/* -*- C++ -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2003-2006

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #include "graph_displayer_canvas.h"

 #include <cmath>

 bool GraphDisplayerCanvas::on_expose_event(GdkEventExpose *event)

 {

   Gnome::Canvas::CanvasAA::on_expose_event(event);

   //usleep(10000);

   //rezoom();

   return true;

 }

 void GraphDisplayerCanvas::changeEditorialTool(int newtool)

 {

   if(actual_tool!=newtool)

     {

       actual_handler.disconnect();

       switch(actual_tool)

 	{

 	case CREATE_EDGE:

 	  {

 	    GdkEvent * generated=new GdkEvent();

 	    generated->type=GDK_BUTTON_RELEASE;

 	    generated->button.button=3;

 	    createEdgeEventHandler(generated);      

 	    break;

 	  }

 	case MAP_EDIT:

 	  {

 	    break;

 	  }

 	default:

 	  break;

 	}

       active_item=NULL; 

       target_item=NULL; 

       active_edge=INVALID;	

       active_node=INVALID;	

       actual_tool=newtool;

       switch(newtool)

 	{

 	case MOVE:

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

 	  break;

 	case CREATE_NODE:

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

 	  break;

 	case CREATE_EDGE:

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

 	  break;

 	case ERASER:

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

 	  break;

 	case MAP_EDIT:

 	  grab_focus();

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

 	  break;

 	default:

 	  break;

 	}

     }

 }

 int GraphDisplayerCanvas::getActualTool()

 {

   return actual_tool;

 }

 bool GraphDisplayerCanvas::moveEventHandler(GdkEvent* e)

 {

   static Gnome::Canvas::Text *coord_text = 0;

   switch(e->type)

     {

     case GDK_BUTTON_PRESS:

       //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);

       active_item=(get_item_at(clicked_x, clicked_y));

       active_node=INVALID;

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

 	{

 	  if(nodesmap[i]==active_item)

 	    {

 	      active_node=i;

 	    }

 	}

       isbutton=e->button.button;

       break;

     case GDK_BUTTON_RELEASE:

       if (coord_text)

 	{

 	  delete coord_text;

 	  coord_text = 0;

 	}

       isbutton=0;

       active_item=NULL;

       active_node=INVALID;

       break;

     case GDK_MOTION_NOTIFY:

       //we only have to do sg. if the mouse button is pressed AND the click was on a node that was found in the set of nodes

       if(active_node!=INVALID)

 	{

 	  (mytab.mapstorage).modified = true;

 	  //new coordinates will be the old values,

 	  //because the item will be moved to the

 	  //new coordinate therefore the new movement

 	  //has to be calculated from here

 	  double new_x, new_y;

 	  window_to_world (e->motion.x, e->motion.y, new_x, new_y);

 	  double dx=new_x-clicked_x;

 	  double dy=new_y-clicked_y;

 	  moveNode(dx, dy);

 	  clicked_x=new_x;

 	  clicked_y=new_y;

 	  // reposition the coordinates text

 	  std::ostringstream ostr;

 	  ostr << "(" <<

 	    (mytab.mapstorage).coords[active_node].x << ", " <<

 	    (mytab.mapstorage).coords[active_node].y << ")";

 	  double radius =

 	    (nodesmap[active_node]->property_x2().get_value() -

 	     nodesmap[active_node]->property_x1().get_value()) / 2.0;

 	  if (coord_text)

 	    {

 	      coord_text->property_text().set_value(ostr.str());

 	      coord_text->property_x().set_value((mytab.mapstorage).coords[active_node].x +

 						 radius);

 	      coord_text->property_y().set_value((mytab.mapstorage).coords[active_node].y -

 						 radius);

 	    }

 	  else

 	    {

 	      coord_text = new Gnome::Canvas::Text(

 						   displayed_graph,

 						   (mytab.mapstorage).coords[active_node].x + radius,

 						   (mytab.mapstorage).coords[active_node].y - radius,

 						   ostr.str());

 	      coord_text->property_fill_color().set_value("black");

 	      coord_text->property_anchor().set_value(Gtk::ANCHOR_SOUTH_WEST);

 	    }

 	}

     default: break;

     }

 return false;

 }

 XY GraphDisplayerCanvas::calcArrowPos(XY moved_node_1, XY moved_node_2, XY fix_node, XY old_arrow_pos, int move_code)

 {

   switch(move_code)

     {

     case 1:

       return XY((moved_node_2.x + fix_node.x) / 2.0, (moved_node_2.y + fix_node.y) / 2.0);

       break;

     case 2:

       return old_arrow_pos;

       break;

     case 3:

       {

 	//////////////////////////////////////////////////////////////////////////////////////////////////////

 	/////////// keeps shape-with scalar multiplication - version 2.

