QSpinBox(3qt)QSpinBox(3qt)NAMEQSpinBox - Spin box widget (spin button)
SYNOPSIS
#include <qspinbox.h>
Inherits QWidget and QRangeControl.
Public Members
QSpinBox ( QWidget * parent = 0, const char * name = 0 )
QSpinBox ( int minValue, int maxValue, int step = 1, QWidget * parent =
0, const char * name = 0 )
~QSpinBox ()
QString text () const
virtual QString prefix () const
virtual QString suffix () const
virtual QString cleanText () const
virtual void setSpecialValueText ( const QString & text )
QString specialValueText () const
virtual void setWrapping ( bool on )
bool wrapping () const
enum ButtonSymbols { UpDownArrows, PlusMinus }
virtual void setButtonSymbols ( ButtonSymbols )
ButtonSymbols buttonSymbols () const
virtual void setValidator ( const QValidator * v )
const QValidator * validator () const
int minValue () const
int maxValue () const
void setMinValue ( int )
void setMaxValue ( int )
int lineStep () const
void setLineStep ( int )
int value () const
QRect upRect () const
QRect downRect () const
Public Slots
virtual void setValue ( int value )
virtual void setPrefix ( const QString & text )
virtual void setSuffix ( const QString & text )
virtual void stepUp ()
virtual void stepDown ()
virtual void selectAll ()
Signals
void valueChanged ( int value )
void valueChanged ( const QString & valueText )
Properties
ButtonSymbols buttonSymbols - the current button symbol mode
QString cleanText - the spin box's text with no prefix(), suffix() or
leading or trailing whitespace (read only)
int lineStep - the line step
int maxValue - the maximum value of the spin box
int minValue - the minimum value of the spin box
QString prefix - the spin box's prefix
QString specialValueText - the special-value text
QString suffix - the suffix of the spin box
QString text - the spin box's text, including any prefix() and suffix()
(read only)
int value - the value of the spin box
bool wrapping - whether it is possible to step the value from the
highest value to the lowest value and vice versa
Protected Members
virtual QString mapValueToText ( int v )
virtual int mapTextToValue ( bool * ok )
QString currentValueText ()
virtual void updateDisplay ()
virtual void interpretText ()
QLineEdit * editor () const
virtual void valueChange ()
virtual void rangeChange ()
virtual bool eventFilter ( QObject * o, QEvent * ev )
Protected Slots
void textChanged ()
DESCRIPTION
The QSpinBox class provides a spin box widget (spin button).
QSpinBox allows the user to choose a value either by clicking the
up/down buttons to increase/decrease the value currently displayed or
by typing the value directly into the spin box. If the value is entered
directly into the spin box, Enter (or Return) must be pressed to apply
the new value. The value is usually an integer.
Every time the value changes QSpinBox emits the valueChanged() signal.
The current value can be fetched with value() and set with setValue().
The spin box keeps the value within a numeric range, and to multiples
of the lineStep() size (see QRangeControl for details). 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
lineStep(). The minimum and maximum value and the step size can be set
using one of the constructors, and can be changed later with
setMinValue(), setMaxValue() and setLineStep().
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. 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). currentValueText() returns the spin box's current
value as text.
Normally the spin box displays up and down arrows in the buttons. You
can use setButtonSymbols() to change the display to show + and -
symbols if you prefer. In either case the up and down arrow keys work
as expected.
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.
The default QWidget::focusPolicy() is StrongFocus.
If using prefix(), suffix() and specialValueText() don't provide enough
control, you can ignore them and subclass QSpinBox instead.
QSpinBox can easily be subclassed to allow the user to input things
other than an integer value as long as the allowed input can be mapped
to a range of integers. This can be done by overriding the virtual
functions mapValueToText() and mapTextToValue(), and setting another
suitable validator using setValidator().
For example, these functions could be changed so that the user provided
values from 0.0 to 10.0, or -1 to signify 'Auto', while the range of
integers used inside the program would be -1 to 100:
class MySpinBox : public QSpinBox
{
Q_OBJECT
public:
...
QString mapValueToText( int value )
{
if ( value == -1 ) // special case
return QString( "Auto" );
return QString( "%1.%2" ) // 0.0 to 10.0
.arg( value / 10 ).arg( value % 10 );
}
int mapTextToValue( bool *ok )
{
if ( text() == "Auto" ) // special case
return -1;
return (int) ( 10 * text().toFloat() ); // 0 to 100
}
};
[Image Omitted]
[Image Omitted]
See also QScrollBar, QSlider, GUI Design Handbook: Spin Box, and Basic
Widgets.
