The QDoubleValidator class provides range checking of floating-point numbers. More...

#include <qvalidator.h>

Inheritance diagram for QDoubleValidator:

Collaboration diagram for QDoubleValidator:

Public Types
enum	Notation { StandardNotation , ScientificNotation }

Public Types inherited from QValidator
enum	State { Invalid , Intermediate , Acceptable }
	This enum type defines the states in which a validated string can exist. More...

Signals
void	bottomChanged (double bottom)
	This signal is emitted after the bottom property changed.

void	topChanged (double top)
	This signal is emitted after the top property changed.

void	decimalsChanged (int decimals)
	This signal is emitted after the decimals property changed.

void	notationChanged (QDoubleValidator::Notation notation)
	This signal is emitted after the notation property changed.

Signals inherited from QValidator
void	changed ()
	This signal is emitted when any property that may affect the validity of a string has changed.

Signals inherited from QObject
void	destroyed (QObject *=nullptr)
	This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked.

void	objectNameChanged (const QString &objectName, QPrivateSignal)
	This signal is emitted after the object's name has been changed.

Public Member Functions
	QDoubleValidator (QObject *parent=nullptr)
	Constructs a validator object with a parent object that accepts any double.

	QDoubleValidator (double bottom, double top, int decimals, QObject *parent=nullptr)
	Constructs a validator object with a parent object.

	~QDoubleValidator ()
	Destroys the validator.

QValidator::State	validate (QString &, int &) const override
	Returns \l Acceptable if the string input is in the correct format and contains a double within the valid range.

void	fixup (QString &input) const override

void	setRange (double bottom, double top, int decimals)
	Sets the validator to accept doubles from minimum to maximum inclusive, with at most decimals digits after the decimal point.

void	setRange (double bottom, double top)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the validator to accept doubles from minimum to maximum inclusive without changing the number of digits after the decimal point.

void	setBottom (double)

void	setTop (double)

void	setDecimals (int)

void	setNotation (Notation)

double	bottom () const

double	top () const

int	decimals () const

Notation	notation () const

Public Member Functions inherited from QValidator
	QValidator (QObject *parent=nullptr)
	Sets up the validator.

	~QValidator ()
	Destroys the validator, freeing any storage and other resources used.

void	setLocale (const QLocale &locale)
	Sets the locale that will be used for the validator.

QLocale	locale () const
	Returns the locale for the validator.

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)
	Constructs an object with parent object parent.

virtual	~QObject ()
	Destroys the object, deleting all its child objects.

virtual bool	event (QEvent *event)
	This virtual function receives events to an object and should return true if the event e was recognized and processed.

virtual bool	eventFilter (QObject watched, QEvent event)
	Filters events if this object has been installed as an event filter for the watched object.

QString	objectName () const

Q_WEAK_OVERLOAD void	setObjectName (const QString &name)
	Sets the object's name to name.

void	setObjectName (QAnyStringView name)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const
	Returns `true` if the object is a widget; otherwise returns `false`.

bool	isWindowType () const
	Returns `true` if the object is a window; otherwise returns `false`.

bool	isQuickItemType () const
	Returns `true` if the object is a QQuickItem; otherwise returns `false`.

bool	signalsBlocked () const noexcept
	Returns `true` if signals are blocked; otherwise returns `false`.

bool	blockSignals (bool b) noexcept
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it).

QThread *	thread () const
	Returns the thread in which the object lives.

bool	moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL)
	Changes the thread affinity for this object and its children and returns `true` on success.

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
	This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds.

int	startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)
	Kills the timer with timer identifier, id.

void	killTimer (Qt::TimerId id)

template<typename T >
T	findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object.

template<typename T >
QList< T >	findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects.

template<typename T >
T	findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

const QObjectList &	children () const
	Returns a list of child objects.

void	setParent (QObject *parent)
	Makes the object a child of parent.

void	installEventFilter (QObject *filterObj)
	Installs an event filter filterObj on this object.

void	removeEventFilter (QObject *obj)
	Removes an event filter object obj from this object.

