decorator
The decorator this node paints its component with, at the node's position in the modifier, or null for none. It paints at the node's own box: the size measure reports, where the node is placed.
Setting a different instance replaces it and setting null removes it, both repainting the component, and, where its paint outsets change, having its Foundation container fit its bounds around its layout bounds. Setting the same instance again gathers the decoration again, re-reading its outsets and isOpaque; set it again after the decorator's outsets or isOpaque change. The node keeps it across a detach, and paints with it only while attached.
While the node places its content with a layer, the layer paints in the decorator's place: this reads null, and setting null leaves the layer painting.
Throws
if set while the node is not attached, if set to a decorator while the component is not a Decoratable, or if set to a decorator while the node places its content with a layer. A decorator set before the component's container has received the node fails as it does.