
18
Selections
The X Window System provides several methods for separate applications to exchange infor-
mation with one another. One of these methods is the use of selections. A selection transfers
arbitrary information between two clients. An in-depth discussion of the selection mecha-
nism that X provides is available in the Xlib Programming Manual. This chapter describes
XView’s new selection package. Previous revisions of XView provided a selection mecha-
nism that did not use objects.
The selection mechanism for previous versions of XView used special functions and struc-
tures to implement selections. The older selection mechanism is still supported and it is
described in Appendix A, The Selection Service. The new package implements selections as
objects. The application programmer interface for the new selection package conforms to the
standard XView model, using xv_create(), xv_set(), and xv_get().
XView selections are used to exchange data between different applications or for commu-
nications within a single application. Many, but not all selections use text; a section of text is
selected, then the selected text is cut or copied, and pasted to another area. The selection
mechanism is not limited to text. For example, selections can be used to transfer filenames,
sound data, a file’s timestamp, or other information. Selections require only that the sender
and the recipient have knowledge ...