don't reload when moving cursor within a word using space bar gesture

gives performance improvement noticeable at least on slow phones

app/src/main/java/org/dslul/openboard/inputmethod/latin/LatinIME.java

@@ -56,6 +56,8 @@ import org.dslul.openboard.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
 import org.dslul.openboard.inputmethod.latin.common.Constants;
 import org.dslul.openboard.inputmethod.latin.common.CoordinateUtils;
 import org.dslul.openboard.inputmethod.latin.common.InputPointers;
+import org.dslul.openboard.inputmethod.latin.common.StringUtils;
+import org.dslul.openboard.inputmethod.latin.common.StringUtilsKt;
 import org.dslul.openboard.inputmethod.latin.define.DebugFlags;
 import org.dslul.openboard.inputmethod.latin.define.ProductionFlags;
 import org.dslul.openboard.inputmethod.latin.inputlogic.InputLogic;
@@ -1397,8 +1399,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         // for RTL languages we want to invert pointer movement
         if (mRichImm.getCurrentSubtype().isRtlSubtype())
             steps = -steps;
-            
+
-        mInputLogic.finishInput();
         if (steps < 0) {
             int availableCharacters = mInputLogic.mConnection.getTextBeforeCursor(64, 0).length();
             steps = availableCharacters < -steps ? -availableCharacters : steps;
@@ -1409,6 +1410,14 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         } else
             return;
 
+        if (mInputLogic.moveCursorByAndReturnIfInsideComposingWord(steps)) {
+            // no need to finish input and restart suggestions if we're still in the word
+            // this is a noticeable performance improvement
+            int newPosition = mInputLogic.mConnection.mExpectedSelStart + steps;
+            mInputLogic.mConnection.setSelection(newPosition, newPosition);
+            return;
+        }
+        mInputLogic.finishInput();
         int newPosition = mInputLogic.mConnection.mExpectedSelStart + steps;
         mInputLogic.mConnection.setSelection(newPosition, newPosition);
         mInputLogic.restartSuggestionsOnWordTouchedByCursor(mSettings.getCurrent(), mKeyboardSwitcher.getCurrentKeyboardScriptId());

app/src/main/java/org/dslul/openboard/inputmethod/latin/RichInputConnection.java

@@ -241,6 +241,10 @@ public final class RichInputConnection implements PrivateCommandPerformer {
      */
     private boolean reloadTextCache() {
         mCommittedTextBeforeComposingText.setLength(0);
+        // Clearing composing text was not in original AOSP and OpenBoard, but why? should actually
+        // be necessary when reloading text. Only when called by setSelection, mComposingText isn't
+        // always empty, but looks like things still work normally
+        mComposingText.setLength(0);
         mIC = mParent.getCurrentInputConnection();
         // Call upon the inputconnection directly since our own method is using the cache, and
         // we want to refresh it.
@@ -382,14 +386,17 @@ public final class RichInputConnection implements PrivateCommandPerformer {
                 spacingAndPunctuations, hasSpaceBefore);
     }
 
-    public int getCodePointBeforeCursor() {
+    public int getCodePointBeforeCursor() { // todo: behavior still correct? also should do this to getCharBeforeBeforeCursor
-        final int length = mCommittedTextBeforeComposingText.length();
+        final CharSequence text = mComposingText.length() == 0 ? mCommittedTextBeforeComposingText : mComposingText;
+        final int length = text.length();
         if (length < 1) return Constants.NOT_A_CODE;
-        return Character.codePointBefore(mCommittedTextBeforeComposingText, length);
+        return Character.codePointBefore(text, length);
     }
 
-    public int getCharBeforeBeforeCursor() {
+    public int getCharBeforeBeforeCursor() { // todo: behavior still correct?
+        if (mComposingText.length() >= 2) return mComposingText.charAt(mComposingText.length() - 2);
         final int length = mCommittedTextBeforeComposingText.length();
+        if (mComposingText.length() == 1) return mCommittedTextBeforeComposingText.charAt(length - 1);
         if (length < 2) return Constants.NOT_A_CODE;
         return mCommittedTextBeforeComposingText.charAt(length - 2);
     }

app/src/main/java/org/dslul/openboard/inputmethod/latin/inputlogic/InputLogic.java

@@ -409,6 +409,10 @@ public final class InputLogic {
         return true;
     }
 
+    public boolean moveCursorByAndReturnIfInsideComposingWord(int distance) {
+        return mWordComposer.moveCursorByAndReturnIfInsideComposingWord(distance);
+    }
+
     /**
      * React to a code input. It may be a code point to insert, or a symbolic value that influences
      * the keyboard behavior.