//#include <QtWidgets>
#include <QtGui>


class MyMainWindow : public QMainWindow {
    Q_OBJECT

    int number;

public slots:
    void newSubWindow ();

public:
    MyMainWindow (QWidget* parent =0);
};


MyMainWindow::MyMainWindow (QWidget* parent) :
    QMainWindow (parent),
    number (0)
{
    QMdiArea* const mdi=new QMdiArea (this);
    mdi->setActivationOrder (QMdiArea::StackingOrder);
    setCentralWidget (mdi);
    menuBar()->addAction ("&New Subwindow", this, SLOT (newSubWindow()));
    resize (840, 220);
}


class MyWidget : public QWidget {
public:
    MyWidget (int number, QWidget* parent =0);
    QSize minimumSizeHint () const;
};


MyWidget::MyWidget (int number, QWidget* parent) :
    QWidget (parent)
{
    setWindowTitle (QString::number (number));
    QVBoxLayout *layout = new QVBoxLayout;
    setLayout(layout);
    for (int i=0; i<5; ++i) {
        QLineEdit* le=new QLineEdit (this);
        //le->move (20, i*20 +20);
        le->setText (QString::number (i));
        if(i==2){
            setFocusProxy(le);
         qDebug()<<"setting focus";
        }
        layout->addWidget(le);
        //le->show ();

    }
}

QSize MyWidget::minimumSizeHint () const { return QSize (200, 150); }


void MyMainWindow::newSubWindow () {
    if ( QMdiArea* const mdi=qobject_cast <QMdiArea *>(centralWidget()) ) {
        QWidget* const w=new MyWidget (number, 0);
        mdi->addSubWindow (w);
       w->show ();
    }
    ++number;



}


int main (int argc, char* argv[]) {
    QApplication a (argc, argv);
    MyMainWindow m;
    m.show();

    return a.exec();
}

#include "main.moc"