 	//////////////////////////////////////////////////////////////////////////////////////////////////////

 	//old vector from one to the other node - a

 	XY a_v(moved_node_1.x-fix_node.x,moved_node_1.y-fix_node.y);

 	//new vector from one to the other node - b

 	XY b_v(moved_node_2.x-fix_node.x,moved_node_2.y-fix_node.y);

 	double absa=sqrt(a_v.normSquare());

 	double absb=sqrt(b_v.normSquare());

 	if ((absa == 0.0) || (absb == 0.0))

 	  {

 	    return old_arrow_pos;

 	  }

 	else

 	  {

 	    //old vector from one node to the breakpoint - c

 	    XY c_v(old_arrow_pos.x-fix_node.x,old_arrow_pos.y-fix_node.y);

 	    //unit vector with the same direction to a_v

 	    XY a_v_u(a_v.x/absa,a_v.y/absa);

 	    //normal vector of unit vector with the same direction to a_v

 	    XY a_v_u_n(((-1)*a_v_u.y),a_v_u.x);

 	    //unit vector with the same direction to b_v

 	    XY b_v_u(b_v.x/absb,b_v.y/absb);

 	    //normal vector of unit vector with the same direction to b_v

 	    XY b_v_u_n(((-1)*b_v_u.y),b_v_u.x);

 	    //vector c in a_v_u and a_v_u_n co-ordinate system

 	    XY c_a(c_v*a_v_u,c_v*a_v_u_n);

 	    //new vector from one node to the breakpoint - d - we have to calculate this one

 	    XY d_v=absb/absa*(c_a.x*b_v_u+c_a.y*b_v_u_n);

 	    return XY(d_v.x+fix_node.x,d_v.y+fix_node.y);

 	  }

 	break;

       }

     default:

       break;

     }

 }

 bool GraphDisplayerCanvas::createNodeEventHandler(GdkEvent* e)

 {

   switch(e->type)

   {

     //move the new node

     case GDK_MOTION_NOTIFY:

       {

         GdkEvent * generated=new GdkEvent();

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

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

         generated->type=GDK_MOTION_NOTIFY;

         moveEventHandler(generated);      

         break;

       }

     case GDK_BUTTON_RELEASE:

       (mytab.mapstorage).modified = true;

       is_drawn=true;

       isbutton=1;

       active_node=(mytab.mapstorage).graph.addNode();

       //initiating values corresponding to new node in maps

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

       // update coordinates

       (mytab.mapstorage).coords.set(active_node, XY(clicked_x, clicked_y));

       // update all other maps

       for (std::map<std::string, Graph::NodeMap<double>*>::const_iterator it =

           (mytab.mapstorage).nodemap_storage.begin(); it !=

           (mytab.mapstorage).nodemap_storage.end(); ++it)

       {

         if ((it->first != "coordinates_x") &&

             (it->first != "coordinates_y"))

         {

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

             (mytab.mapstorage).nodemap_default[it->first];

         }

       }

       // increment the id map's default value

       (mytab.mapstorage).nodemap_default["label"] += 1.0;

       nodesmap[active_node]=new Gnome::Canvas::Ellipse(displayed_graph,

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

       active_item=(Gnome::Canvas::Item *)(nodesmap[active_node]);

       *(nodesmap[active_node]) <<

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

       *(nodesmap[active_node]) <<

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

       active_item->raise_to_top();

       (nodesmap[active_node])->show();

       nodetextmap[active_node]=new Gnome::Canvas::Text(displayed_graph,

           clicked_x+node_property_defaults[N_RADIUS]+5,

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

       nodetextmap[active_node]->property_fill_color().set_value("darkblue");

       nodetextmap[active_node]->raise_to_top();

 //       mapwin.updateNode(active_node);

       propertyUpdate(active_node);

       isbutton=0;

       target_item=NULL;

       active_item=NULL;

       active_node=INVALID;

       break;

     default:

       break;

   }

   return false;

 }

 bool GraphDisplayerCanvas::createEdgeEventHandler(GdkEvent* e)

