cachedContentLines property
Returns the cached content lines (all lines before viewport slicing). If no cache exists, paints the child and caches the result.
Implementation
List<String> get cachedContentLines {
if (_cachedChildPaintLines != null) return _cachedChildPaintLines!;
if (children.isEmpty) return const [];
final child = children.first;
final content = child.paint();
if (content.isEmpty) return const [];
_cachedChildPaintLines = content.split('\n');
return _cachedChildPaintLines!;
}