Member Type Documentation
QSpinBox::ButtonSymbols
This enum type determines what the buttons in a spin box show.
QSpinBox::UpDownArrows - the buttons show little arrows in the classic
style.
QSpinBox::PlusMinus - the buttons show + and - symbols.
See also QSpinBox::buttonSymbols.
MEMBER FUNCTION DOCUMENTATIONQSpinBox::QSpinBox ( QWidget * parent = 0, const char * name = 0 )
Constructs a spin box with the default QRangeControl range and step
values. It is called name and has parent parent.
See also minValue, maxValue, setRange(), lineStep, and setSteps().
QSpinBox::QSpinBox ( int minValue, int maxValue, int step = 1, QWidget *
parent = 0, const char * name = 0 )
Constructs a spin box that allows values from minValue to maxValue
inclusive, with step amount step. The value is initially set to
minValue.
The spin box is called name and has parent parent.
See also minValue, maxValue, setRange(), lineStep, and setSteps().
QSpinBox::~QSpinBox ()
Destroys the spin box, freeing all memory and other resources.
ButtonSymbols QSpinBox::buttonSymbols () const
Returns the current button symbol mode. See the "buttonSymbols"
property for details.
QString QSpinBox::cleanText () const [virtual]
Returns the spin box's text with no prefix(), suffix() or leading or
trailing whitespace. See the "cleanText" property for details.
QString QSpinBox::currentValueText () [protected]
Returns the full text calculated from the current value, including any
prefix and suffix. If there is special value text and the value is
minValue() the specialValueText() is returned.
QRect QSpinBox::downRect () const
Returns the geometry of the "down" button.
QLineEdit * QSpinBox::editor () const [protected]
Returns a pointer to the embedded QLineEdit.
bool QSpinBox::eventFilter ( QObject * o, QEvent * ev ) [virtual protected]
Intercepts and handles the events coming to the embedded QLineEdit that
have special meaning for the QSpinBox. The object is passed as o and
the event is passed as ev.
Reimplemented from QObject.
void QSpinBox::interpretText () [virtual protected]
QSpinBox calls this after the user has manually edited the contents of
the spin box (i.e. by typing in the embedded QLineEdit, rather than
using the up/down buttons/keys).
The default implementation of this function interprets the new text
using mapTextToValue(). If mapTextToValue() is successful, it changes
the spin box's value; if not, the value is left unchanged.
See also editor().
int QSpinBox::lineStep () const
Returns the line step. See the "lineStep" property for details.
int QSpinBox::mapTextToValue ( bool * ok ) [virtual protected]
This virtual function is used by the spin box whenever it needs to
interpret text entered by the user as a value. The text is available as
text() and as cleanText(), and this function must parse it if possible.
If ok is not 0: if it parses the text successfully, *ok is set to TRUE;
otherwise *ok is set to FALSE.
Subclasses that need to display spin box values in a non-numeric way
need to reimplement this function.
Note that Qt handles specialValueText() separately; this function is
only concerned with the other values.
The default implementation tries to interpret the text() as an integer
in the standard way and returns the integer value.
See also interpretText() and mapValueToText().
QString QSpinBox::mapValueToText ( int v ) [virtual protected]
This virtual function is used by the spin box whenever it needs to
display value v. The default implementation returns a string containing
v printed in the standard way. Reimplementations may return anything.
(See the example in the detailed description.)
Note that Qt does not call this function for specialValueText() and
that neither prefix() nor suffix() are included in the return value.
If you reimplement this, you may also need to reimplement
mapTextToValue().
See also updateDisplay() and mapTextToValue().
int QSpinBox::maxValue () const
Returns the maximum value of the spin box. See the "maxValue" property
for details.
int QSpinBox::minValue () const
Returns the minimum value of the spin box. See the "minValue" property
for details.
QString QSpinBox::prefix () const [virtual]
Returns the spin box's prefix. See the "prefix" property for details.
void QSpinBox::rangeChange () [virtual protected]
This virtual function is called by QRangeControl whenever the range has
changed. It adjusts the default validator and updates the display; if
you need additional processing, you can reimplement this function.
