cleaner machine stop

@@ -51,7 +51,9 @@ class Bones :
             button.set_sensitive(sensitive)
     def update (self, *args) :
         time.sleep(0.01)
-        if self.view.queue.can_do() and not self._autorun :
+        if self.view is None :
+            return gtk.FALSE
+        elif self.view.queue.can_do() and not self._autorun :
             self.control_set_sensitive(gtk.TRUE)
         else :
             self.control_set_sensitive(gtk.FALSE)
@@ -68,6 +70,8 @@ class Bones :
         except :
             pass
     def do_run (self, *args) :
+        if self.gui is None :
+            return gtk.FALSE
         try :
             self.do()
             speed = (101 - int(self.gui.control.speed.get_value())) * 10
@@ -82,7 +86,7 @@ class Bones :
         self._remove_id()
         self.update()
     def do (self, cycle=False) :
-        while True :
+        while self.view is not None :
             try :
                 if cycle == self.view.queue.do(self.gui.cursor) :
                     break
@@ -110,6 +114,11 @@ class Bones :
         self.gui.run(self)
     def quit (self) :
         self.machine.quit()
+        try :
+            self.gui.destroy()
+        except :
+            pass
+        self.gui = self.view = None
 
 if __name__ == "__main__" :
     warnings.filterwarnings("ignore", category=DeprecationWarning)