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)
