splitColorTags function

List<ColoredText> splitColorTags(String text)

Implementation

List<ColoredText> splitColorTags(String text) {
  final startTagIndexes =
      RegExp(r"<color=(\w+)>").allMatches(text).map((tag) => tag.start);
  final endTagIndexes =
      RegExp(r"</color>").allMatches(text).map((tag) => tag.end);
  final tagMatches = <List<int>>[];

  for (int startIndex in startTagIndexes) {
    final lastIndex = tagMatches.lastOrNull?.lastOrNull;
    if (lastIndex != null && startIndex < lastIndex) {
      continue;
    }
    final endIndex = endTagIndexes.firstWhereOrNull((i) => i > startIndex);
    if (endIndex == null) {
      continue;
    }
    tagMatches.add([startIndex, endIndex]);
  }

  final coloredTextStart = tagMatches.map((e) => e.first);
  final normalTextStart = tagMatches.map((e) => e.last + 1).toList();
  if (coloredTextStart.firstOrNull != 0) {
    normalTextStart.insert(0, 0);
  }
  if (normalTextStart.lastOrNull != null &&
      normalTextStart.last > text.length) {
    normalTextStart.removeLast();
  }

  int pointer = 0;
  final coloredTexts = <ColoredText>[];

  tagMatches.forEach((tagMatch) {
    if (pointer < tagMatch.first) {
      coloredTexts
          .add(ColoredText.deligate(text.substring(pointer, tagMatch.first)));
      pointer = tagMatch.first;
    }
    final coloredText =
        ColoredText.generate(text.substring(pointer, tagMatch.last));
    if (coloredText != null) {
      coloredTexts.add(coloredText);
      pointer = tagMatch.last;
    }
  });

  if (pointer != text.length) {
    coloredTexts
        .add(ColoredText.deligate(text.substring(pointer, text.length)));
  }

  return coloredTexts;
}