replace old fix from 9713c4a25a with improved consistency check

and avoid somewhat unexpected crash

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

@@ -449,12 +449,13 @@ public final class RichInputConnection implements PrivateCommandPerformer {
         final long startTime = SystemClock.uptimeMillis();
         final CharSequence result = mIC.getTextBeforeCursor(n, flags);
         detectLaggyConnection(operation, timeout, startTime);
-        if (result != null && result.length() > 1 && (mComposingText.length() > 0 || mCommittedTextBeforeComposingText.length() > 0)) {
+        // inconsistent state can occur for (at least) two reasons
-            final char actualLastChar = result.charAt(result.length() - 1);
+        // 1. the app actively changes text field content, e.g. joplin when deleting "list markers like 2.
-            final char cachedLastChar = mComposingText.length() > 0
+        // 2. the app has outdated contents in the text field, e.g. notepad (com.farmerbb.notepad) returns the
-                    ? mComposingText.charAt(mComposingText.length() - 1)
+        //     just deleted char right after deletion, instead of the correct one
-                    : mCommittedTextBeforeComposingText.charAt(mCommittedTextBeforeComposingText.length() - 1);
+        //     todo: understand where this inconsistent state comes from, is it really the other app's fault, or is it HeliBoard?
-            if (actualLastChar != cachedLastChar) {
+        if (result != null) {
+            if (!checkTextBeforeCursorConsistency(result)) {
                 Log.w(TAG, "cached text out of sync, reloading");
                 ExtractedTextRequest r = new ExtractedTextRequest();
                 final ExtractedText et = mIC.getExtractedText(r, 0);
@@ -467,6 +468,41 @@ public final class RichInputConnection implements PrivateCommandPerformer {
         return result;
     }
 
+    // checks whether the end of cached text before cursor is the same as end of the given CharSequence
+    // this is done to find inconsistencies that arise in some text fields when characters are deleted, but also in some other cases
+    // only checks the end for performance reasons
+    // may need to check more than just the last character, because the text may end in e.g. rrrrr and even there a single car offset should be found
+    private boolean checkTextBeforeCursorConsistency(final CharSequence textField) {
+        final int lastIndex = textField.length() - 1;
+        if (lastIndex == -1) return true;
+        final char lastChar = textField.charAt(lastIndex);
+        final int composingLength = mComposingText.length();
+        for (int i = 0; i <= lastIndex; i++) {
+            // get last minus i character and compare
+            final char currentTextFieldChar = textField.charAt(lastIndex - i);
+            final char currentCachedChar;
+            if (i < composingLength) {
+                // take char from composing text
+                currentCachedChar = mComposingText.charAt(composingLength - 1 - i);
+            } else {
+                // take last char from mCommittedTextBeforeComposingText, consider composing length
+                final int index = mCommittedTextBeforeComposingText.length() - 1 - (i - composingLength);
+                if (index < mCommittedTextBeforeComposingText.length() && index >= 0)
+                    currentCachedChar = mCommittedTextBeforeComposingText.charAt(index);
+                else return lastIndex > 100; // still let it pass if the same character is repeated many times, but cached text too short
+            }
+
+            if (currentTextFieldChar != currentCachedChar)
+                // different character -> inconsistent
+                return false;
+
+            if (lastChar != currentTextFieldChar)
+                // not the same, and no inconsistency found so far -> unlikely there is one that won't be found later -> return early
+                return true;
+        }
+        return true; // no inconsistency found after going through everything
+    }
+
     @Nullable public CharSequence getTextAfterCursor(final int n, final int flags) {
         return getTextAfterCursorAndDetectLaggyConnection(
                 OPERATION_GET_TEXT_AFTER_CURSOR,
@@ -595,6 +631,7 @@ public final class RichInputConnection implements PrivateCommandPerformer {
     public void setComposingRegion(final int start, final int end) {
         if (DEBUG_BATCH_NESTING) checkBatchEdit();
         if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
+        final int moveBy = mExpectedSelStart - start; // determine now, as mExpectedSelStart may change in getTextBeforeCursor
         final CharSequence textBeforeCursor =
                 getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE + (end - start), 0);
         mCommittedTextBeforeComposingText.setLength(0);
@@ -603,8 +640,7 @@ public final class RichInputConnection implements PrivateCommandPerformer {
             // position in mExpectedSelStart and mExpectedSelEnd. In this case we want the start
             // of the text, so we should use mExpectedSelStart. In other words, the composing
             // text starts (mExpectedSelStart - start) characters before the end of textBeforeCursor
-            final int indexOfStartOfComposingText =
+            final int indexOfStartOfComposingText = Math.max(textBeforeCursor.length() - moveBy, 0);
-                    Math.max(textBeforeCursor.length() - (mExpectedSelStart - start), 0);
             mComposingText.append(textBeforeCursor.subSequence(indexOfStartOfComposingText,
                     textBeforeCursor.length()));
             mCommittedTextBeforeComposingText.append(
@@ -666,7 +702,7 @@ public final class RichInputConnection implements PrivateCommandPerformer {
     public void selectWord(final SpacingAndPunctuations spacingAndPunctuations, final String script) {
         if (!isConnected()) return;
         if (mExpectedSelStart != mExpectedSelEnd) return; // already something selected
-        final TextRange range = getWordRangeAtCursor(spacingAndPunctuations, script, false);
+        final TextRange range = getWordRangeAtCursor(spacingAndPunctuations, script);
         if (range == null) return;
         mIC.setSelection(mExpectedSelStart - range.getNumberOfCharsInWordBeforeCursor(), mExpectedSelStart + range.getNumberOfCharsInWordAfterCursor());
     }
@@ -766,7 +802,7 @@ public final class RichInputConnection implements PrivateCommandPerformer {
      * @return a range containing the text surrounding the cursor
      */
     @Nullable public TextRange getWordRangeAtCursor(final SpacingAndPunctuations spacingAndPunctuations,
-            final String script, final boolean justDeleted) {
+            final String script) {
         mIC = mParent.getCurrentInputConnection();
         if (!isConnected()) {
             return null;
@@ -785,26 +821,6 @@ public final class RichInputConnection implements PrivateCommandPerformer {
             return null;
         }
 
