source: lemon-0.x/gui/graph_displayer_canvas-event.cc @ 1596:44897b1ba4e2

#include <graph_displayer_canvas.h>
#include <broken_edge.h>
#include <math.h>


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:
          {
            GdkEvent * generated=new GdkEvent();
            generated->type=GDK_KEY_PRESS;
            ((GdkEventKey*)generated)->keyval=GDK_KP_Enter;
            entryWidgetChangeHandler(generated);
            entrywidget.hide();
            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)
{
  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(g); 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:
      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)
      {
        //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);

        clicked_x=new_x;
        clicked_y=new_y;

        //all the edges connected to the moved point has to be redrawn
        EdgeIt ei;

        g.firstOut(ei,active_node);

        for(;ei!=INVALID;g.nextOut(ei))
        {
            Gnome::Canvas::Points coos;
            double x1, x2, y1, y2;

            nodesmap[g.source(ei)]->get_bounds(x1, y1, x2, y2);
            coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

            nodesmap[g.target(ei)]->get_bounds(x1, y1, x2, y2);
            coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

            if(isbutton==3)
              {
                edgesmap[ei]->setPoints(coos);
              }
            else
              {
                edgesmap[ei]->setPoints(coos,true);
              }

            //reposition of edgetext
            xy<double> text_pos=edgesmap[ei]->getArrowPos();
            text_pos+=(xy<double>(10,10));
            edgetextmap[ei]->property_x().set_value(text_pos.x);
            edgetextmap[ei]->property_y().set_value(text_pos.y);
        }

        g.firstIn(ei,active_node);
        for(;ei!=INVALID;g.nextIn(ei))
        {
            Gnome::Canvas::Points coos;
            double x1, x2, y1, y2;

            nodesmap[g.source(ei)]->get_bounds(x1, y1, x2, y2);
            coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

            nodesmap[g.target(ei)]->get_bounds(x1, y1, x2, y2);
            coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));

            if(isbutton==3)
              {
                edgesmap[ei]->setPoints(coos);
              }
            else
              {
                edgesmap[ei]->setPoints(coos,true);
              }

            xy<double> text_pos=edgesmap[ei]->getArrowPos();
            text_pos+=(xy<double>(10,10));
            edgetextmap[ei]->property_x().set_value(text_pos.x);
            edgetextmap[ei]->property_y().set_value(text_pos.y);
        }
      }
    default: break;
  }

  return false;
}

bool GraphDisplayerCanvas::createNodeEventHandler(GdkEvent* e)
{
  switch(e->type)
    {

      //draw the new node in red at the clicked place
    case GDK_2BUTTON_PRESS:
      std::cout << "double click" << std::endl;
      break;
    case GDK_BUTTON_PRESS:
      isbutton=1;

      active_node=NodeIt(g,g.addNode());

      //initiating values corresponding to new node in maps

      window_to_world (e->button.x, e->button.y, 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("red");
      *(nodesmap[active_node]) << Gnome::Canvas::Properties::outline_color("black");
      (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");

      mapwin->updateNode(active_node);

      break;

      //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;
      }

      //finalize the new node
    case GDK_BUTTON_RELEASE:
      window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);

      active_item->lower_to_bottom();

      target_item=NULL;
      target_item=get_item_at(clicked_x, clicked_y);

      active_item->raise_to_top();

      isbutton=0;
      if(target_item==active_item)
        {
          //Its appropriate color is given by update.
          *active_item << Gnome::Canvas::Properties::fill_color("blue");
        }
      else
        {
          //In this case the given color has to be overwritten, because the noe covers an other item.
          *active_item << Gnome::Canvas::Properties::fill_color("lightblue");
        }
      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(g); 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));
              Graph::NodeIt target_node=INVALID;
              for (NodeIt i(g); 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)          
                    {
                      *(nodesmap[target_node]) << Gnome::Canvas::Properties::fill_color("red");

                      //creating new edge
                      active_edge=EdgeIt(g,g.addEdge(active_node, target_node));

