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This will cause the flickering screensaver of death!
Authored by: Basilisk on Jul 17, '03 12:57:15PM

I've posted info on this before. Here it is again (editted slightly for clarity)...

This technique is a bad idea. It will cause the flickering screensaver issue (double-launched saver).

Yes, I'm aware that this method is popular, and is even covered in many hints on this site, but it is wrong, and doesn't do what people think. Launching the screensaver engine directly is not the same method used by the system itself. Try the following test (be careful, this leads to a problem documented below):

1. Set you system screensaver start time to 5 minutes.
2. Launch ScreenSaverEngine.app directly (same way as the suggested script)
3. Wait 5 minutes.

After the 5 minutes have passed the windowmanager will start the screensaver a second time, leading to flickering screensaver of doom (both savers fight to be front and recieve keystrokes during password entry). With some patience you can usually get one to take a password and eventually quit, or just force restart the machine.

Properly launching the screensaver requires the use of an undocumented API in ScreenSaver.framework, which uses the windowmanager to launch the screensaver. This works correctly, and the screensaver won't double launch (no flicker of doom) and doesn't conflict with the desktop screensaver.

How do I know all this? Becuase I had a similar problem and had to figure out how Apple's keychain menu extra does this properly (never double-launched, no conflcit with desktop background). I've since written an app to do this properly, get SleepTight:

http://www.ragingmenace.com/software/sleeptight/index.html

The current 1.0 version has a pref pane bug causing the pref to crash on some systems (this does not affect the agent which actually launches the saver). I'll have a 1.0.1 release available shortly.

Bas



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This will cause the flickering screensaver of death!
Authored by: atverd on Jul 17, '03 04:25:23PM

Confirmed, though I never had this problem in real life. I'd sugest SleepTight solution instead of this script as more clean. But actually that flickering "screen of death" is not deadly at all. If you ssh to machine over network and kill all running instances of ScreenSaver everything will be just fine.

And in any case - sleepwatcher still very usefull program.

Thank you, Bas for another great program after my favorite MenuMeters :)



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