is a series of filters that are useful at the root
of applications.
INTERFACE InstalledVBT;
IMPORT DpyFilter, VBT, JoinedVBT;
TYPE
T <: DpyFilter.T;
Join <: JoinedVBT.T;
PROCEDURE New (ch: VBT.T; p: DeleteProc := NIL): T;
Return a stack of filters over ch that implement et-agenting,
teleportation, highlighting, palette initialization on rescreening, and
calls p(ch) before forwarding a deleted or disconnected code to ch,
if p # NIL. In any case, after a deleted or disconnected code it
removes the child from the filter.
PROCEDURE NewParent(ch: VBT.T): T;
If ch is attached, return a new parent for the Join above ch. Otherwise,
return NIL
PROCEDURE InitChild(j: Join; ch: VBT.T; p: DeleteProc := NIL);
Like New, except without the topmost VBT, and you allocate
PROCEDURE InitParent(p: T; ch: Join);
Like NewParent, except you pass the parent and the
Join, and it doesn't check to see if ch is attached.
PROCEDURE Child (v: VBT.T): VBT.T; <* LL.sup = VBT.mu *>
Return the installed child of the tree containing v, or the root
of the tree containing v if it isn't installed.
TYPE DeleteProc = PROCEDURE(v: VBT.T) <* LL.sup = VBT.mu *>;
END InstalledVBT.