picture method

Picture picture(BackgroundSpec spec, Size size, Picture build())

The cached picture for spec at size, built by build on a miss.

Implementation

ui.Picture picture(
  BackgroundSpec spec,
  Size size,
  ui.Picture Function() build,
) {
  final key = (spec, size);
  final hit = _pictures.remove(key);
  if (hit != null) return _pictures[key] = hit;
  builds++;
  final picture = _pictures[key] = build();
  while (_pictures.length > capacity) {
    _pictures.remove(_pictures.keys.first)?.dispose();
  }
  return picture;
}