Nullable final PopupKeySpec[] popupKeys,
+                @Nullable final String labelHint, final int backgroundType, final int popupKeysColumnNumber) {
         // Final attributes.
         mCode = key.mCode;
         mLabel = key.mLabel;
@@ -249,7 +267,8 @@ protected Key(@NonNull final Key key, @Nullable final PopupKeySpec[] popupKeys,
         mY = key.mY;
         mHitBox.set(key.mHitBox);
         mPopupKeys = popupKeys;
-        mPopupKeysColumnAndFlags = key.mPopupKeysColumnAndFlags;
+        mPopupKeysColumnAndFlags = (key.mPopupKeysColumnAndFlags & ~POPUP_KEYS_COLUMN_NUMBER_MASK)
+                | (popupKeysColumnNumber & POPUP_KEYS_COLUMN_NUMBER_MASK);
         mBackgroundType = backgroundType;
         mActionFlags = key.mActionFlags;
         mKeyVisualAttributes = key.mKeyVisualAttributes;

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

@@ -164,6 +164,35 @@ public void removeAllKeys() {
         }
     }
 
+    public boolean isRecents() {
+        return mIsRecents;
+    }
+
+    public void removeKey(final Key usedKey) {
+        synchronized (mLock) {
+            boolean removed = false;
+            while (mGridKeys.remove(usedKey)) {
+                // Remove all keys matching the removed one.
+                removed = true;
+            }
+            if (!removed) {
+                return;
+            }
+            mCachedGridKeys = null;
+            updateKeyCoordinates();
+        }
+        if (mIsRecents) {
+            removeRecentKey(usedKey);
+        }
+    }
+
+    public void clearRecentKeys() {
+        removeAllKeys();
+        if (mIsRecents) {
+            RecentEmojis.clear();
+        }
+    }
+
     private void addKey(final Key usedKey, final boolean addFirst) {
         if (usedKey == null) {
             return;
@@ -191,18 +220,22 @@ private void addKey(final Key usedKey, final boolean addFirst) {
             while (mGridKeys.size() > mMaxKeyCount) {
                 mGridKeys.removeLast();
             }
-            int index = 0;
-            for (final GridKey gridKey : mGridKeys) {
-                while (mEmptyColumnIndices.contains(index % mColumnsNum)) {
-                    index++;
-                }
-                final int keyX0 = getKeyX0(index);
-                final int keyY0 = getKeyY0(index);
-                final int keyX1 = getKeyX1(index);
-                final int keyY1 = getKeyY1(index);
-                gridKey.updateCoordinates(keyX0, keyY0, keyX1, keyY1);
+            updateKeyCoordinates();
+        }
+    }
+
+    private void updateKeyCoordinates() {
+        int index = 0;
+        for (final GridKey gridKey : mGridKeys) {
+            while (mEmptyColumnIndices.contains(index % mColumnsNum)) {
                 index++;
             }
+            final int keyX0 = getKeyX0(index);
+            final int keyY0 = getKeyY0(index);
+            final int keyX1 = getKeyX1(index);
+            final int keyY1 = getKeyY1(index);
+            gridKey.updateCoordinates(keyX0, keyY0, keyX1, keyY1);
+            index++;
         }
     }
 
@@ -213,6 +246,13 @@ private void saveRecentKey(@Nullable Key key) {
         else RecentEmojis.addCodepoint(key.getCode());
     }
 
+    private void removeRecentKey(@Nullable Key key) {
+        if (key == null) return;
+        String outputText = key.getOutputText();
+        if (outputText != null) RecentEmojis.remove(outputText);
+        else RecentEmojis.removeCodepoint(key.getCode());
+    }
+
     private Key getKeyByCode(final Collection<DynamicGridKeyboard> keyboards,
             final int code) {
         for (final DynamicGridKeyboard keyboard : keyboards) {
@@ -304,6 +344,11 @@ public GridKey(@NonNull final Key originalKey, @Nullable final PopupKeySpec[] po
             super(originalKey, popupKeys, labelHint, backgroundType);
         }
 
