#include <QApplication>
#include <QtGui>

class CSpyLineEdit : virtual public QLineEdit
{
    //Q_OBJECT

public:
    CSpyLineEdit(QWidget *parent = 0):QLineEdit(parent){}

protected:
    void keyPressEvent(QKeyEvent *pKeyEvent)
    {
        if (pKeyEvent->key()==Qt::Key_0 && pKeyEvent->modifiers()==Qt::AltModifier)
        {
            this->setText("Clear complete");
        }

        else
        {
            QLineEdit::keyPressEvent(pKeyEvent);
        }
    }
};


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

    QApplication app(argc, argv);

    QWidget wgt;

    QVBoxLayout *pVboxLayout = new QVBoxLayout();

    CSpyLineEdit *pSpyLineEdit = new CSpyLineEdit();
    pSpyLineEdit->setMinimumSize(QSize(200,100));
    pVboxLayout->addWidget(pSpyLineEdit);

    pVboxLayout->setMargin(20);
    wgt.setLayout(pVboxLayout);
    wgt.show();

   return app.exec();
}