# HG changeset patch
# User ladanyi
# Date 1158138989 0
# Node ID 10ef59f6633cfb28b6e71b4484df19513d84309c
# Parent  afd1d8bfcccde056fcc062a1b406cc9151acf8dc
Loop edges.

diff -r afd1d8bfcccd -r 10ef59f6633c gdc-broken_edge.cc
--- a/gdc-broken_edge.cc	Wed Aug 30 15:55:18 2006 +0000
+++ b/gdc-broken_edge.cc	Wed Sep 13 09:16:29 2006 +0000
@@ -1,133 +1,203 @@
 #include "graph_displayer_canvas.h"
 #include <cmath>
 
-GraphDisplayerCanvas::BrokenEdge::BrokenEdge(Gnome::Canvas::Group & g, Edge _edge, GraphDisplayerCanvas & gc) : Line(g), edge(_edge), gdc(gc), isbutton(false)
+GraphDisplayerCanvas::EdgeBase::EdgeBase(Gnome::Canvas::Group& _group, Edge _edge, GraphDisplayerCanvas& _canvas) : 
+  Gnome::Canvas::Group(_group), edge(_edge), canvas(_canvas), arrow(*this)
 {
-  arrow=new Gnome::Canvas::Polygon(g);
-  *arrow << Gnome::Canvas::Properties::fill_color("red");
-  arrow->signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::BrokenEdge::edgeFormerEventHandler));
-  arrow->lower_to_bottom();
+  arrow.property_fill_color().set_value("red");
+  arrow.lower_to_bottom();
+}
+
+GraphDisplayerCanvas::EdgeBase::~EdgeBase()
+{
+}
+
+void GraphDisplayerCanvas::EdgeBase::drawArrow(XY unit_vector_in_dir)
+{
+  MapStorage& ms = canvas.mytab.mapstorage;
+  XY center(ms.arrow_pos[edge]);
+  XY unit_norm_vector(0-unit_vector_in_dir.y, unit_vector_in_dir.x);
+
+  //       /\       // top
+  //      /  \      //
+  //      -  -      // c(enter)l(eft), ccl, ccr, cr
+  //       ||       //
+  //       ||       // b(ottom)l, br
+
+  double size=3;
+
+  XY bl (center - unit_vector_in_dir * 3 * size + unit_norm_vector * size );
+  XY br (center - unit_vector_in_dir * 3 * size - unit_norm_vector * size );
+  XY ccl(center + unit_vector_in_dir *  size + unit_norm_vector * size );
+  XY ccr(center + unit_vector_in_dir *  size - unit_norm_vector * size );
+  XY cl (center + unit_vector_in_dir *  size + unit_norm_vector * 2 * size );
+  XY cr (center + unit_vector_in_dir *  size - unit_norm_vector * 2 * size );
+  XY top(center + unit_vector_in_dir * 3 * size);
+
+  Gnome::Canvas::Points arrow_points;
+  arrow_points.push_back(Gnome::Art::Point( bl.x , bl.y  ) );
+  arrow_points.push_back(Gnome::Art::Point( br.x , br.y  ) );
+  arrow_points.push_back(Gnome::Art::Point( ccr.x, ccr.y ) );
+  arrow_points.push_back(Gnome::Art::Point( cr.x , cr.y  ) );
+  arrow_points.push_back(Gnome::Art::Point( top.x, top.y ) );
+  arrow_points.push_back(Gnome::Art::Point( cl.x , cl.y  ) );
+  arrow_points.push_back(Gnome::Art::Point( ccl.x, ccl.y ) );
+
+  arrow.property_points().set_value(arrow_points);
+}
+
+GraphDisplayerCanvas::BrokenEdge::BrokenEdge(Gnome::Canvas::Group & g,
+    Edge _edge, GraphDisplayerCanvas & gc) : EdgeBase(g, _edge, gc),
+  isbutton(false), line(*this)
+{
+  arrow.signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::BrokenEdge::edgeFormerEventHandler));
+
+  line.property_fill_color().set_value("green");
+  line.property_width_units().set_value(10);    
+  line.lower_to_bottom();
+
   draw();
 }
 