 {

   switch(e->type)

   {

     case GDK_BUTTON_PRESS:

       //in edge creation right button has special meaning

       if(e->button.button!=3)

       {

         //there is not yet selected node

         if(active_node==INVALID)

         {

           //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);

           active_item=(get_item_at(clicked_x, clicked_y));

           active_node=INVALID;

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

           {

             if(nodesmap[i]==active_item)

             {

               active_node=i;

             }

           }

           //the clicked item is really a node

           if(active_node!=INVALID)

           {

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

             isbutton=1;

           }

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

           else

           {

             active_item=NULL;

           }

         }

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

         // is pressed already once AND the click was

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

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

         //node

         else

         {

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

           target_item=(get_item_at(clicked_x, clicked_y));

           Node target_node=INVALID;

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

           {

             if(nodesmap[i]==target_item)

             {

               target_node=i;

             }

           }

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

           if(target_node!=INVALID)

           {

             (mytab.mapstorage).modified = true;

             *(nodesmap[target_node]) <<

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

             //creating new edge

             active_edge=(mytab.mapstorage).graph.addEdge(active_node,

                 target_node);

             // update maps

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

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

                 (mytab.mapstorage).edgemap_storage.begin(); it !=

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

             {

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

                 (mytab.mapstorage).edgemap_default[it->first];

             }

             // increment the id map's default value

             (mytab.mapstorage).edgemap_default["label"] += 1.0;

             if(target_node!=active_node)		

             {

               // set the coordinates of the arrow on the new edge

               MapStorage& ms = mytab.mapstorage;

               ms.arrow_pos.set(active_edge,

                   (ms.coords[ms.graph.source(active_edge)] +

                    ms.coords[ms.graph.target(active_edge)])/ 2.0);

               //drawing new edge

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

                   *this);

             }

             else

             {

               // set the coordinates of the arrow on the new edge

               MapStorage& ms = mytab.mapstorage;

               ms.arrow_pos.set(active_edge,

                   (ms.coords[ms.graph.source(active_edge)] +

                    XY(0.0, 80.0)));

               //drawing new edge

               edgesmap[active_edge]=new LoopEdge(displayed_graph, active_edge,

                   *this);

             }

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

             XY text_pos=mytab.mapstorage.arrow_pos[active_edge];

             text_pos+=(XY(10,10));

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

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

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

                 "darkgreen");

             edgetextmap[active_edge]->raise_to_top();

             propertyUpdate(active_edge);

           }

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

           //deal with it furthermore.

           else

           {

             target_item=NULL;

           }

         }

       }

       break;

     case GDK_BUTTON_RELEASE:

       isbutton=0;

       //we clear settings in two cases

       //1: the edge is ready (target_item has valid value)

       //2: the edge creation is cancelled with right button

       if((target_item)||(e->button.button==3))

       {

         if(active_item)

         {

 	  propertyUpdate(active_node,N_COLOR);

           active_item=NULL;

         }

         if(target_item)

         {

 	  propertyUpdate((mytab.mapstorage).graph.target(active_edge),N_COLOR);

           target_item=NULL;

         }

         active_node=INVALID;

         active_edge=INVALID;

       }

       break;

     default:

       break;

   }

   return false;

 }

 bool GraphDisplayerCanvas::eraserEventHandler(GdkEvent* e)

 {

   switch(e->type)

     {

     case GDK_BUTTON_PRESS:

       //finding the clicked items

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

       active_item=(get_item_at(clicked_x, clicked_y));

       active_node=INVALID;

       active_edge=INVALID;

       //was it a node?

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

 	{

 	  if(nodesmap[i]==active_item)

 	    {

 	      active_node=i;

 	    }

 	}

       //or was it an edge?

       if(active_node==INVALID)

 	{

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

 	    {

 	      if(edgesmap[i]->getLine()==active_item)

 		{

 		  active_edge=i;

 		}

 	    }

 	}

       // return if the clicked object is neither an edge nor a node

       if (active_edge == INVALID) return false;

       //recolor activated item

       if(active_item)

 	{

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

 	}

       break;

     case GDK_BUTTON_RELEASE:

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

       if(active_item)

 	{

 	  //the cursor was not moved since pressing it

 	  if( active_item == ( get_item_at (clicked_x, clicked_y) ) )

 	    {

 	      //a node was found

 	      if(active_node!=INVALID)

