graph_displayer_canvas.cc
author hegyi
Thu, 23 Jun 2005 17:56:24 +0000
branchgui
changeset 26 b0c76a4d5801
parent 25 c45a34eaa118
child 27 e2c86ae158cf
permissions -rwxr-xr-x
A bug, explored by Alpar is corrected, but with value-checking, and not with correct values. (There is some problem with map values of new items! Maybe refreshemnt is the responsible thing?)
     1 #include <graph_displayer_canvas.h>
     2 #include <broken_edge.h>
     3 #include <math.h>
     4 
     5 GraphDisplayerCanvas::GraphDisplayerCanvas(Graph & gr, CoordinatesMap & cm, MapStorage & ms):g(gr),nodesmap(g),edgesmap(g),edgetextmap(g),displayed_graph(*(root()), 0, 0),mapstorage(ms),isbutton(0),active_item(NULL),target_item(NULL)
     6 {
     7   
     8   actual_handler=signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::create_node_event_handler), false);
     9   actual_tool=CREATE_NODE;
    10 
    11   active_node=INVALID;
    12   active_edge=INVALID;
    13 
    14   //set_center_scroll_region(true);
    15 
    16   //first edges are drawn, to hide joining with nodes later
    17 
    18   for (EdgeIt i(g); i!=INVALID; ++i)
    19   {
    20 
    21     //drawing green lines, coordinates are from cm
    22 
    23     Gnome::Canvas::Points coos;
    24     coos.push_back(Gnome::Art::Point(cm[g.source(i)].x,cm[g.source(i)].y));
    25     coos.push_back(Gnome::Art::Point(cm[g.target(i)].x,cm[g.target(i)].y));
    26     
    27     edgesmap[i]=new BrokenEdge(displayed_graph, coos, *this);
    28     *(edgesmap[i]) << Gnome::Canvas::Properties::fill_color("green");
    29     edgesmap[i]->property_width_pixels().set_value(10);    
    30     
    31     //initializing edge-text as well, to empty string
    32 
    33     xy<double> text_pos=edgesmap[i]->get_arrow_pos();
    34     text_pos+=(xy<double>(10,10));
    35 
    36     edgetextmap[i]=new Gnome::Canvas::Text(displayed_graph, text_pos.x, text_pos.y, "");
    37     edgetextmap[i]->property_fill_color().set_value("black");
    38   }
    39 
    40   //afterwards nodes come to be drawn
    41 
    42   NodeIt i(g);
    43   int maxx=0, maxy=0, minx=(int)cm[i].x, miny=(int)cm[i].y;
    44 
    45   for (; i!=INVALID; ++i)
    46   {
    47     //minimum and maximum is gathered to be able to zoom to the graph correctly (whole figure should be seen)
    48 
    49     if(cm[i].x>maxx)maxx=(int)cm[i].x;
    50     if(cm[i].y>maxy)maxy=(int)cm[i].y;
    51     if(cm[i].x<minx)minx=(int)cm[i].x;
    52     if(cm[i].y<miny)miny=(int)cm[i].y;
    53 
    54     //drawing bule nodes, with black line around them
    55 
    56     nodesmap[i]=new Gnome::Canvas::Ellipse(displayed_graph, cm[i].x-20, cm[i].y-20, cm[i].x+20, cm[i].y+20);
    57     *(nodesmap[i]) << Gnome::Canvas::Properties::fill_color("blue");
    58     *(nodesmap[i]) << Gnome::Canvas::Properties::outline_color("black");
    59     //!!!!!!! (nodesmap[i])->signal_event().connect(sigc::bind(sigc::mem_fun(*this, &GraphDisplayerCanvas::event_handler),i));
    60   }
    61 
    62   updateScrollRegion();
    63 }
    64 
    65 GraphDisplayerCanvas::~GraphDisplayerCanvas()
    66 {
    67 
    68   //writing out the end state of the graph
    69   //\todo all the maps has to be write out!