 GraphDisplayerCanvas::BrokenEdge::~BrokenEdge()
 {
-  if(arrow)delete(arrow);
 }
 
 void GraphDisplayerCanvas::BrokenEdge::draw()
 {
-  MapStorage& ms = gdc.mytab.mapstorage;
+  MapStorage& ms = canvas.mytab.mapstorage;
+
+  //calculating coordinates of the direction indicator arrow
+  XY head(ms.coords[ms.graph.target(edge)]);
+  XY center(ms.arrow_pos[edge]);
+
+  XY unit_vector_in_dir(head-center);
+  double length=sqrt( unit_vector_in_dir.normSquare() );
+
+  unit_vector_in_dir/=length;
+
+  // update the arrow
+  drawArrow(unit_vector_in_dir);
 
   // update the edge
-  {
-    Gnome::Canvas::Points points;
-    Node source = ms.graph.source(edge);
-    Node target = ms.graph.target(edge);
-    points.push_back(Gnome::Art::Point(ms.coords[source].x,
-          ms.coords[source].y));
-    points.push_back(Gnome::Art::Point(ms.arrow_pos[edge].x,
-          ms.arrow_pos[edge].y));
-    points.push_back(Gnome::Art::Point(ms.coords[target].x,
-          ms.coords[target].y));
-    property_points().set_value(points);
-  }
-
-  // update the arrow
-  {
-    //calculating coordinates of the direction indicator arrow
-    XY target(ms.coords[ms.graph.target(edge)]);
-    XY center(ms.arrow_pos[edge]);
-
-    XY unit_vector_in_dir(target-center);
-    double length=sqrt( unit_vector_in_dir.normSquare() );
-
-    //       std::cout << target << " - " << center << " = " << unit_vector_in_dir << "    / " <<unit_vector_in_dir.normSquare() ;
-    unit_vector_in_dir/=length;
-    //       std::cout << " = " << unit_vector_in_dir << std::endl;
-
-    XY unit_norm_vector(0-unit_vector_in_dir.y, unit_vector_in_dir.x);
-    //       std::cout << unit_norm_vector << std::endl;
-
-    {      
-      //       /\       // top
-      //      /  \      //
-      //      -  -      // c(enter)l(eft), ccl, ccr, cr
-      //       ||       //
-      //       ||       // b(ottom)l, br
-    }
-
-    double size=3;
-
-    XY bl (center - unit_vector_in_dir * 3 * size + unit_norm_vector * size );
-    XY br (center - unit_vector_in_dir * 3 * size - unit_norm_vector * size );
-    XY ccl(center + unit_vector_in_dir *  size + unit_norm_vector * size );
-    XY ccr(center + unit_vector_in_dir *  size - unit_norm_vector * size );
-    XY cl (center + unit_vector_in_dir *  size + unit_norm_vector * 2 * size );
-    XY cr (center + unit_vector_in_dir *  size - unit_norm_vector * 2 * size );
-    XY top(center + unit_vector_in_dir * 3 * size);
-
-    //std::cout << bl << " " << br << " " << ccl << " "  << ccr << " " << cl << " " << cr << " " << top << std::endl;
-
-    Gnome::Canvas::Points arrow_points;
-    arrow_points.push_back(Gnome::Art::Point( bl.x , bl.y  ) );
-    arrow_points.push_back(Gnome::Art::Point( br.x , br.y  ) );
-    arrow_points.push_back(Gnome::Art::Point( ccr.x, ccr.y ) );
-    arrow_points.push_back(Gnome::Art::Point( cr.x , cr.y  ) );
-    arrow_points.push_back(Gnome::Art::Point( top.x, top.y ) );
-    arrow_points.push_back(Gnome::Art::Point( cl.x , cl.y  ) );
-    arrow_points.push_back(Gnome::Art::Point( ccl.x, ccl.y ) );
-
-    arrow->property_points().set_value(arrow_points);
-  }
+  Gnome::Canvas::Points points;
+  Node source = ms.graph.source(edge);
+  Node target = ms.graph.target(edge);
+  points.push_back(Gnome::Art::Point(ms.coords[source].x,
+        ms.coords[source].y));
+  points.push_back(Gnome::Art::Point(ms.arrow_pos[edge].x,
+        ms.arrow_pos[edge].y));
+  points.push_back(Gnome::Art::Point(ms.coords[target].x,
+        ms.coords[target].y));
+  line.property_points().set_value(points);
 }
 