                      //initiating values corresponding to new edge in maps
                      mapstorage.initMapsForEdge(active_edge);
          
                      //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, coos, *this);
                      *(edgesmap[active_edge]) << Gnome::Canvas::Properties::fill_color("green");
                      edgesmap[active_edge]->property_width_pixels().set_value(10);

                      //redraw nodes to blank terminations of the new edge
                      target_item->raise_to_top();
                      active_item->raise_to_top();

                      //initializing edge-text as well, to empty string
                      xy<double> text_pos=edgesmap[active_edge]->getArrowPos();
                      text_pos+=(xy<double>(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");

                      //updating its properties
                      mapwin->updateEdge(active_edge);
                    }
                  else
                    {
                      target_node=INVALID;
                      std::cout << "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(g); i!=INVALID; ++i)
        {
          if(nodesmap[i]==active_item)
            {
              active_node=i;
            }
        }
      //or was it an edge?
      if(active_node==INVALID)
        {
          for (EdgeIt i(g); 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)
                {

                  //collecting edges to delete
                  EdgeIt e;
                  std::set<Graph::Edge> edges_to_delete;

                  g.firstOut(e,active_node);
                  for(;e!=INVALID;g.nextOut(e))
                    {
                      edges_to_delete.insert(e);
                    }

                  g.firstIn(e,active_node);
                  for(;e!=INVALID;g.nextIn(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)
{
  switch(e->type)
    {
    case GDK_KEY_PRESS:
      //for Escape or Enter hide the displayed widget
      {
        nodeMapEditEventHandler(e);
        break;
      }
    case GDK_BUTTON_PRESS:
      //If the click happened on an edge we place the entrywidget there and fill in the value of the activated map at that edge.
      {
        //find the activated item
        window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);
        active_item=(get_item_at(clicked_x, clicked_y));

        //determine, whether it was an edge
        Graph::EdgeIt clicked_edge=INVALID;
        for (EdgeIt i(g); i!=INVALID; ++i)
          {
            if(edgesmap[i]==active_item)
              {
                clicked_edge=i;
              }
          }
        //if it was really an edge...
        if(clicked_edge!=INVALID)
          {
            //If there is already edited edge, it has to be saved first
            if(entrywidget.is_visible())
              {
                GdkEvent * generated=new GdkEvent();
                generated->type=GDK_KEY_PRESS;
                ((GdkEventKey*)generated)->keyval=GDK_KP_Enter;
                entryWidgetChangeHandler(generated);
              }
            //If the previous value could be saved, we can go further, otherwise not
            if(!entrywidget.is_visible())
              {
                //and there is activated map
                if(edgetextmap[clicked_edge]->property_text().get_value()!="")
                  {
                    //activate the general variable for it
                    active_edge=clicked_edge;
                    //delete visible widget if there is
                    if(canvasentrywidget)
                      {
                        delete(canvasentrywidget);
                      }

                    //initialize the entry
                    entrywidget.show();

                    //fill in the correct value
                    entrywidget.set_text(edgetextmap[active_edge]->property_text().get_value());

                    //replace and resize the entry to the activated edge and put it in a Canvas::Widget to be able to display it on gdc
                    xy<double> entry_coos;
                    entry_coos.x=(edgetextmap[active_edge])->property_x().get_value();
                    entry_coos.x-=edgetextmap[active_edge]->property_text_width().get_value()/2;
                    entry_coos.y=(edgetextmap[active_edge])->property_y().get_value();
                    entry_coos.y-=edgetextmap[active_edge]->property_text_height().get_value()*1.5/2;
                    canvasentrywidget=new Gnome::Canvas::Widget(displayed_graph, entry_coos.x, entry_coos.y, entrywidget);
                    canvasentrywidget->property_width().set_value(edgetextmap[active_edge]->property_text_width().get_value()*1.5);
                    canvasentrywidget->property_height().set_value(edgetextmap[active_edge]->property_text_height().get_value()*1.5);
                  }
              }
          }
        //if it was not an edge...
        else
          {
            //In this case the click did not happen on an edge
            //if there is visible entry we save the value in it
            //we pretend like an Enter was presse din the Entry widget
            GdkEvent * generated=new GdkEvent();
            generated->type=GDK_KEY_PRESS;
            ((GdkEventKey*)generated)->keyval=GDK_KP_Enter;
            entryWidgetChangeHandler(generated);
          }
        break;
      }
    default:
      break;
    }
  return false;  
}