 		{

                   (mytab.mapstorage).modified = true;

 		  std::set<Graph::Edge> edges_to_delete;

 		  for(OutEdgeIt e((mytab.mapstorage).graph,active_node);e!=INVALID;++e)

 		    {

 		      edges_to_delete.insert(e);

 		    }

 		  for(InEdgeIt e((mytab.mapstorage).graph,active_node);e!=INVALID;++e)

 		    {

 		      edges_to_delete.insert(e);

 		    }

 		  //deleting collected edges

 		  for(std::set<Graph::Edge>::iterator

 			edge_set_it=edges_to_delete.begin();

 		      edge_set_it!=edges_to_delete.end();

 		      ++edge_set_it)

 		    {

 		      deleteItem(*edge_set_it);

 		    }

 		  deleteItem(active_node);

 		}

 	      //a simple edge was chosen

 	      else if (active_edge != INVALID)

 		{

 		  deleteItem(active_edge);

 		}

 	    }

 	  //pointer was moved, deletion is cancelled

 	  else

 	    {

 	      if(active_node!=INVALID)

 		{

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

 		}

 	      else if (active_edge != INVALID)

 		{

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

 		}

 	    }

 	}

       //reseting datas

       active_item=NULL;

       active_edge=INVALID;

       active_node=INVALID;

       break;

     case GDK_MOTION_NOTIFY:

       break;

     default:

       break;

     }

   return false;

 }

 bool GraphDisplayerCanvas::mapEditEventHandler(GdkEvent* e)

 {

   if(actual_tool==MAP_EDIT)

     {

       switch(e->type)

 	{

 	case GDK_BUTTON_PRESS:

 	  {

 	    //for determine, whether it was an edge

 	    Edge clicked_edge=INVALID;

 	    //for determine, whether it was a node

 	    Node clicked_node=INVALID;

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

 	    active_item=(get_item_at(clicked_x, clicked_y));

 	    //find the activated item between text of nodes

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

 	      {

 		//at the same time only one can be active

 		if(nodetextmap[i]==active_item)

 		  {

 		    clicked_node=i;

 		  }

 	      }

 	    //if there was not, search for it between nodes

 	    if(clicked_node==INVALID)

 	      {

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

 		  {

 		    //at the same time only one can be active

 		    if(nodesmap[i]==active_item)

 		      {

 			clicked_node=i;

 		      }

 		  }

 	      }

 	    if(clicked_node==INVALID)

 	      {

 		//find the activated item between texts

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

 		  {

 		    //at the same time only one can be active

 		    if(edgetextmap[i]==active_item)

 		      {

 			clicked_edge=i;

 		      }

 		  }

 		//if it was not between texts, search for it between edges

 		if(clicked_edge==INVALID)

 		  {

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

 		      {

 			//at the same time only one can be active

 			if((edgesmap[i]->getLine())==active_item)

 			  {

 			    clicked_edge=i;

 			  }

 		      }

 		  }

 	      }

 	    //if it was really a node...

 	    if(clicked_node!=INVALID)

 	      {

 		// the id map is not editable

 		if (nodemap_to_edit == "label") return 0;

 		//and there is activated map

 		if(nodetextmap[clicked_node]->property_text().get_value()!="")

 		  {

 		    //activate the general variable for it

 		    active_node=clicked_node;

 		    //create a dialog

 		    Gtk::Dialog dialog("Edit value", true);

 		    dialog.add_button(Gtk::Stock::CANCEL, Gtk::RESPONSE_CANCEL);

 		    dialog.add_button(Gtk::Stock::OK, Gtk::RESPONSE_ACCEPT);

 		    Gtk::VBox* vbox = dialog.get_vbox();

 		    Gtk::SpinButton spin(0.0, 4);

 		    spin.set_increments(1.0, 10.0);

 		    spin.set_range(-1000000.0, 1000000.0);

 		    spin.set_numeric(true);

 		    spin.set_value(atof(nodetextmap[active_node]->property_text().get_value().c_str()));

 		    vbox->add(spin);

 		    spin.show();

 		    switch (dialog.run())

 		      {

 		      case Gtk::RESPONSE_NONE:

 		      case Gtk::RESPONSE_CANCEL:

 			break;

 		      case Gtk::RESPONSE_ACCEPT:

 			double new_value = spin.get_value();

 			(*(mytab.mapstorage).nodemap_storage[nodemap_to_edit])[active_node] =

 			  new_value;

 			std::ostringstream ostr;

 			ostr << new_value;

 			nodetextmap[active_node]->property_text().set_value(ostr.str());

