/* -*- 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 <mapstorage.h>

 #include <nbtab.h>

 #include <cmath>

 #include <set>

 bool DigraphDisplayerCanvas::on_expose_event(GdkEventExpose *event)

 {

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

   //usleep(10000);

   //rezoom();

   return true;

 }

 void DigraphDisplayerCanvas::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;

           createArcEventHandler(generated);      

           break;

         }

       case MAP_EDIT:

         {

           break;

         }

       default:

         break;

     }

     active_item=NULL; 

     target_item=NULL; 

     active_arc=INVALID;	

     active_node=INVALID;	

     actual_tool=newtool;

     switch(newtool)

     {

       case MOVE:

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

         break;

       case CREATE_NODE:

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

         break;

       case CREATE_EDGE:

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

         break;

       case ERASER:

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

         break;

       case MAP_EDIT:

         grab_focus();

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

         break;

       default:

         break;

     }

   }

 }

 int DigraphDisplayerCanvas::getActualTool()

 {

   return actual_tool;

 }

 bool DigraphDisplayerCanvas::scrollEventHandler(GdkEvent* e)

 {

   bool handled=false;

   if(e->type==GDK_SCROLL)

     {

       //pointer shows this win point before zoom

       XY win_coord(((GdkEventScroll*)e)->x, ((GdkEventScroll*)e)->y);

       //the original scroll settings

       int scroll_offset_x, scroll_offset_y;

       get_scroll_offsets(scroll_offset_x, scroll_offset_y);

       //pointer shows this canvas point before zoom

       XY canvas_coord;

       window_to_world(win_coord.x, win_coord.y, canvas_coord.x, canvas_coord.y);

       if(((GdkEventScroll*)e)->direction) //IN

 	{

 	  zoomIn();

 	}

       else

 	{

 	  zoomOut();

 	}

       //pointer shows this window point after zoom

       XY post_win_coord;

       world_to_window(canvas_coord.x, canvas_coord.y, post_win_coord.x, post_win_coord.y);

       //we have to add the difference between new and old window point to original scroll offset

       scroll_to(scroll_offset_x+(int)(post_win_coord.x-win_coord.x),scroll_offset_y+(int)(post_win_coord.y-win_coord.y));

       //no other eventhandler is needed

       handled=true;

     }

   return handled;

 }

 bool DigraphDisplayerCanvas::moveEventHandler(GdkEvent* e)

 {

   MapStorage& ms = *mytab.mapstorage;

   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(ms.digraph); 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)

       {

         ms.setModified();

         //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 << "(" <<

           ms.getNodeCoords(active_node).x << ", " <<

           ms.getNodeCoords(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(

               ms.getNodeCoords(active_node).x + radius);

           coord_text->property_y().set_value(

               ms.getNodeCoords(active_node).y - radius);

         }

         else

         {

           coord_text = new Gnome::Canvas::Text(

               displayed_graph,

               ms.getNodeCoords(active_node).x + radius,

               ms.getNodeCoords(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 DigraphDisplayerCanvas::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 DigraphDisplayerCanvas::createNodeEventHandler(GdkEvent* e)

 {

   MapStorage& ms = *mytab.mapstorage;

   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:

       ms.setModified();

       is_drawn=true;

       isbutton=1;

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

       active_node = ms.addNode(XY(clicked_x, clicked_y));

       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 DigraphDisplayerCanvas::createArcEventHandler(GdkEvent* e)

 {

   MapStorage& ms = *mytab.mapstorage;

   switch(e->type)

   {

     case GDK_BUTTON_PRESS:

       //in arc 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(ms.digraph); 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. arc.

           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(ms.digraph); i!=INVALID; ++i)

           {

             if(nodesmap[i]==target_item)

             {

               target_node=i;

             }

           }

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

           if(target_node!=INVALID)

           {

             ms.setModified();

             *(nodesmap[target_node]) <<

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

             active_arc = ms.addArc(active_node, target_node);

             if(target_node!=active_node)		

             {

               arcsmap[active_arc]=new BrokenArc(displayed_graph, active_arc, *this);

             }

             else

             {

               arcsmap[active_arc]=new LoopArc(displayed_graph, active_arc, *this);

             }

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

             XY text_pos=ms.getArrowCoords(active_arc);

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

             arctextmap[active_arc]=new Gnome::Canvas::Text(displayed_graph,

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

             arctextmap[active_arc]->property_fill_color().set_value(

                 "darkgreen");

             arctextmap[active_arc]->raise_to_top();

             propertyUpdate(active_arc);

