@Override
public boolean isOpeningQuote(HighlighterIterator iterator, int offset)
{
	boolean openingQuote = super.isOpeningQuote(iterator, offset);

	if(openingQuote)
	{
		// check escape next
		if(!iterator.atEnd())
		{
			iterator.retreat();

			if(!iterator.atEnd() && StringEscapesTokenTypes.STRING_LITERAL_ESCAPES.contains(iterator.getTokenType()))
			{
				openingQuote = false;
			}
			iterator.advance();
		}
	}
	return openingQuote;
}
 

@Override
public boolean isClosingQuote(HighlighterIterator iterator, int offset)
{
	boolean closingQuote = super.isClosingQuote(iterator, offset);

	if(closingQuote)
	{
		// check escape next
		if(!iterator.atEnd())
		{
			iterator.advance();

			if(!iterator.atEnd() && StringEscapesTokenTypes.STRING_LITERAL_ESCAPES.contains(iterator.getTokenType()))
			{
				closingQuote = false;
			}
			iterator.retreat();
		}
	}
	return closingQuote;
}
 

public static void addWordHonoringEscapeSequences(CharSequence editorText,
                                                  TextRange literalTextRange,
                                                  int cursorOffset,
                                                  Lexer lexer,
                                                  List<TextRange> result) {
  lexer.start(editorText, literalTextRange.getStartOffset(), literalTextRange.getEndOffset());

  while (lexer.getTokenType() != null) {
    if (lexer.getTokenStart() <= cursorOffset && cursorOffset < lexer.getTokenEnd()) {
      if (StringEscapesTokenTypes.STRING_LITERAL_ESCAPES.contains(lexer.getTokenType())) {
        result.add(new TextRange(lexer.getTokenStart(), lexer.getTokenEnd()));
      }
      else {
        TextRange word = getWordSelectionRange(editorText, cursorOffset, JAVA_IDENTIFIER_PART_CONDITION);
        if (word != null) {
          result.add(new TextRange(Math.max(word.getStartOffset(), lexer.getTokenStart()),
                                   Math.min(word.getEndOffset(), lexer.getTokenEnd())));
        }
      }
      break;
    }
    lexer.advance();
  }
}
 

private static boolean isInStringLiteral(@Nonnull Editor editor, @Nonnull DataContext dataContext, int offset) {
  Language language = EnterHandler.getLanguage(dataContext);
  if (offset > 0 && language != null) {
    QuoteHandler quoteHandler = TypedHandler.getLanguageQuoteHandler(language);
    if (quoteHandler == null) {
      FileType fileType = language.getAssociatedFileType();
      quoteHandler = fileType != null ? TypedHandler.getQuoteHandlerForType(fileType) : null;
    }
    if (quoteHandler != null) {
      EditorHighlighter highlighter = ((EditorEx)editor).getHighlighter();
      HighlighterIterator iterator = highlighter.createIterator(offset - 1);
      return StringEscapesTokenTypes.STRING_LITERAL_ESCAPES.contains(iterator.getTokenType()) || quoteHandler.isInsideLiteral(iterator);
    }
  }
  return false;
}
 

private static boolean distinctTokens(@Nullable IElementType token1, @Nullable IElementType token2) {
  if (token1 == token2) return false;
  if (token1 == null || token2 == null) return true;
  if (StringEscapesTokenTypes.STRING_LITERAL_ESCAPES.contains(token1) || StringEscapesTokenTypes.STRING_LITERAL_ESCAPES.contains(token2)) return false;
  if (token1 != TokenType.WHITE_SPACE && token2 != TokenType.WHITE_SPACE && !token1.getLanguage().is(token2.getLanguage())) return true;
  Language language = token1.getLanguage();
  if (language == Language.ANY) language = token2.getLanguage();
  BidiRegionsSeparator separator = LanguageBidiRegionsSeparator.INSTANCE.forLanguage(language);
  return separator.createBorderBetweenTokens(token1, token2);
}
 