 bool GraphDisplayerCanvas::BrokenEdge::edgeFormerEventHandler(GdkEvent* e)
 {
   switch(e->type)
-    {
+  {
     case GDK_BUTTON_PRESS:
-      //we mark the location of the event to be able to calculate parameters of dragging
-      if(gdc.getActualTool()!=CREATE_NODE)
-	{
-	  gdc.toggleEdgeActivity(this, true);
-	  clicked_x=e->button.x;
-	  clicked_y=e->button.y;
-	  isbutton=true;
-	}
+      //we mark the location of the event to be able to calculate parameters
+      //of dragging
+      if(canvas.getActualTool()!=CREATE_NODE)
+      {
+        canvas.toggleEdgeActivity(this, true);
+        clicked_x=e->button.x;
+        clicked_y=e->button.y;
+        isbutton=true;
+      }
       break;
     case GDK_BUTTON_RELEASE:
-      if(gdc.getActualTool()!=CREATE_NODE)
-	{
-	  gdc.toggleEdgeActivity(this, false);
-	  isbutton=false;
-	}
+      if(canvas.getActualTool()!=CREATE_NODE)
+      {
+        canvas.toggleEdgeActivity(this, false);
+        isbutton=false;
+      }
       break;
     case GDK_MOTION_NOTIFY:
       //we only have to do sg. if the mouse button is pressed
       if(isbutton)
-	{
-	  //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
+      {
+        //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 dx=e->motion.x-clicked_x;
-	  double dy=e->motion.y-clicked_y;
+        double dx=e->motion.x-clicked_x;
+        double dy=e->motion.y-clicked_y;
 
-	  Gnome::Canvas::Points points_new;
+        Gnome::Canvas::Points points_new;
 
-          gdc.mytab.mapstorage.arrow_pos.set(edge, gdc.mytab.mapstorage.arrow_pos[edge] + XY(dx, dy));
+        canvas.mytab.mapstorage.arrow_pos.set(edge, canvas.mytab.mapstorage.arrow_pos[edge] + XY(dx, dy));
 
-	  draw();
-	  gdc.textReposition(gdc.mytab.mapstorage.arrow_pos[edge]);
+        draw();
+        canvas.textReposition(canvas.mytab.mapstorage.arrow_pos[edge]);
 
-	  clicked_x=e->motion.x;
-	  clicked_y=e->motion.y;
+        clicked_x=e->motion.x;
+        clicked_y=e->motion.y;
 
