Re: [xmonad] 'resetScreenSaver' from 'Graphics.X11.Xlib.Misc'

8 Feb 2015

      On Wed, Jan 21, 2015 at 3:22 PM, Dontdie YCH  
wrote:
...
Hello,
I'm looking for what is proper method to inhibit screensaver(DPMS)
without xscreensaver, KDE, GNOME ... .
My video player 'bomi'(was cmplayer) try these, in order,
~~~
[App] Initialize screensaver functions.
[App] Try to connect 'org.gnome.SessionManager'.
[App] Failed to connect 'org.gnome.SessionManager'. Fallback to
'org.freedesktop.ScreenSaver'.
[App] Failed to connect 'org.freedesktop.ScreenSaver'. Fallback to
XResetScreenSaver().
[App] Disable screensaver with XResetScreenSaver().
~~~
But it does not working. I didn't know how I directly deal with X11
lib. Fortunately, I found 'resetScreenSaver' from
'Graphics.X11.Xlib.Misc' that say interface to XResetScreenSaver().
resetScreenSaver.hs :
~~~
import Graphics.X11.Xlib
import Graphics.X11.Xlib.Misc
import Control.Concurrent
import Control.Monad
main = do
    dpy <- openDisplay ""
    forever $ do
        putStrLn "reset"
        resetScreenSaver dpy
        threadDelay (5*1000000)
~~~
~~~
$ xset s 10
$ runhaskell resetScreenSaver.hs
~~~
Unfortunately, It does not working. `activateScreenSaver` and
`forceScreenSaver` also does not working.
But `xset s reset` is working as intended and also there is
`xdg-screensaver [ suspend | resume | reset ]` command from
'xdg-utils' package (Arch). It looks like abstraction layer for xset,
xscreensaver, KDE, GNOME ... .
So I'm curious about whether this is bug of xorg or I misunderstand
something. And what is right way to do this if I don't want any
screensaver daemon? `xset s` or `xdg-screensaver`?
Thanks.
I've experiment couple of things and then find relation between 
`getScreenSaver` and `resetScreenSaver`. resetScreenSaver only works if 
I call getScreenSaver immediately before.

Any know about this?

Working as intended,

~~~
$ xset s 5; runhaskell withgetScreenSaver.hs
$ cat withgetScreenSaver.hs
import Graphics.X11.Xlib
import Graphics.X11.Xlib.Misc
import Control.Concurrent
import Control.Monad

main = do
    dpy <- openDisplay ""
    forever $ do
        getScreenSaver dpy
        resetScreenSaver dpy
        threadDelay (3*1000000)
~~~

Does not working as intended,

~~~
$ xset s 5; runhaskell onlyresetScreenSaver.hs
$ cat onlyresetScreenSaver.hs
import Graphics.X11.Xlib
import Graphics.X11.Xlib.Misc
import Control.Concurrent
import Control.Monad

main = do
    dpy <- openDisplay ""
    forever $ do
        resetScreenSaver dpy
        threadDelay (3*1000000)
~~~

If I call `getScreenSaver` outside loop, it also does not working.

~~~
import Graphics.X11.Xlib
import Graphics.X11.Xlib.Misc
import Control.Concurrent
import Control.Monad

main = do
    dpy <- openDisplay ""
    getScreenSaver dpy
    forever $ do
        resetScreenSaver dpy
        threadDelay (3*1000000)
~~~

Thanks