Hi!

I'm running OpenSUSE with two monitors in Twinview configuration.

With the latest KDE (4.9 and 4.10) when I run a screen saver, instead of using BOTH screens, I get a separate instance of the screensaver at each monitor. For instance, if I use "Pinion" (an OpenGL screen saver) instead of a single set of gears moving from right to left, I get TWO sets, one on each screen; each set starts at the right side of its monitor, and exits out of the left side of the same monitor.

With earlier KDE versions, I would get a single screen saver, which would run on both monitors at the same time. With the same "Pinion", I would have gotten a single line of gears, which would start from the right at the right monitor, and would exit out of the left side of the left monitor.

Is this a configuration option? Can I change it back to the earlier behavior? Having two separate instances frankly looks somewhat weird...

Thanks!
Federico Kereki

This is not likely to be a configuration option.

I suspect this behaviour is because the screens are considered to be separate by the system, and so therefore are given their own instances of the screen savers. This is necessary because the height (or width if the screens are on top of each other) of the screens is not always the same, and the configuration you desire introduces many corner cases in the event of this.

To confirm this, can you compare the output of "echo $DISPLAY" on each screen? I suspect they will be different.

Hi!

Both screens are 1600x900 pixels. The nvidia-settings tool shows it as a single screen #0 (3200x900 pixels) albeit with two displays. I'm not sure about how to go to "echo $DISPLAY" -- if I just open a console on each screen, I get ":0" (without the quotes) in each case. Using the OpenSUSE desktop configuration tool, one monitor is recognized as VGA-0 and the other (primary output) as DVI-I-0; this is logical, for that's the way they are connected to my NVIDIA card.

I must also point out that this behavior started with KDE 4.9 -- with earlier versions, the screen saver simply showed in both screens as if they were a single one, and there was a single screen saver running, not two.

Best regards,
F.Kereki

bcooksley wrote:This is not likely to be a configuration option.

I suspect this behaviour is because the screens are considered to be separate by the system, and so therefore are given their own instances of the screen savers. This is necessary because the height (or width if the screens are on top of each other) of the screens is not always the same, and the configuration you desire introduces many corner cases in the event of this.

To confirm this, can you compare the output of "echo $DISPLAY" on each screen? I suspect they will be different.

I've checked with a developer who works in this area (screens, etc) and this is intended behaviour.

bcooksley wrote:I've checked with a developer who works in this area (screens, etc) and this is intended behaviour.

Hi!

Was he able to explain why the change from earlier versions of KDE?

To add insult to injury, when you pick a screen saver and click on "test", savers do run on the twinview screens as they used to -- it's only when you lock the screen that the "double screen saver" problem occurs.

Best regards,
F.Kereki

From my understanding the change was made to ensure that the screens are always properly covered and to aid interaction with the screen locker.
In previous iterations, there were a large number of corner cases where windows could escape and get on top of the screen saver, or sections of the screen would not be covered (or would exist off screen, due to non-matching screen heights).

As for why this behaviour still exists when you press - not sure why that happens...
The screensaver system is quite old, and the screen locker system is quite new.

Hi,
sorry for bringing this topic back again, but I've got just the same problem, but with 4 screens, three are in the line and one is over the middle one. And let me tell you: four instances of any screensaver look ugly with this configuration!

Is there any workaround for this? Is there any way to contact the developer who works in this area and try to talk him out of this idea? I know for sure that there are thousands of people who use several monitors, I believe there are a lot of them being unhappy with the way their screensavers look today.

To my knowledge, there is no workaround.
Given the points made previously regarding spreading wallpapers or panels across multiple screens, I doubt an exception would be made for screen saver. However, configuration to allow a different screensaver (or different screensaver config) for each screen would probably be acceptable I suspect.

With regards to the people who use multiple monitors - unfortunately few KDE developers have this sort of setup, which makes diagnosing multiple screen specific issues complicated.

It is a pity the dual view screensaver does not work anymore (it impressed all the other people in the lab ). It is also weird since it does work in the preview.

Wouldn't it be possible to span a single screensaver over the maximum rectangular space spanned by all screens and show only those parts that are covered by actual screen area? Then there would be screensaver space outside of monitors (is that a problem?), but no monitor space outside of screensavers.

Is there already a bug report / feature request for this?

The "spanning" over multiple screens you are mentioning is how it used to work. As you noted, it has flaws when there are areas of the virtual screen not shown by a physical monitor.