NAME

       GVUpdater - updates GraphicViews structure to match its subject

SYNOPSIS

       #include <Unidraw/Components/gvupdater.h>

DESCRIPTION

       GVUpdater  is  an  implementation class that GraphicViews uses to keep its state and structure consistent
       with its GraphicComps subject.  GVUpdater ensures that subject's immediate children are identical to  the
       view's  in  number  and  graphics  state  attributes.  It  also  ensures  that  the root GraphicViews and
       GraphicComps themselves have the same graphics state.  GVUpdater does not ensure that it will detect  and
       update changes made to deeper child nodes.

PUBLIC OPERATIONS

       GVUpdater(GraphicView*)
              The constructor takes the GraphicView that it will be updating as a parameter and stores it in the
              protected member _gv. Normally, GraphicViews are the only objects that will instantiate GVUpdater.

       virtual void Update()
              Update the GraphicView to make it consistent with its subject.

PROTECTED OPERATIONS

       void UpdateStructure()
       void UpdateState()
              The Update procedure takes  place  in  two  stages.   The  subject's  and  view's  structures  are
              reconciled  first  by  UpdateStructure,  and then the view's graphic state is changed to match the
              subjects with UpdateState.

       void AddDamage(Graphic*)
       void IncurDamage(Graphic*)
       void Unselect(GraphicView*)
       virtual void Add(GraphicView*)
       virtual void Append(GraphicView*)
       virtual void InsertBefore(Iterator, GraphicView*)
        virtual void Remove(Iterator&)
       virtual void DeleteView(Iterator&)
              GVUpdater is a friend of GraphicViews.  These convenience operations provide an interface  to  the
              corresponding protected GraphicViews operations.

       virtual ClassId ViewCategory()
              Returns  the  view category (see classes(3U)) GVUpdater will use to instantiate views of subjects.
              ViewCategory returns COMPONENT_VIEW by default.

SEE ALSO

       GraphicComp(3U), GraphicView(3U), classes(3U)