+        public GridKey(@NonNull final Key originalKey, @Nullable final PopupKeySpec[] popupKeys,
+             @Nullable final String labelHint, final int backgroundType, final int popupKeysColumnNumber) {
+            super(originalKey, popupKeys, labelHint, backgroundType, popupKeysColumnNumber);
+        }
+
         public void updateCoordinates(final int x0, final int y0, final int x1, final int y1) {
             mCurrentX = x0;
             mCurrentY = y0;

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

@@ -38,11 +38,14 @@
 import helium314.keyboard.keyboard.PopupKeysKeyboard;
 import helium314.keyboard.keyboard.PopupKeysKeyboardView;
 import helium314.keyboard.keyboard.PopupKeysPanel;
+import helium314.keyboard.keyboard.internal.KeyboardIconsSet;
 import helium314.keyboard.keyboard.internal.PopupKeySpec;
+import helium314.keyboard.keyboard.internal.keyboard_parser.floris.KeyCode;
 import helium314.keyboard.latin.R;
 import helium314.keyboard.latin.common.CoordinateUtils;
 import helium314.keyboard.latin.settings.Settings;
 
+import java.util.Locale;
 import java.util.WeakHashMap;
 
 /**
@@ -56,12 +59,20 @@ public final class EmojiPageKeyboardView extends KeyboardView implements
     private static final long KEY_PRESS_DELAY_TIME = 250;  // msec
     private static final long KEY_RELEASE_DELAY_TIME = 30;  // msec
 
+    // Single delete button shown when long-pressing a key in the recents category.
+    private static final PopupKeySpec[] REMOVE_RECENT_POPUP_KEYS = {
+            new PopupKeySpec(KeyboardIconsSet.PREFIX_ICON + KeyboardIconsSet.NAME_BIN
+                    + "|!code/" + KeyCode.EMOJI_RECENT_REMOVE, false, Locale.ROOT)
+    };
+
     private static final EmojiViewCallback EMPTY_EMOJI_VIEW_CALLBACK = new EmojiViewCallback() {
         @Override
         public void onPressKey(final Key key) {}
         @Override
         public void onReleaseKey(final Key key) {}
         @Override
+        public void onRemoveRecentKey(final Key key) {}
+        @Override
         public String getDescription(String emoji) {
             return null;
         }
@@ -200,6 +211,51 @@ private PopupKeysPanel showPopupKeysKeyboard(@NonNull final Key key) {
         return mPopupKeysKeyboardView;
     }
 
+    // Builds a single-key popup holding a delete button, used to remove a key from the recents category.
+    @NonNull
+    private PopupKeysPanel showRemoveKeyboard(@NonNull final Key key) {
+        Keyboard popupKeysKeyboard = mPopupKeysKeyboardCache.get(key);
+        if (popupKeysKeyboard == null) {
+            // A recent key restored from settings can report zero popup-key columns, which cannot
+            // lay out popup keys. Give the remove popup one column per delete button it contains.
+            final Key removeKey = new DynamicGridKeyboard.GridKey(key, REMOVE_RECENT_POPUP_KEYS, null,
+                    key.getBackgroundType(), REMOVE_RECENT_POPUP_KEYS.length);
+            // The delete button is icon-only, so size the single-key popup explicitly instead of
+            // measuring a label (which would divide by a zero base width). Fall back to the most
+            // common key height so the width is always non-zero.
+            final Keyboard keyboard = getKeyboard();
+            final int keyWidth = Math.max(key.getHitBox().width(), keyboard.mMostCommonKeyHeight);
+            final int keyHeight = Math.max(key.getHitBox().height(), keyboard.mMostCommonKeyHeight);
+            final PopupKeysKeyboard.Builder builder = new PopupKeysKeyboard.Builder(
+                    getContext(), removeKey, keyboard, true, keyWidth, keyHeight, newLabelPaint(removeKey));
+            popupKeysKeyboard = builder.build();
+            mPopupKeysKeyboardCache.put(key, popupKeysKeyboard);
+        }
+
+        mPopupKeysKeyboardView.setKeyboard(popupKeysKeyboard);
+        mPopupKeysKeyboardView.setVisibility(VISIBLE);
+        return mPopupKeysKeyboardView;
+    }
+
+    // Wraps the regular callback so that selecting the delete button removes the given recent key,
+    // while emoji descriptions keep being resolved through the original callback.
+    private EmojiViewCallback createRemoveRecentCallback(@NonNull final Key key) {
+        return new EmojiViewCallback() {
+            @Override
+            public void onPressKey(final Key pressedKey) {}
+            @Override
+            public void onReleaseKey(final Key releasedKey) {
+                mEmojiViewCallback.onRemoveRecentKey(key);
+            }
+            @Override
+            public void onRemoveRecentKey(final Key removedKey) {}
+            @Override
+            public String getDescription(final String emoji) {
+                return mEmojiViewCallback.getDescription(emoji);
+            }
+        };
+    }
+
     private void dismissPopupKeysPanel() {
         if (isShowingPopupKeysPanel()) {
             mPopupKeysPanel.dismissPopupKeysPanel();
@@ -298,7 +354,13 @@ private void onLongPressed(final Key key) {
         }
 
