Fix state update in MSC

asn1_value_editor/sdlHandler.py

@@ -186,15 +186,17 @@ class sdlHandler(QObject):
             self.dock.hide()
 
     def check_state(self):
-        ''' Highlight the current state on the statechart diagram '''
+        ''' Highlight the current state on the statechart diagram 
+        Return True if the state has changed '''
         state = self.get_sdl_state()
         if state != self.current_sdl_state:
             self.current_sdl_state = state
             self.sdl_scene.clear_highlight()
             for each in self.sdl_scene.find_text(u'\\b{}\\b'.format(state)):
                 self.sdl_scene.highlight(each)
-            self.add_to_msc('condition', state)
             self.log_area.addItem('New state: {}'.format(state))
+            return True
+        return False
 
     def reset_simulation(self):
         ''' Jump to the first step of simulation '''
@@ -236,7 +238,7 @@ class sdlHandler(QObject):
         set_state = getattr(self.dll, "_set_state")
         set_state(ctypes.c_char_p(state_value))
         #self.current_sdl_state = state_value
-        #self.check_state()
+        self.check_state()
         #self.on_event()
 
     def on_event(self, tc_name=None, param=None):
@@ -349,7 +351,9 @@ class sdlHandler(QObject):
             else:
                 tc_func_ptr()
 
-            self.check_state()
+            if self.check_state():
+                # If state changed, update the MSC
+                self.add_to_msc('condition', self.current_sdl_state)
             # Update windows, highlight state, enable/disable buttons, etc.
             self.current_hash = self.on_event(tc_name=name,
                                               param=param.GSER() if param