void MyWidget:

n_lineEdit_textChanged(QString text)
{
if(text.startsWith('.'))
{
QMessageBox::information(this, "Info", "Range should be between 60 and 150.", QMessageBox::Ok);
ui->lineEdit->setText("");
ui->lineEdit->setFocus();
return;
}
if(text.at(2) == '.')
{
QMessageBox::information(this, "Info", "Range should be between 60 and 150.", QMessageBox::Ok);
ui->lineEdit->setText("");
ui->lineEdit->setFocus();
return;
}
if ((text.size() >= 3) && (text.toFloat() > 150 || text.toFloat() < 60))
{
QMessageBox::information(this, "Info", "Range should be between 60 and 150.", QMessageBox::Ok);
ui->lineEdit->setText("");
ui->lineEdit->setFocus();
return;
}
else
{
ui->lineEdit->setText(text);
}
}
void MyWidget:

n_lineEdit_editingFinished()
{
QString text = ui->lineEdit->text();
if (text.toFloat() < 60)
{
QMessageBox::information(this, "Info", "Range should be between 60 and 150.", QMessageBox::Ok);
ui->lineEdit->setText("");
ui->lineEdit->setFocus();
}
else
{
ui->lineEdit->setText(text);
}
}