Do I need a delegate for double numbers in a QStandardItemModel?

I want to use a scientific QStandardItemModel model which will receive some values from comboboxes and some double numbers that the user will insert in a QTableView. I successfully managed to implement the delegate for the combobox. Do I need to program seperately a delegate for the cells that the user inserts a double number? Perhaps it would be good to protect the program by not allowing the user to insert any other value (characters, symbols) in the cells for double numbers.

Have you tried how does the default delegate acts by default before you posted this question?

yes,

• if I don't initialize the cell it's a string delegate
• if I initialize it with an int it's like a spinbox delegate
• if I initialize it with a double number like 0.1 it's again like a spinbox delegate BUT it does not allow me to insert more than 2 decimal digits(why?!)

The reasons I am asking are:

1. avoid conversion errors (double to string and vice versa)
2. when I append a new row the new default delegate is just a string one
3. protect the system and allow the user to insert only valid values (just doubles, not symbols or characters)

Therefore, I am asking if there is an option or a default delegate for double numbers

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Originally Posted by fatecasino

if I don't initialize the cell it's a string delegate

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There is no such thing as a "string delegate".

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if I initialize it with an int it's like a spinbox delegate

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same as above

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if I initialize it with a double number like 0.1 it's again like a spinbox delegate BUT it does not allow me to insert more than 2 decimal digits(why?!)

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Because the widget returned has default properties and the default properties of QDoubleSpinBox are such that they allow a default number of digits and a default range.

Quote:

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• avoid conversion errors (double to string and vice versa)
• when I append a new row the new default delegate is just a string one
• protect the system and allow the user to insert only valid values (just doubles, not symbols or characters)

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I think you need to read more what a delegate is and how the model-view framework in Qt works.