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const

bool	disconnect (const char signal=nullptr, const QObject receiver=nullptr, const char *member=nullptr) const

bool	disconnect (const QObject receiver, const char member=nullptr) const

void	dumpObjectTree () const
	Dumps a tree of children to the debug output.

void	dumpObjectInfo () const
	Dumps information about signal connections, etc.

bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value.

bool	setProperty (const char *name, QVariant &&value)

QVariant	property (const char *name) const
	Returns the value of the object's name property.

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const
	Returns a pointer to the parent object.

bool	inherits (const char *classname) const
	Returns `true` if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns `false`.

Properties
double	bottom
	the validator's minimum acceptable value

double	top
	the validator's maximum acceptable value

int	decimals
	the validator's maximum number of digits after the decimal point

Notation	notation
	the notation of how a string can describe a number

Properties inherited from QObject
QString	objectName
	the name of this object

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Static Public Member Functions inherited from QObject
static QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char member, Qt::ConnectionType=Qt::AutoConnection)
	\threadsafe

static QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static QMetaObject::Connection	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)
	\threadsafe

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::Connection &)
	Disconnect a connection.

template<typename Func1 , typename Func2 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object receiver, Func2 slot)

template<typename Func1 >
static bool	disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject receiver, void **zero)

Protected Member Functions inherited from QValidator
	QValidator (QObjectPrivate &d, QObject *parent)

	QValidator (QValidatorPrivate &d, QObject *parent)

Protected Member Functions inherited from QObject
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr.

int	senderSignalIndex () const

int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal.

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	timerEvent (QTimerEvent *event)
	This event handler can be reimplemented in a subclass to receive timer events for the object.

virtual void	childEvent (QChildEvent *event)
	This event handler can be reimplemented in a subclass to receive child events.

virtual void	customEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive custom events.

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Related Symbols inherited from QObject
template< class T > T	qobject_cast (const QObject *object)
	Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr.

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList
	\macro Q_CLASSINFO(Name, Value)

Detailed Description

The QDoubleValidator class provides range checking of floating-point numbers.

\inmodule QtGui

QDoubleValidator provides an upper bound, a lower bound, and a limit on the number of digits after the decimal point.

You can set the acceptable range in one call with setRange(), or with setBottom() and setTop(). Set the number of decimal places with setDecimals(). The validate() function returns the validation state.

QDoubleValidator uses its locale() to interpret the number. For example, in the German locale, "1,234" will be accepted as the fractional number 1.234. In Arabic locales, QDoubleValidator will accept Arabic digits.

Note: The QLocale::NumberOptions set on the locale() also affect the way the number is interpreted. For example, since QLocale::RejectGroupSeparator is not set by default (except on the "C" locale), the validator will accept group separators. If the string passes validation, pass it to locale().toDouble() to obtain its numeric value.

See also: QIntValidator, QRegularExpressionValidator, QLocale::toDouble(), {Line Edits Example}

Definition at line 88 of file qvalidator.h.

Member Enumeration Documentation

◆ Notation

enum QDoubleValidator::Notation

Since: 4.3 This enum defines the allowed notations for entering a double.

\value StandardNotation The string is written in the standard format, a whole number part optionally followed by a separator and fractional part, for example {"0.015"}.

\value ScientificNotation The string is written in scientific form, which optionally appends an exponent part to the standard format, for example {"1.5E-2"}.

The whole number part may, as usual, include a sign. This, along with the separators for fractional part, exponent and any digit-grouping, depend on locale. QDoubleValidator doesn't check the placement (which would also depend on locale) of any digit-grouping separators it finds, but it will reject input that contains them if \l QLocale::RejectGroupSeparator is set in locale().numberOptions().

See also: QLocale::numberOptions(), QLocale::decimalPoint(), QLocale::exponential(), QLocale::negativeSign()

Enumerator
StandardNotation
ScientificNotation

Definition at line 101 of file qvalidator.h.

Constructor & Destructor Documentation

◆ QDoubleValidator() [1/2]

QDoubleValidator::QDoubleValidator ( QObject * parent = nullptr )

explicit

Constructs a validator object with a parent object that accepts any double.

Definition at line 583 of file qvalidator.cpp.

◆ QDoubleValidator() [2/2]

QDoubleValidator::QDoubleValidator	(	double	bottom,
		double	top,
		int	decimals,
		QObject *	parent = nullptr )

Constructs a validator object with a parent object.

