Re: [Qemu-devel] [PATCH 6/6] gtk: make default UI

[Stefano Stabellini]

On Mon, 20 Feb 2012, Anthony Liguori wrote:
> On 02/20/2012 08:06 AM, Stefano Stabellini wrote:
> > On Mon, 20 Feb 2012, Anthony Liguori wrote:
> >> On 02/19/2012 08:52 PM, Brad Smith wrote:
> >>> On 19/02/12 9:44 PM, Anthony Liguori wrote:
> >>>> On 02/19/2012 08:24 PM, Brad Smith wrote:
> >>>>> On 19/02/12 8:10 PM, Anthony Liguori wrote:
> >>>>>>> If not, it will be nice to keep
> >>>>>>> SDL because GTK huge and not that portable for win32 users.
> >>>>>>
> >>>>>> Neither are true. GTK is a reasonably small dependency especially given
> >>>>>> that GLIB is a mandatory dependency. I can't imagine that in terms of
> >>>>>> binary size, libsdl is much bigger than gtk/gdk.
> >>>>>
> >>>>> Double check your facts. That's not even close to being true.
> >>>>>
> >>>>> SDL is a tiny fraction of Gtk+.
> >>>>>
> >>>>> Just as an example taking a look at package sizes..
> >>>>>
> >>>>> 549KB for SDL vs 17.3MB for just Gtk+ and its dependencies (7 libraries)
> >>>>> excluding Glib2 and what it depends on.
> >>>>
> >>>> I don't see how 17.3MB qualifies as "huge".
> >>>
> >>> It's FAR from small not to mention dragging in A LOT of libraries for 
> >>> what?
> >>> A prettier looking UI?
> >>
> >> An accessible UI that meets the most basic definition of usable.  Sit 
> >> someone
> >> down with the SDL interface for the first time, how in the world are they
> >> supposed to figure out that you hit Ctrl+Alt+2 to get to a command prompt?
> >
> > I think that having a GTK UI is quite important for QEMU and having it
> > be the default is also a good idea.
> >
> > BUT we should not deprecate and plan to remove SDL.
> 
> Actually, I think Cairo can be a better SDL than SDL.
> 
> It doesn't have the same level of backend support (or input support) as SDL 
> does, but it can render to Win32, Quartz, and a raw X11 window.

Cairo seems to be quite popular and well maintained, however I am not
sure how well it would work without GTK.

Granted that I don't particularly care about which library we use for
rendering the "lightweight UI", if the entire UI can be written in
Cairo, without any other library or dependency of any kind, then it
is probably OK to replace SDL with Cairo.


> > Do we really want to force everybody that uses QEMU on X11 to compile
> > the entire set of GTK dependencies?
> > Keep in mind that QEMU is not just used on Linux distros but it also
> > used as a component in other projects that might have very different
> > constraints.
> > I think that having a lightweight graphical UI with very few and small
> > dependencies is NOT something we should give up.
> 
> If we went in a different direction with SDL, I wouldn't mind it so much.  
> For 
> instance, removing the console emulation and reducing the use of magic 
> accelerators.

Strictly speaking the console emulation is not part of the SDL UI, also
we need to keep it because of VNC.
But I agree that the SDL UI should stay light and simple, rather than
duplicating the fully featured desktop experience that is going to be
provided by GTK.