updateTextColor function

Implementation

List<TextSpan> updateTextColor(
  List<TextSpan> originalSpans,
  List<int> targetLines,
  Color newColor,
) {
  // Check if the target line is within the range of the list
  if (targetLines.isEmpty) {
    return originalSpans;
  }

  // Clone the original list to avoid mutating it directly
  List<TextSpan> updatedSpans = List<TextSpan>.from(originalSpans);

  // Detect line break from the list of text spans
  // This is done by checking if the previous span is a line break
  // If it is, then the current span is the start of a new line
  int line = 1;

  for (int i = 0; i < updatedSpans.length; i++) {
    if (i > 0) {
      final currentValue = updatedSpans[i].text ?? '';

      if (currentValue.startsWith('\n')) {
        line++;
      }
    }
    final originalSpan = originalSpans[i];

    final textStyle = originalSpan.style ?? const TextStyle();

    if (targetLines.contains(line)) {
      updatedSpans[i] = TextSpan(
        text: originalSpan.text,
        children: originalSpan.children,
        recognizer: originalSpan.recognizer,
        mouseCursor: originalSpan.mouseCursor,
        onEnter: originalSpan.onEnter,
        onExit: originalSpan.onExit,
        semanticsLabel: originalSpan.semanticsLabel,
        locale: originalSpan.locale,
        spellOut: originalSpan.spellOut,
        style: textStyle.copyWith(
          backgroundColor: newColor,
        ),
      );
    }
  }

  return updatedSpans;
}