{

   {

     //move the new node

       //draw the new node in red at the clicked place

     case GDK_MOTION_NOTIFY:

     case GDK_2BUTTON_PRESS:

       {

       //std::cout << "double click" << std::endl;

         GdkEvent * generated=new GdkEvent();

       break;

         generated->motion.x=e->motion.x;

     case GDK_BUTTON_PRESS:

         generated->motion.y=e->motion.y;

         generated->type=GDK_MOTION_NOTIFY;

         moveEventHandler(generated);      

         break;

       }

     case GDK_BUTTON_RELEASE:

         clicked_x-20, clicked_y-20, clicked_x+20, clicked_y+20);

           clicked_x-20, clicked_y-20, clicked_x+20, clicked_y+20);

       *(nodesmap[active_node]) << Gnome::Canvas::Properties::fill_color("red");

       *(nodesmap[active_node]) <<

       *(nodesmap[active_node]) << Gnome::Canvas::Properties::outline_color("black");

         Gnome::Canvas::Properties::fill_color("blue");

       *(nodesmap[active_node]) <<

         Gnome::Canvas::Properties::outline_color("black");

       active_item->raise_to_top();

         clicked_x+node_property_defaults[N_RADIUS]+5,

           clicked_x+node_property_defaults[N_RADIUS]+5,

         clicked_y+node_property_defaults[N_RADIUS]+5, "");

           clicked_y+node_property_defaults[N_RADIUS]+5, "");

     }

   }

     {

   {

 	{

       {

 	  //there is not yet selected node

         //there is not yet selected node

 	  if(active_node==INVALID)

         if(active_node==INVALID)

 	    {

         {

 	      //we mark the location of the event to be able to calculate parameters of dragging

           //we mark the location of the event to be able to calculate parameters of dragging

 	      window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);

           window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);

 	      active_item=(get_item_at(clicked_x, clicked_y));

           active_item=(get_item_at(clicked_x, clicked_y));

 	      active_node=INVALID;

           active_node=INVALID;

 	      for (NodeIt i(mapstorage.graph); i!=INVALID; ++i)

           for (NodeIt i(mapstorage.graph); i!=INVALID; ++i)

 		{

           {

 		  if(nodesmap[i]==active_item)

             if(nodesmap[i]==active_item)

 		    {

             {

 		      active_node=i;

               active_node=i;

 		    }

             }

 		}

           }

 	      //the clicked item is really a node

           //the clicked item is really a node

 	      if(active_node!=INVALID)

           if(active_node!=INVALID)

 		{

           {

 		  *(nodesmap[active_node]) << Gnome::Canvas::Properties::fill_color("red");

             *(nodesmap[active_node]) << Gnome::Canvas::Properties::fill_color("red");

 		  isbutton=1;

             isbutton=1;

 		}

           }

 	      //clicked item was not a node. It could be e.g. edge.

           //clicked item was not a node. It could be e.g. edge.

 	      else

           else

 		{

           {

 		  active_item=NULL;

             active_item=NULL;

 		}

           }

 	    }

         }

 	  //we only have to do sg. if the mouse button

         //we only have to do sg. if the mouse button

 	  // is pressed already once AND the click was

         // is pressed already once AND the click was

 	  // on a node that was found in the set of 

         // on a node that was found in the set of 

 	  //nodes, and now we only search for the second 

         //nodes, and now we only search for the second 

 	  //node

         //node

 	  else

         else

 	    {

         {

 	      window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);

           window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);

 	      target_item=(get_item_at(clicked_x, clicked_y));

           target_item=(get_item_at(clicked_x, clicked_y));

 	      Node target_node=INVALID;

           Node target_node=INVALID;

 	      for (NodeIt i(mapstorage.graph); i!=INVALID; ++i)

           for (NodeIt i(mapstorage.graph); i!=INVALID; ++i)

 		{

           {

 		  if(nodesmap[i]==target_item)

             if(nodesmap[i]==target_item)

 		    {

             {

 		      target_node=i;

               target_node=i;

 		    }

             }

 		}

           }

 	      //the clicked item is a node, the edge can be drawn

           //the clicked item is a node, the edge can be drawn

 	      if(target_node!=INVALID)

           if(target_node!=INVALID)

 		{

           {

 		  if(target_node!=active_node)		

             if(target_node!=active_node)		

 		    {

             {

           mapstorage.modified = true;

               mapstorage.modified = true;

 		      *(nodesmap[target_node]) <<

               *(nodesmap[target_node]) <<

 			Gnome::Canvas::Properties::fill_color("red");

                 Gnome::Canvas::Properties::fill_color("red");