 			//mapwin.updateNode(active_node);

 			//mapwin.updateNode(Node(INVALID));

 			propertyUpdate(Node(INVALID));

 		      }

 		  }

 	      }

 	    else

 	      //if it was really an edge...

 	      if(clicked_edge!=INVALID)

 		{

 		  // the id map is not editable

 		  if (edgemap_to_edit == "label") return 0;

 		  //and there is activated map

 		  if(edgetextmap[clicked_edge]->property_text().get_value()!="")

 		    {

 		      //activate the general variable for it

 		      active_edge=clicked_edge;

 		      //create a dialog

 		      Gtk::Dialog dialog("Edit value", true);

 		      dialog.add_button(Gtk::Stock::CANCEL, Gtk::RESPONSE_CANCEL);

 		      dialog.add_button(Gtk::Stock::OK, Gtk::RESPONSE_ACCEPT);

 		      Gtk::VBox* vbox = dialog.get_vbox();

 		      Gtk::SpinButton spin(0.0, 4);

 		      spin.set_increments(1.0, 10.0);

 		      spin.set_range(-1000000.0, 1000000.0);

 		      spin.set_numeric(true);

 		      spin.set_value(atof(edgetextmap[active_edge]->property_text().get_value().c_str()));

 		      vbox->add(spin);

 		      spin.show();

 		      switch (dialog.run())

 			{

 			case Gtk::RESPONSE_NONE:

 			case Gtk::RESPONSE_CANCEL:

 			  break;

 			case Gtk::RESPONSE_ACCEPT:

 			  double new_value = spin.get_value();

 			  (*(mytab.mapstorage).edgemap_storage[edgemap_to_edit])[active_edge] =

 			    new_value;

 			  std::ostringstream ostr;

 			  ostr << new_value;

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

 									      ostr.str());

 			  //mapwin.updateEdge(active_edge);

 			  //                   mapwin.updateEdge(Edge(INVALID));

 			  propertyUpdate(Edge(INVALID));

 			}

 		    }

 		}

 	    break;

 	  }

 	default:

 	  break;

 	}

     }

   return false;  

 }

 void GraphDisplayerCanvas::deleteItem(Node node_to_delete)

 {

   delete(nodetextmap[node_to_delete]);

   delete(nodesmap[node_to_delete]);

   (mytab.mapstorage).graph.erase(node_to_delete);

 }

 void GraphDisplayerCanvas::deleteItem(Edge edge_to_delete)

 {

   delete(edgetextmap[edge_to_delete]);

   delete(edgesmap[edge_to_delete]);

   (mytab.mapstorage).graph.erase(edge_to_delete);

 }

 void GraphDisplayerCanvas::textReposition(XY new_place)

 {

   new_place+=(XY(10,10));

   edgetextmap[forming_edge]->property_x().set_value(new_place.x);

   edgetextmap[forming_edge]->property_y().set_value(new_place.y);

 }

 void GraphDisplayerCanvas::toggleEdgeActivity(EdgeBase* active_bre, bool on)

 {

   if(on)

   {

     if(forming_edge!=INVALID)

     {

       std::cerr << "ERROR!!!! Valid edge found!" << std::endl;

     }

     else

     {

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

       {

         if(edgesmap[i]==active_bre)

         {

           forming_edge=i;

         }

       }

     }

   }

   else

     {

       if(forming_edge!=INVALID)

 	{

 	  forming_edge=INVALID;

 	}

       else

 	{

 	  std::cerr << "ERROR!!!! Invalid edge found!" << std::endl;

 	}

     }

 }

 void GraphDisplayerCanvas::moveNode(double dx, double dy, Gnome::Canvas::Item * item, Node node)

 {

   Gnome::Canvas::Item * moved_item=item;

   Node moved_node=node;

   if(item==NULL && node==INVALID)

     {

       moved_item=active_item;

       moved_node=active_node;

     }

   else

     {

       isbutton=1;

     }

   //repositioning node and its text

   moved_item->move(dx, dy);

   nodetextmap[moved_node]->move(dx, dy);

   // the new coordinates of the centre of the node 

   double coord_x = dx + (mytab.mapstorage).coords[moved_node].x;

   double coord_y = dy + (mytab.mapstorage).coords[moved_node].y;

