Make building the Python GTK+3 user interface conditional.

[fcambus]

This introduces an ENABLE_UI configuration option (enabled by default),
which allows disabling the user interface on systems where the Python
GTK+3 bindings are not available.

[huth]

Hi! Thanks for the patch, but I think introducing a user-selectable switch is the wrong approach here. It would be better if the cmake script probes for the availability of the right python stuff and then selects automatically whether to include the python-ui or not.

[huth]

I think something like this should do the job:

diff a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -325,7 +325,18 @@ if(PYTHONINTERP_FOUND AND PYTHON_VERSION_MAJOR LESS 3)
        unset(PYTHONINTERP_FOUND)
 endif()
 if(PYTHONINTERP_FOUND)
-       add_subdirectory(python-ui)
+       execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "\
+import gi\n\
+gi.require_version('Gtk', '3.0')\n\
+from gi.repository import Gtk\n\
+from gi.repository import Gdk\n\
+from gi.repository import GdkPixbuf\n\
+from gi.repository import GLib"
+                       RESULT_VARIABLE PYTHON_GTK_RESULT
+                       OUTPUT_QUIET ERROR_QUIET)
+       if(${PYTHON_GTK_RESULT} EQUAL 0)
+               add_subdirectory(python-ui)
+       endif()
 endif(PYTHONINTERP_FOUND)
 
 if(UNIX AND NOT ENABLE_OSX_BUNDLE)

[fcambus]

Yes, that makes sense. I tested your diff and I can confirm the detection works correctly, thanks!

[huth]

Patch has been committed: 7464d78