-        // we need text before, and text after is either empty or a separator or similar
-        if (justDeleted && before.length() > 0 &&
-                (after.length() == 0
-                        || !isPartOfCompositionForScript(Character.codePointAt(after, 0), spacingAndPunctuations, script)
-                )
-        ) {
-            // issue:
-            //  type 2 words and space, press delete twice -> remaining word and space before are selected
-            //   now on next key press, the space before the word is removed
-            //  or complete a word by choosing a suggestion, then press backspace -> same thing
-            // what is sometimes happening (depending on app, or maybe input field attributes):
-            //  we just pressed delete, and getTextBeforeCursor gets the correct text,
-            //  but getTextBeforeCursorAndDetectLaggyConnection returns the old word, before the deletion (not sure why)
-            //  -> we try to detect this difference, and then try to fix it
-            // interestingly, getTextBeforeCursor seems to only get the correct text because it uses
-            //  mCommittedTextBeforeComposingText, where the text is cached
-            // what could be actually going on? we probably need to fetch the text, because we want updated styles (if any)
-            before = fixIncorrectLength(before);
-        }
-
         // Going backward, find the first breaking point (separator)
         int startIndexInBefore = before.length();
         int endIndexInAfter = -1;
@@ -890,37 +906,6 @@ public final class RichInputConnection implements PrivateCommandPerformer {
                         hasUrlSpans);
     }
 
-    // mostly fixes an issue where the space before the word is selected after deleting a codepoint,
-    // because the text length is not yet updated in the field (i.e. trying to select "word length"
-    // before cursor, but the last letter has just been deleted and thus the space before is also selected)
-    private CharSequence fixIncorrectLength(final CharSequence before) {
-        // don't use codepoints, just do the simple thing...
-        int initialCheckLength = Math.min(3, before.length());
-        // this should have been checked before calling this method, but better be safe
-        if (initialCheckLength == 0) return before;
-        final CharSequence lastCharsInBefore = before.subSequence(before.length() - initialCheckLength, before.length());
-        final CharSequence lastCharsBeforeCursor = getTextBeforeCursor(initialCheckLength, 0);
-        // if the last 3 chars are equal, we can be relatively sure to not have this bug (can still be e.g. rrrr, which is not detected)
-        // (we could also check everything though, it's just a little slower)
-        if (TextUtils.equals(lastCharsInBefore, lastCharsBeforeCursor)) return before;
-
-        // delete will hopefully have deleted a codepoint, not only a char
-        // we want to compare whether the text before the cursor is the same as "before" without
-        // the last codepoint. if yes, return "before" without the last codepoint
-        final int lastBeforeCodePoint = Character.codePointBefore(before, before.length());
-        int lastBeforeLength = Character.charCount(lastBeforeCodePoint);
-        final CharSequence codePointBeforeCursor = getTextBeforeCursor(lastBeforeLength, 0);
-        if (codePointBeforeCursor == null || codePointBeforeCursor.length() == 0) return before;
-
-        // now check whether they are the same if the last codepoint of before is removed
-        final CharSequence beforeWithoutLast = before.subSequence(0, before.length() - lastBeforeLength);
-        final CharSequence beforeCursor = getTextBeforeCursor(beforeWithoutLast.length(), 0);
-        if (beforeCursor == null || beforeCursor.length() != beforeWithoutLast.length()) return before;
-        if (TextUtils.equals(beforeCursor, beforeWithoutLast))
-            return beforeWithoutLast;
-        return before;
-    }
-
     public boolean isCursorTouchingWord(final SpacingAndPunctuations spacingAndPunctuations,
             boolean checkTextAfter) {
         if (checkTextAfter && isCursorFollowedByWordCharacter(spacingAndPunctuations)) {

app/src/main/java/helium314/keyboard/latin/inputlogic/InputLogic.java

@@ -1353,9 +1353,7 @@ public final class InputLogic {
         if (!mConnection.hasSelection()
                 && settingsValues.isSuggestionsEnabledPerUserSettings()
                 && settingsValues.mSpacingAndPunctuations.mCurrentLanguageHasSpaces) {
-            final TextRange range = mConnection.getWordRangeAtCursor(
+            final TextRange range = mConnection.getWordRangeAtCursor(settingsValues.mSpacingAndPunctuations, currentKeyboardScript);
-                    settingsValues.mSpacingAndPunctuations,
-                    currentKeyboardScript, false);
             if (range != null) {
                 return range.mWord.toString();
             }
@@ -1709,8 +1707,7 @@ public final class InputLogic {
             mConnection.finishComposingText();
             return;
         }
-        final TextRange range =
+        final TextRange range = mConnection.getWordRangeAtCursor(settingsValues.mSpacingAndPunctuations, currentKeyboardScript);
-                mConnection.getWordRangeAtCursor(settingsValues.mSpacingAndPunctuations, currentKeyboardScript, true);
         if (null == range) return; // Happens if we don't have an input connection at all
         if (range.length() <= 0) {
             // Race condition, or touching a word in a non-supported script.