Finding the number of X11 screens from Haskell

Question

I'd like to know how many X screens the current machine has, to make my .xmonad a little more general; I have a netbook as well as a desktop with two monitors, and I use several single monitored machines too.

To this end, I'd like to be able to find out how many X screens the current machine has. (I think screens is the correct words, I mean physical monitors).

The reason being is that I want multiple instances of xmobar, one per monitor. I've hard coded it to be on two at the moment.

score 4 · Accepted Answer · answered Apr 09 '11 at 19:41

4

If you use the X11 package:

 import Graphics.X11.Xinerama (getScreenInfo)

that will dynamically return a list of Rectangles, telling you how many screens, and their dimensions.

answered Apr 09 '11 at 19:41

Don Stewart

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How do I get the Display to use as a parameter? – Squidly Apr 09 '11 at 19:56
In the case of xmonad, `display` is part of the `XConf` state, so use e.g. `withDisplay` from `XMonad.Core`. – Don Stewart Apr 09 '11 at 20:02

score 0 · Answer 2 · answered Apr 12 '11 at 12:56

0

For the curious, I ended up using

 screenCount :: X Int  
 screenCount = withDisplay (io.fmap length.getScreenInfo)

I also found out that the XMonad module has a function

 screenCount :: Display -> Foreign.C.Types.CInt

answered Apr 12 '11 at 12:56

Squidly

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Finding the number of X11 screens from Haskell

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