Reimplemented from QRangeControl.
void QSpinBox::selectAll () [virtual slot]
Selects all the text in the spin box's editor.
void QSpinBox::setButtonSymbols ( ButtonSymbols ) [virtual]
Sets the current button symbol mode. See the "buttonSymbols" property
for details.
void QSpinBox::setLineStep ( int )
Sets the line step. See the "lineStep" property for details.
void QSpinBox::setMaxValue ( int )
Sets the maximum value of the spin box. See the "maxValue" property for
details.
void QSpinBox::setMinValue ( int )
Sets the minimum value of the spin box. See the "minValue" property for
details.
void QSpinBox::setPrefix ( const QString & text ) [virtual slot]
Sets the spin box's prefix to text. See the "prefix" property for
details.
void QSpinBox::setSpecialValueText ( const QString & text ) [virtual]
Sets the special-value text to text. See the "specialValueText"
property for details.
void QSpinBox::setSuffix ( const QString & text ) [virtual slot]
Sets the suffix of the spin box to text. See the "suffix" property for
details.
void QSpinBox::setValidator ( const QValidator * v ) [virtual]
Sets the validator to v. The validator controls what keyboard input is
accepted when the user is editing in the value field. The default is to
use a suitable QIntValidator.
Use setValidator(0) to turn off input validation (entered input will
still be kept within the spin box's range).
void QSpinBox::setValue ( int value ) [virtual slot]
Sets the value of the spin box to value. See the "value" property for
details.
void QSpinBox::setWrapping ( bool on ) [virtual]
Sets whether it is possible to step the value from the highest value to
the lowest value and vice versa to on. See the "wrapping" property for
details.
QString QSpinBox::specialValueText () const
Returns the special-value text. See the "specialValueText" property for
details.
void QSpinBox::stepDown () [virtual slot]
Decreases the spin box's value one lineStep(), wrapping as necessary if
wrapping() is TRUE. This is the same as clicking on the pointing-down
button and can be used for keyboard accelerators, for example.
See also stepUp(), subtractLine(), lineStep, setSteps(), value, and
value.
void QSpinBox::stepUp () [virtual slot]
Increases the spin box's value by one lineStep(), wrapping as necessary
if wrapping() is TRUE. This is the same as clicking on the pointing-up
button and can be used for keyboard accelerators, for example.
See also stepDown(), addLine(), lineStep, setSteps(), value, and value.
QString QSpinBox::suffix () const [virtual]
Returns the suffix of the spin box. See the "suffix" property for
details.
QString QSpinBox::text () const
Returns the spin box's text, including any prefix() and suffix(). See
the "text" property for details.
void QSpinBox::textChanged () [protected slot]
This slot is called whenever the user edits the spin box's text.
QRect QSpinBox::upRect () const
Returns the geometry of the "up" button.
void QSpinBox::updateDisplay () [virtual protected]
Updates the contents of the embedded QLineEdit to reflect the current
value using mapValueToText(). Also enables/disables the up/down push
buttons accordingly.
See also mapValueToText().
const QValidator * QSpinBox::validator () const
Returns the validator that constrains editing for this spin box if
there is any; otherwise returns 0.
See also setValidator() and QValidator.
int QSpinBox::value () const
Returns the value of the spin box. See the "value" property for
details.
void QSpinBox::valueChange () [virtual protected]
This virtual function is called by QRangeControl whenever the value has
changed. The QSpinBox reimplementation updates the display and emits
the valueChanged() signals; if you need additional processing, either
reimplement this or connect to one of the valueChanged() signals.
Reimplemented from QRangeControl.
void QSpinBox::valueChanged ( int value ) [signal]
This signal is emitted every time the value of the spin box changes;
the new value is passed in value. This signal will be emitted as a
result of a call to setValue(), or because the user changed the value
by using a keyboard accelerator or mouse click, etc.
Note that the valueChanged() signal is emitted every time, not just for
the "last" step; i.e. if the user clicks "up" three times, this signal
is emitted three times.
See also value.
Examples:
void QSpinBox::valueChanged ( const QString & valueText ) [signal]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This signal is emitted whenever the valueChanged( int ) signal is
emitted, i.e. every time the value of the spin box changes (whatever
the cause, e.g. by setValue(), by a keyboard accelerator, by mouse
clicks, etc.).
The valueText parameter is the same string that is displayed in the
edit field of the spin box.
See also value, prefix, suffix, and specialValueText.
bool QSpinBox::wrapping () const
Returns TRUE if it is possible to step the value from the highest value
to the lowest value and vice versa; otherwise returns FALSE. See the
"wrapping" property for details.
