QSpinBox

[ToddAtWSU]

I have some QSpinBoxes in which I always want to display 2 digits, even if the value is a single digit value. In other words, for values like 1 and 5 I would like to display 01 and 05. I have looked into valueFromText and textFromValue but don't think I need these since I am still just displaying integers and not characters besides 0-9. I also looked at validate, but I can't think of why I would need validate because the QSpinBox already limits the user to entering digits. I just want to prefix the single digit values with a 0. I thought about connecting the valueChanged signal to a slot to add a prefix to the number if it were less than 10, but would prefer to not handle this by connecting to the signal in case I need to capture this signal at a later time and do more complex things with it. Thanks for any ideas you may have!

[jpn]

I have looked into valueFromText and textFromValue but don't think I need these since I am still just displaying integers and not characters besides 0-9.

Yes, this is the way to go.

[ToddAtWSU]

How exactly do I use textFromValue and valueFromText? I was hoping to avoid them because the docs don't really explain this very well. What exactly am I supposed to do with these functions and how I do get the QSpinBox to display my 2 digit numbers? Are there any examples of this? Thanks again!

[jpn]

In a locale unaware way it's as simple as this:

class SpinBox : public QSpinBox
{
protected:
    virtual QString textFromValue(int value) const
    {
        return QString("%1").arg(value, 2, 10, QLatin1Char('0'));
    }
};

class SpinBox : public QSpinBox
{
protected:
    virtual QString textFromValue(int value) const
    {
        return QString("%1").arg(value, 2, 10, QLatin1Char('0'));
    }
};

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[Andrewgaven]

Hello, Sorry for reviving an old post.
Did this solution work for you?, I need to implement two or more digits on a Spinbox, but I don't know how, I used Designer so I don't have the Spinbox class, is there any other way?
Thanks in advance

[Ginsengelf]

Hi, in the Qt Designer you can use "Promote to" to create a SpinBox instead of QSpinBox. Just create a QSpinBox, right-click and select "Promote to", then in the dialog enter the details of your class, in this case SpinBox.

Ginsengelf

[Andrewgaven]

Thanks for the reply, I Have been trying for a couple of days, with no succest I created a QWidget with a QSpinbox and a label, then promote the QSpinbox to spinbox.h, this is my spinbox.h file

#ifndef SPINBOX_H
#define SPINBOX_H

#include <QSpinBox>
#include <QString>

class SpinBox : public QSpinBox
{
protected:
virtual QString textFromValue(int value) const
{
return QString("%1").arg(value, 2, 10, QLatin1Char('0'));
}
};

#endif // SPINBOX_H

this code produce a error

ui_myqwidget.h:35: error: no matching function for call to 'SpinBox::SpinBox(QWidget*&)'

Wich is generated by designer, I'm I doing something wrong?

[Ginsengelf]

Hi, your promotion dialog should look like this:
spinbox.png
Then click "Add" and "Promote", and Designer should use your SpinBox instead of the QSpinBox. Make sure the path for the header file is correct.

Ginsengelf

[Andrewgaven]

I don't think the problem is on Designer, I'm runing QT on Linux (that why it looks a little bit different)
instantánea2.jpeg
and this are the issues that the compiler give me
issues.jpg

my Qwidget is named pcargar.ui
as you can see the error point to autogenerated ui_pcargar.h line 35

/********************************************************************************
** Form generated from reading UI file 'pcargar.ui'
**
** Created: Thu Aug 30 17:42:07 2012
**      by: Qt User Interface Compiler version 4.7.4
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/
 
#ifndef UI_PCARGAR_H
#define UI_PCARGAR_H
 
#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QHeaderView>
#include <QtGui/QLabel>
#include <QtGui/QWidget>
#include "spinbox.h"
 