-	}
+      }
     default: break;
-    }
+  }
 
   return true;
 }
+
+void GraphDisplayerCanvas::BrokenEdge::setLineWidth(int w)
+{
+  line.property_width_units().set_value(w);
+}
+
+void GraphDisplayerCanvas::BrokenEdge::setFillColor(Gdk::Color c)
+{
+  line.property_fill_color_gdk().set_value(c);
+}
+
+GraphDisplayerCanvas::LoopEdge::LoopEdge(Gnome::Canvas::Group& _group,
+    Edge _edge, GraphDisplayerCanvas& _canvas) :
+  EdgeBase(_group, _edge, _canvas), line(*this)
+{
+  line.property_fill_color().set_value("green");
+  line.property_width_units().set_value(10);    
+  line.lower_to_bottom();
+
+  draw();
+}
+
+GraphDisplayerCanvas::LoopEdge::~LoopEdge()
+{
+}
+
+void GraphDisplayerCanvas::LoopEdge::draw()
+{
+  MapStorage& ms = canvas.mytab.mapstorage;
+
+  Node node = ms.graph.source(edge);
+  XY center = (ms.coords[node] + ms.arrow_pos[edge]) / 2.0;
+
+  XY unit_vector_in_dir(rot90(center - ms.arrow_pos[edge]));
+  double length = sqrt(unit_vector_in_dir.normSquare());
+  unit_vector_in_dir /= length;
+
+  drawArrow(unit_vector_in_dir);
+
+  double radius =
+    sqrt((ms.arrow_pos[edge] - ms.coords[node]).normSquare()) / 2.0;
+
+  XY p1 = center + XY(-radius,  radius);
+  XY p2 = center + XY( radius, -radius);
+  line.property_x1().set_value(p1.x);
+  line.property_y1().set_value(p1.y);
+  line.property_x2().set_value(p2.x);
+  line.property_y2().set_value(p2.y);
+}
+
+void GraphDisplayerCanvas::LoopEdge::setLineWidth(int w)
+{
+  line.property_width_units().set_value(w);
+}
+
+void GraphDisplayerCanvas::LoopEdge::setFillColor(Gdk::Color c)
+{
+  line.property_fill_color_gdk().set_value(c);
+}
diff -r afd1d8bfcccd -r 10ef59f6633c graph_displayer_canvas-edge.cc
--- a/graph_displayer_canvas-edge.cc	Wed Aug 30 15:55:18 2006 +0000
+++ b/graph_displayer_canvas-edge.cc	Wed Sep 13 09:16:29 2006 +0000
@@ -24,7 +24,7 @@
 	    {
 	      w=(int)(MIN_EDGE_WIDTH+(v-min)/(max-min)*(MAX_EDGE_WIDTH-MIN_EDGE_WIDTH));
 	    }
-	  edgesmap[i]->property_width_units().set_value(w);
+	  edgesmap[i]->setLineWidth(w);
 	}
     }
   else
@@ -32,7 +32,7 @@
       int w=(int)actual_map[edge];
       if(w>=0)
 	{
-	  edgesmap[edge]->property_width_units().set_value(w);
+	  edgesmap[edge]->setLineWidth(w);
 	}
     }
   return 0;
@@ -62,7 +62,7 @@
 	    {
 	      w=(int)(MIN_EDGE_WIDTH+(v-min)/(max-min)*(MAX_EDGE_WIDTH-MIN_EDGE_WIDTH));
 	    }
-	  edgesmap[i]->property_width_units().set_value(w);
+	  edgesmap[i]->setLineWidth(w);
 	}
     }
   else
@@ -70,7 +70,7 @@
       int w=(int)(*actual_map)[edge];
       if(w>=0)
 	{
-	  edgesmap[edge]->property_width_units().set_value(w);
+	  edgesmap[edge]->setLineWidth(w);
 	}
     }
   return 0;
@@ -105,7 +105,7 @@
 	    {
 	      color.set_rgb_p (0, 100, 0);
 	    }
-	  edgesmap[i]->property_fill_color_gdk().set_value(color);
+	  edgesmap[i]->setFillColor(color);
 	}
     }
   else
@@ -123,7 +123,7 @@
 	  color.set_rgb_p (0, 100, 0);
 	}
 
-      edgesmap[edge]->property_fill_color_gdk().set_value(color);
+      edgesmap[edge]->setFillColor(color);
     }
   return 0;
 };
@@ -156,7 +156,7 @@
 	    {
 	      color.set_rgb_p (0, 100, 0);
 	    }
-	  edgesmap[i]->property_fill_color_gdk().set_value(color);
+	  edgesmap[i]->setFillColor(color);
 	}
     }
   else
@@ -174,7 +174,7 @@
 	  color.set_rgb_p (0, 100, 0);
 	}
 
-      edgesmap[edge]->property_fill_color_gdk().set_value(color);
+      edgesmap[edge]->setFillColor(color);
     }
   return 0;
 };
diff -r afd1d8bfcccd -r 10ef59f6633c graph_displayer_canvas-event.cc
--- a/graph_displayer_canvas-event.cc	Wed Aug 30 15:55:18 2006 +0000
+++ b/graph_displayer_canvas-event.cc	Wed Sep 13 09:16:29 2006 +0000
@@ -462,11 +462,6 @@
               //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];
@@ -829,34 +824,34 @@
   edgetextmap[forming_edge]->property_y().set_value(new_place.y);
 }
 
