Hmm, I think I now know how to work with XEventPtr's with allocaXEvent
event, what I have now is this:
raiseWin :: Win -> IO ();
raiseWin w = let {
d = disp w;
r = root w;
xID = xid w;
} in
do {
ctime <- Monad.liftM (\(Time.TOD t _) -> fromIntegral t)
Time.getClockTime;
atom <- Xlib.Atom.internAtom d "_NET_ACTIVE_WINDOW" True;
Xlib.Event.allocaXEvent $ \ePtr -> do {
Xlib.Extras.setEventType ePtr XTypes.clientMessage;
Xlib.Extras.setClientMessageEvent ePtr xID atom 32 2 ctime;
Xlib.Event.sendEvent d r False
(Xlib.substructureNotifyMask .|. Xlib.substructureRedirectMask)
ePtr;
};
};
where root in the Win record is derived from:
(root, parent, _)
<- Xlib.Extras.queryTree d xid;
The code compiles and type checks, it just doesn't... work, it does
nothing. Replacing the code with:
raiseWin w =
System.Process.rawSystem "xdotool" ["windowactivate", show x] >> return
() where {
x = xid w;
}
Makes it work without errors, inspecting the code of xdotool makes it
reveal to use the "_NET_ACTIVE_WINDOW" client message to the root hole? Any
idea what I could be doing wrongly, is this the correct root window?
On 10 December 2013 06:22, Brandon Allbery
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