makeSafeForPresentation static method

String makeSafeForPresentation(String unclean, int maxCharactersToConsider, double ellipsizeDip, int flags,)

Implementation

static String makeSafeForPresentation(String unclean,
    int maxCharactersToConsider, double ellipsizeDip, int flags) {
  bool onlyKeepFirstLine = ((flags & SAFE_STRING_FLAG_FIRST_LINE) != 0);
  bool forceSingleLine = ((flags & SAFE_STRING_FLAG_SINGLE_LINE) != 0);
  bool trim = ((flags & SAFE_STRING_FLAG_TRIM) != 0);

  String shortString;

  if (maxCharactersToConsider > 0) {
    shortString = unclean.substring(
        0, Math.min(unclean.length, maxCharactersToConsider));
  } else {
    shortString = unclean;
  }

  // Treat string as HTML. This
  // - converts HTML symbols: e.g. ß -> ß
  // - applies some HTML tags: e.g. <br> -> \n
  // - removes invalid characters such as \b
  // - removes html styling, such as <b>
  // - applies html formatting: e.g. a<p>b</p>c -> a\n\nb\n\nc
  // - replaces some html tags by "object replacement" markers: <img> -> \ufffc
  // - Removes leading white space
  // - Removes all trailing white space beside a single space
  // - Collapses double white space
  _StringWithRemovedChars gettingCleaned =
      _StringWithRemovedChars((shortString));
  int firstNonWhiteSpace = -1;
  int firstTrailingWhiteSpace = -1;

  // Remove new lines (if requested) and control characters.
  int uncleanLength = gettingCleaned.length();
  for (int offset = 0; offset < uncleanLength;) {
    int codePoint = gettingCleaned.codePointAt(offset);
    // int type = String.fromCharCode(codePoint);
    int codePointLen = String.fromCharCode(codePoint).length;
    bool isNewline = _isNewline(codePoint);
    if (onlyKeepFirstLine && isNewline) {
      gettingCleaned.removeAllCharAfter(offset);
      break;
    } else if (forceSingleLine && isNewline) {
      gettingCleaned.removeRange(offset, offset + codePointLen);
    }
    // else if (type == Character.CONTROL && !isNewline) {
    //   gettingCleaned.removeRange(offset, offset + codePointLen);
    // }
    else if (trim && !_isWhiteSpace(codePoint)) {
      // This is only executed if the code point is not removed
      if (firstNonWhiteSpace == -1) {
        firstNonWhiteSpace = offset;
      }
      firstTrailingWhiteSpace = offset + codePointLen;
    }
    offset += codePointLen;
  }

  if (trim) {
    // Remove leading and trailing white space
    if (firstNonWhiteSpace == -1) {
      // No non whitespace found, remove all
      gettingCleaned.removeAllCharAfter(0);
    } else {
      if (firstNonWhiteSpace > 0) {
        gettingCleaned.removeAllCharBefore(firstNonWhiteSpace);
      }
      if (firstTrailingWhiteSpace < uncleanLength) {
        gettingCleaned.removeAllCharAfter(firstTrailingWhiteSpace);
      }
    }
  }

  return gettingCleaned.toString();
}