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)