Re: texinfo documentation

[Marko Rauhamaa <marko at pacujo dot net>]

Kevin Ryde <user42@zip.com.au>:

> Marko Rauhamaa <marko@pacujo.net> writes:
> >
> > Kevin Ryde <user42@zip.com.au>:
> >
> >> `app'
> >>      Don't be tempted to define `app' to some sort of widget or the
> >>      like.  In Guile 1.6.4 `app' is used for the implementation of the
> >>      module system.
> >
> > What does that mean?
> 
> Exactly what it says.  Try defining app to something and then doing a
> use-modules.

Oh, if you mean:

  `app'
      This global symbol is reserved by guile. Don't define it.

then better state it that way.

I was confused because I didn't know why I would "be tempted to define"
it "to some sort of widget".

> > I don't know (yet) how much of the whole story needs to be exposed to
> > the application developer, but the GTK functions dealing with signals
> > come in two C variants: regular and full. The guile code always uses the
> > full variant but strips the "-full" suffix from the procedure name.
> 
> I haven't looked closely enough to see if full variants work or can be
> usefully used from scheme code.  The regular forms are presumably what
> will be used most often.

There are no scheme procedures for the full variants. (But guile-gtk
secretly uses the full variants to implement the plain-vanilla
variants.)

> > Also: GdkRectangle is a pair of pairs. However, whenever it is an input
> > parameter, GdkRectangle is expanded into (x y w h). Thus the
> > pair-of-pairs format is used only to return a GdkRectangle.
> 
> That's rather inconsistent, and will probably make life hard if one
> wants to pass a returned value on to another function.

Some of the inconsistency is there in the C functions themselves. But
guile-gtk expands rectangles "consistently" everywhere. The reason is
obviously that it's nicer to call

   (gdk-useful-function window x y w h)

than

   (gdk-useful-function window (cons (cons x y) (cons w h)))


Well, you probably need rectangles most often to process exposures. It
would be nice to be able to call:

   (gdk-gc-set-clip-rectangle gc (gdk-event-area e))

instead of

   (let ((r (gdk-event-area e)))
      (gdk-gc-set-clip-rectangle (caar r) (cdar r) (cadr r) (cddr r)))

Since gdk-gc-set-clip-rectangle was added recently by me (following
existing examples), I could change it to take a rectangle.


Marko

-- 
Marko Rauhamaa      mailto:marko@pacujo.net     http://pacujo.net/marko/