[BUGGED] xmonad tri-screen non-xinerama problems

Question

Hello All!
New Archer here.  I'm really enjoying playing with Arch.  Ran it about a week on a VM, and then promptly backed up/tore up/re-created my 3 TB RAID array as a shrine in deciation to its glory.  I haven't posted much along the process, because I've generally been able to put things together to my liking other than a few minor setbacks that I mostly managed to handle myself.  I have even gave Arch the coveted position of my "Laptop Linux."  I have a slightly odd setup and it seems to be tied in with an issue that I am having, so I thought I might post here, especially since some of you seem to be xmonad users.
The Paragraph
Most wm's seem to handle non-Xinerama multi-display fine (I've been trying out as many as I could find since switching over to Arch.  I figured new Linux/new Look).  It seems that xmonad handles Xinerama better but has a less friendly non-Xinerama out of the box experience, and it is terribly hard to find the information I am after since when I go looking for multi-monitor resources, I find alot about Xinerama and praise for its Xinerama way of doing things.  Apparently, you still can't enable Composite and Xinerama at the same time, and in general, I prefer funny fade effects and what not to being able to move windows from screen to screen so have opted for a standard non-Xinerama multi-card, multi-display setup of xorg.
Bullet Points
1 - Minor Problem:  xmonad only runs on one screen if I don't enable Xinerama
2 - Entertwined Problem:  Composite extension becomes disabled if I enable Xinerama
3 - Other Entertwined Problem:  Most wm's I try if they don't support dual screen natively, I can simply put calls in my .xinitrc to load on the various display (ie. 'DISPLAY=:0.2 wmii &; DISPLAY=:0.1 wmii&; exec wmii'), and it's no big.  If I try that with xmonad, the session on DISPLAY :0.0 won't give up control of the keyboard to the displays on the other monitors.  That's pretty weird, since it gives up control to my unmanaged windows just fine, or gives up control to another WM (as I type this, I have openbox managing my second monitor so I have an easy way to resize windows and such, but that is a somewhat imperfect solution in my opinion).  If I leave the screens unmanaged , I can launch apps on them easily enough by 'DISPLAY=:0.1 thunderbird' (like I do with openbox managing them if I don't want to use the menu) through command-line or scripts, but there is no way to move the apps or resize them or anything without some WM (like openbox) attached to the DISPLAY.
4 - Minor Entertwined Problem That Makes This Whole Mess Harder To Ignore:
When you go off the screen to an unmanaged window or a window managed by another window manager, apparently xmonad continues to think you are focused on the app that you hovered over last on your way to the other screen (ie. if I go over to Thunderbird now, xmonad will leave the active border around Firefox since I have it on the left side of my primary monitor and the other screen is to the left).  This is no big, although I would prefer it to gray out or whatever.  At the same time, xmobar displays that I am still over my Firefox window.  I am fine with it not knowing that I am over messing around in another WM or on an unmanaged screen.  The big problem is that when I bring the mouse back, it seems to get confused about whether I left or not, and doesn't pass focus back to the app in question.  It still thinks the app has focus (according to its border and xmobar), but keystrokes still go to the other screen and the window on the first screen will no longer even directly respond to mouse clicks.  It is easy to fix, I can simply move to any other window on the same screen, and then back to my firefox and things work fine.  I know that's a weird wall of text, so a quick explanation:
If I take my mouse off the screen to the left, passing over Firefox, I end up on my Screen 1 that is currently displaying Thunderbird and managed by Openbox.  I can then click message, type things, all no problem.  If I move my mouse back to the Firefox screen, it looks like it is active, but I cannot click on anything (no links work, the buttons that control formatting of this message darken when I hover over them but do nothing on click, the check boxes at the bottom of this compose message window darken but do not respond to clicks, etc).  If I do nothing else other than but my mouse over one of my terminal windows (which will receive the focus border and receive input fine), and then move it back to Firefox - everything in Firefox will at that point work great.
That last note is the primary reason I can't just let another WM loose on my secondary display and go about my day (I mean, I tend to just leave e-mail up on the thing, and I suppose a valid argument can be made for having a floating manager on your second screen anyway).  It's most annoying when I just barely go off the edge of the main monitor by mistake, say on my way to a tab or something, and can't click my tabs anymore without dragging the mouse back to a terminal and back over to Firefox.  Of course, I would be fine with messing with xmonad on all my screens really if I didn't have to turn off my Composite extension to do it.
One easy solution is to just use Awesome.  It looks nice and seems to offer some of the same features, but I kind of like xmonad's way of configuring things and the idea that my configs seemingly shouldn't break on minor version numbers.  Awesome has already bit me in my playing around by making widget obselete two days after I put the widgets in my config file, and it seems they have a history of this type of action. 
I can happily provide any configuration files on request.  My xorg.conf is probably of the most interest, I would think, but if I knew how to fix this, I wouldn't be on here asking for help.  It doesn't appear to be related to xmonad.hs, since I can use the default or a heavily customized one and get the same behavior.  There might be a way to fix the problem somehow in xmonad.hs; I don't know.
Oh well, sorry my first post was such a wall of text, but I wanted to provide a solid idea of what was going on here.  Any help would be greatly appreciated.
Lewis
Last edited by llcawthorne (2009-11-18 02:26:08)

