Porting GTK3.0 project to GTK2.0

Question

I am building a simple GUI application which I have successfully deployed and run on my Raspberry PI dev board. However, due to issues with OpenCV being dependent on GTK+ v2.0, I have to back-port my application to an old version of GTK+. I'm already familiar with changing include paths, and so on, and library linking orders in my makefiles. However, when I make all the necessary changes, a fatal error occurs during build.

Building dependencies file for main.o
In file included from /opt/rpi/usr/include/gtk-2.0/gdk/gdkscreen.h:32:0,
             from /opt/rpi/usr/include/gtk-2.0/gdk/gdkapplaunchcontext.h:31,
             from /opt/rpi/usr/include/gtk-2.0/gdk/gdk.h:32,
             from /opt/rpi/usr/include/gtk-2.0/gtk/gtk.h:32,
             from inc/ui.h:8,
             from main.c:10:
/opt/rpi/usr/include/gtk-2.0/gdk/gdktypes.h:55:23: fatal error:
   gdkconfig.h: No such file or directory

I've confirmed that the missing file, gdkconfig.h exists for my GTK+ v3.0 installation:

find /opt/rpi/usr/include -iname "gdkconfig*"
./gtk-3.0/gdk/gdkconfig.h

But there is no such file for my GTK+ v2.0 installation. I've already installed the latest version via apt-get, but still no luck.

Are there any solutions to this issue?

Thank you.

"But there is no such file for my GTK+ v2.0 installation": two choices. Either the GTK2 packaging is broken (if the file really is totally missing) or the file is in some other directory and something is wrong with your include paths. — Jussi Kukkonen
Hmm, actually a third option: Make sure your build is completely clean from earlier GTK3 build config: if you aren't sure, try with a completely new source checkout. — Jussi Kukkonen
OpenCV >= 3.0.0 is compatible with GTK+ 3. Not linking with libopencv_highgui would have done the trick too. You should never downgrade an application if other choices are available. — liberforce

Cloud Cloud · Accepted Answer · 2014-02-26T17:50:05

It turns out certain folders, including those with arm-linux-gnueabihf in the path, were not included by me manually, when they should have. In the end, I SSH'ed into the RPI device, and copied the output from the following command:

pkgconfig --clfags --libs gtk+-2.0

I then copied all the include directory statements (ie: those beginning with -I) and made a variable containing that massive string, and did something similar for all the library inclusions. The output from the above command is included below.

-pthread -I/usr/include/gtk-2.0 -I/usr/lib/arm-linux-gnueabihf/gtk-2.0/include
-I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/gdk-pixbuf-2.0
-I/usr/include/pango-1.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/glib-2.0
-I/usr/lib/arm-linux-gnueabihf/glib-2.0/include -I/usr/include/pixman-1
-I/usr/include/freetype2 -I/usr/include/libpng12  -lgtk-x11-2.0 -lgdk-x11-2.0 
-latk-1.0 -lgio-2.0 -lpangoft2-1.0 -lpangocairo-1.0 -lgdk_pixbuf-2.0 -lcairo -lpango-1.0
-lfreetype -lfontconfig -lgobject-2.0 -lglib-2.0

So, in short, this worked, and I didn't even have to change a single line of my code. Now everything works fine.

Porting GTK3.0 project to GTK2.0

1 Answers