doesSelectedTextContainAttributions method

Implementation

bool doesSelectedTextContainAttributions(DocumentSelection selection, Set<Attribution> attributions) {
  final nodes = getNodesInside(selection.base, selection.extent);
  if (nodes.isEmpty) {
    return false;
  }

  // Calculate a DocumentRange so we know which DocumentPosition
  // belongs to the first node, and which belongs to the last node.
  final nodeRange = getRangeBetween(selection.base, selection.extent);

  for (final textNode in nodes) {
    if (textNode is! TextNode) {
      continue;
    }

    int startOffset = -1;
    int endOffset = -1;

    if (textNode == nodes.first && textNode == nodes.last) {
      // Handle selection within a single node
      final baseOffset = (selection.base.nodePosition as TextPosition).offset;
      final extentOffset = (selection.extent.nodePosition as TextPosition).offset;
      startOffset = baseOffset < extentOffset ? baseOffset : extentOffset;
      endOffset = baseOffset < extentOffset ? extentOffset : baseOffset;

      // -1 because TextPosition's offset indexes the character after the
      // selection, not the final character in the selection.
      endOffset -= 1;
    } else if (textNode == nodes.first) {
      // Handle partial node selection in first node.
      startOffset = (nodeRange.start.nodePosition as TextPosition).offset;
      endOffset = max(textNode.text.text.length - 1, 0);
    } else if (textNode == nodes.last) {
      // Handle partial node selection in last node.
      startOffset = 0;

      // -1 because TextPosition's offset indexes the character after the
      // selection, not the final character in the selection.
      endOffset = (nodeRange.end.nodePosition as TextPosition).offset - 1;
    } else {
      // Handle full node selection.
      startOffset = 0;
      endOffset = max(textNode.text.text.length - 1, 0);
    }

    final selectionRange = SpanRange(startOffset, endOffset);

    if (textNode.text.hasAttributionsWithin(
      attributions: attributions,
      range: selectionRange,
    )) {
      return true;
    }
  }

  return false;
}