Answer 1

vogt wrote:
I have had composite enabled with xinerama.
Some graphics drivers restrict the size of all screens to fit within 2048x2048 pixels if you still want compositing, but if you have 3 monitors, it is unlikely that that you can find an arrangement that satisfies that driver/hardware limitation.
Yeah, 2048x2048 woudln't work for me.  My main monitor runs 1920x1200, secondary is 1680x1050, and the tv is at 1920x1080.
Apparently since the xorg upgrade the other day, I can't even turn on Xinerama anymore.  I know it worked when I tested just to see if things worked in Xinerama mode the other day (but it automatically disabled Composite).  Now I can turn on Xinerama but I get a strange cursor flicker and segfault when trying to go to the other screen.  Apparently some other people have that problem with the latest x-server and xinerama with Nvidia, but I haven't looked into fixing it, since I don't tend to use Xinerama anyway.  It makes testing some solutions a bit harder though not being able to temporarily turn it on.
I have done some more testing though.  With my current multi-screen Xinerama off X-layout, things definitely work as expected in other Window managers.  I have played around in GNOME, compiz, fluxbox, openbox, awesome and ratpoison with this separate screen X-layout without problems. 
The problem seems to be more with xmonad accepting the cursor than letting it go.  When I run :0.1 unmanaged or with another window manager, I can switch over to the other display with 100% reliability, but only have the problem when coming back to my xmonad display.  However, if I spawn xmonad to :0.1 in addition to having xmonad on :0.0, I almost always have problems switching over to :0.1, but once I get switched over to :0.1, I have trouble coming back to :0.0.
Also, strangely enough, I can reliably switch to any other display with two windows on it.  I have taken to running a clock on display :0.1, since 90% of the time when I switch over to my e-mail client I will not get proper focus.  I can fix this 100% of the time by mousing over the clock, then back over the e-mail client.  To come back to my main screen, I will not get focus on my browser 90% of the time, but can reliably get focus to it 100% of the time there is a problem by mousing over one of the terminals to the right of my browser and then coming back to the browser.  Since the problem is predictable, I can work around it, but either way it is annoying.
The problem is easy to duplicate with both a default xmonad.hs, another xmonad.hs pulled off the site (tried it with andrea's and arossato's, and with my personal customized and overly large xmonad.hs that I have been trying out various features with.
Curiously enough, since it was a focus problem, I though "maybe if it updated focus more often?" and I tried 'import XMonad.Actions.UpdateFocus" with the proper startupHook's and handleEventHooks to make it attempt to update focus whenever you move the mouse within a window.  This did nothing to alleviate the problem, although it obviously took ince I noticed the change in focus handling when I didn't leave a monitor.
Oh, and as another test to see if it might relate back to my drivers somehow, I removed nvidia's proprietary drivers and installed Nouveau.  While the Nouveau drivers are pretty neat (the fast frame buffer switching is fun!), I found them annoying since I don't know how to make my console come up on the right monitor with them, but that is unrelated.  I changed around my config and brought up X and was able to duplicate the problem exactly with the alternate drivers (but same configuration otherwise). 
And lastly, I booted to my Gentoo install (that does use the same hardware are xorg.conf).  I can't get the 0.9 xmonad from the overlay to compile on it for whatever reason, so it conveniently has 0.8 installed.  I see the same behavior with a default config and a sample config swiped from the website (I cannot test with my custom config, since it has multiple 0.9 imports in it, but I have no reason to believe it would react differently).
I welcome any ideas.
Lewis Cawthorne