This validator will accept doubles from bottom to top inclusive, with up to decimals digits after the decimal point.

Definition at line 595 of file qvalidator.cpp.

References bottom, decimals, and top.

◆ ~QDoubleValidator()

QDoubleValidator::~QDoubleValidator ( )

Destroys the validator.

Definition at line 609 of file qvalidator.cpp.

Member Function Documentation

◆ bottom()

double QDoubleValidator::bottom ( ) const

inline

Definition at line 116 of file qvalidator.h.

◆ bottomChanged

void QDoubleValidator::bottomChanged ( double bottom )

signal

This signal is emitted after the bottom property changed.

See also: QDoubleValidator::top(), QDoubleValidator::setTop(), QDoubleValidator::bottom(), QDoubleValidator::setBottom()

Referenced by setRange().

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◆ decimals()

int QDoubleValidator::decimals ( ) const

inline

Definition at line 118 of file qvalidator.h.

References dec.

◆ decimalsChanged

void QDoubleValidator::decimalsChanged ( int decimals )

signal

This signal is emitted after the decimals property changed.

Referenced by setRange().

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◆ fixup()

void QDoubleValidator::fixup ( QString & input ) const

overridevirtual

Since: 6.3 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Attempts to fix the input string to an \l Acceptable representation of a double.

The format of the number is determined by \l notation(), \l decimals(), \l locale() and the latter's \l {QLocale::}{numberOptions()}.

To comply with \l notation(), when \l ScientificNotation is used, the fixed value will be represented in its normalized form, which means that any non-zero value will have one non-zero digit before the decimal point.

QString input = "0.98765e2";
QDoubleValidator val;
val.setLocale(QLocale::C);
val.setNotation(QDoubleValidator::ScientificNotation);
val.fixup(input); // input == "9.8765e+01"

To comply with \l decimals(), when it is {-1} the number of digits used will be determined by \l QLocale::FloatingPointShortest. Otherwise, the fractional part of the number is truncated (with rounding, as appropriate) if its length exceeds \l decimals(). When \l notation() is \l ScientificNotation this is done after the number has been put into its normalized form.

input = "-1234.6789";
val.setDecimals(2);
val.setLocale(QLocale::C);
val.setNotation(QDoubleValidator::StandardNotation);
val.fixup(input); // input == "-1234.68"

Note: If \l decimals() is set to, and the string provides, more than {std::numeric_limits<double>::digits10}, digits beyond that many in the fractional part may be changed. The resulting string shall encode the same floating-point number, when parsed to a double.

Reimplemented from QValidator.

Definition at line 731 of file qvalidator.cpp.

References d, QLocaleData::DoubleScientificMode, QLocaleData::DoubleStandardMode, QValidator::locale(), and StandardNotation.

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◆ notation()

QDoubleValidator::Notation QDoubleValidator::notation ( ) const

Definition at line 895 of file qvalidator.cpp.

References d.

◆ notationChanged

void QDoubleValidator::notationChanged ( QDoubleValidator::Notation notation )

signal

This signal is emitted after the notation property changed.

QDoubleValidator::Notation is not a registered metatype, so for queued connections, you will have to register it with Q_DECLARE_METATYPE() and qRegisterMetaType().

Referenced by setNotation().

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◆ setBottom()

void QDoubleValidator::setBottom ( double bottom )

Definition at line 840 of file qvalidator.cpp.

References decimals, setRange(), and top.

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◆ setDecimals()

void QDoubleValidator::setDecimals ( int decimals )

Definition at line 870 of file qvalidator.cpp.

References bottom, decimals, setRange(), and top.

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◆ setNotation()

void QDoubleValidator::setNotation ( Notation newNotation )

Definition at line 885 of file qvalidator.cpp.

References QValidator::changed(), d, emit, and notationChanged().

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◆ setRange() [1/2]

void QDoubleValidator::setRange	(	double	bottom,
		double	top )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the validator to accept doubles from minimum to maximum inclusive without changing the number of digits after the decimal point.

Definition at line 826 of file qvalidator.cpp.

References decimals, and setRange().