    70 
    71   Graph::NodeMap <int> id(g);
    72   Graph::NodeMap <double> xc(g);
    73   Graph::NodeMap <double> yc(g);
    74   
    75   int j=1;
    76   
    77   for (NodeIt i(g); i!=INVALID; ++i)
    78   {
    79     double x1,y1,x2,y2;
    80     nodesmap[i]->get_bounds(x1, y1, x2, y2);
    81     
    82     id[i]=j++;
    83     xc[i]=(x1+x2)/2;
    84     yc[i]=(y1+y2)/2;
    85   }
    86 
    87   GraphWriter<Graph> writer(std::cout,g);
    88   
    89   writer.writeNodeMap("id", id);
    90   writer.writeNodeMap("coordinates_x", xc);
    91   writer.writeNodeMap("coordinates_y", yc);
    92   writer.run();
    93 }
    94 
    95 int GraphDisplayerCanvas::changeLineWidth (std::string mapname)
    96 {
    97   for (EdgeIt i(g); i!=INVALID; ++i)
    98     {
    99       int w=(int)(*(mapstorage.edgemap_storage)[mapname])[i];
   100       if(w>=0)
   101 	{
   102 	  edgesmap[i]->property_width_pixels().set_value(w);
   103 	}
   104     }
   105   return 0;
   106 };
   107 
   108 int GraphDisplayerCanvas::changeColor (std::string mapname)
   109 {  
   110 
   111   //function maps the range of the maximum and
   112   //the minimum of the nodemap to the range of
   113   //green in RGB
   114 
   115   for (EdgeIt i(g); i!=INVALID; ++i)
   116   {
   117     double w=(*(mapstorage.edgemap_storage)[mapname])[i];
   118     double max=mapstorage.maxOfEdgeMap(mapname);
   119     double min=mapstorage.minOfEdgeMap(mapname);
   120       
   121     //std::cout<<w<<" "<<max<<" "<<min<<" "<<100*(w-min)/(max-min)<<std::endl;
   122     Gdk::Color color;
   123     if(max!=min)
   124     {
   125       color.set_rgb_p (0, 100*(w-min)/(max-min), 0);
   126     }
   127     else
   128     {
   129       color.set_rgb_p (0, 100, 0);
   130     }
   131 
   132     edgesmap[i]->property_fill_color_gdk().set_value(color);
   133   }
   134   return 0;
   135 };
   136 
   137 int GraphDisplayerCanvas::changeText (std::string mapname)
   138 {
   139 
   140   //the number in the map will be written on the edge
   141   //EXCEPT when the name of the map is Text, because
   142   //in that case empty string will be written, because
   143   //that is the deleter map
   144   //\todo isn't it a bit woodcutter?
   145 
   146   for (EdgeIt i(g); i!=INVALID; ++i)
   147     {
   148       if(mapname!="Text")
   149 	{
   150 	  double number=(*(mapstorage.edgemap_storage)[mapname])[i];
   151 	  int length=1;
   152 	  //if number is smaller than one, length would be negative, or invalid
   153 	  if(number>=1)
   154 	    {
   155 	      length=(int)(floor(log(number)/log(10)))+1;
   156 	    }
   157 	  int maxpos=(int)(pow(10,length-1));
   158 	  int strl=length+1+RANGE;
   159 	  char * str=new char[strl];
   160 	  str[length]='.';
   161 	  str[strl]='\0';
   162       
   163 	  for(int j=0;j<strl;j++)
   164 	    {
   165 	      if(j!=length)
   166 		{
   167 		  int digit=(int)(number/maxpos);
   168 		  str[j]=(digit+'0');
   169 		  number-=digit*maxpos;
   170 		  number*=10;
   171 		}
   172 	    }
   173       
   174 	  edgetextmap[i]->property_text().set_value(str);
   175 	}
   176       else
   177 	{
   178 	  edgetextmap[i]->property_text().set_value("");
   179 	}
   180     }
   181   return 0;
   182 };
   183 
   184 //Deprecated
   185 bool GraphDisplayerCanvas::event_handler(GdkEvent* e, Node n)
   186 {
   187   switch(e->type)
   188   {
   189     case GDK_BUTTON_PRESS:
   190       //we mark the location of the event to be able to calculate parameters of dragging
   191       clicked_x=e->button.x;
   192       clicked_y=e->button.y;
   193       active_item=(get_item_at(e->button.x, e->button.y));
   194       isbutton=1;
   195       break;
   196     case GDK_BUTTON_RELEASE:
   197       isbutton=0;
   198       active_item=NULL;
   199       updateScrollRegion();
   200       break;
   201     case GDK_MOTION_NOTIFY:
   202       //we only have to do sg. if the mouse button is pressed
