case ERASER:

       actual_handler=displayed_graph.signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::eraser_event_handler), false);

       break;

 bool GraphDisplayerCanvas::eraser_event_handler(GdkEvent* e)

 {

   switch(e->type)

     {

     case GDK_BUTTON_PRESS:

       active_item=(get_item_at(e->button.x, e->button.y));

       active_node=INVALID;

       active_edge=INVALID;

       for (NodeIt i(g); i!=INVALID; ++i)

 	{

 	  if(nodesmap[i]==active_item)

 	    {

 	      active_node=i;

 	    }

 	}

       if(active_node==INVALID)

 	{

 	  for (EdgeIt i(g); i!=INVALID; ++i)

 	    {

 	      if(edgesmap[i]==active_item)

 		{

 		  active_edge=i;

 		}

 	    }

 	}

     *active_item << Gnome::Canvas::Properties::fill_color("red");

       break;

     case GDK_BUTTON_RELEASE:

       if(active_item==(get_item_at(e->button.x, e->button.y)))

 	{

 	  if(active_node!=INVALID)

 	    {

 	      EdgeIt e;

 	      g.firstOut(e,active_node);

 	      for(;e!=INVALID;g.nextOut(e))

 		{

 		  delete_item(edgesmap[e]);

 		  //edgesmap[e]->property_points().set_value(coos);

 		  //edgetextmap[e]->property_y().set_value((y1+y2)/2);

 		}

 	      g.firstIn(e,active_node);

 	      for(;e!=INVALID;g.nextIn(e))

 		{

 		  delete_item(edgesmap[e]);

 		  //edgesmap[e]->get_bounds(x1, y1, x2, y2);

 		  //edgetextmap[e]->property_y().set_value((y1+y2)/2);

 		}

 	    }

 	  delete_item(active_item);

 	}

       else

 	{

 	  if(active_node!=INVALID)

 	    {

 	      *active_item << Gnome::Canvas::Properties::fill_color("blue");

 	    }

 	  else

 	    {

 	      *active_item << Gnome::Canvas::Properties::fill_color("green");

 	    }

 	}

       active_item=NULL;

       active_edge=INVALID;

       active_node=INVALID;

       break;

     case GDK_MOTION_NOTIFY:

       break;

     default:

       break;

     }

   return true;

 }

 void GraphDisplayerCanvas::delete_item(Gnome::Canvas::Item * item_to_delete)

 {

   //item_to_delete->hide();

   delete(item_to_delete);

 }