If you ever try to run a GUI Java application when using xmonad as the Window Manager, you'll probably end up with a nice flat grey window where your buttons, toolbars and other desktop GUI goodies should be. I ran into that problem the other day when trying to evaluate the RubyMine Ruby on Rails IDE from which I heard such good things. After a rather painful installation of the official Java 6 JDK from Oracle in Ubuntu Lucid Lynx (which I'll write about in some other time), I managed to start up RubyMine just to find out I was seeing absolutely nothing on the screen.

I Googled a bit and essentially I found out that the problem was with the Java GUI Toolkit rather than RubyMine, because the framework relies on a list of window managers to handle some things, and xmonad is not in that list.

So since I was not using OpenJDK, I opted for the setWMName option and added this final line into my xmonad.hs file:

    xmonad $ defaultConfig
      { terminal            = myTerminal
      , workspaces          = myWorkspaces
      , keys                = keys'
      , modMask             = modMask'
      , layoutHook          = layoutHook'
      , manageHook          = manageHook'
      , logHook             = myLogHook dzenLeftBar >> fadeInactiveLogHook 0xdddddddd
      , normalBorderColor   = colorNormalBorder
      , focusedBorderColor  = colorFocusedBorder
      , borderWidth         = 2
      , startupHook         = setWMName "LG3D"

Setting the window manager name to LG3D will trick the Java GUI Toolkit and the application will be painted correctly.

Enjoy your Java applications with the power of xmonad!