main.cpp

#include <QApplication>
#include <QBoxLayout>
#include <QPushButton>
#include "myT.h"


int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QString s;

    for(int i = 0; i < 256; ++i)
        s.append("123\n");

    QWidget w;
    QBoxLayout l(QBoxLayout::TopToBottom);
    myT ed;
    QPushButton b("push");
    l.addWidget(&ed);
    l.addWidget(&b);
    w.setLayout(&l);
    ed.setText(s);

    QObject::connect(&b,SIGNAL(clicked()),&ed,SLOT(v()));

    w.show();

    return a.exec();
}