additionalPositiveXOverflowFromAtomicPlaceholders method

Implementation

double additionalPositiveXOverflowFromAtomicPlaceholders() {
  if (_paragraph == null || _placeholderBoxes.isEmpty || _allPlaceholders.isEmpty) return 0.0;

  // Base paragraph right edge is the visual max line width.
  final double baseRight = (_paraLines.isEmpty)
      ? (_paragraph?.maxIntrinsicWidth ?? _paragraph?.width ?? 0.0)
      : _paraLines.fold<double>(0.0, (maxR, lm) => math.max(maxR, lm.left + lm.width));

  double maxRight = baseRight;
  final int n = math.min(_placeholderBoxes.length, _allPlaceholders.length);
  for (int i = 0; i < n; i++) {
    final ph = _allPlaceholders[i];
    if (ph.kind != _PHKind.atomic) continue;
    final tb = _placeholderBoxes[i];
    final RenderBox? rb = ph.atomic;
    if (rb == null) continue;
    final RenderBoxModel? styleBox = _resolveStyleBoxForPlaceholder(rb);
    if (styleBox == null || !styleBox.hasSize) continue;

    final rs = styleBox.renderStyle;
    final bool childScrolls =
        rs.effectiveOverflowX != CSSOverflowType.visible || rs.effectiveOverflowY != CSSOverflowType.visible;
    final Size childExtent = childScrolls ? (styleBox.boxSize ?? styleBox.size) : styleBox.scrollableSize;

    double candidateRight = tb.left + (childExtent.width.isFinite ? childExtent.width : 0.0);
    final Offset? rel = CSSPositionedLayout.getRelativeOffset(rs);
    if (rel != null && rel.dx > 0) candidateRight += rel.dx;
    final Offset? tr = rs.effectiveTransformOffset;
    if (tr != null && tr.dx > 0) candidateRight += tr.dx;

    // Include right margin since line layout accounts for margins horizontally
    // when distributing inline-level boxes.
    candidateRight += rs.marginRight.computedValue;

    if (candidateRight > maxRight) maxRight = candidateRight;
  }

  final double extra = maxRight - baseRight;
  return extra > 0 ? extra : 0.0;
}