build/platform: make lib SigC++ available for GUI test code

Explanation: sigC++ was already linked as transitive dependency
from gtkmm, since it is used for the "signal-slot" system wihin GTK.
But now we want to use sigC++ itself from our generic UI-Backbone,
so we need to pick up the additional compiler and linker flags
and use them when building the relevant parts of both the application
and the test suite

admin/scons/Platform.py

@@ -114,6 +114,9 @@ def configure(env):
     if not conf.CheckPkgConfig('glibmm-2.4', '2.39'):
         problems.append('Unable to configure the mm-bindings for Glib')
     
+    if not conf.CheckPkgConfig('sigc++-2.0', '2.2.10'):
+        problems.append('Need the signal-slot-binding library SigC++2')
+    
     if not conf.CheckPkgConfig('glib-2.0', '2.40'):
         problems.append('Need a suitable Glib version.')
     

src/SConscript

@@ -37,7 +37,7 @@ plugins = [] # currently none
 
 # the Lumiera GTK GUI
 envGtk = env.Clone()
-envGtk.mergeConf(['gtkmm-3.0','gthread-2.0','cairomm-1.0','gdl','xv','x11','xext','sm'])
+envGtk.mergeConf(['gtkmm-3.0','sigc++-2.0','gthread-2.0','cairomm-1.0','gdl','xv','x11','xext','sm'])
 envGtk.Append(LIBS=core)
 
 guimodule = envGtk.LumieraPlugin('gtk_gui', srcSubtree('gui'), install=True)

src/gui/model/tangible.hpp

@@ -44,6 +44,7 @@
 //#include "lib/util.hpp"
 
 #include <boost/noncopyable.hpp>
+#include <sigc++/trackable.h>
 #include <string>
 
 
@@ -65,7 +66,8 @@ namespace model {
    * @todo write type comment...
    */
   class Tangible
-    : boost::noncopyable
+    : public sigc::trackable
+    , boost::noncopyable
     {
     protected:
       using GenNode = lib::diff::GenNode;

tests/SConscript

@@ -48,6 +48,9 @@ def testCases(env,dir):
     """
     env = env.Clone()
     env.Append(CPPPATH=dir) # add subdir to Includepath
+    if dir.startswith('gui'):
+        # additional libs used from gui tests
+        env.mergeConf(['sigc++-2.0'])
     
     # pick up all test classes and link them shared
     testlib = []