How to use QTableView with SpinBoxes?

Stonebull

Hello,
I'm desperately trying to implement SpinBoxes within a QTableView. I have a working GUI Application where I would like to integrate it inside a Tab Widget.
I followed one of the countless tutorials and it kind of works. When I double click on the table I get a SpinBox BUT it is disabled (the controls cannot be clicked) and Qt automatically fills in the minimum value specified in the SpinBoxDelegate class.
See attached gif for more details:

For reference, here is the code I'm using:

SpinBoxDelegate.h:

#pragma once

#include <QStyledItemDelegate>

class SpinBoxDelegate : public QStyledItemDelegate
{
    Q_OBJECT

public:
    SpinBoxDelegate(QObject* parent = nullptr);

    QWidget* createEditor(QWidget* parent, const QStyleOptionViewItem& option,
        const QModelIndex& index) const override;

    void setEditorData(QWidget* editor, const QModelIndex& index) const override;
    void setModelData(QWidget* editor, QAbstractItemModel* model,
        const QModelIndex& index) const override;

    void updateEditorGeometry(QWidget* editor, const QStyleOptionViewItem& option,
        const QModelIndex& index) const override;
};

SpinBoxDelegate.cpp:

#include "SpinBoxDelegate.h"
#include <QSpinBox>

/* Delegates are often stateless. The constructor only needs to call the base class's constructor with the parent QObject as its argument. */
SpinBoxDelegate::SpinBoxDelegate(QObject* parent)
    : QStyledItemDelegate(parent)
{

}

/* The createEditor() function returns an editor widget, in this case a spin box that restricts values from the model to integers from 0 to 100 inclusive. */
QWidget* SpinBoxDelegate::createEditor(QWidget* parent, const QStyleOptionViewItem& /* option */, const QModelIndex& /* index */) const
{
    QSpinBox* editor = new QSpinBox(parent);
    editor->setFrame(false);
    editor->setMinimum(30);
    editor->setMaximum(-30);

    return editor;
}


/* The setEditorData() function reads data from the model, converts it to an integer value, and writes it to the editor widget. */
void SpinBoxDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const
{
    int value = index.model()->data(index, Qt::EditRole).toInt();

    QSpinBox* spinBox = static_cast<QSpinBox*>(editor);
    spinBox->setValue(value);
}

/* The setModelData() function reads the contents of the spin box, and writes it to the model. */
void SpinBoxDelegate::setModelData(QWidget* editor, QAbstractItemModel* model, const QModelIndex& index) const
{
    QSpinBox* spinBox = static_cast<QSpinBox*>(editor);

    /* We call interpretText() to make sure that we obtain the most up-to-date value in the spin box. */
    spinBox->interpretText();

    int value = spinBox->value();

    model->setData(index, value, Qt::EditRole);
}

/* The updateEditorGeometry() function updates the editor widget's geometry using the information supplied in the style option. This is the minimum that the delegate must do in this case.*/
void SpinBoxDelegate::updateEditorGeometry(QWidget* editor, const QStyleOptionViewItem& option, const QModelIndex&/* index */) const
{
    editor->setGeometry(option.rect);
}

Main application window constructor:

        /* Creating and assigning a model */
	pModel = new QStandardItemModel(122, 2, this);
	ui.tableView->setModel(pModel);

	/* Assigning a delegator */
	pDelegate = new SpinBoxDelegate(this);
	ui.tableView->setItemDelegateForColumn(0, pDelegate);

	/* Initializing the all entries to zero */
	for (int row = 0; row < pModel->rowCount(); ++row) 
	{
		for (int col = 0; col < pModel->columnCount(); ++col) 
		{
			QModelIndex index = pModel->index(row, col, QModelIndex());
			pModel->setData(index, 0);

		}
	}

I really don't know what else to try, would be great if somebody could help me.

jsulm

@Stonebull said in How to use QTableView with SpinBoxes?:

Do you know what goes wrong

Well, 30 > -30, but you set maximum as -30 and minimum as 30. Means: your minimum is bigger than maximum...

JonB

@Stonebull said in How to use QTableView with SpinBoxes?:

editor->setMinimum(30);
editor->setMaximum(-30);

I would start by looking at these two lines of code....

Stonebull

@JonB thanks for your reply.

@JonB said in How to use QTableView with SpinBoxes?:

I would start by looking at these two lines of code....

I followed the approach explained on the official Qt website:
https://doc.qt.io/archives/qt-4.8/qt-itemviews-spinboxdelegate-example.html

and by this guys here (which is exactly the same as the offitial approach)
https://programmer.group/using-various-custom-delegates-in-qtableview.html

Do you know what goes wrong and are giving me a hint or is it just an advice where you would start to search?
The code is pretty short and I cannot think of what I did wrong in this section.

Best Regards,

jsulm

@Stonebull said in How to use QTableView with SpinBoxes?:

Do you know what goes wrong

Well, 30 > -30, but you set maximum as -30 and minimum as 30. Means: your minimum is bigger than maximum...

Stonebull

@JonB, @jsulm OMG you are right!!!! I kept looking at it withought realizing ...

Yeah, that was it, thanks for your help!!