Skip to Main Content
Volume 7A: XView Programming Manual
book

Volume 7A: XView Programming Manual

by Dan Heller
October 1994
Intermediate to advanced content levelIntermediate to advanced
770 pages
22h 58m
English
O'Reilly Media, Inc.
Content preview from Volume 7A: XView Programming Manual
subwindow had its text modified since the last update, this would give the package an oppor-
tunity to prompt the user for an update. Or you might install a routine that interposes any
request for destruction on a particular object (such as a frame).*
The quit() routine looks like this:
void
quit()
{
if (xv_destroy_safe(frame) == XV_OK)
exit(0);
}
Rather than calling xv_destroy_safe() on all objects, it is only called for the base
frame. Because the base frame is the owner of all the other objects, xv_destroy() and
xv_destroy_safe() descend into the objects’ children and destroys all of them with the
same call.
Use the function xv_destroy_safe() to destroy objects from within the object’s call-
back procedures. xv_destroy_safe() will delay destroying the object until it is safe to
do so (that is, not while in the object’s callback). For example, when a frame is destroyed
from within the frame’s FRAME_DONE_PROC, you need to use xv_destroy_safe() to
ensure that the frame object is removed. (See FRAME_DONE_PROC in the next chapter for a
description of a frame’s “done” callback.)
xv_destroy() may be called at any time without notice. It may result from actions the
user takes with the window manager, from a separate process or from events sent by other
applications.
3.3.4 Using xv_set( ) and xv_get( )
As discussed in the previous chapter, attributes about objects can be set, reset and retrieved
using the calls ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Volume 6A: Motif Programming Manual

Volume 6A: Motif Programming Manual

David Brennan, Dan Heller, Paula Ferguson
Java™ Media APIs: Cross-Platform Imaging, Media, and Visualization

Java™ Media APIs: Cross-Platform Imaging, Media, and Visualization

Alejandro Terrazas, John Ostuni, Michael Barlow

Publisher Resources

ISBN: 9780937175873