   203       if(isbutton)
   204       {
   205 	//new coordinates will be the old values,
   206 	//because the item will be moved to the
   207 	//new coordinate therefore the new movement
   208 	//has to be calculated from here
   209 
   210         double dx=e->motion.x-clicked_x;
   211         double dy=e->motion.y-clicked_y;
   212         active_item->move(dx, dy);
   213         clicked_x=e->motion.x;
   214         clicked_y=e->motion.y;
   215 
   216 	//all the edges connected to the moved point has to be redrawn
   217 
   218         EdgeIt e;
   219         g.firstOut(e,n);
   220         for(;e!=INVALID;g.nextOut(e))
   221         {
   222             Gnome::Canvas::Points coos;
   223             double x1, x2, y1, y2;
   224 
   225             nodesmap[g.source(e)]->get_bounds(x1, y1, x2, y2);
   226             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   227 
   228             nodesmap[g.target(e)]->get_bounds(x1, y1, x2, y2);
   229             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   230 
   231             edgesmap[e]->property_points().set_value(coos);
   232 
   233 	    edgesmap[e]->get_bounds(x1, y1, x2, y2);
   234 
   235 	    edgetextmap[e]->property_x().set_value((x1+x2)/2);
   236 	    edgetextmap[e]->property_y().set_value((y1+y2)/2);
   237         }
   238 
   239         g.firstIn(e,n);
   240         for(;e!=INVALID;g.nextIn(e))
   241         {
   242             Gnome::Canvas::Points coos;
   243             double x1, x2, y1, y2;
   244 
   245             nodesmap[g.source(e)]->get_bounds(x1, y1, x2, y2);
   246             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   247 
   248             nodesmap[g.target(e)]->get_bounds(x1, y1, x2, y2);
   249             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   250 
   251             edgesmap[e]->property_points().set_value(coos);
   252 
   253 	    edgesmap[e]->get_bounds(x1, y1, x2, y2);
   254 
   255 	    edgetextmap[e]->property_x().set_value((x1+x2)/2);
   256 	    edgetextmap[e]->property_y().set_value((y1+y2)/2);
   257         }
   258       }
   259     default: break;
   260   }
   261   return true;
   262 }
   263 
   264 bool GraphDisplayerCanvas::on_expose_event(GdkEventExpose *event)
   265 {
   266   Gnome::Canvas::CanvasAA::on_expose_event(event);
   267   //usleep(10000);
   268   //rezoom();
   269   return true;
   270 }
   271 
   272 void GraphDisplayerCanvas::zoomIn()
   273 {
   274   set_pixels_per_unit(
   275       (1.0 + (double) zoom_step / 100.0) * get_pixels_per_unit());
   276 }
   277 
   278 void GraphDisplayerCanvas::zoomOut()
   279 {
   280   set_pixels_per_unit(
   281       (1.0 - (double) zoom_step / 100.0) * get_pixels_per_unit());
   282 }
   283 
   284 void GraphDisplayerCanvas::zoomFit()
   285 {
   286   // get the height and width of the canvas
   287   Gtk::Allocation a = get_allocation();
   288   int aw = a.get_width();
   289   int ah = a.get_height();
   290   // add some space
   291   aw -= 5; if (aw < 0) aw = 0;
   292   ah -= 5; if (ah < 0) ah = 0;
   293 
   294   // get the bounding box of the graph
   295   double wx1, wy1, wx2, wy2;
   296   Gnome::Canvas::Item* pCanvasItem = root();
   297   pCanvasItem->get_bounds(wx1, wy1, wx2, wy2);
   298 
   299   // fit the graph to the window
   300   double ppu1 = (double) aw / fabs(wx2 - wx1);
   301   double ppu2 = (double) ah / fabs(wy2 - wy1);
   302   set_pixels_per_unit((ppu1 < ppu2) ? ppu1 : ppu2);
   303 }
   304 
   305 void GraphDisplayerCanvas::zoom100()
   306 {
   307   set_pixels_per_unit(1.0);
   308 }
   309 
   310 void GraphDisplayerCanvas::updateScrollRegion()
   311 {
   312   double wx1, wy1, wx2, wy2;
   313   Gnome::Canvas::Item* pCanvasItem = root();
   314   pCanvasItem->get_bounds(wx1, wy1, wx2, wy2);
   315   set_scroll_region(wx1, wy1, wx2, wy2);
   316 }
   317 
   318 void GraphDisplayerCanvas::changeEditorialTool(int newtool)
   319 {
   320   actual_handler.disconnect();
