Re: gtk layering

["Bill Cunningham" <billcm charter net>]

----- Original Message ----- 
From: "Paul Davis" <paul linuxaudiosystems com>
To: "Bill Cunningham" <billcm charter net>
Cc: "Matt Hoosier" <mwhoosier gmail com>; <gtk-list gnome org>
Sent: Wednesday, October 04, 2006 9:35 AM
Subject: Re: gtk layering


> On Wed, 2006-10-04 at 01:19 -0400, Bill Cunningham wrote:
> > ----- Original Message ----- 
> > From: "Matt Hoosier" <mwhoosier gmail com>
> > To: "Bill Cunningham" <billcm charter net>
> > Cc: <gtk-list gnome org>
> > Sent: Wednesday, October 04, 2006 1:12 AM
> > Subject: Re: gtk layering
> >
> >
> > > Bill,
> > >
> > > glib and X11 are orthogonal; neither depends on the other. Gtk+ uses
> > > each one directly.
> >
> >     I see. Thanks Matt. These internals are fascinating to me. I
understand
> > things better. Does gtk use glib for frame buffering or just X? What
does
> > gtk use pango and cairo for?
>
> lets be a little more accurate.
>
> Gtk does not use X11 directly at all.
>
> Gtk uses glib to provide data structures and portability for general
> programming.
>
> Gtk uses Gdk to provide a set of mechanisms for creating windows,
> drawing various kinds of things in them, managing their visibility and
> handling events from a window system. There are implementations of Gdk
> that work with X11, with the win32 GUI API (not sure which level it sits
> at, possibly GDI but i don't know), with Aqua and with the linux
> DirectFb API (amongst others). the window system is what actually
> implements the things that Gdk is merely a wrapper around.
>
> Pango is a library that handles drawing and data management for fonts
> and text. It has a variety of ways of rendering font information, some
> via Gdk, some via other means entirely such as Cairo.
>
> Cairo is a general purpose drawing library that new versions of Gdk use
> to draw things in windows. Cairo also can interface with a variety of
> backends, include PostScript, X11, win32, etc etc. In current GTK
> versions (2.10 etc) when you see a standard office-productivity style
> application, most of it is being drawn using Cairo to actually control
> the pixels, Gdk to provide a higher level abstraction of that stuff, and
> Gtk to provide widgets.
>
> --p

    So could you give me an example of gtk+ using indirectly as you say X?
Would glib-2 be involved?

Bill