neideck@wsl.dec.com (Burkhard Neidecker) (05/04/91)
I have a question about the behaviour of the ScreenSaver in the server (X11R4
and higher).
I have a program that needs to prevent the screen from going blank as
long as it receives events (The program couples multiple machines into
behaving as a single multiscreen machine). I don't want to touch the
parameters of the screensaver (timeout) on the Displays in question,
but rather wanted to reset the timer for the screensaver from the program.
According to the documentation for XSetScreenSaver(3X11):
...
XResetScreenSaver(display)
...
If the specified mode is Screen-
SaverReset and the screen saver currently is enabled, XFor-
ceScreenSaver deactivates the screen saver if it was
activated, and the activation timer is reset to its initial
state (as if device input had been received).
At first I understood the above sentence to mean that whenever I make a call
to XResetScreenSaver, the clock starts ticking again, so if timeout
is set to 60 seconds, the screen will go blank only 60 seconds after
the last call to XResetScreenSaver. What happens instead is that the
screen goes blank after 60 seconds, no matter how many calls to
XResetScreenSaver have been done, the first call *after* the blanking
triggers the timer again and all further calls are ignored again.
Reading the sentence above again, I looks to me like it can be interpreted
to mean the behaviour I'm seeing. The logic as implemented by the server
is
if (screen_saver_enabled && screen_saver_activated) {
unsafe_screen;
retrigger_timer;
}
whereas the behaviour I wanted was
if (screen_saver_enabled) {
if (screen_saver_activated) {
unsafe_screen;
}
retrigger_timer;
}
Did I misinterpret the documentation or is this a server bug ? If it's
intentional, what's the reasoning behind this behaviour. It doesn't
seem terribly useful to me the way it's now.
Burkhard Neidecker-Lutz, CEC Karlsruhe
neideck@nestvx.enet.dec.com