If we are in ssh, you can't launch alignak-app

Refs #8 now test we are in desktop_session

alignak_app/application.py

@@ -323,6 +323,9 @@ def update_hosts_menu(self, hosts_states, services_states):
         :param hosts_states: number of hosts UP or DOWN
         :param services_states: number of services UP, UNKNOWN or DOWN
         """
+        assert isinstance(self.hosts_up_item, Gtk.ImageMenuItem)
+        assert isinstance(self.services_up_item, Gtk.ImageMenuItem)
+
         self.hosts_up_item.set_label(
             'Hosts UP (' + str(hosts_states['up']) + ')')
         self.hosts_down_item.set_label(

alignak_app/launch.py

@@ -19,14 +19,22 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with (AlignakApp).  If not, see <http://www.gnu.org/licenses/>.
 
-from alignak_app.application import AlignakApp as App
+import os, sys
 
+from alignak_app.application import AlignakApp as App
 
 def launch():
     """
         Launch Alignak-App.
     """
+    # Actually, we must verify we are in DESKTOP_SESSION or not
+    try:
+        os.environ['DESKTOP_SESSION']
+    except KeyError as e:
+        sys.exit('--> ERROR: you must be in desktop session to launch alignak-app : ' + str(e))
+
     App().run()
 
+
 if __name__ == "__main__":
     launch()