@Override
public IElementType getTokenType() {
  if (myStart >= myEnd) return null;

  if (myBuffer.charAt(myStart) != '\\') {
    mySeenEscapedSpacesOnly = false;
    return myOriginalLiteralToken;
  }

  if (myStart + 1 >= myEnd) return StringEscapesTokenTypes.INVALID_CHARACTER_ESCAPE_TOKEN;
  char nextChar = myBuffer.charAt(myStart + 1);
  mySeenEscapedSpacesOnly &= nextChar == ' ';
  if (myCanEscapeEolOrFramingSpaces &&
      (nextChar == '\n' || nextChar == ' ' && (mySeenEscapedSpacesOnly || isTrailingSpace(myStart+2)))
          ) {
    return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
  }
  if (nextChar == 'u') {
    for(int i = myStart + 2; i < myStart + 6; i++) {
      if (i >= myEnd || !StringUtil.isHexDigit(myBuffer.charAt(i))) return StringEscapesTokenTypes.INVALID_UNICODE_ESCAPE_TOKEN;
    }
    return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
  }

  if (nextChar == 'x' && myAllowHex) {
    for(int i = myStart + 2; i < myStart + 4; i++) {
      if (i >= myEnd || !StringUtil.isHexDigit(myBuffer.charAt(i))) return StringEscapesTokenTypes.INVALID_UNICODE_ESCAPE_TOKEN;
    }
    return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
  }

  switch (nextChar) {
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
      if (!myAllowOctal) return StringEscapesTokenTypes.INVALID_CHARACTER_ESCAPE_TOKEN;
      //noinspection fallthrough
    case 'n':
    case 'r':
    case 'b':
    case 't':
    case 'f':
    case '\'':
    case '\"':
    case '\\':
      return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
  }
  if (myAdditionalValidEscapes != null && myAdditionalValidEscapes.indexOf(nextChar) != -1) {
    return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
  }

  return StringEscapesTokenTypes.INVALID_CHARACTER_ESCAPE_TOKEN;
}
 

@Override
public Result preprocessEnter(@Nonnull final PsiFile file, @Nonnull final Editor editor, @Nonnull Ref<Integer> caretOffsetRef,
                              @Nonnull final Ref<Integer> caretAdvanceRef, @Nonnull final DataContext dataContext,
                              final EditorActionHandler originalHandler) {
  int caretOffset = caretOffsetRef.get().intValue();
  int caretAdvance = caretAdvanceRef.get().intValue();
  if (!isInStringLiteral(editor, dataContext, caretOffset)) return Result.Continue;
  PsiDocumentManager.getInstance(file.getProject()).commitDocument(editor.getDocument());
  PsiElement psiAtOffset = file.findElementAt(caretOffset);
  if (psiAtOffset != null && psiAtOffset.getTextOffset() < caretOffset) {
    Document document = editor.getDocument();
    CharSequence text = document.getText();
    ASTNode token = psiAtOffset.getNode();
    JavaLikeQuoteHandler quoteHandler = getJavaLikeQuoteHandler(editor, psiAtOffset);

    if (quoteHandler != null &&
        quoteHandler.getConcatenatableStringTokenTypes() != null &&
        quoteHandler.getConcatenatableStringTokenTypes().contains(token.getElementType())) {
      TextRange range = token.getTextRange();
      final char literalStart = token.getText().charAt(0);
      final StringLiteralLexer lexer = new StringLiteralLexer(literalStart, token.getElementType());
      lexer.start(text, range.getStartOffset(), range.getEndOffset());

      while (lexer.getTokenType() != null) {
        if (lexer.getTokenStart() < caretOffset && caretOffset < lexer.getTokenEnd()) {
          if (StringEscapesTokenTypes.STRING_LITERAL_ESCAPES.contains(lexer.getTokenType())) {
            caretOffset = lexer.getTokenEnd();
          }
          break;
        }
        lexer.advance();
      }

      if (quoteHandler.needParenthesesAroundConcatenation(psiAtOffset)) {
        document.insertString(psiAtOffset.getTextRange().getEndOffset(), ")");
        document.insertString(psiAtOffset.getTextRange().getStartOffset(), "(");
        caretOffset++;
        caretAdvance++;
      }

      final String insertedFragment = literalStart + " " + quoteHandler.getStringConcatenationOperatorRepresentation();
      document.insertString(caretOffset, insertedFragment + " " + literalStart);
      caretOffset += insertedFragment.length();
      caretAdvance = 1;
      CommonCodeStyleSettings langSettings =
              CodeStyleSettingsManager.getSettings(file.getProject()).getCommonSettings(file.getLanguage());
      if (langSettings.BINARY_OPERATION_SIGN_ON_NEXT_LINE) {
        caretOffset -= 1;
        caretAdvance = 3;
      }
      caretOffsetRef.set(caretOffset);
      caretAdvanceRef.set(caretAdvance);
      return Result.DefaultForceIndent;
    }
  }
  return Result.Continue;
}