Layer System Notifications

#layerCreated: BaseLayer (reftarg) 

Sent after layer created.

Calling callbacks.notificationParam() returns a layer ReferenceTarget.

Note: There is a known problem with #layerCreated - a layer may be created if an object is merged or an object XRef is performed, but these actions do not broadcast a #layerCreated event.
#layerDeleted: BaseLayer (reftarg) 

Sent before layer deleted, callbacks.notificationParam() returns the layer.

#layerParentChanged: #(BaseLayer, BaseLayer) 

Sent after the parent of a layer was changed.

Calling callbacks.notificationParam() returns an array containing two elements, the new parent and the old parent.

#nodeLayerChanged: #(node, BaseLayer, BaseLayer) 

Sent after node placed on new layer, callbacks.notificationParam() returns an array containing 3 elements - the node, the old layer and the new layer