/* -*- 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;
}