On Mon, Dec 9, 2013 at 10:57 PM, EatsKittens <temporalabstraction@gmail.com> wrote:

Xlib.Event seems to define the interestingly recursive type data XEvent = XEvent (Ptr XEvent) and otherwise give no information about that type.

Anything on the far side of a Ptr is defined by C and accessed via the FFI. In this case, you're looking for the XEvent structure defined by the C Xlib and described in X11/X.h (constants) and X11/Xlib.h (structs; note that there is a separate struct for each event type although they all have a common preamble).

You may be better served by the event definitions in http://xmonad.org/xmonad-docs/X11/Graphics-X11-Xlib-Extras.html which is a Haskell, instead of FFI, interface. (I pointed to the xmonad copy of the docs because that's what I already have loaded in a tab, but it's part of the same X11 binding as Graphics.X11.Xlib.Event.)

I need this type to send an XEvent message to a window, is this a mistake or am I overlooking something in how to use it, or is the idea that the only way to make XEvent data is to make it in C and import it from there?

allocaXEvent is defined in Graphics.X11.Xlib.Event, but you need to refer to the C Xlib definitions and use FFI marshaling to work with it (and may need to know C type sizes and how the C compiler packs structs on your system). There's some code in xmonad-contrib which uses that interface to send custom events.

brandon s allbery kf8nh sine nomine associates

allbery.b@gmail.com ballbery@sinenomine.net

unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net