source: glemon-0.x/gdc-broken_edge.cc @ 103:3a263e57e1d9

#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)
{
  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();
  draw();
}

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

void GraphDisplayerCanvas::BrokenEdge::draw()
{
  MapStorage& ms = gdc.mytab.mapstorage;

  // 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);
  }
}

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;

          gdc.mytab.mapstorage.arrow_pos.set(edge, gdc.mytab.mapstorage.arrow_pos[edge] + XY(dx, dy));

          draw();
          gdc.textReposition(gdc.mytab.mapstorage.arrow_pos[edge]);

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

        }
    default: break;
    }

  return true;
}