   // write back the new coordinates to the coords map

   (mytab.mapstorage).coords.set(moved_node, XY(coord_x, coord_y));

   //all the edges connected to the moved point has to be redrawn

   for(OutEdgeIt ei((mytab.mapstorage).graph,moved_node);ei!=INVALID;++ei)

     {

       XY arrow_pos;

       if (mytab.mapstorage.graph.source(ei) == mytab.mapstorage.graph.target(ei))

 	{

 	  arrow_pos = mytab.mapstorage.arrow_pos[ei] + XY(dx, dy);

 	}

       else

 	{

 	  XY moved_node_1(coord_x - dx, coord_y - dy);

 	  XY moved_node_2(coord_x, coord_y);

 	  Node target = mytab.mapstorage.graph.target(ei);

 	  XY fix_node(mytab.mapstorage.coords[target].x,

 		      mytab.mapstorage.coords[target].y);

 	  XY old_arrow_pos(mytab.mapstorage.arrow_pos[ei]);

 	  arrow_pos = calcArrowPos(moved_node_1, moved_node_2, fix_node, old_arrow_pos, isbutton);

 	}

       mytab.mapstorage.arrow_pos.set(ei, arrow_pos);

       edgesmap[ei]->draw();

       //reposition of edgetext

       XY text_pos=mytab.mapstorage.arrow_pos[ei];

       text_pos+=(XY(10,10));

       edgetextmap[ei]->property_x().set_value(text_pos.x);

       edgetextmap[ei]->property_y().set_value(text_pos.y);

     }

   for(InEdgeIt ei((mytab.mapstorage).graph,moved_node);ei!=INVALID;++ei)

     {

       if (mytab.mapstorage.graph.source(ei) != mytab.mapstorage.graph.target(ei))

 	{

 	  XY moved_node_1(coord_x - dx, coord_y - dy);

 	  XY moved_node_2(coord_x, coord_y);

 	  Node source = mytab.mapstorage.graph.source(ei);

 	  XY fix_node(mytab.mapstorage.coords[source].x,

 		      mytab.mapstorage.coords[source].y);

 	  XY old_arrow_pos(mytab.mapstorage.arrow_pos[ei]);

 	  XY arrow_pos;

 	  arrow_pos = calcArrowPos(moved_node_1, moved_node_2, fix_node, old_arrow_pos, isbutton);

 	  mytab.mapstorage.arrow_pos.set(ei, arrow_pos);

 	  edgesmap[ei]->draw();

 	  //reposition of edgetext

 	  XY text_pos=mytab.mapstorage.arrow_pos[ei];

 	  text_pos+=(XY(10,10));

 	  edgetextmap[ei]->property_x().set_value(text_pos.x);

 	  edgetextmap[ei]->property_y().set_value(text_pos.y);

 	}

     }

 }

 Gdk::Color GraphDisplayerCanvas::rainbowColorCounter(double min, double max, double w)

 {

   Gdk::Color color;

   double pos=(w-min)/(max-min);

   int phase=0;

   //rainbow transitions contain 6 phase

   //in each phase only one color is changed

   //first we determine the phase, in which

   //the actual value belongs to

   for (int i=0;i<=5;i++)

     {

       if(((double)i/6<pos)&&(pos<=(double(i+1)/6)))

 	{

 	  phase=i;

 	}

     }

   if(phase<6)

     {

       //within its 1/6 long phase the relativ position

       //determines the power of the color changed in

       //that phase

       //we normalize that to one, to be able to give percentage

       //value for the function

       double rel_pos=(pos-(phase/6))*6;

       switch(phase)

 	{

 	case 0:

 	  color.set_rgb_p (1, 0, 1-rel_pos);

 	  break;

 	case 1:

 	  color.set_rgb_p (1, rel_pos, 0);

 	  break;

 	case 2:

 	  color.set_rgb_p (1-rel_pos, 1, 0);

 	  break;

 	case 3:

 	  color.set_rgb_p (0, 1, rel_pos);

 	  break;

 	case 4:

 	  color.set_rgb_p (0, 1-rel_pos, 1);

 	  break;

 	case 5:

 	  color.set_rgb_p ((rel_pos/3), 0, 1);

 	  break;

 	default:

 	  std::cout << "Wrong phase: " << phase << " " << pos << std::endl;

 	}

     }

   else

     {

       std::cout << "Wrong phase: " << phase << " " << pos << std::endl;

     }

   return color;

 }