Re: [Chicken-users] setting a callback in xlib

[Eduardo Cavazos]

Eduardo Cavazos <address@hidden> wrote:

> > Here's how I'm defining 'XSetErrorHandler' on the Chicken side:
> >
> > (define XSetErrorHandler
> >  (foreign-safe-lambda c-pointer XSetErrorHandler
> >    (function int (c-pointer c-pointer))))
> >
> > And finally, a test error handler:
> >
> > (define-external (xerrorhandler (c-pointer dpy) (c-pointer ev)) int
> >  (display "Error handler called\n"))
> >
> > If I trigger an X error, I get a pretty wacky error:
> >
> >    Error: bad argument count - received 134902918 but expected 2: #()

felix winkelmann wrote:

> How do you invoke XSetErrorHandler?

In this particular case, like this:

    (XSetErrorHandler xerrorhandler)

But ideally, the API should work such that you can do flexible stuff like:

    (XSetErrorHandler (lambda (dpy ev) ...))

I.e. pass arbitrary callbacks at runtime.

Ed