addToScene method

  1. @override
EngineLayer addToScene (SceneBuilder builder, [ Offset layerOffset = Offset.zero ])
override

Override this method to upload this layer to the engine.

Return the engine layer for retained rendering. When there's no corresponding engine layer, null is returned.

Implementation 

@override
ui.EngineLayer addToScene(ui.SceneBuilder builder, [Offset layerOffset = Offset.zero]) {
  assert(offset != null);
  _lastOffset = offset + layerOffset;
  if (_lastOffset != Offset.zero)
    builder.pushTransform(Matrix4.translationValues(_lastOffset.dx, _lastOffset.dy, 0.0).storage);
  addChildrenToScene(builder);
  if (_lastOffset != Offset.zero)
    builder.pop();
  return null; // this does not have an engine layer.
}