oracular (3) StateVarView.3U.gz

NAME

       StateVarView - state variable view base class

SYNOPSIS

       #include <Unidraw/stateview.h>

DESCRIPTION

       StateVarView  is  the  base  class  for  state  variable views.  State variable views provide a graphical
       interface to examining and potentially modifying a state variable subject.  The StateVarView  base  class
       is an abstract class derived from MonoScene.  Like MonoScene, the StateVarView class is not instantiated;
       instead, subclasses add state and behavior appropriate for displaying and editing  their  subject.   Like
       other  MonoScene  subclasses,  StateVarView  subclasses  use  an  interactor  composition to define their
       appearance.

PUBLIC OPERATIONS

       virtual void Update()
              Update the state variable view in response to a change in  state  it  depends  on  (typically  the
              subject's).   This  operation  does  not  normally  need redefinition if Init and Stale (described
              below) are redefined.

PROTECTED OPERATIONS

       StateVarView(StateVar*)
              Subclass constructors normally take an instance of the corresponding subject as an argument.   The
              base class constructor automatically attaches the view to the subject.

       virtual void Init()
              Initialize  the  view  based  on  information  in the subject.  Subclasses redefine this operation
              according to their semantics; it does nothing by default.

       virtual boolean Stale()
              Return whether the view is in any way  inconsistent  with  its  subject.   This  operation  always
              returns true by default; subclasses can redefine it to make a more discerning decision.

SEE ALSO

       MonoScene(3I), StateVar(3U)