qt 소스 질문

nNum = 0;
 
    edit = new QLineEdit("", parent);
    edit->setGeometry(rect.x()+0,rect.y()+0,300,40);
 
    button1 = new QPushButton("up", parent);
    button1->setGeometry(rect.x()+305,rect.y()+0,60,40);
 
    button2 = new QPushButton("down", parent);
    button2->setGeometry(rect.x()+365,rect.y()+0,60,40);
 
    connect(button1,SIGNAL(pressed()),this,SLOT(p_up()));
    connect(button2,SIGNAL(pressed()),this,SLOT(p_down()));
 
}
 
void comboWidget::p_up()
{
    nNum++;
    QString temp;
    temp.sprintf("%d", nNum);
 
    edit->setText(temp);
 
    emit minePressed(this, nNum);
 
 
 
}
 
void comboWidget::p_down()
{
    nNum--;
    QString temp;
    temp.sprintf("%d", nNum);
 
    edit->setText(temp);
 
    emit minePressed(this, nNum);
}