Re: [AD] GTK requirement

[Peter Wang <novalazy@xxxxxxxxxx>]

On Mon, 17 Dec 2012 01:08:43 -0700, Trent Gamblin <nooskewl@xxxxxxxxxx> wrote:
> On 2012-12-15, at 4:31 AM, Peter Wang <novalazy@xxxxxxxxxx> wrote:
> > Hi,
> > 
> > I'm not completely pleased about GTK turning into a dependency of the
> > core library.  Even though it can be compiled out, the nature of Linux
> > distributions means that it *will* be compiled in.  I really don't like
> > the idea of all keyboard and mouse input being filtered through GTK,
> > even in programs which won't use the menu support nor even the native
> > dialogs addon.
> > 
> > It seems like it should be possible to move the GTK dependency back out,
> > leaving hooks in the core to be filled by the native_dialog addon when
> > it is actually used (e.g. setting an auxiliary system vtable pointer or
> > something).  We don't already have an al_init_native_dialog_addon
> > function, but that would be the obvious place to do it.  The user would
> > be required to call al_init_native_dialog_addon before create the
> > ALLEGRO_DISPLAY.  Programs which don't link with the native_dialog addon
> > on X11 would go back to working as if GTK support were compiled out.
> > 
> > What do you think?
> > 
> > Peter
> 
> So would this be something like this in the display driver instead of
> compile time checks?
> 
> if (al_native_dialog_addon_inited()) {
>   gtk_vtable = system->get_native_dialog_data();
>   gtk_vtable->do_something(...);
> }
> else {
>   /* Normal GLX code that's always been there */
> }

I was thinking that the GTK backend would call a private function
in al_init_native_dialog_addon(), e.g.

    _al_xwin_set_aux_interface(ALLEGRO_XWIN_AUX_INTERFACE *vtable);

which sets a global,

    ALLEGRO_XWIN_AUX_INTERFACE *_al_xwin_aux_vt = NULL;

Then where the GTK-specific behaviour is required,

    if (_al_xwin_aux_vt && _al_xwin_aux_vt->do_something) {
	_al_xwin_aux_vt->do_something(...);
    }
    else {
	...
    }

I think the hard part will be trying to reduce the amount of X port
internals leaking into the native dialog addon.

Peter