         var descriptionPanel = showDescription(key);
-        final PopupKeysPanel popupKeysPanel = showPopupKeysKeyboard(key);
+        // In the recents category, long-pressing a key offers a delete button to remove it from
+        // recents (similar to deleting a suggestion), instead of the skin tone variants panel.
+        final Keyboard keyboard = getKeyboard();
+        final boolean isRecents = keyboard instanceof DynamicGridKeyboard && ((DynamicGridKeyboard) keyboard).isRecents();
+        final PopupKeysPanel popupKeysPanel = isRecents ? showRemoveKeyboard(key) : showPopupKeysKeyboard(key);
+        // Route the delete button to recents removal, everything else to the regular callback.
+        final EmojiViewCallback callback = isRecents ? createRemoveRecentCallback(key) : mEmojiViewCallback;
 
         final int x = mLastX;
         final int y = mLastY;
@@ -314,7 +376,7 @@ private void onLongPressed(final Key key) {
                     : key.getX() + key.getWidth() / 2;
             final int pointY = key.getY() - getKeyboard().mVerticalGap;
             (popupKeysPanel != null? popupKeysPanel : descriptionPanel)
-                            .showPopupKeysPanel(this, this, pointX, pointY, mEmojiViewCallback);
+                            .showPopupKeysPanel(this, this, pointX, pointY, callback);
         }
 
         if (popupKeysPanel != null) {

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

@@ -246,6 +246,12 @@ private void addTab(LinearLayout host, EmojiCategory.Category category) {
         host.addView(iconView);
         iconView.setLayoutParams(new LinearLayout.LayoutParams(0, ViewGroup.LayoutParams.MATCH_PARENT, 1f));
         iconView.setOnClickListener(this);
+        if (category == EmojiCategory.Category.RECENTS) {
+            iconView.setOnLongClickListener(v -> {
+                clearRecentKeys();
+                return true;
+            });
+        }
     }
 
     @SuppressLint("ClickableViewAccessibility")
@@ -317,6 +323,25 @@ public void onReleaseKey(final Key key) {
             mKeyboardActionListener.onCodeInput(KeyCode.ALPHA, NOT_A_COORDINATE, NOT_A_COORDINATE, false);
     }
 
