1  #include "mainwindow.h"
2  #include <QApplication>
3  #include <QPushButton>
4  #include <QVBoxLayout>
5  int main(int argc, char *argv[])
6  {
7      QApplication a(argc, argv);
8      QWidget* win = new QWidget;
9      QVBoxLayout* layout = new QVBoxLayout(win);
10     QPushButton* but1 = new QPushButton("About Qt");
11     QPushButton* but2 = new QPushButton("Maximize");
12     QPushButton* but3 = new QPushButton("Minimize");
13     QPushButton* but4 = new QPushButton("Normal");
14     QPushButton* but5 = new QPushButton("Close");
15     //Font of buttons
16     but1->setFont(QFont("times", 12, QFont::Bold));
17     but2->setFont(QFont("times", 12, QFont::Bold));
18     but3->setFont(QFont("times", 12, QFont::Bold));
19     but4->setFont(QFont("times", 12, QFont::Bold));
20     but5->setFont(QFont("times", 12, QFont::Bold));
21     // add widgets to the vertical box
22     layout->addWidget(but1);
23     layout->addWidget(but2);
24     layout->addWidget(but3);
25     layout->addWidget(but4);
26     layout->addWidget(but5);
27     // make signal-and-slot connections
28     QObject::connect( but1, SIGNAL(clicked()),
            &a, SLOT(aboutQt()));
29     QObject::connect( but1, SIGNAL(clicked()),
           win, SLOT( showNormal()));
30     QObject::connect( but2, SIGNAL(clicked()),
         win, SLOT( showMaximized()));
31     QObject::connect( but3, SIGNAL(clicked()),
         win, SLOT( showMinimized()));
32     QObject::connect( but4, SIGNAL(clicked()),
         win, SLOT( showNormal()));
33     QObject::connect( but5, SIGNAL(clicked()),
         &a, SLOT( quit()));
34     win->show();
35     return a.exec();
36 }