QT_BEGIN_NAMESPACE
 
class Ui_pcargar
{
public:
    SpinBox *spinBox;
    QLabel *label;
 
    void setupUi(QWidget *pcargar)
    {
        if (pcargar->objectName().isEmpty())
            pcargar->setObjectName(QString::fromUtf8("pcargar"));
        pcargar->resize(400, 300);
        spinBox = new SpinBox(pcargar);
        spinBox->setObjectName(QString::fromUtf8("spinBox"));
        spinBox->setGeometry(QRect(190, 50, 56, 22));
        label = new QLabel(pcargar);
        label->setObjectName(QString::fromUtf8("label"));
        label->setGeometry(QRect(260, 60, 57, 14));
 
        retranslateUi(pcargar);
 
        QMetaObject::connectSlotsByName(pcargar);
    } // setupUi
 
    void retranslateUi(QWidget *pcargar)
    {
        pcargar->setWindowTitle(QApplication::translate("pcargar", "Form", 0, QApplication::UnicodeUTF8));
        label->setText(QApplication::translate("pcargar", "TextLabel", 0, QApplication::UnicodeUTF8));
    } // retranslateUi
 
};
 
namespace Ui {
    class pcargar: public Ui_pcargar {};
} // namespace Ui
 
QT_END_NAMESPACE
 
#endif // UI_PCARGAR_H

/********************************************************************************
** Form generated from reading UI file 'pcargar.ui'
**
** Created: Thu Aug 30 17:42:07 2012
**      by: Qt User Interface Compiler version 4.7.4
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

#ifndef UI_PCARGAR_H
#define UI_PCARGAR_H

#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QHeaderView>
#include <QtGui/QLabel>
#include <QtGui/QWidget>
#include "spinbox.h"

QT_BEGIN_NAMESPACE

class Ui_pcargar
{
public:
    SpinBox *spinBox;
    QLabel *label;

    void setupUi(QWidget *pcargar)
    {
        if (pcargar->objectName().isEmpty())
            pcargar->setObjectName(QString::fromUtf8("pcargar"));
        pcargar->resize(400, 300);
        spinBox = new SpinBox(pcargar);
        spinBox->setObjectName(QString::fromUtf8("spinBox"));
        spinBox->setGeometry(QRect(190, 50, 56, 22));
        label = new QLabel(pcargar);
        label->setObjectName(QString::fromUtf8("label"));
        label->setGeometry(QRect(260, 60, 57, 14));

        retranslateUi(pcargar);

        QMetaObject::connectSlotsByName(pcargar);
    } // setupUi

    void retranslateUi(QWidget *pcargar)
    {
        pcargar->setWindowTitle(QApplication::translate("pcargar", "Form", 0, QApplication::UnicodeUTF8));
        label->setText(QApplication::translate("pcargar", "TextLabel", 0, QApplication::UnicodeUTF8));
    } // retranslateUi

};

namespace Ui {
    class pcargar: public Ui_pcargar {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_PCARGAR_H

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Any ideas.

[d_stranz]

Promoting the widget in Designer has nothing to do with this error. Your definition of your SpinBox class is incorrect. Read what the compiler is telling you: It is looking for a constructor SpinBox( QWidget *& ). First, you need to define (and implement it). Second, QSpinBox is a QObject-based class, so any class derived from it must also include the Q_OBJECT macro as part of the class definition so the Qt meta-object and signal/sot mechanism work correctly for your class.

class SpinBox : public QSpinBox
{
    Q_OBJECT
 
public:
    SpinBox( QWidget * parent ) : QSpinBox( parent ) {}
 
protected:
    virtual QString textFromValue(int value) const
    {
        return QString("%1").arg(value, 2, 10, QLatin1Char('0'));
    }
};

class SpinBox : public QSpinBox
{
    Q_OBJECT

public:
    SpinBox( QWidget * parent ) : QSpinBox( parent ) {}

protected:
    virtual QString textFromValue(int value) const
    {
        return QString("%1").arg(value, 2, 10, QLatin1Char('0'));
    }
};

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[Andrewgaven]

Sorry for the newbie mistake that solve the problem, Thank you very much.