   321 
   322   if(actual_tool==CREATE_EDGE)
   323     {
   324 	GdkEvent * generated=new GdkEvent();
   325 	generated->type=GDK_BUTTON_RELEASE;
   326 	generated->button.button=3;
   327 	create_edge_event_handler(generated);      
   328     }
   329 
   330   actual_tool=newtool;
   331 
   332   switch(newtool)
   333     {
   334     case MOVE:
   335       actual_handler=displayed_graph.signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::move_event_handler), false);
   336       break;
   337 
   338       //it has to assigned to canvas, because all the canvas has to be monitored, not only the elements of the already drawn group
   339     case CREATE_NODE:
   340       actual_handler=signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::create_node_event_handler), false);
   341       break;
   342 
   343     case CREATE_EDGE:
   344       actual_handler=displayed_graph.signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::create_edge_event_handler), false);
   345       break;
   346 
   347     case ERASER:
   348       actual_handler=displayed_graph.signal_event().connect(sigc::mem_fun(*this, &GraphDisplayerCanvas::eraser_event_handler), false);
   349       break;
   350 
   351     default:
   352       break;
   353     }
   354 }
   355 
   356 int GraphDisplayerCanvas::get_actual_tool()
   357 {
   358   return actual_tool;
   359 }
   360 
   361 bool GraphDisplayerCanvas::move_event_handler(GdkEvent* e)
   362 {
   363   switch(e->type)
   364   {
   365     case GDK_BUTTON_PRESS:
   366       //we mark the location of the event to be able to calculate parameters of dragging
   367       clicked_x=e->button.x;
   368       clicked_y=e->button.y;
   369       active_item=(get_item_at(e->button.x, e->button.y));
   370       active_node=INVALID;
   371       for (NodeIt i(g); i!=INVALID; ++i)
   372 	{
   373 	  if(nodesmap[i]==active_item)
   374 	    {
   375 	      active_node=i;
   376 	    }
   377 	}
   378       switch(e->button.button)
   379 	{
   380 	case 3:      
   381 	  isbutton=3;
   382 	  break;
   383 	default:
   384 	  isbutton=1;
   385 	  break;
   386 	}
   387       break;
   388     case GDK_BUTTON_RELEASE:
   389       isbutton=0;
   390       active_item=NULL;
   391       active_node=INVALID;
   392       updateScrollRegion();
   393       break;
   394     case GDK_MOTION_NOTIFY:
   395       //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
   396       if(active_node!=INVALID)
   397       {
   398 	//new coordinates will be the old values,
   399 	//because the item will be moved to the
   400 	//new coordinate therefore the new movement
   401 	//has to be calculated from here
   402 
   403         double dx=e->motion.x-clicked_x;
   404         double dy=e->motion.y-clicked_y;
   405 
   406         active_item->move(dx, dy);
   407 
   408         clicked_x=e->motion.x;
   409         clicked_y=e->motion.y;
   410 
   411 	//all the edges connected to the moved point has to be redrawn
   412         EdgeIt ei;
   413 
   414         g.firstOut(ei,active_node);
   415 
   416         for(;ei!=INVALID;g.nextOut(ei))
   417         {
   418             Gnome::Canvas::Points coos;
   419             double x1, x2, y1, y2;
   420 
   421             nodesmap[g.source(ei)]->get_bounds(x1, y1, x2, y2);
   422             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   423 
   424             nodesmap[g.target(ei)]->get_bounds(x1, y1, x2, y2);
   425             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   426 
   427 	    if(isbutton==3)
   428 	      {
   429 		edgesmap[ei]->set_points(coos);
   430 	      }
   431 	    else
   432 	      {
   433 		edgesmap[ei]->set_points(coos,true);
   434 	      }
   435 
   436 	    xy<double> text_pos=edgesmap[ei]->get_arrow_pos();
   437 	    text_pos+=(xy<double>(10,10));
   438 	    edgetextmap[ei]->property_x().set_value(text_pos.x);
   439 	    edgetextmap[ei]->property_y().set_value(text_pos.y);