           }

           //clicked item was not a node. it could be an e.g. arc. 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 arc is ready (target_item has valid value)

       //2: the arc 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(ms.digraph.target(active_arc),N_COLOR);

           target_item=NULL;

         }

         active_node=INVALID;

         active_arc=INVALID;

       }

       break;

     default:

       break;

   }

   return false;

 }

 bool DigraphDisplayerCanvas::eraserEventHandler(GdkEvent* e)

 {

   MapStorage& ms = *mytab.mapstorage;

   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_arc=INVALID;

       //was it a node?

       for (NodeIt i(ms.digraph); i!=INVALID; ++i)

       {

         if(nodesmap[i]==active_item)

         {

           active_node=i;

         }

       }

       //or was it an arc?

       if(active_node==INVALID)

       {

         for (ArcIt i(ms.digraph); i!=INVALID; ++i)

         {

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

           {

             active_arc=i;

           }

         }

       }

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

       if (active_arc == 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)

           {

             ms.setModified();

             std::set<Digraph::Arc> arcs_to_delete;

             for(OutArcIt e(ms.digraph,active_node);e!=INVALID;++e)

             {

               arcs_to_delete.insert(e);

             }

             for(InArcIt e(ms.digraph,active_node);e!=INVALID;++e)

             {

               arcs_to_delete.insert(e);

             }

             //deleting collected arcs

             for(std::set<Digraph::Arc>::iterator

                 arc_set_it=arcs_to_delete.begin();

                 arc_set_it!=arcs_to_delete.end();

                 ++arc_set_it)

             {

               deleteItem(*arc_set_it);

             }

             deleteItem(active_node);

           }

           //a simple arc was chosen

           else if (active_arc != INVALID)

           {

             deleteItem(active_arc);

           }

         }

         //pointer was moved, deletion is cancelled

         else

         {

           if(active_node!=INVALID)

           {

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

           }

           else if (active_arc != INVALID)

           {

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

           }

         }

       }

       //reseting datas

       active_item=NULL;

       active_arc=INVALID;

       active_node=INVALID;

       break;

     case GDK_MOTION_NOTIFY:

       break;

     default:

       break;

   }

   return false;

 }

 bool DigraphDisplayerCanvas::mapEditEventHandler(GdkEvent* e)

 {

   MapStorage& ms = *mytab.mapstorage;

   if(actual_tool==MAP_EDIT)

   {

     switch(e->type)

     {

       case GDK_BUTTON_PRESS:

         {

           //for determine, whether it was an arc

           Arc clicked_arc=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(ms.digraph); 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(ms.digraph); 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 (ArcIt i(ms.digraph); i!=INVALID; ++i)

             {

               //at the same time only one can be active

               if(arctextmap[i]==active_item)

               {

                 clicked_arc=i;

               }

             }

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

             if(clicked_arc==INVALID)

             {

               for (ArcIt i(ms.digraph); i!=INVALID; ++i)

               {

                 //at the same time only one can be active

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

                 {

                   clicked_arc=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();

               */

               Gtk::Entry entry;

               entry.set_text(nodetextmap[active_node]->property_text().get_value());

               vbox->add(entry);

               entry.show();

               switch (dialog.run())

               {

                 case Gtk::RESPONSE_NONE:

                 case Gtk::RESPONSE_CANCEL:

                   break;

                 case Gtk::RESPONSE_ACCEPT:

                   switch (ms.getNodeMapElementType(nodemap_to_edit))

                   {

                     case MapValue::NUMERIC:

                       ms.set(nodemap_to_edit, active_node,

                           atof(entry.get_text().c_str()));

                       break;

                     case MapValue::STRING:

                       ms.set(nodemap_to_edit, active_node,

                           static_cast<std::string>(entry.get_text()));

                       break;

                   }

                   nodetextmap[active_node]->property_text().set_value(

                       static_cast<std::string>(ms.get(nodemap_to_edit, active_node)));

                   //mapwin.updateNode(active_node);

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

                   propertyUpdate(Node(INVALID));

               }

             }

           }

           else

             //if it was really an arc...

             if(clicked_arc!=INVALID)

             {

               // the id map is not editable

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

               //and there is activated map

               if(arctextmap[clicked_arc]->property_text().get_value()!="")

               {

                 //activate the general variable for it

                 active_arc=clicked_arc;

