[xmonad] Re: two beginner's questions on XMonad config

11 Dec 2008

      Riccardo Murri  writes:
...
1) Since I have no modifier keys left on my laptop, and I'm an Emacs
user (which takes away many C- and M- keybindings), I'd like to bind
most XMonad actions with "C-z" as a prefix (using EZConfig).
Is there a way to bind a key so that "C-z C-z" sends a C-z to the
currently focused window? (Ratpoison has a similar feature for C-t)
I did some googling and found out that:

1) the quickest solution is to use "xdotool"
[http://www.semicomplete.com/projects/xdotool/], which can (among
other nifty things), send a fake keypress to the currently focused
window::

  ("C-z C-z", spawn "xdotool key ctrl+z")

2) According to:

  http://www.handhelds.org/moin/moin.cgi/GeneratingSyntheticX11Events

there are two Xlib programmatic solution, one using the XTest
extension (recommended), and one using XSendEvent().  As far as I
understand, there are no bindings for XTest in the Graphics.X11
module, so one has to code using sendEvent...

With the following code, I have been able to send a Ctrl+Z to urxvt
and "xev" windows directly from XMonad::

  -- send Ctrl+Z to focused window
  sendCtrlZ = sendKey controlMask xK_z

  sendKey modmask keysym = withDisplay $ \d -> do
    keycode <- io $ keysymToKeycode d keysym
    root <- asks theRoot
    let subw = none -- FIXME: should this be the subwindow which the pointer is in?
    withFocused $ \w -> do
      io $ allocaXEvent $ \ev -> do
                          setEventType ev keyPress
                          setKeyEvent ev w root subw modmask keycode True
                          sendEvent d w False noEventMask ev
      io $ allocaXEvent $ \ev -> do
                          setEventType ev keyRelease
                          setKeyEvent ev w root subw modmask keycode True
                          sendEvent d w False noEventMask ev
      return ()

Thanks to all those who replied with suggestions to my original post!

Cheers,
Riccardo