Generic (leaf)
A placeholder, intended to be taken over by the application.
Should always be given a name, so the application can access it.
Often has some application-defined interactive behavior. Until taken
over, this has the shape and appearance of
(Shape (Width 0 + 0) (Height 0 + 0) "")
- Notes
- To take over a Generic, use PutGeneric; to retrieve
the VBT, use GetGeneric. A Generic is implemented as
a Filter.T, whose child is the VBT specified using
PutGeneric. Whenever PutGeneric is invoked, the
size of the new VBT is propagated appropriately.
Generic should be used only when there is no comparable
interactor provided by FormsVBT, or when the VBT will change
dynamically. If you want to use a subtype of an interactor,
you should override the realize method of the FormsVBT
object; see FormsVBT.i3.