QLabel
bool className::eventFilter(QObject* object, QEvent* event)
{
if( object == ui->label )
{
if ( event->type() == QEvent::Enter )
{
ui->button->setStyleSheet("color:blue; font-size:12pt");
}
 
if( event ->type() == QEvent::Leave )
{
ui->button->setStyleSheet("color:black; font-size:12pt");
}
}
return false;
}