bool GraphDisplayerCanvas::nodeMapEditEventHandler(GdkEvent* e)
{
  switch(e->type)
    {
    case GDK_KEY_PRESS:
      //for Escape or Enter hide the displayed widget
      {
        switch(((GdkEventKey*)e)->keyval)
          {
          case GDK_Escape:
            entrywidget.hide();
            break;
          case GDK_Return:
          case GDK_KP_Enter:
            entrywidget.hide();
            break;
          default:
            break;
          }
  
        break;
      }
    case GDK_BUTTON_PRESS:
      //If the click happened on an edge we place the entrywidget there and fill in the value of the activated map at that edge.
      {
        //find the activated item
        window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);
        active_item=(get_item_at(clicked_x, clicked_y));

        //determine, whether it was a node
        Graph::NodeIt clicked_node=INVALID;
        for (NodeIt i(g); i!=INVALID; ++i)
          {
            if(nodesmap[i]==active_item)
              {
                clicked_node=i;
              }
          }

        //if it was really an edge...
        if(clicked_node!=INVALID)
          {
            //If there is already edited edge, it has to be saved first
            if(entrywidget.is_visible())
              {
                GdkEvent * generated=new GdkEvent();
                generated->type=GDK_KEY_PRESS;
                ((GdkEventKey*)generated)->keyval=GDK_KP_Enter;
                entryWidgetChangeHandler(generated);
              }
            //If the previous value could be saved, we can go further, otherwise not
            if(!entrywidget.is_visible())
              {
                //and there is activated map
                if(nodetextmap[clicked_node]->property_text().get_value()!="")
                  {
                    //activate the general variable for it
                    active_node=clicked_node;
                    //delete visible widget if there is
                    if(canvasentrywidget)
                      {
                        delete(canvasentrywidget);
                      }

                    //initialize the entry
                    entrywidget.show();

                    //fill in the correct value
                    entrywidget.set_text(nodetextmap[active_node]->property_text().get_value());

                    //replace and resize the entry to the activated node and put it in a Canvas::Widget to be able to display it on gdc
                    xy<double> entry_coos;
                    entry_coos.x=(nodetextmap[active_node])->property_x().get_value();
                    entry_coos.x-=nodetextmap[active_node]->property_text_width().get_value()/2;
                    entry_coos.y=(nodetextmap[active_node])->property_y().get_value();
                    entry_coos.y-=nodetextmap[active_node]->property_text_height().get_value()*1.5/2;
                    canvasentrywidget=new Gnome::Canvas::Widget(displayed_graph, entry_coos.x, entry_coos.y, entrywidget);
                    canvasentrywidget->property_width().set_value(nodetextmap[active_node]->property_text_width().get_value()*1.5);
                    canvasentrywidget->property_height().set_value(nodetextmap[active_node]->property_text_height().get_value()*1.5);
                  }
              }
          }
        //if it was not an edge...
        else
          {
            //In this case the click did not happen on an edge
            //if there is visible entry we save the value in it
            //we pretend like an Enter was presse din the Entry widget
            GdkEvent * generated=new GdkEvent();
            generated->type=GDK_KEY_PRESS;
            ((GdkEventKey*)generated)->keyval=GDK_KP_Enter;
            entryWidgetChangeHandler(generated);
          }
        break;
      }
    default:
      break;
    }
  return false;  
}

bool GraphDisplayerCanvas::entryWidgetChangeHandler(GdkEvent* e)
{
  if(entrywidget.is_visible())
    {
      if(e->type==GDK_KEY_PRESS)
        {
          switch(((GdkEventKey*)e)->keyval)
            {
            case GDK_Escape:
              entrywidget.hide();
              break;
            case GDK_KP_Enter:
            case GDK_Return:
              {
                //these variables check whether the text in the entry is valid
                bool valid_double=true;
                int point_num=0;