   440         }
   441 
   442         g.firstIn(ei,active_node);
   443         for(;ei!=INVALID;g.nextIn(ei))
   444         {
   445             Gnome::Canvas::Points coos;
   446             double x1, x2, y1, y2;
   447 
   448             nodesmap[g.source(ei)]->get_bounds(x1, y1, x2, y2);
   449             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   450 
   451             nodesmap[g.target(ei)]->get_bounds(x1, y1, x2, y2);
   452             coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   453 
   454 	    if(isbutton==3)
   455 	      {
   456 		edgesmap[ei]->set_points(coos);
   457 	      }
   458 	    else
   459 	      {
   460 		edgesmap[ei]->set_points(coos,true);
   461 	      }
   462 
   463 	    xy<double> text_pos=edgesmap[ei]->get_arrow_pos();
   464 	    text_pos+=(xy<double>(10,10));
   465 	    edgetextmap[ei]->property_x().set_value(text_pos.x);
   466 	    edgetextmap[ei]->property_y().set_value(text_pos.y);
   467         }
   468       }
   469     default: break;
   470   }
   471 
   472   return true;
   473 }
   474 
   475 bool GraphDisplayerCanvas::create_node_event_handler(GdkEvent* e)
   476 {
   477   switch(e->type)
   478     {
   479 
   480       //draw the new node in red at the clicked place
   481     case GDK_BUTTON_PRESS:
   482       isbutton=1;
   483 
   484       active_node=NodeIt(g,g.addNode());
   485 
   486       //initiating values corresponding to new node in maps
   487       
   488 
   489       window_to_world (e->button.x, e->button.y, clicked_x, clicked_y);
   490 
   491       nodesmap[active_node]=new Gnome::Canvas::Ellipse(displayed_graph, clicked_x-20, clicked_y-20, clicked_x+20, clicked_y+20);
   492       active_item=(Gnome::Canvas::Item *)(nodesmap[active_node]);
   493       *(nodesmap[active_node]) << Gnome::Canvas::Properties::fill_color("red");
   494       *(nodesmap[active_node]) << Gnome::Canvas::Properties::outline_color("black");
   495       (nodesmap[active_node])->show();
   496       break;
   497 
   498       //move the new node
   499     case GDK_MOTION_NOTIFY:
   500       {
   501 	double world_motion_x, world_motion_y;
   502 	GdkEvent * generated=new GdkEvent();
   503 	window_to_world (e->motion.x, e->motion.y, world_motion_x, world_motion_y);
   504 	generated->motion.x=world_motion_x;
   505 	generated->motion.y=world_motion_y;
   506 	generated->type=GDK_MOTION_NOTIFY;
   507 	move_event_handler(generated);      
   508 	break;
   509       }
   510 
   511       //finalize the new node
   512     case GDK_BUTTON_RELEASE:
   513       isbutton=0;
   514       *active_item << Gnome::Canvas::Properties::fill_color("blue");
   515       active_item=NULL;
   516       active_node=INVALID;
   517       updateScrollRegion();
   518       break;
   519     default:
   520       break;
   521     }
   522   return false;
   523 }
   524 
   525 bool GraphDisplayerCanvas::create_edge_event_handler(GdkEvent* e)
   526 {
   527   switch(e->type)
   528     {
   529     case GDK_BUTTON_PRESS:
   530       //in edge creation right button has special meaning
   531       if(e->button.button!=3)
   532 	{
   533 	  //there is not yet selected node
   534 	  if(active_node==INVALID)
   535 	    {
   536 	      //we mark the location of the event to be able to calculate parameters of dragging
   537 	      clicked_x=e->button.x;
   538 	      clicked_y=e->button.y;
   539 	      active_item=(get_item_at(e->button.x, e->button.y));
   540 	      active_node=INVALID;
   541 	      for (NodeIt i(g); i!=INVALID; ++i)
   542 		{
   543 		  if(nodesmap[i]==active_item)
   544 		    {
   545 		      active_node=i;
   546 		    }
   547 		}
   548 	      //the clicked item is really a node
   549 	      if(active_node!=INVALID)
   550 		{
   551 		  *(nodesmap[active_node]) << Gnome::Canvas::Properties::fill_color("red");
   552 		  isbutton=1;
   553 		}
   554 	      //clicked item was not a node. It could be e.g. edge.
