[Buildroot] GTK+ for framebuffer?

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Woody Wu,

On Wed, 4 Sep 2013 10:40:19 +0800, Woody Wu wrote:

> Even I cannot find libgtk (neither 2.x or 3.x) in buildroot.  I
> enabled a lot of options which looks like related to gtk, then I got
> libraries like glib, pango, atk, etc., but just no gtk.  Where is the
> option to enable it? I think I looked through all the options :(

Hint: in menuconfig, hit '/', and then search for LIBGTK2. This will
show you where the option for Gtk is located, what are its
dependencies, and which of its dependencies are not satisfied at the
moment.

Here is what I have here:

Symbol: BR2_PACKAGE_LIBGTK2 [=n]
Type  : boolean
Prompt: libgtk2
  Defined at package/libgtk2/Config.in:1
  Depends on: BR2_PACKAGE_XORG7 [=n] && BR2_USE_WCHAR [=y] && BR2_TOOLCHAIN_HAS_THREADS [=y] && BR2_INSTALL_LIBSTDCPP [=y]
  Location:
    -> Target packages
       -> Libraries
 (2)      -> Graphics

This tells you that libgtk2 package is currently not selected ([=n] on
the first line). This tells you the libgtk2 package is located in
Target packages -> Libraries -> Graphics. And more importantly, the
line "Depends on:" gives you the list of dependencies. In the example
above, there are four dependencies: the last three dependencies (wchar,
threads and C++) are satisfied. However, the first dependency,
BR2_PACKAGE_XORG7 is not satisfied (see the [=n]).

So to be able to enable Gtk, you need to enable X.org.

> BTW: in your opinion, GtkFB and gtk on TinyX, which one is faster?

I have no idea as I haven't benchmarked. However, I'm not sure why you
keep talking about GtkFB: the DirectFB for Gtk is no longer maintained,
so it cannot be used. Your only reasonable option today for Gtk 2.x is
with X.org.

A while ago, I remember switching a project from Gtk/DirectFB (at the
time it was more or less working) to Gtk/X.org because it ended up
working better. I don't quite remember if it was a font rendering
problem, or a performance problem, but clearly, Gtk/X.org fixed the
problem.

Best regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com