GPRCN - Remove Class Name from Set

Purpose

Use GPRCN to insert a Remove Class Name from Set structure element into the open structure following the element pointer or to replace the element pointed at by the element pointer with a Remove Class Name from Set structure element depending on the current edit mode.

The class set traversal state consists of a list of class names. During structure traversal, this structure element removes one or more names from the list but does not completely replace the traversal state as other attributes do.

Class names let an application control the eligibility of a primitive for pickability (detectability), highlighting, and invisibility by associating it with a class set. The effects of adding or removing a class name to the current class set are inherited (i.e., by child structures).

When the graPHIGS API encounters a primitive during structure traversal, it uses the list of class names in the class set to determine the pickability (detectability), highlighting, and invisibility aspects. If the workstation does not support a specified name, then the graPHIGS API ignores the name and the name has no effect on the primitive.

Also use class names are to create inclusion and exclusion filters for the specified workstation. The graPHIGS API uses these filters in conjunction with the class set traversal state to determine if pickability, highlighting, and visibility apply. The filters act independently of each other.

During structure traversal, the graPHIGS API compares the current class set to the current filters. When root structure traversal begins, the current class set is null.

For a complete discussion of class names and filters, see The graPHIGS Programming Interface: Understanding Concepts

Parameters