source: lemon-0.x/gui/gdc-broken_edge.cc @ 1833:6d107b0b6b46

#include "graph_displayer_canvas.h"
#include <cmath>

GraphDisplayerCanvas::BrokenEdge::BrokenEdge(Gnome::Canvas::Group & g, Gnome::Canvas::Points p, GraphDisplayerCanvas & gc) : Line(g), gdc(gc), isbutton(false)
{
  my_points=new Gnome::Art::Point[3];

  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();
  setPoints(p);
}

GraphDisplayerCanvas::BrokenEdge::~BrokenEdge()
{
  if(arrow)delete(arrow);
}

void GraphDisplayerCanvas::BrokenEdge::setPoints(Gnome::Canvas::Points p, bool move)
{
  bool set_arrow=false;
  //red arrow losts its position-right button
  if(!move)
    {
      if(p.size()==2)
        {
          set_arrow=true;
          Gnome::Canvas::Points points_with_center;
          points_with_center.push_back(my_points[0]=p[0]);
          points_with_center.push_back(my_points[1]=Gnome::Art::Point( (p[0].get_x()+p[1].get_x())/2+0 , (p[0].get_y()+p[1].get_y())/2 )+0 );
          points_with_center.push_back(my_points[2]=p[1]);
          property_points().set_value(points_with_center);
        }  
      if(p.size()==3)
        {
          set_arrow=true;
          property_points().set_value(p);
          for(int i=0;i<3;i++)
            {
              my_points[i]=p[i];
            }
        }
    }
  else
    {
      //arrow keeps its position-left button

//       if(p.size()==2)
//              {
//                Gnome::Canvas::Points points;
//                my_points[0]=p[0];
//                my_points[2]=p[1];
//                for(int i=0;i<3;i++)
//                  {
//                    points.push_back(my_points[i]);
//                  }
//                property_points().set_value(points);
//              }
      set_arrow=true;

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

      if(p.size()==2)
        {
          //old vector from one to the other node - a
          xy<double> a_v(my_points[2].get_x()-my_points[0].get_x(),my_points[2].get_y()-my_points[0].get_y());
          //new vector from one to the other node - b
          xy<double> b_v(p[1].get_x()-p[0].get_x(),p[1].get_y()-p[0].get_y());

          double absa=sqrt(a_v.normSquare());
          double absb=sqrt(b_v.normSquare());

          if((absa!=0)&&(absb!=0))
            {
              //old vector from one node to the breakpoint - c
              xy<double> c_v(my_points[1].get_x()-my_points[0].get_x(),my_points[1].get_y()-my_points[0].get_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);

              my_points[1]=Gnome::Art::Point(d_v.x+p[0].get_x(),d_v.y+p[0].get_y());

              my_points[0]=p[0];
              my_points[2]=p[1];
          
              Gnome::Canvas::Points points;
              for(int i=0;i<3;i++)
                {
                  points.push_back(my_points[i]);
                }
              property_points().set_value(points);
            }
          else
            {
              //if distance is 0, segmentation would be occured
              //in calculations, because of division by zero
              //But we have luck: the edge cannot be seen in
              //this case, so no update needed
              set_arrow=false;
            }
        }
    }
  if(set_arrow)
    {
      //calculating coordinates of the direction indicator arrow

      xy<gdouble> target( my_points[2].get_x(), my_points[2].get_y() );
      xy<gdouble> center( my_points[1].get_x(), my_points[1].get_y() );

      xy<gdouble> 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<gdouble> 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<gdouble> bl (center - unit_vector_in_dir * 3 * size + unit_norm_vector * size );
      xy<gdouble> br (center - unit_vector_in_dir * 3 * size - unit_norm_vector * size );
      xy<gdouble> ccl(center + unit_vector_in_dir *  size + unit_norm_vector * size );
      xy<gdouble> ccr(center + unit_vector_in_dir *  size - unit_norm_vector * size );
      xy<gdouble> cl (center + unit_vector_in_dir *  size + unit_norm_vector * 2 * size );
      xy<gdouble> cr (center + unit_vector_in_dir *  size - unit_norm_vector * 2 * size );
      xy<gdouble> 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);
    }
}

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;
        }
      break;
    case GDK_BUTTON_RELEASE:
      if(gdc.getActualTool()!=CREATE_NODE)
        {
          gdc.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

          double dx=e->motion.x-clicked_x;
          double dy=e->motion.y-clicked_y;

          Gnome::Canvas::Points points_new;

          points_new.push_back(my_points[0]);
          points_new.push_back(my_points[1]=Gnome::Art::Point(my_points[1].get_x()+dx,my_points[1].get_y()+dy));
          points_new.push_back(my_points[2]);

          setPoints(points_new);
          gdc.textReposition(xy<double>(my_points[1].get_x(),my_points[1].get_y()));

          clicked_x=e->motion.x;
          clicked_y=e->motion.y;

        }
    default: break;
    }

  return true;
}

xy<double> GraphDisplayerCanvas::BrokenEdge::getArrowPos()
{
  xy<double> ret_val(my_points[1].get_x(),my_points[1].get_y());
  return ret_val;
}