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statevars(3U) InterViews Reference Manual statevars(3U)


BrushVar, ColorVar, CompNameVar, FontVar, GravityVar, MagnifVar, ModifStatusVar, NameVar, PatternVar - state variable subject subclasses


#include <Unidraw/statevars.h>


Unidraw predefines several state variable subject subclasses: BrushVar, ColorVar, FontVar, and PatternVar store the graphics state information their names suggest; GravityVar records whether gravity is in effect; MagnifVar records the current viewer magnification; ModifStatusVar records whether state-modifying operations have been applied to a component being edited; NameVar stores a string of interest; and CompNameVar is a NameVar that stores a component and keeps track of its catalog name. These variables represent state that is basic to graphical components and state that is often globally accessible in graphics applications.


Each graphics state state variable subclass defines a constructor that takes an initial value for the state it represents and adds operations for assigning and retrieving that state.
The GravityVar constructor takes an initial value that specifies whether gravity is on or off. IsActive returns the current value, and Activate changes it to the one supplied.
The MagnifVar constructor takes an initial value for the magnification factor, and SetMagnify and GetMagnif assign and return the current value.
The ModifStatusVar constructor takes a component instance and an initial value as arguments. The ModifStatusVar is responsible for indicating whether the given component is modified. GetModifStatus, SetModifStatus, GetComponent, and SetComponent get and set these arguments. The modification status will be set automatically (in editors that maintain a ModifStatusVar instance) when an reversible operation is performed on the component.
The NameVar constructor takes a string as an optional argument, while GetName and SetName retrieve and assign the string.
The CompNameVar constructor takes a component as an optional argument. CompNameVar inherits the GetName operation from NameVar; calling GetName returns the name associated with the component that the CompNameVar stores. The GetComponent and SetComponent calls get and set the component. UpdateName updates the string that GetName returns to reflect the component's catalog name. SetComponent calls this operation automatically when it changes the CompNameVar's component. PartOf returns the name of the root component in the CompNameVar component's hierarchy.


Catalog(3U), Component(3U), Editor(3U), StateVar(3U), pspaint(3U)

6 August 1990 Unidraw