How to add validation in column data in Qtableview?

[n-2204]

Hi,
I have requirement I'm using Qtableview (Qstandrdmodel)
and doing some calculation e.g. when result in column 2 is -ve value then it should show with brackets like this (1.15) if not then 1.15.
How to do this?
As this validation i have to do for 4-5 columns.

[VRonin]

This is just manipulation of the displayed output, not validation. In any case you can use:

class AccountingDelegate : public QStyledItemDelegate{
    Q_OBJECT
    Q_DISABLE_COPY(AccountingDelegate)
    template <class T>
    QString accountingDisplayText(const T& value, const QLocale &locale) const{
        if(value<T(0))
            return tr("(%1)").arg(QStyledItemDelegate::displayText(-value,locale));
        return QStyledItemDelegate::displayText(value,locale);
    }
public:
    explicit AccountingDelegate(QObject *parent = nullptr)
        : QStyledItemDelegate(parent) {}
    QString displayText(const QVariant &value, const QLocale &locale) const override{
        switch (value.userType()){
        case QMetaType::Long:
            return accountingDisplayText(value.value<long>(),locale);
        case QMetaType::LongLong:
            return accountingDisplayText(value.value<long long>(),locale);
        case QMetaType::Short:
            return accountingDisplayText(value.value<short>(),locale);
        case QMetaType::Float:
            return accountingDisplayText(value.value<float>(),locale);
        case QMetaType::Int:
            return accountingDisplayText(value.value<int>(),locale);
        case QMetaType::Double:
            return accountingDisplayText(value.value<double>(),locale);
        default:
            return QStyledItemDelegate::displayText(value,locale);
        }
    }
};

Then you can use it with something like:

AccountingDelegate *accDelegate = new AccountingDelegate(this);
for(int column =0;column <4;++column)
    tableView->setItemDelegateForColumn(column,accDelegate);

[n-2204]

@VRonin thanks, so this will show () braces for all the data I mean not only -ve data in column

[VRonin]

@n-2204 said in How to add validation in column data in Qtableview?:

so this will show () braces for all the data I mean not only -ve data in column

That's exactly what this code does. I'd direct your attention on the if(value<T(0)) condition