Volume 7A: XView Programming Manual

15.5 The FULLSCREEN Package

The FULLSCREEN package allows XView clients to grab the server for keyboard and/or

pointer use either exclusively or nonexclusively with other applications. This package is

used primarily to prompt the user for immediate feedback on a question or to notify the user

of an error that needs attention. Typically, the user responds with a button press or a key-

board event. The NOTICE package uses the FULLSCREEN package extensively to implement

its functionality. In most cases, you need nothing more than the NOTICE package and should

rarely need to use the FULLSCREEN package. The need for this package arises if you choose

to implement your own notice or perhaps a user interface item that is not OPEN LOOK-

compliant. In either case, this is advanced usage and is beyond the scope of this book. Using

the FULLSCREEN package can be very dangerous because it uses the X server’s grabbing

functions in Xlib. It is possible to get into a state from which you cannot get out except by

killing the server remotely or rebooting your workstation. When using a debugger, be

extremely careful that you do not set breakpoints within code when the server is in the

middle of a grab of some kind. Whatever you do, do not step through code that creates a

FULLSCREEN instance. If this is unavoidable, you should prepare for it by making sure that

you have remote access to your workstation or by attaching ...