getSemanticsData method Null safety

Implementation

SemanticsData getSemanticsData() {
  int flags = _flags;
  int actions = _actionsAsBits;
  AttributedString attributedLabel = _attributedLabel;
  AttributedString attributedValue = _attributedValue;
  AttributedString attributedIncreasedValue = _attributedIncreasedValue;
  AttributedString attributedDecreasedValue = _attributedDecreasedValue;
  AttributedString attributedHint = _attributedHint;
  String tooltip = _tooltip;
  TextDirection? textDirection = _textDirection;
  Set<SemanticsTag>? mergedTags = tags == null ? null : Set<SemanticsTag>.of(tags!);
  TextSelection? textSelection = _textSelection;
  int? scrollChildCount = _scrollChildCount;
  int? scrollIndex = _scrollIndex;
  double? scrollPosition = _scrollPosition;
  double? scrollExtentMax = _scrollExtentMax;
  double? scrollExtentMin = _scrollExtentMin;
  int? platformViewId = _platformViewId;
  int? maxValueLength = _maxValueLength;
  int? currentValueLength = _currentValueLength;
  final double elevation = _elevation;
  double thickness = _thickness;
  final Set<int> customSemanticsActionIds = <int>{};
  for (final CustomSemanticsAction action in _customSemanticsActions.keys) {
    customSemanticsActionIds.add(CustomSemanticsAction.getIdentifier(action));
  }
  if (hintOverrides != null) {
    if (hintOverrides!.onTapHint != null) {
      final CustomSemanticsAction action = CustomSemanticsAction.overridingAction(
        hint: hintOverrides!.onTapHint!,
        action: SemanticsAction.tap,
      );
      customSemanticsActionIds.add(CustomSemanticsAction.getIdentifier(action));
    }
    if (hintOverrides!.onLongPressHint != null) {
      final CustomSemanticsAction action = CustomSemanticsAction.overridingAction(
        hint: hintOverrides!.onLongPressHint!,
        action: SemanticsAction.longPress,
      );
      customSemanticsActionIds.add(CustomSemanticsAction.getIdentifier(action));
    }
  }

  if (mergeAllDescendantsIntoThisNode) {
    _visitDescendants((SemanticsNode node) {
      assert(node.isMergedIntoParent);
      flags |= node._flags;
      actions |= node._actionsAsBits;
      textDirection ??= node._textDirection;
      textSelection ??= node._textSelection;
      scrollChildCount ??= node._scrollChildCount;
      scrollIndex ??= node._scrollIndex;
      scrollPosition ??= node._scrollPosition;
      scrollExtentMax ??= node._scrollExtentMax;
      scrollExtentMin ??= node._scrollExtentMin;
      platformViewId ??= node._platformViewId;
      maxValueLength ??= node._maxValueLength;
      currentValueLength ??= node._currentValueLength;
      if (attributedValue == null || attributedValue.string == '') {
        attributedValue = node._attributedValue;
      }
      if (attributedIncreasedValue == null || attributedIncreasedValue.string == '') {
        attributedIncreasedValue = node._attributedIncreasedValue;
      }
      if (attributedDecreasedValue == null || attributedDecreasedValue.string == '') {
        attributedDecreasedValue = node._attributedDecreasedValue;
      }
      if (tooltip == '') {
        tooltip = node._tooltip;
      }
      if (node.tags != null) {
        mergedTags ??= <SemanticsTag>{};
        mergedTags!.addAll(node.tags!);
      }
      for (final CustomSemanticsAction action in _customSemanticsActions.keys) {
        customSemanticsActionIds.add(CustomSemanticsAction.getIdentifier(action));
      }
      if (node.hintOverrides != null) {
        if (node.hintOverrides!.onTapHint != null) {
          final CustomSemanticsAction action = CustomSemanticsAction.overridingAction(
            hint: node.hintOverrides!.onTapHint!,
            action: SemanticsAction.tap,
          );
          customSemanticsActionIds.add(CustomSemanticsAction.getIdentifier(action));
        }
        if (node.hintOverrides!.onLongPressHint != null) {
          final CustomSemanticsAction action = CustomSemanticsAction.overridingAction(
            hint: node.hintOverrides!.onLongPressHint!,
            action: SemanticsAction.longPress,
          );
          customSemanticsActionIds.add(CustomSemanticsAction.getIdentifier(action));
        }
      }
      attributedLabel = _concatAttributedString(
        thisAttributedString: attributedLabel,
        thisTextDirection: textDirection,
        otherAttributedString: node._attributedLabel,
        otherTextDirection: node._textDirection,
      );
      attributedHint = _concatAttributedString(
        thisAttributedString: attributedHint,
        thisTextDirection: textDirection,
        otherAttributedString: node._attributedHint,
        otherTextDirection: node._textDirection,
      );

      thickness = math.max(thickness, node._thickness + node._elevation);

      return true;
    });
  }

  return SemanticsData(
    flags: flags,
    actions: actions,
    attributedLabel: attributedLabel,
    attributedValue: attributedValue,
    attributedIncreasedValue: attributedIncreasedValue,
    attributedDecreasedValue: attributedDecreasedValue,
    attributedHint: attributedHint,
    tooltip: tooltip,
    textDirection: textDirection,
    rect: rect,
    transform: transform,
    elevation: elevation,
    thickness: thickness,
    tags: mergedTags,
    textSelection: textSelection,
    scrollChildCount: scrollChildCount,
    scrollIndex: scrollIndex,
    scrollPosition: scrollPosition,
    scrollExtentMax: scrollExtentMax,
    scrollExtentMin: scrollExtentMin,
    platformViewId: platformViewId,
    maxValueLength: maxValueLength,
    currentValueLength: currentValueLength,
    customSemanticsActionIds: customSemanticsActionIds.toList()..sort(),
  );
}