-void GraphDisplayerCanvas::toggleEdgeActivity(BrokenEdge* active_bre, bool on)
+void GraphDisplayerCanvas::toggleEdgeActivity(EdgeBase* active_bre, bool on)
 {
   if(on)
+  {
+    if(forming_edge!=INVALID)
     {
-      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;
-		}
-	    }
-	}
+      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)
     {
-      if(forming_edge!=INVALID)
-	{
-	  forming_edge=INVALID;
-	}
-      else
-	{
-	  std::cerr << "ERROR!!!! Invalid edge found!" << std::endl;
-	}
+      forming_edge=INVALID;
     }
+    else
+    {
+      std::cerr << "ERROR!!!! Invalid edge found!" << std::endl;
+    }
+  }
 }
diff -r afd1d8bfcccd -r 10ef59f6633c graph_displayer_canvas.cc
--- a/graph_displayer_canvas.cc	Wed Aug 30 15:55:18 2006 +0000
+++ b/graph_displayer_canvas.cc	Wed Sep 13 09:16:29 2006 +0000
@@ -169,9 +169,6 @@
           (mytab.mapstorage).coords[(mytab.mapstorage).graph.target(i)].y));
     
     edgesmap[i]=new BrokenEdge(displayed_graph, i, *this);
-    *(edgesmap[i]) << Gnome::Canvas::Properties::fill_color("green");
-    edgesmap[i]->property_width_units().set_value(10);    
-    edgesmap[i]->lower_to_bottom();
     
     //initializing edge-text as well, to empty string
 
diff -r afd1d8bfcccd -r 10ef59f6633c graph_displayer_canvas.h
--- a/graph_displayer_canvas.h	Wed Aug 30 15:55:18 2006 +0000
+++ b/graph_displayer_canvas.h	Wed Sep 13 09:16:29 2006 +0000
@@ -15,6 +15,35 @@
 class GraphDisplayerCanvas : public Gnome::Canvas::CanvasAA
 {
   friend class BrokenEdge;
+  friend class LoopEdge;
+
+  class EdgeBase : public Gnome::Canvas::Group
+  {
+    protected:
+      ///Reference to the canvas, on which the graph is drawn.
+
+      ///It is needed, because some datas needed from
+      ///graph can be accessed by this or should be sent
+      ///as parameter, but it would be complicated
+      GraphDisplayerCanvas& canvas;
+
+      ///The edge that the class displays.
+
+      ///It is needed, because some datas needed from
+      ///graph can be accessed by this or should be sent
+      ///as parameter, but it would be complicated
+      Edge edge;
+
+      Gnome::Canvas::Polygon arrow;
+
+      void drawArrow(XY);
+    public:
+      EdgeBase(Gnome::Canvas::Group&, Edge, GraphDisplayerCanvas&);
+      virtual ~EdgeBase();
+      virtual void draw() = 0;
+      virtual void setLineWidth(int) = 0;
+      virtual void setFillColor(Gdk::Color) = 0;
+  };
 
   ///Edge displayer class
 
@@ -23,65 +52,63 @@
   ///aim of this is to be able to indicate direction of edges
   ///and to be able to display more then one edges between the
   ///same source and target
-  class BrokenEdge : public Gnome::Canvas::Line
+  class BrokenEdge : public EdgeBase
   {
-    ///The edge that the class displays.
+    private:
+      Gnome::Canvas::Line line;
 
-    ///It is needed, because some datas needed from
-    ///graph can be accessed by this or should be sent
-    ///as parameter, but it would be complicated
-    Edge edge;
+      ///Indicates whether the button of mouse is pressed or not at the moment.
+      bool isbutton;
 
-    ///Reference to the canvas, on which the graph is drawn.
+      ///At this location was the mousebutton pressed. Horizontal component.
 
