source: glemon-0.x/graph_displayer_canvas-event.cc @ 197:c1084e2bff10

/* -*- 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>


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::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 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;
}