[Xcb] gtk, to xcb or not

[Yang JianJun]

On 11/8/06, Havoc Pennington <hp at redhat.com> wrote:
>
>
> It seems pretty clear that gtk-x11 has to continue to be installed -
> gdkx.h is in the ABI.


XCB is a replacement for Xlib, so if we contribute the gtk-xcb backend, it
should replace gtk-x11. Accordingly, there is gdkxcb.h, instead gdkx.h.
However, gtk-xcb cannot provide the compatibility, because of the new
gdkxcb.h. The gtk-based application have used gdkx.h, and want to link to
gtk-xcb also, it must migrate to use XCB API. Otherwise, you may use
Xlib/XCB for compatibility, not the X11-Free-Gtk.

That means a path forward would have to make maintaining both XCB and
> libX11 GDK targets a viable option, i.e. just cut-and-pasting the X11
> backend and modifying it to be the XCB backend is not feasible. Instead,
> for the next many years GTK+ would install a gtk-x11 and a gtk-xcb.


I ported like that just as the fist step. Sharing codes between the two X
backend is not an easy problem. Also I think gtk-x11 and gtk-xcb should not
coexistence.

The simplest path to have both seems to be to have an abstraction API
> that could use libX11 or XCB on the backend. Doesn't XCB have a
> libX11-like wrapper API? If so, why not make that the abstraction API?
> If not, why not write one that implements what gdk-x11 uses? So an XCB
> backend shares virtually all code with the libX11 backend and the libX11
> backend is pretty much unchanged.


The XCB API is entirely different from Xlib, it supports latency hiding. XCB
would not provide som x11-wrapper API, i think.

In the public XCB API (gdkxcb.h vs. gdkx.h) native XCB API could be
> used, and gdk-xcb would not support gdkx.h or would support it only with
> footnotes and caveats. This would allow apps to migrate to a
> libX11-API-free state by requiring the xcb backend and using gdkxcb.h
> instead of gdkx.h.
>
The resulting gtk-xcb would give people the ability to avoid installing
> libX11 on embedded devices, and would give a shot at thread safety
> (though gdk and gtk aren't threadsafe anyway).


Now gtk-xcb has arrived the goal. Peple who use gtk need not install libX11
any more. And  gtk-xcb have its own gdkxcb.h, I just have not rename it:)

Whether it's worth all the pain, I really don't know though ;-)


I would like to know whether  gtk-team has  the  plan for xcb port.
Anyway, thanks for your suggestions!

Jianjun

Havoc
>
> _______________________________________________
> gtk-devel-list mailing list
> gtk-devel-list at gnome.org
> http://mail.gnome.org/mailman/listinfo/gtk-devel-list
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freedesktop.org/archives/xcb/attachments/20061109/fdb513fa/attachment.html