+    /**
+     * Called from {@link EmojiPageKeyboardView} through {@link EmojiViewCallback}
+     * interface to remove a single emoji from the recents category.
+     */
+    @Override
+    public void onRemoveRecentKey(final Key key) {
+        AudioAndHapticFeedbackManager.getInstance().performHapticAndAudioFeedback(KeyCode.NOT_SPECIFIED, this, HapticEvent.KEY_LONG_PRESS);
+        getRecentsKeyboard().removeKey(key);
+        if (initialized)
+            mPager.getAdapter().notifyItemChanged(mEmojiCategory.getRecentTabId());
+    }
+
+    private void clearRecentKeys() {
+        AudioAndHapticFeedbackManager.getInstance().performHapticAndAudioFeedback(KeyCode.NOT_SPECIFIED, this, HapticEvent.KEY_LONG_PRESS);
+        getRecentsKeyboard().clearRecentKeys();
+        if (initialized)
+            mPager.getAdapter().notifyItemChanged(mEmojiCategory.getRecentTabId());
+    }
+
     @Override
     public String getDescription(String emoji) {
         if (sDictionaryFacilitator == null) {

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

@@ -319,6 +319,9 @@ class EmojiSearchActivity : ComponentActivity() {
                 finish()
             }
 
+            override fun onRemoveRecentKey(key: Key) {
+            }
+
             override fun getDescription(emoji: String): String? = if (Settings.getValues().mShowEmojiDescriptions)
                 dictionaryFacilitator?.getWordProperty(getEmojiNeutralVersion(emoji))?.let {
                     if (it.mHasShortcuts) it.mShortcutTargets[0]?.mWord else null

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

@@ -22,6 +22,11 @@ public interface EmojiViewCallback {
      */
     void onReleaseKey(Key key);
 
+    /**
+     * Called when a key in the recents category is long-pressed, to remove it from recents.
+     */
+    void onRemoveRecentKey(Key key);
+
     /**
      * Called from keyboard view to get an emoji description
      */

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

@@ -33,6 +33,23 @@ object RecentEmojis {
          if (emoji > 0) add(StringUtils.newSingleCodePointString(emoji))
      }
 
+    @JvmStatic
+    fun remove(emoji: String) {
+        if (emoji.isEmpty()) return
+        val recents = get()
+        if (recents.removeAll { it == emoji }) set(recents)
+    }
+
+    @JvmStatic
+    fun removeCodepoint(emoji: Int) {
+        if (emoji > 0) remove(StringUtils.newSingleCodePointString(emoji))
+    }
+
+    @JvmStatic
+    fun clear() {
+        set(emptyList())
+    }
+
     fun get(): MutableList<String> {
         val pref = prefs.getString(Settings.PREF_RECENT_EMOJIS, Defaults.PREF_RECENT_EMOJIS)
         if (pref.isNullOrEmpty()) return mutableListOf()

app/src/main/java/helium314/keyboard/keyboard/internal/keyboard_parser/floris/KeyCode.kt

@@ -127,6 +127,7 @@ object KeyCode {
     const val CJK_SPACE =                  12288
 
     // heliboard only codes
+    const val EMOJI_RECENT_REMOVE =       -10000 // remove a single emoji from the recents category
     const val SYMBOL_ALPHA =              -10001
     const val TOGGLE_ONE_HANDED_MODE =    -10002
     const val TOGGLE_ONE_HANDED_MODE_2 =  -10003 // does the same as TOGGLE_ONE_HANDED_MODE (used to be start & stop)
@@ -211,7 +212,7 @@ object KeyCode {
         MEDIA_PREVIOUS, VOL_UP, VOL_DOWN, MUTE, F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, BACK,
         TIMESTAMP, CTRL_LEFT, CTRL_RIGHT, ALT_LEFT, ALT_RIGHT, META_LEFT, META_RIGHT, SEND_INTENT_ONE, SEND_INTENT_TWO,
         SEND_INTENT_THREE, EMOJI_SEARCH, INLINE_EMOJI_SEARCH_DONE, META_LOCK,
-        BACKGROUND_GATHERING, BACKGROUND_GATHERING_TEMP_OFF, DPAD,
+        BACKGROUND_GATHERING, BACKGROUND_GATHERING_TEMP_OFF, DPAD, EMOJI_RECENT_REMOVE
         -> this
 
         KEY_REPEAT if (longPress) -> this