#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 EDGE_MAP_EDIT:

	  //has to do the same thing as in the case of NODE_MAP_EDIT

	case NODE_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 EDGE_MAP_EDIT:

	  grab_focus();

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

	  break;

	case NODE_MAP_EDIT:

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

	    }

	}

      switch(e->button.button)

	{

	case 3:      

	  isbutton=3;

	  break;

	default:

	  isbutton=1;

	  break;

	}

      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;

	//repositioning node and its text

        active_item->move(dx, dy);

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

        // the new coordinates of the centre of the node 

        double coord_x = new_x - (clicked_x - (mytab.mapstorage).coords[active_node].x);

        double coord_y = new_y - (clicked_y - (mytab.mapstorage).coords[active_node].y);

        // write back the new coordinates to the coords map

        (mytab.mapstorage).coords.set(active_node, xy<double>(coord_x, coord_y));

        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);

        }

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

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

        {

            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]);

            XY arrow_pos;

	    if(isbutton==3)

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

	    else

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

            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,active_node);ei!=INVALID;++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;

	    if(isbutton==3)

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

	    else

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

            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);

        }

      }

    default: break;

  }

  return false;

}

XY GraphDisplayerCanvas::calcArrowPos(XY moved_node_1, XY moved_node_2, XY fix_node, XY old_arrow_pos, bool move)

{

  if(!move)

  {

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

  }

  else

  {

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

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

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

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

    xy<double> 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<double> 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<double> 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<double> a_v_u(a_v.x/absa,a_v.y/absa);

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

      xy<double> a_v_u_n(((-1)*a_v_u.y),a_v_u.x);

      //unit vector with the same direction to b_v

      xy<double> b_v_u(b_v.x/absb,b_v.y/absb);

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

      xy<double> 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<double> 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<double> 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);

    }

  }

}

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;

      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<double>(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["id"] += 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)

          {

            if(target_node!=active_node)		

            {

              (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["id"] += 1.0;

              //calculating coordinates of new edge

              Gnome::Canvas::Points coos;

              double x1, x2, y1, y2;

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

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

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

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

              //drawing new edge

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

                  *this);

              *(edgesmap[active_edge]) <<

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

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

              edgesmap[active_edge]->lower_to_bottom();

              //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();

              //updating its properties

//               mapwin.updateEdge(active_edge);

              propertyUpdate(active_edge);

            }

            else

            {

              target_node=INVALID;

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

            }

          }

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

          //deal with it furthermore.

          else

          {

            target_item=NULL;

          }

        }

      }

      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)

        {

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

          active_item=NULL;

        }

        if(target_item)

        {

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

          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]==active_item)

		{

		  active_edge=i;

		}

	    }

	}

      //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

		{

		  deleteItem(active_edge);

		}

	    }

	  //pointer was moved, deletion is cancelled

	  else

	    {

	      if(active_node!=INVALID)

		{

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

		}

	      else

		{

		  *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::edgeMapEditEventHandler(GdkEvent* e)

{

  if(actual_tool==EDGE_MAP_EDIT)

  {

    switch(e->type)

    {

      case GDK_BUTTON_PRESS:

        {

          //for determine, whether it was an edge

          Edge clicked_edge=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 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]==active_item)||(edgetextmap[i]==active_item))

              {

                clicked_edge=i;

              }

            }

          }

          //if it was really an edge...

          if(clicked_edge!=INVALID)

          {

            // the id map is not editable

            if (edgemap_to_edit == "id") 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);

              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;  

}

bool GraphDisplayerCanvas::nodeMapEditEventHandler(GdkEvent* e)

{

  if(actual_tool==NODE_MAP_EDIT)

  {

    switch(e->type)

    {

      case GDK_BUTTON_PRESS:

        {

          //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 texts

          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 it was really a node...

          if(clicked_node!=INVALID)

          {

            // the id map is not editable

            if (nodemap_to_edit == "id") 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);

              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));

              }

            }

          }

          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<double> new_place)

{

  new_place+=(xy<double>(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(BrokenEdge* 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;

	}

    }

}