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◆ setRange() [2/2]

void QDoubleValidator::setRange	(	double	minimum,
		double	maximum,
		int	decimals )

Sets the validator to accept doubles from minimum to maximum inclusive, with at most decimals digits after the decimal point.

Note: Setting the number of decimals to -1 effectively sets it to unlimited. This is also the value used by a default-constructed validator.

Definition at line 796 of file qvalidator.cpp.

References bottomChanged(), QValidator::changed(), decimals, decimalsChanged(), emit, and topChanged().

Referenced by setBottom(), setDecimals(), setRange(), and setTop().

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◆ setTop()

void QDoubleValidator::setTop ( double top )

Definition at line 855 of file qvalidator.cpp.

References bottom, decimals, and setRange().

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◆ top()

double QDoubleValidator::top ( ) const

inline

Definition at line 117 of file qvalidator.h.

◆ topChanged

void QDoubleValidator::topChanged ( double top )

signal

This signal is emitted after the top property changed.

See also: QDoubleValidator::top(), QDoubleValidator::setTop(), QDoubleValidator::bottom(), QDoubleValidator::setBottom()

Referenced by setRange().

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◆ validate()

QValidator::State QDoubleValidator::validate	(	QString &	input,
		int &	pos ) const

overridevirtual

Returns \l Acceptable if the string input is in the correct format and contains a double within the valid range.

Returns \l Intermediate if input is in the wrong format or contains a double outside the range.

Returns \l Invalid if the input doesn't represent a double or has too many digits after the decimal point.

Note: If the valid range consists of just positive doubles (e.g. 0.0 to 100.0) and input is a negative double then \l Invalid is returned. If notation() is set to StandardNotation, and the input contains more digits before the decimal point than a double in the valid range may have, \l Invalid is returned. If notation() is ScientificNotation, and the input is not in the valid range, \l Intermediate is returned. The value may yet become valid by changing the exponent.

By default, the pos parameter is not used by this validator.

Implements QValidator.

Definition at line 640 of file qvalidator.cpp.

References d, QLocaleData::DoubleScientificMode, QLocaleData::DoubleStandardMode, QValidator::locale(), ScientificNotation, and StandardNotation.

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Property Documentation

◆ bottom

QDoubleValidator::bottom

readwrite

the validator's minimum acceptable value

By default, this property contains a value of -infinity.

See also: setRange()

Definition at line 91 of file qvalidator.h.

Referenced by QDoubleValidator(), setDecimals(), and setTop().

◆ decimals

QDoubleValidator::decimals

readwrite

the validator's maximum number of digits after the decimal point

By default, this property contains a value of -1, which means any number of digits is accepted.

See also: setRange()

Definition at line 93 of file qvalidator.h.

Referenced by QDoubleValidator(), setBottom(), setDecimals(), setRange(), setRange(), and setTop().

◆ notation

QDoubleValidator::notation

readwrite

the notation of how a string can describe a number

Since: 4.3

By default, this property is set to ScientificNotation.

See also: Notation

Definition at line 94 of file qvalidator.h.

◆ top

QDoubleValidator::top

readwrite

the validator's maximum acceptable value

By default, this property contains a value of infinity.

See also: setRange()

Definition at line 92 of file qvalidator.h.

Referenced by QDoubleValidator(), setBottom(), and setDecimals().

The documentation for this class was generated from the following files:

qtbase/src/gui/util/qvalidator.h (05fc3aef53348fb58be6308076e000825b704e58)
qtbase/src/gui/util/qvalidator.cpp (f1077737426ca18511cc074186ed180dd2119975)

Public Types

Signals

Public Member Functions

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ Notation

Constructor & Destructor Documentation

◆ QDoubleValidator() [1/2]

◆ QDoubleValidator() [2/2]

◆ ~QDoubleValidator()

Member Function Documentation

◆ bottom()

◆ bottomChanged

◆ decimals()

◆ decimalsChanged

◆ fixup()

◆ notation()

◆ notationChanged

◆ setBottom()

◆ setDecimals()

◆ setNotation()

◆ setRange() [1/2]

◆ setRange() [2/2]

◆ setTop()

◆ top()

◆ topChanged

◆ validate()

Property Documentation

◆ bottom

◆ decimals

◆ notation

◆ top