   555 	      else
   556 		{
   557 		  active_item=NULL;
   558 		}
   559 	    }
   560 	  //we only have to do sg. if the mouse button
   561 	  // is pressed already once AND the click was
   562 	  // on a node that was found in the set of 
   563 	  //nodes, and now we only search for the second 
   564 	  //node
   565 	  else
   566 	    {
   567 	      target_item=(get_item_at(e->button.x, e->button.y));
   568 	      Graph::NodeIt target_node=INVALID;
   569 	      for (NodeIt i(g); i!=INVALID; ++i)
   570 		{
   571 		  if(nodesmap[i]==target_item)
   572 		    {
   573 		      target_node=i;
   574 		    }
   575 		}
   576 	      //the clicked item is a node, the edge can be drawn
   577 	      if(target_node!=INVALID)
   578 		{
   579 		  *(nodesmap[target_node]) << Gnome::Canvas::Properties::fill_color("red");
   580 
   581 		  //creating new edge
   582 		  active_edge=EdgeIt(g,g.addEdge(active_node, target_node));
   583 
   584 		  //initiating values corresponding to new edge in maps
   585 		  mapstorage.init_maps_for_edge(active_edge);
   586 	  
   587 		  //calculating coordinates of new edge
   588 		  Gnome::Canvas::Points coos;
   589 		  double x1, x2, y1, y2;
   590 	  
   591 		  active_item->get_bounds(x1, y1, x2, y2);
   592 		  coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   593 
   594 		  target_item->get_bounds(x1, y1, x2, y2);
   595 		  coos.push_back(Gnome::Art::Point((x1+x2)/2,(y1+y2)/2));
   596 
   597 		  //drawing new edge
   598 		  edgesmap[active_edge]=new BrokenEdge(displayed_graph, coos, *this);
   599 		  *(edgesmap[active_edge]) << Gnome::Canvas::Properties::fill_color("green");
   600 		  edgesmap[active_edge]->property_width_pixels().set_value(10);
   601 
   602 		  //redraw nodes to blank terminations of the new edge
   603 		  target_item->raise_to_top();
   604 		  active_item->raise_to_top();
   605 
   606 		  //initializing edge-text as well, to empty string
   607 		  xy<double> text_pos=edgesmap[active_edge]->get_arrow_pos();
   608 		  text_pos+=(xy<double>(10,10));
   609 
   610 		  edgetextmap[active_edge]=new Gnome::Canvas::Text(displayed_graph, text_pos.x, text_pos.y, "");
   611 		  edgetextmap[active_edge]->property_fill_color().set_value("black");
   612 		}
   613 	      //clicked item was not a node. it could be an e.g. edge. we do not deal with it furthermore.
   614 	      else
   615 		{
   616 		  target_item=NULL;
   617 		}
   618 	    }
   619 	}
   620       break;
   621     case GDK_BUTTON_RELEASE:
   622       isbutton=0;
   623       //we clear settings in two cases
   624       //1: the edge is ready (target_item has valid value)
   625       //2: the edge creation is cancelled with right button
   626       if((target_item)||(e->button.button==3))
   627 	{
   628 	  if(active_item)
   629 	    {
   630 	      *active_item << Gnome::Canvas::Properties::fill_color("blue");
   631 	      active_item=NULL;
   632 	    }
   633 	  if(target_item)
   634 	    {
   635 	      *target_item << Gnome::Canvas::Properties::fill_color("blue");
   636 	      target_item=NULL;
   637 	    }
   638 	  active_node=INVALID;
   639 	  active_edge=INVALID;
   640 	}
   641       break;
   642     default:
   643       break;
   644     }
   645   return false;
   646 }
   647 
   648 bool GraphDisplayerCanvas::eraser_event_handler(GdkEvent* e)
   649 {
   650   switch(e->type)
   651     {
   652     case GDK_BUTTON_PRESS:
   653       active_item=(get_item_at(e->button.x, e->button.y));
   654       active_node=INVALID;
   655       active_edge=INVALID;
   656       for (NodeIt i(g); i!=INVALID; ++i)
   657 	{
