How to refactor this if else code containing object constructors?

[Guerrian]

QWidget *MyDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &index) const
{
QLineEdit *lineEdit = new QLineEdit(parent);
if (index.column() == 0)
{
QRegularExpression regExp(REG_EXP1);
QRegularExpressionValidator *validator = new QRegularExpressionValidator(regExp, parent);
lineEdit->setValidator(validator);
}
else
{
QRegularExpression regExp(REG_EXP2);
QRegularExpressionValidator *validator = new QRegularExpressionValidator(regExp, parent);
lineEdit->setValidator(validator);
}
return lineEdit;
}

There must be a way of refactoring this so that it is shorter.

[Paul Colby]

Hi @Guerrian,

There must be a way of refactoring this so that it is shorter.

Well, shorter is not necessarily always best (eg when it reduces readability), but in this case, I'd write it like:

QWidget *MyDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &index) const
{
    QRegularExpression regExp((index.column() == 0) ? REG_EXP1 : REG_EXP2);
    QRegularExpressionValidator *validator = new QRegularExpressionValidator(regExp, parent);
    QLineEdit * const lineEdit = new QLineEdit(parent);
    lineEdit->setValidator(validator);
    return lineEdit;
}

or possibly:

QWidget *MyDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &index) const
    QRegularExpression regExp((index.column() == 0) ? REG_EXP1 : REG_EXP2);
    QLineEdit *lineEdit = new QLineEdit(parent);
    lineEdit->setValidator(new QRegularExpressionValidator(regExp, parent));
    return lineEdit;
}

It is possible to make it even shorter, but I think readability begins to be impacted then.

Cheers.