Boost.Graph example. It defines a graph of person names and their relationships. Then the graph is written to .dot file, converted to pdf and displayed in the application.

Operating system: Ubuntu 10.04 LTS Lucid Lynx

IDE: Qt Creator 2.0.0

Project type: GUI application

Compiler: G++ 4.4.1

Libraries used:

Boost: version 1.40
Poppler: version 0.12.4-0ubuntu5
Qt: version 4.7.0 (32 bit)
STL: from GCC, shipped with Qt Creator 2.0.0

Qt project file


#-------------------------------------------------

#

# Project created by QtCreator 2010-09-18T12:40:50

#

#-------------------------------------------------

QT       += core gui xml

TARGET = CppGraphExample4

LIBS += -L/usr/local/bin -lpoppler-qt4

TEMPLATE = app

SOURCES += main.cpp\

        dialogmain.cpp

HEADERS  += dialogmain.h

FORMS    += dialogmain.ui



RESOURCES += \

    resources.qrc

dialogmain.cpp


//---------------------------------------------------------------------------

#include <cstdio>

//---------------------------------------------------------------------------

#include <boost/graph/adjacency_list.hpp>

#include <boost/graph/graphviz.hpp>

//---------------------------------------------------------------------------

#include <poppler/qt4/poppler-qt4.h>

//---------------------------------------------------------------------------

#include "dialogmain.h"

#include "ui_dialogmain.h"

//---------------------------------------------------------------------------

DialogMain::DialogMain(QWidget *parent) :

    QDialog(parent, Qt::Window),

    ui(new Ui::DialogMain)

{

  ui->setupUi(this);



  //Write a graph to file

  //Define the type of graph:

  //boost::adjacency_list is the 'Swiss army knife' graph

  typedef boost::adjacency_list

  <

    //Store all edges as a std::vector

    boost::vecS,

    //Store all vertices in a std::vector

    boost::vecS,

    //Relations are both ways (in this example)

    //(note: but you can freely change it to boost::directedS)

    boost::undirectedS,

    //All vertices are person names of type std::string

    boost::property<boost::vertex_name_t,std::string>,

    //All edges are weights equal to the encounter frequencies

    boost::property<boost::edge_weight_t,double>,

    //Graph itself has a std::string name

    boost::property<boost::graph_name_t,std::string>

  > Graph;



  Graph  g;



  //All vertex names

  //Note: cannot use spaces

  std::vector<std::string> names;

  names.push_back("Mr_A");

  names.push_back("Mrs_B");

  names.push_back("Dr_C");

  names.push_back("Prof_D");



  const Graph::vertex_descriptor v0 = boost::add_vertex(names[0],g);

  const Graph::vertex_descriptor v1 = boost::add_vertex(names[1],g);

  const Graph::vertex_descriptor v2 = boost::add_vertex(names[2],g);

  const Graph::vertex_descriptor v3 = boost::add_vertex(names[3],g);



  std::vector<double> frequencies;

  frequencies.push_back(0.9);

  frequencies.push_back(0.5);

  frequencies.push_back(0.6);

  frequencies.push_back(0.1);



  boost::add_edge(v0,v1,frequencies[0],g);

  boost::add_edge(v1,v2,frequencies[1],g);

  boost::add_edge(v2,v3,frequencies[2],g);

  boost::add_edge(v0,v3,frequencies[3],g);



  //Writing graph to file

  {

    std::ofstream f("test.dot");



    boost::dynamic_properties p;

    p.property("label", boost::get(boost::edge_weight, g));

    p.property("weight", boost::get(boost::edge_weight, g));

    p.property("node_id", boost::get(boost::vertex_name, g));

    boost::write_graphviz(f,g,p);

    f.close();

  }

  //Convert test.dot file to test.pdf

  std::system("dot2tex test.dot > test.tex");

  std::system("texi2pdf test.tex");



  //Load test.pdf in QLabel

  Poppler::Document *doc = Poppler::Document::load("test.pdf");

  const int current_page = 0;

  const double scale = 1.0;



  QImage image = doc->page(current_page)->renderToImage(

                            scale * physicalDpiX(),

                            scale * physicalDpiY());



  ui->label->setPixmap(QPixmap::fromImage(image));

}

//---------------------------------------------------------------------------

DialogMain::~DialogMain()

{

  delete ui;

}

//---------------------------------------------------------------------------

void DialogMain::changeEvent(QEvent *e)

{

  QDialog::changeEvent(e);

  switch (e->type()) {

  case QEvent::LanguageChange:

    ui->retranslateUi(this);

    break;

  default:

    break;

  }

}

//---------------------------------------------------------------------------

dialogmain.h


//---------------------------------------------------------------------------

#ifndef DIALOGMAIN_H

#define DIALOGMAIN_H

//---------------------------------------------------------------------------

#include <QDialog>

//---------------------------------------------------------------------------

namespace Ui {

  class DialogMain;

}

//---------------------------------------------------------------------------

class DialogMain : public QDialog

{

  Q_OBJECT



public:

  explicit DialogMain(QWidget *parent = 0);

  ~DialogMain();



protected:

  void changeEvent(QEvent *e);



private:

  Ui::DialogMain *ui;

};

//---------------------------------------------------------------------------

#endif // DIALOGMAIN_H

main.cpp


#include <QtGui/QApplication>

#include "dialogmain.h"



int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    DialogMain w;

    w.show();



    return a.exec();

}

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(C++) Boost.Graph example 4: four human names and their relationships displayed in Qt

Qt project file

dialogmain.cpp

dialogmain.h

main.cpp