   658 	  if(nodesmap[i]==active_item)
   659 	    {
   660 	      active_node=i;
   661 	    }
   662 	}
   663       if(active_node==INVALID)
   664 	{
   665 	  for (EdgeIt i(g); i!=INVALID; ++i)
   666 	    {
   667 	      if(edgesmap[i]==active_item)
   668 		{
   669 		  active_edge=i;
   670 		}
   671 	    }
   672 	}
   673     *active_item << Gnome::Canvas::Properties::fill_color("red");
   674       break;
   675 
   676     case GDK_BUTTON_RELEASE:
   677       if(active_item==(get_item_at(e->button.x, e->button.y)))
   678 	{
   679 	  if(active_node!=INVALID)
   680 	    {
   681 
   682 	      //collecting edges to delete
   683 	      EdgeIt e;
   684 	      std::set<Graph::Edge> edges_to_delete;
   685 
   686 	      g.firstOut(e,active_node);
   687 	      for(;e!=INVALID;g.nextOut(e))
   688 		{
   689 		      edges_to_delete.insert(e);
   690 		}
   691 
   692 	      g.firstIn(e,active_node);
   693 	      for(;e!=INVALID;g.nextIn(e))
   694 		{
   695 		      edges_to_delete.insert(e);
   696 		}
   697 
   698 	      //deleting collected edges
   699 	      for(std::set<Graph::Edge>::iterator edge_set_it=edges_to_delete.begin();edge_set_it!=edges_to_delete.end();edge_set_it++)
   700 		{
   701 		  delete_item(*edge_set_it);
   702 		}
   703 	      delete_item(active_node);
   704 	    }
   705 	  //a simple edge was chosen
   706 	  else
   707 	    {
   708 	      delete_item(active_edge);
   709 	    }
   710 
   711 	  
   712 	}
   713       //pointer was moved, deletion is cancelled
   714       else
   715 	{
   716 	  if(active_node!=INVALID)
   717 	    {
   718 	      *active_item << Gnome::Canvas::Properties::fill_color("blue");
   719 	    }
   720 	  else
   721 	    {
   722 	      *active_item << Gnome::Canvas::Properties::fill_color("green");
   723 	    }
   724 	}
   725       //reseting datas
   726       active_item=NULL;
   727       active_edge=INVALID;
   728       active_node=INVALID;
   729       break;
   730 
   731     case GDK_MOTION_NOTIFY:
   732       break;
   733 
   734     default:
   735       break;
   736     }
   737   return true;
   738 }
   739 
   740 void GraphDisplayerCanvas::delete_item(NodeIt node_to_delete)
   741 {
   742   delete(nodesmap[node_to_delete]);
   743   g.erase(node_to_delete);
   744 }
   745 
   746 void GraphDisplayerCanvas::delete_item(EdgeIt edge_to_delete)
   747 {
   748   delete(edgesmap[edge_to_delete]);
   749   g.erase(edge_to_delete);
   750 }
   751 
   752 void GraphDisplayerCanvas::delete_item(Graph::Edge edge_to_delete)
   753 {
   754   delete(edgesmap[edge_to_delete]);
   755   g.erase(edge_to_delete);
   756 }
   757 
   758 void GraphDisplayerCanvas::text_reposition(xy<double> new_place)
   759 {
   760   new_place+=(xy<double>(10,10));
   761   edgetextmap[active_edge]->property_x().set_value(new_place.x);
   762   edgetextmap[active_edge]->property_y().set_value(new_place.y);
   763 }
   764 
   765 void GraphDisplayerCanvas::toggle_edge_activity(BrokenEdge* active_bre, bool on)
   766 {
   767   if(on)
   768     {
   769       if(active_edge!=INVALID)
   770 	{
   771 	  std::cout << "ERROR!!!! Valid edge found!" << std::endl;
   772 	}
   773       else
   774 	{
   775 	  for (EdgeIt i(g); i!=INVALID; ++i)
   776 	    {
   777 	      if(edgesmap[i]==active_bre)
   778 		{
   779 		  active_edge=i;
   780 		}
   781 	    }
   782 	}
   783     }
   784   else
   785     {
   786       if(active_edge!=INVALID)
   787 	{
   788 	  active_edge=INVALID;
   789 	}
   790       else
   791 	{
   792 	  std::cout << "ERROR!!!! Invalid edge found!" << std::endl;
   793 	}
   794     }
   795 
   796 }