                 //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(arctextmap[active_arc]->property_text().get_value().c_str()));

                 vbox->add(spin);

                 spin.show();

                 */

                 Gtk::Entry entry;

                 entry.set_text(arctextmap[active_arc]->property_text().get_value());

                 vbox->add(entry);

                 entry.show();

                 std::cout << arcmap_to_edit << std::endl;

                 switch (dialog.run())

                 {

                   case Gtk::RESPONSE_NONE:

                   case Gtk::RESPONSE_CANCEL:

                     break;

                   case Gtk::RESPONSE_ACCEPT:

                     switch (ms.getArcMapElementType(arcmap_to_edit))

                     {

                       case MapValue::NUMERIC:

                         ms.set(arcmap_to_edit, active_arc,

                             atof(entry.get_text().c_str()));

                         break;

                       case MapValue::STRING:

                         ms.set(arcmap_to_edit, active_arc,

                             static_cast<std::string>(entry.get_text()));

                         break;

                     }

                     arctextmap[active_arc]->property_text().set_value(

                         static_cast<std::string>(ms.get(arcmap_to_edit, active_arc)));

                     //mapwin.updateArc(active_arc);

                     //                   mapwin.updateArc(Arc(INVALID));

                     propertyUpdate(Arc(INVALID));

                 }

               }

             }

           break;

         }

       default:

         break;

     }

   }

   return false;  

 }

 void DigraphDisplayerCanvas::deleteItem(Node node_to_delete)

 {

   delete(nodetextmap[node_to_delete]);

   delete(nodesmap[node_to_delete]);

   mytab.mapstorage->digraph.erase(node_to_delete);

 }

 void DigraphDisplayerCanvas::deleteItem(Arc arc_to_delete)

 {

   delete(arctextmap[arc_to_delete]);

   delete(arcsmap[arc_to_delete]);

   mytab.mapstorage->digraph.erase(arc_to_delete);

 }

 void DigraphDisplayerCanvas::textReposition(XY new_place)

 {

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

   arctextmap[forming_arc]->property_x().set_value(new_place.x);

   arctextmap[forming_arc]->property_y().set_value(new_place.y);

 }

 void DigraphDisplayerCanvas::toggleArcActivity(ArcBase* active_bre, bool on)

 {

   if(on)

   {

     if(forming_arc!=INVALID)

     {

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

     }

     else

     {

       for (ArcIt i(mytab.mapstorage->digraph); i!=INVALID; ++i)

       {

         if(arcsmap[i]==active_bre)

         {

           forming_arc=i;

         }

       }

     }

   }

   else

   {

     if(forming_arc!=INVALID)

     {

       forming_arc=INVALID;

     }

     else

     {

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

     }

   }

 }

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

 {

   MapStorage& ms = *mytab.mapstorage;

   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 + ms.getNodeCoords(moved_node).x;

   double coord_y = dy + ms.getNodeCoords(moved_node).y;

   // write back the new coordinates to the coords map

   ms.setNodeCoords(moved_node, XY(coord_x, coord_y));

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

   for(OutArcIt ei(ms.digraph,moved_node);ei!=INVALID;++ei)

   {

     XY arrow_pos;

     if (ms.digraph.source(ei) == ms.digraph.target(ei))

     {

       arrow_pos = ms.getArrowCoords(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 = ms.digraph.target(ei);

       XY fix_node = ms.getNodeCoords(target);

       XY old_arrow_pos(ms.getArrowCoords(ei));

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

     }

     ms.setArrowCoords(ei, arrow_pos);

     arcsmap[ei]->draw();

     //reposition of arctext

     XY text_pos=ms.getArrowCoords(ei);

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

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

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

   }

   for(InArcIt ei(ms.digraph,moved_node);ei!=INVALID;++ei)

   {

     if (ms.digraph.source(ei) != ms.digraph.target(ei))

     {

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

       XY moved_node_2(coord_x, coord_y);

       Node source = ms.digraph.source(ei);

       XY fix_node = ms.getNodeCoords(source);

       XY old_arrow_pos(ms.getArrowCoords(ei));

       XY arrow_pos;

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

       ms.setArrowCoords(ei, arrow_pos);

       arcsmap[ei]->draw();

       //reposition of arctext

       XY text_pos=ms.getArrowCoords(ei);

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

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

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

     }

   }

 }

 Gdk::Color DigraphDisplayerCanvas::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/6.0))*6.0;

     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), 0, 1);

         break;

       default:

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

     }

   }

   else

   {

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

   }

   return color;

 }