Property Documentation
ButtonSymbols buttonSymbols
This property holds the current button symbol mode.
The possible values can be either UpDownArrows or PlusMinus. The
default is UpDownArrows.
See also ButtonSymbols.
Set this property's value with setButtonSymbols() and get this
property's value with buttonSymbols().
QString cleanText
This property holds the spin box's text with no prefix(), suffix() or
leading or trailing whitespace.
Get this property's value with cleanText().
See also text, prefix, and suffix.
int lineStep
This property holds the line step.
When the user uses the arrows to change the spin box's value the value
will be incremented/decremented by the amount of the line step.
The setLineStep() function calls the virtual stepChange() function if
the new line step is different from the previous setting.
See also QRangeControl::setSteps() and setRange().
Set this property's value with setLineStep() and get this property's
value with lineStep().
int maxValue
This property holds the maximum value of the spin box.
When setting this property, QSpinBox::minValue is adjusted, if
necessary, to ensure that the range remains valid.
See also setRange() and specialValueText.
Set this property's value with setMaxValue() and get this property's
value with maxValue().
int minValue
This property holds the minimum value of the spin box.
When setting this property, QSpinBox::maxValue is adjusted, if
necessary, to ensure that the range remains valid.
See also setRange() and specialValueText.
Set this property's value with setMinValue() and get this property's
value with minValue().
QString prefix
This property holds the spin box's prefix.
The prefix is prepended to the start of the displayed value. Typical
use is to display a unit of measurement or a currency symbol. For
example:
sb->setPrefix( "$" );
To turn off the prefix display, set this property to an empty string.
The default is no prefix. The prefix is not displayed for the
minValue() if specialValueText() is not empty.
If no prefix is set, prefix() returns QString::null.
See also suffix.
Set this property's value with setPrefix() and get this property's
value with prefix().
QString specialValueText
This property holds the special-value text.
If set, the spin box will display this text instead of a numeric value
whenever the current value is equal to minVal(). Typical use is to
indicate that this choice has a special (default) meaning.
For example, if your spin box allows the user to choose the margin
width in a print dialog and your application is able to automatically
choose a good margin width, you can set up the spin box like this:
QSpinBox marginBox( -1, 20, 1, parent, "marginBox" );
marginBox->setSuffix( " mm" );
marginBox->setSpecialValueText( "Auto" );
The user will then be able to choose a margin width from 0-20
millimeters or select "Auto" to leave it to the application to choose.
Your code must then interpret the spin box value of -1 as the user
requesting automatic margin width.
All values are displayed with the prefix() and suffix() (if set),
except for the special value, which only shows the special value text.
To turn off the special-value text display, call this function with an
empty string. The default is no special-value text, i.e. the numeric
value is shown as usual.
If no special-value text is set, specialValueText() returns
QString::null.
Set this property's value with setSpecialValueText() and get this
property's value with specialValueText().
QString suffix
This property holds the suffix of the spin box.
The suffix is appended to the end of the displayed value. Typical use
is to display a unit of measurement or a currency symbol. For example:
sb->setSuffix( " km" );
To turn off the suffix display, set this property to an empty string.
The default is no suffix. The suffix is not displayed for the
minValue() if specialValueText() is not empty.
If no suffix is set, suffix() returns a QString::null.
See also prefix.
Set this property's value with setSuffix() and get this property's
value with suffix().
QString text
This property holds the spin box's text, including any prefix() and
suffix().
There is no default text.
See also value.
Get this property's value with text().
int value
This property holds the value of the spin box.
Set this property's value with setValue() and get this property's value
with value().
See also QRangeControl::setValue().
bool wrapping
This property holds whether it is possible to step the value from the
highest value to the lowest value and vice versa.
By default, wrapping is turned off.
If you have a range of 0..100 and wrapping is off when the user reaches
100 and presses the Up Arrow nothing will happen; but if wrapping is on
the value will change from 100 to 0, then to 1, etc. When wrapping is
on, navigating past the highest value takes you to the lowest and vice
versa.
See also minValue, maxValue, and setRange().
Set this property's value with setWrapping() and get this property's
value with wrapping().
SEE ALSO
http://doc.trolltech.com/qspinbox.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
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http://doc.trolltech.com/bughowto.html. Good bug reports help us to
help you. Thank you.
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If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qspinbox.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QSpinBox(3qt)