-    ///It is needed, because some datas needed from
-    ///graph can be accessed by this or should be sent
-    ///as parameter, but it would be complicated
-    GraphDisplayerCanvas & gdc;
+      ///It helps to calculate the
+      ///distance of dragging.
+      double clicked_x;
 
-    ///An arrow that indicates the direction of the edges
+      ///At this location was the mousebutton pressed. Vertical component.
 
-    ///in case of directional graph direction can be indicated
-    ///by this polygon. The polygon formulates a red arrow.
-    Gnome::Canvas::Polygon * arrow;
+      ///It helps to calculate the
+      ///distance of dragging.
+      double clicked_y;
 
-    ///Indicates whether the button of mouse is pressed or not at the moment.
-    bool isbutton;
+      ///event handler for forming broken edges
 
-    ///At this location was the mousebutton pressed. Horizontal component.
+      ///\param event the
+      ///event to handle
+      bool edgeFormerEventHandler(GdkEvent* event);
 
-    ///It helps to calculate the
-    ///distance of dragging.
-    double clicked_x;
+    public:
+      ///Constructor of broken edge class.
 
-    ///At this location was the mousebutton pressed. Vertical component.
+      ///\param g the group to which the edge belongs
+      ///\param _edge the represented edge
+      ///\param gc the canvas
+      BrokenEdge(Gnome::Canvas::Group&, Edge, GraphDisplayerCanvas&);
 
-    ///It helps to calculate the
-    ///distance of dragging.
-    double clicked_y;
+      ///Destructor of broken edge class
 
-    ///event handler for forming broken edges
+      ///Frees up
+      ///reserved memory
+      ~BrokenEdge();
 
-    ///\param event the
-    ///event to handle
-    bool edgeFormerEventHandler(GdkEvent* event);
-  public:
+      ///The function that draws the edge based on collected data
+      void draw();
 
-    ///Constructor of broken edge class.
+      void setLineWidth(int);
+      void setFillColor(Gdk::Color);
+  };
 
-    ///\param g the group to which the edge belongs
-    ///\param _edge the represented edge
-    ///\param gc the canvas
-    BrokenEdge(Gnome::Canvas::Group & g, Edge _edge, GraphDisplayerCanvas & gc);
-
-    ///Destructor of broken edge class
-
-    ///Frees up
-    ///reserved memory
-    ~BrokenEdge();
-
-    ///The function that draws the edge based on collected data
-    void draw();
+  class LoopEdge : public EdgeBase
+  {
+    private:
+      Gnome::Canvas::Ellipse line;
+    public:
+      LoopEdge(Gnome::Canvas::Group&, Edge, GraphDisplayerCanvas&);
+      ~LoopEdge();
+      void draw();
+      void setLineWidth(int);
+      void setFillColor(Gdk::Color);
   };
 
   ///Type of canvas, on which the graph is drawn
@@ -241,14 +268,14 @@
   ///Moves the text to new place
   void textReposition(xy<double>);
 
-  ///Activates an edge belonging to a BrokenEdge
+  ///Activates an edge belonging to an EdgeBase
 
   ///After we have activated an edge this way,
   ///the GDC object will know, which edge is under forming
   ///therefore it can redraw the necessary elements on the canvas,
-  ///for example the text belonging to the \ref BrokenEdge can be
+  ///for example the text belonging to the \ref EdgeBase can be
   ///redrawn (\ref textReposition).
-  void toggleEdgeActivity(BrokenEdge*, bool);
+  void toggleEdgeActivity(EdgeBase*, bool);
 
 public:
 
@@ -289,7 +316,7 @@
   Graph::NodeMap<Gnome::Canvas::Ellipse *> nodesmap;
 
   ///Map of edges of graph
-  Graph::EdgeMap<BrokenEdge *> edgesmap;
+  Graph::EdgeMap<EdgeBase*> edgesmap;
 
   ///Map of texts to write on edges
   Graph::EdgeMap<Gnome::Canvas::Text *> edgetextmap;