 		      //creating new edge

               //creating new edge

 		      active_edge=mapstorage.graph.addEdge(active_node,

               active_edge=mapstorage.graph.addEdge(active_node,

 							   target_node);

                   target_node);

 		      //initiating values corresponding to new edge in maps

               // update id map

 		      mapstorage.initMapsForEdge(active_edge);

               (*mapstorage.edgemap_storage["id"])[active_edge] = 

                       (*mapstorage.edgemap_storage["id"])[active_edge] = 

                 mapstorage.graph.id(active_edge);

 			mapstorage.graph.id(active_edge);

               // update all other maps

 		      //calculating coordinates of new edge

               for (std::map<std::string,

 		      Gnome::Canvas::Points coos;

                   Graph::EdgeMap<double>*>::const_iterator it =

 		      double x1, x2, y1, y2;

                   mapstorage.edgemap_storage.begin(); it !=

                   mapstorage.edgemap_storage.end(); ++it)

 		      active_item->get_bounds(x1, y1, x2, y2);

               {

 		      coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

                 if (it->first != "id")

                 {

 		      target_item->get_bounds(x1, y1, x2, y2);

                   (*(it->second))[active_edge] =

 		      coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

                     mapstorage.edgemap_default[it->first];

                 }

 		      //drawing new edge

               }

 		      edgesmap[active_edge]=new BrokenEdge(displayed_graph, coos, *this);

 		      *(edgesmap[active_edge]) << Gnome::Canvas::Properties::fill_color("green");

               //calculating coordinates of new edge

 		      edgesmap[active_edge]->property_width_pixels().set_value(10);

               Gnome::Canvas::Points coos;

               double x1, x2, y1, y2;

 		      //redraw nodes to blank terminations of the new edge

 		      target_item->raise_to_top();

               active_item->get_bounds(x1, y1, x2, y2);

 		      active_item->raise_to_top();

               coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

 		      //initializing edge-text as well, to empty string

               target_item->get_bounds(x1, y1, x2, y2);

 		      xy<double> text_pos=edgesmap[active_edge]->getArrowPos();

               coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

 		      text_pos+=(xy<double>(10,10));

               //drawing new edge

 		      edgetextmap[active_edge]=new Gnome::Canvas::Text(displayed_graph, text_pos.x, text_pos.y, "");

               edgesmap[active_edge]=new BrokenEdge(displayed_graph, coos,

 		      edgetextmap[active_edge]->property_fill_color().set_value("darkgreen");

                   *this);

               *(edgesmap[active_edge]) <<

 		      //updating its properties

                 Gnome::Canvas::Properties::fill_color("green");

 		      mapwin.updateEdge(active_edge);

               edgesmap[active_edge]->property_width_pixels().set_value(10);

 		    }

 		  else

               edgesmap[active_edge]->lower_to_bottom();

 		    {

 		      target_node=INVALID;

               //initializing edge-text as well, to empty string

 		      std::cerr << "Loop edge is not yet implemented!" << std::endl;

               xy<double> text_pos=edgesmap[active_edge]->getArrowPos();

 		    }

               text_pos+=(xy<double>(10,10));

 		}

 	      //clicked item was not a node. it could be an e.g. edge. we do not deal with it furthermore.

               edgetextmap[active_edge]=new Gnome::Canvas::Text(displayed_graph,

 	      else

                   text_pos.x, text_pos.y, "");

 		{

               edgetextmap[active_edge]->property_fill_color().set_value(

 		  target_item=NULL;

                   "darkgreen");

 		}

               edgetextmap[active_edge]->raise_to_top();

 	    }

 	}

               //updating its properties

               mapwin.updateEdge(active_edge);

             }

             else

             {

               target_node=INVALID;

               std::cerr << "Loop edge is not yet implemented!" << std::endl;

             }

           }

           //clicked item was not a node. it could be an e.g. edge. we do not

           //deal with it furthermore.

           else

           {

             target_item=NULL;

           }

         }

       }

 	{

       {

 	  if(active_item)

         if(active_item)

 	    {

         {

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

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

 	      active_item=NULL;

           active_item=NULL;

 	    }

         }

 	  if(target_item)

         if(target_item)

 	    {

         {

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

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

 	      target_item=NULL;

           target_item=NULL;

 	    }

         }

 	  active_node=INVALID;

         active_node=INVALID;

 	  active_edge=INVALID;

         active_edge=INVALID;

 	}

       }

     }

   }

   if(mapstorage.addEdgeMap(mapname,emptr))

   if(mapstorage.addEdgeMap(mapname,emptr, default_value))

   if(mapstorage.addNodeMap(mapname,emptr))

   if(mapstorage.addNodeMap(mapname,emptr, default_value))