In need of a 64-bit unsigned QSpinBox (to fit large numbers like pointers, etc)

[boohbah]

Hello, in a program I'm currently writing, users should be able to operations on and relating to binary data.

I'm attempting to create a prompt that should allow the user to choose a minimum and maximum range to operate on, however QSpinBox only accepts an int, which is a signed 32-bit value and can only store up to 0x7FFFFFFF, when values the software handles can exceed that.

At first I tried seeing if a QDoubleSpinBox would suffice if I did setDecimals(0), however I should be displaying the number in hexadecimal, and a QDoubleSpinBox doesn't have a setDisplayIntegerBase method like QSpinBox does.

So far the only other options I can see are unwillingly falling back to a QLineEdit that parses hex number strings, however that's far from preferable as it won't have the step buttons and won't filter out invalid characters, or I can see about reimplementing my own spin box. The latter is more preferable but QAbstractSpinBox annoyingly seemingly has all the relevant QVariants and other important properties private, so I cannot use them.

Any ideas on how to approach this? Thank you.

[Bonnie]

I don't feel step buttons are necessary to input pointer values.
To me, QLineEdit with input mask set to "HHHHHHHHHHHHHHHH;_" seems enough if there's no request for min/max value.

[boohbah]

Hmm, that's one way of doing it, but minimum/maximum values are one of the main reasons I chose a QSpinBox originally, as in the case of pointers they should preferably be constrained to a specific region in address space.
Step buttons aren't so necessary, but it's the scroll wheel behaviour that comes with it that increments/decrements the value which would save a bit of time and make usage a bit better..

[JonB]

@boohbah
If you go @Bonnie's route you could add a QDoubleValidator or derive from QValidator for the range.

If you look at https://codebrowser.dev/qt5/qtbase/src/widgets/widgets/qspinbox.cpp.html you can see the implementation of QSpinBox/QDoubleSpinBox and derive from QAbstractSpinBox for 64-bit. Most of the code there is either comments or QDoubleSpinBox so it's not so much.

The solution at How to subclass QSpinBox so it could have int64 values as maxium and minimum suggests following that approach and that it's not too much work.

[boohbah]

The steps from the linked post do not seem to give a working spin box (as in, it doesn't even show a value). It seems I might have to reimplement a whole bunch of methods, like valueFromText, textFromValue, fixup, validate, the value/textChanged signals, and possibly even more.

[boohbah]

Hmm, a lot of QSpinBox's implementation also calls rather large private methods, so this goes beyond just a simple subclass to something quite a lot more arduous. Not sure what to do here. (Perhaps I could be mistaken, though.)

[JonB]

@boohbah
That is true if you re-implement from QAbstractSpinBox. But to just make 64-bit if the outline solution at my referenced https://stackoverflow.com/a/15655190/489865 solution is sufficient (maybe with the addition for you of hex values) that does not involve private stuff.

[boohbah]

I don't understand. Doing what that post sent and the information it provides doesn't seem sufficient and I'm not sure how I'd approach the other two steps it mentioned.

This is what I currently have, and it does practically nothing:

class SpinBoxU64 : public QAbstractSpinBox {
public:
	explicit SpinBoxU64(QWidget* parent = nullptr);

	uint64_t minimum() const;
	void setMinimum(uint64_t min);

	uint64_t maximum() const;
	void setMaximum(uint64_t max);

	void setRange(uint64_t min, uint64_t max);

	uint64_t value() const;

	void stepBy(int steps) override;

public slots:
	void setValue(uint64_t val);

signals:
	void valueChanged(uint64_t);

private:
	uint64_t m_minimum, m_maximum, m_value;
};

SpinBoxU64::SpinBoxU64(QWidget* parent) :
	QAbstractSpinBox(parent),
	m_minimum(0), m_maximum(100), m_value(0) {}

uint64_t SpinBoxU64::minimum() const {
	return m_minimum;
}

uint64_t SpinBoxU64::maximum() const {
	return m_maximum;
}

uint64_t SpinBoxU64::value() const {
	return m_value;
}

void SpinBoxU64::setMinimum(uint64_t min) {
	m_minimum = min;
}

void SpinBoxU64::setMaximum(uint64_t max) {
	m_maximum = max;
}

void SpinBoxU64::setValue(uint64_t value) {
	m_value = value;
}

void SpinBoxU64::stepBy(int steps) {
	m_value += steps;
}

I implemented some of the methods and properties that I need, such as minimum and maximum, I also implemented stepBy (which doesn't even seem to be called by anything at all when I put a qDebug call inside it), and derived from QAbstractSpinBox itself. Interacting with this spin box just does nothing.

Where would I put the relevant lineEdit()->setText() call? Why a validator on the lineEdit itself when QAbstractSpinBox has its own virtual validate and fixup methods themselves, implying those should be reimplemented? What would be a good way to approach such a validator? Things are rather ambiguous and confusing at this point.

[SamiV123]

I don't know what your use case is exactly but can't you use this as an offset relative to some known base value? Would that help?

[boohbah]

That could be one way of approaching it, but unfortunately less preferable than just a regular QLineEdit as now I would need a label next to the spin box to indicate what the address actually is.

[JonB]

@boohbah
A little extra Googling might have led you to 64bit int Spin Box in QT. The post there https://stackoverflow.com/a/32628421/489865, the See code of my Сustom QSpinBox. class QLongLongSpinBox derived from QAbstractSpinBox one, is 10 years old but looks like a complete implementation to me. Not that big. It's for a qlonglong/ qint64. You can change it to qulonglong/quint64/uint64_t. When you have it working add your hex/integer base code.

Read through qspinbox64 in QT5.15.2 for updates to code/comments/other peoples' changes. The last post there may have an alternative implementation.

[Gaobo]

you may can refer to this code: https://github.com/AlekseyDurachenko/QtLongLongSpinBox，

[JonB]

@Gaobo
Clicking on that link gives a "404 not found".
Correct link is: https://github.com/AlekseyDurachenko/QtLongLongSpinBox

[Gaobo]

@JonB I'm getting some errors when editing the link🌚 Thanks for the correction.