Picture(3U)						    InterViews Reference Manual 					       Picture(3U)

NAME

       Picture - composite structured graphic

SYNOPSIS

       #include <Unidraw/Graphic/picture.h>

DESCRIPTION

       A  Picture defines a composition of graphic objects.  A picture has its own graphics state, which it concatenates with its children's state
       when it is drawn or erased.  Picture adopts the default concatenation semantics supported by the Graphic base class: The picture's graphics
       state  effectively  overrides  its  children's  so  that  they are drawn with the picture's state information substituted for their own.  A
       child's attribute is used only when the picture does not already define it.  Moreover, each child's transformer is  postmultiplied  by  the
       picture's transformer when the picture is drawn; thus children are drawn relative to the picture's coordinate system.

PUBLIC OPERATIONS

       Picture(Graphic* = nil)
	      Construct  a  new picture, optionally supply a graphic from which to copy an initial set of graphics state.  Picture is derived from
	      FullGraphic and therefore defines a full set of graphics state.

       virtual ~Picture()
	      The picture deletes its children when it is deleted.

       boolean IsEmpty()
	      Picture defines IsEmpty in addition to the standard Graphic child traversal operations to provide a convenient way to check  if  the
	      picture has any children.

PROTECTED OPERATIONS

       Graphic* graphic(UList*)
       UList* Elem(Iterator)
	      Convenience functions for extracting a graphic from a UList element and a UList from an iterator.

SEE ALSO

       Graphic(3U), Iterator(3U), Transformer(3I), UList(3U), pspaint(3U)

Unidraw 							  1 February 1991						       Picture(3U)