headerToOp method

@override List<Operation> headerToOp(Element element)

Converts a header HTML element (<h1> to <h6>) to Delta operations.

Implementation

@override
List<Operation> headerToOp(dom.Element element) {
  final Delta delta = Delta();
  Map<String, dynamic> attributes = {};
  Map<String, dynamic> blockAttributes = {};

  if (element.attributes.containsKey('style') ||
      element.attributes.containsKey('align') ||
      element.attributes.containsKey('dir')) {
    final String style = element.getSafeAttribute('style');
    final String styles2 = element.getSafeAttribute('align');
    final String styles3 = element.getSafeAttribute('dir');
    final styleAttributes = parseStyleAttribute(style);
    final alignAttribute = parseStyleAttribute(styles2);
    final dirAttribute = parseStyleAttribute(styles3);
    styleAttributes.addAll({...alignAttribute, ...dirAttribute});
    if (styleAttributes.containsKey('align') ||
        styleAttributes.containsKey('direction') ||
        styleAttributes.containsKey('indent')) {
      blockAttributes['align'] = styleAttributes['align'];
      blockAttributes['direction'] = styleAttributes['direction'];
      blockAttributes['indent'] = styleAttributes['indent'];
      styleAttributes.remove('align');
      styleAttributes.remove('direction');
      styleAttributes.remove('indent');
    }
    attributes.addAll(styleAttributes);
  }

  final headerLevel = element.localName ?? 'h1';
  blockAttributes['header'] = int.parse(headerLevel.substring(1));

  final nodes = element.nodes;
  for (final node in nodes) {
    processNode(node, attributes, delta,
        addSpanAttrs: true, removeTheseAttributesFromSpan: ['size']);
  }
  // Ensure a newline is added at the end of the header with the correct attributes
  if (blockAttributes.isNotEmpty) {
    blockAttributes.removeWhere((key, value) => value == null);
    delta.insert('\n', blockAttributes);
  }
  return delta.toList();
}