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QSpinBox Class Reference
[QtGui module]

The QSpinBox class provides a spin box widget. More...

Inherits QAbstractSpinBox.


Qt Signals

Detailed Description

The QSpinBox class provides a spin box widget.

QSpinBox is designed to handle integers and discrete sets of values (e.g., month names); use QDoubleSpinBox for floating point values.

QSpinBox allows the user to choose a value by clicking the up/down buttons or pressing up/down on the keyboard to increase/decrease the value currently displayed. The user can also type the value in manually. The spin box supports integer values but can be extended to use different strings with validate(), textFromValue() and valueFromText().

Every time the value changes QSpinBox emits the valueChanged() signals. The current value can be fetched with value() and set with setValue().

Clicking the up/down buttons or using the keyboard accelerator's up and down arrows will increase or decrease the current value in steps of size singleStep(). If you want to change this behaviour you can reimplement the virtual function stepBy(). The minimum and maximum value and the step size can be set using one of the constructors, and can be changed later with setMinimum(), setMaximum() and setSingleStep().

Most spin boxes are directional, but QSpinBox can also operate as a circular spin box, i.e. if the range is 0-99 and the current value is 99, clicking "up" will give 0 if wrapping() is set to true. Use setWrapping() if you want circular behavior.

The displayed value can be prepended and appended with arbitrary strings indicating, for example, currency or the unit of measurement. See setPrefix() and setSuffix(). The text in the spin box is retrieved with text() (which includes any prefix() and suffix()), or with cleanText() (which has no prefix(), no suffix() and no leading or trailing whitespace).

It is often desirable to give the user a special (often default) choice in addition to the range of numeric values. See setSpecialValueText() for how to do this with QSpinBox.

Screenshot of a Windows XP spin box A spin box shown in the Windows XP widget style.
Screenshot of a Plastique spin box A spin box shown in the Plastique widget style.
Screenshot of a Macintosh spin box A spin box shown in the Macintosh widget style.

Subclassing QSpinBox

If using prefix(), suffix(), and specialValueText() don't provide enough control, you subclass QSpinBox and reimplement valueFromText() and textFromValue(). For example, here's the code for a custom spin box that allows the user to enter icon sizes (e.g., "32 x 32"):

 int IconSizeSpinBox.valueFromText(const QString &text) const
     QRegExp regExp(tr("(\\d+)(\\s*[xx]\\s*\\d+)?"));

     if (regExp.exactMatch(text)) {
         return regExp.cap(1).toInt();
     } else {
         return 0;

 QString IconSizeSpinBox.textFromValue(int value) const
     return tr("%1 x %1").arg(value);

See the Icons example for the full source code.

Method Documentation

QSpinBox.__init__ (self, QWidget parent = None)

The parent argument, if not None, causes self to be owned by Qt instead of PyQt.

Constructs a spin box with 0 as minimum value and 99 as maximum value, a step value of 1. The value is initially set to 0. It is parented to parent.

See also setMinimum(), setMaximum(), and setSingleStep().

QString QSpinBox.cleanText (self)

bool QSpinBox.event (self, QEvent e)

Reimplemented from QObject.event().

QString str QSpinBox.fixup (self, QString str)

Reimplemented from QAbstractSpinBox.fixup().

QSpinBox.fixup (self, QString str)

int QSpinBox.maximum (self)

int QSpinBox.minimum (self)

QString QSpinBox.prefix (self)

QSpinBox.setMaximum (self, int max)

QSpinBox.setMinimum (self, int min)

QSpinBox.setPrefix (self, QString p)

QSpinBox.setRange (self, int min, int max)

Convenience function to set the minimum, and maximum values with a single function call.

 setRange(minimum, maximum);

is equivalent to:


See also minimum and maximum.

QSpinBox.setSingleStep (self, int val)

QSpinBox.setSuffix (self, QString s)

QSpinBox.setValue (self, int val)

This method is also a Qt slot with the C++ signature void setValue(int).

int QSpinBox.singleStep (self)

QString QSpinBox.suffix (self)

QString QSpinBox.textFromValue (self, int v)

This virtual function is used by the spin box whenever it needs to display the given value. The default implementation returns a string containing value printed in the standard way using QWidget.locale().toString(), but with the thousand separator removed. Reimplementations may return anything. (See the example in the detailed description.)

Note: QSpinBox does not call this function for specialValueText() and that neither prefix() nor suffix() should be included in the return value.

If you reimplement this, you may also need to reimplement valueFromText() and validate()

See also valueFromText(), validate(), and QLocale.groupSeparator().

(QValidator.State, QString input, int pos) QSpinBox.validate (self, QString input, int pos)

Reimplemented from QAbstractSpinBox.validate().

(QValidator.State, int pos) QSpinBox.validate (self, QString input, int pos)

int QSpinBox.value (self)

int QSpinBox.valueFromText (self, QString text)

This virtual function is used by the spin box whenever it needs to interpret text entered by the user as a value.

Subclasses that need to display spin box values in a non-numeric way need to reimplement this function.

Note: QSpinBox handles specialValueText() separately; this function is only concerned with the other values.

See also textFromValue() and validate().

Qt Signal Documentation

void valueChanged (int)

This is the default overload of this signal.

This signal is emitted whenever the spin box's value is changed. The new value's integer value is passed in i.

void valueChanged (const QString&)

This is an overloaded function.

The new value is passed literally in text with no prefix() or suffix().

PyQt 4.9.4 for WindowsCopyright © Riverbank Computing Ltd and Nokia 2012Qt 4.8.2