                //getting the value from the entry and converting it to double
                Glib::ustring mapvalue_str = entrywidget.get_text();

                char * mapvalue_ch=new char [mapvalue_str.length()];
                for(int i=0;i<(int)(mapvalue_str.length());i++)
                  {
                    if(((mapvalue_str[i]<'0')||(mapvalue_str[i]>'9'))&&(mapvalue_str[i]!='.'))
                      {
                        valid_double=false;
                      }
                    else
                      {
                        if(mapvalue_str[i]=='.')
                          {
                            point_num++;
                          }
                      }
                    mapvalue_ch[i]=mapvalue_str[i];
                  }
              
                //if the text in the entry was correct
                if((point_num<=1)&&(valid_double))
                  {
                    double mapvalue_d=atof(mapvalue_ch);

                    //reconvert the double to string for the correct format
                    std::ostringstream ostr;
                    ostr << mapvalue_d;

                    //save the value to the correct place
                    switch(actual_tool)
                      {
                      case EDGE_MAP_EDIT:
                        edgetextmap[active_edge]->property_text().set_value(ostr.str());
                        (*(mapstorage.edgemap_storage)[edgemap_to_edit])[active_edge]=mapvalue_d;
                        break;
                      case NODE_MAP_EDIT:
                        nodetextmap[active_node]->property_text().set_value(ostr.str());
                        (*(mapstorage.nodemap_storage)[nodemap_to_edit])[active_node]=mapvalue_d;
                        break;
                      default:
                        break;
                      }
                    entrywidget.hide();
                  }
                //the text in the entry was not correct for a double
                else
                  {
                    std::cout << "ERROR: only handling of double values is implemented yet!" << std::endl;
                  }

                break;
              }
            default:
              break;
            }
        }
    }
  return false;
}

void GraphDisplayerCanvas::deleteItem(NodeIt node_to_delete)
{
  delete(nodetextmap[node_to_delete]);
  delete(nodesmap[node_to_delete]);
  g.erase(node_to_delete);
}

void GraphDisplayerCanvas::deleteItem(EdgeIt edge_to_delete)
{
  delete(edgetextmap[edge_to_delete]);
  delete(edgesmap[edge_to_delete]);
  g.erase(edge_to_delete);
}

void GraphDisplayerCanvas::deleteItem(Graph::Edge edge_to_delete)
{
  delete(edgetextmap[edge_to_delete]);
  delete(edgesmap[edge_to_delete]);
  g.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::cout << "ERROR!!!! Valid edge found!" << std::endl;
        }
      else
        {
          for (EdgeIt i(g); i!=INVALID; ++i)
            {
              if(edgesmap[i]==active_bre)
                {
                  forming_edge=i;
                }
            }
        }
    }
  else
    {
      if(forming_edge!=INVALID)
        {
          forming_edge=INVALID;
        }
      else
        {
          std::cout << "ERROR!!!! Invalid edge found!" << std::endl;
        }
    }

}

void GraphDisplayerCanvas::addNewEdgeMap(double default_value, std::string mapname)
{
  //create the new map
  Graph::EdgeMap<double> * emptr=new Graph::EdgeMap<double> (g,default_value);
  mapstorage.addEdgeMap(mapname,emptr);

  //add it to the list of the displayable maps
  mapwin->registerNewEdgeMap(mapname);

  //display it
  changeEdgeText(mapname);
}

void GraphDisplayerCanvas::addNewNodeMap(double default_value, std::string mapname)
{
  //create the new map
  Graph::NodeMap<double> * emptr=new Graph::NodeMap<double> (g,default_value);
  mapstorage.addNodeMap(mapname,emptr);

  //add it to the list of the displayable maps
  mapwin->registerNewNodeMap(mapname);

  //display it
  changeNodeText(mapname);
}