StateVarView - state variable view base class
#include <Unidraw/stateview.h>
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.
- 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.
- 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.
MonoScene(3I), StateVar(3U)