The QValidator class provides validation of input text. More...

#include <qvalidator.h>

Inheritance diagram for QValidator:

Collaboration diagram for QValidator:

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

Signals
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
	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.

virtual State	validate (QString &, int &) const =0
	This virtual function returns \l Invalid if input is invalid according to this validator's rules, \l Intermediate if it is likely that a little more editing will make the input acceptable (e.g.

virtual void	fixup (QString &) const
	This function attempts to change input to be valid according to this validator's rules.

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`.

Protected Member Functions
	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)

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 Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Properties inherited from QObject
QString	objectName
	the name of this object

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 QValidator class provides validation of input text.

\inmodule QtGui

The class itself is abstract. Two subclasses, \l QIntValidator and \l QDoubleValidator, provide basic numeric-range checking, and \l QRegularExpressionValidator provides general checking using a custom regular expression.

If the built-in validators aren't sufficient, you can subclass QValidator. The class has two virtual functions: validate() and fixup().

\l validate() must be implemented by every subclass. It returns \l Invalid, \l Intermediate or \l Acceptable depending on whether its argument is valid (for the subclass's definition of valid).

These three states require some explanation. An \l Invalid string is clearly invalid. \l Intermediate is less obvious: the concept of validity is difficult to apply when the string is incomplete (still being edited). QValidator defines \l Intermediate as the property of a string that is neither clearly invalid nor acceptable as a final result. \l Acceptable means that the string is acceptable as a final result. One might say that any string that is a plausible intermediate state during entry of an \l Acceptable string is \l Intermediate.

Here are some examples:

\list

For a line edit that accepts integers from 10 to 1000 inclusive, 42 and 123 are \l Acceptable, the empty string, 5, or 1234 are \l Intermediate, and "asdf" and 10114 is \l Invalid.

For an editable combobox that accepts URLs, any well-formed URL is \l Acceptable, "http://example.com/," is \l Intermediate (it might be a cut and paste action that accidentally took in a comma at the end), the empty string is \l Intermediate (the user might select and delete all of the text in preparation for entering a new URL) and "http:///./" is \l Invalid.

For a spin box that accepts lengths, "11cm" and "1in" are \l Acceptable, "11" and the empty string are \l Intermediate, and "http://example.com" and "hour" are \l Invalid.

\endlist

\l fixup() is provided for validators that can repair some user errors. The default implementation does nothing. QLineEdit, for example, will call fixup() if the user presses Enter (or Return) and the content is not currently valid. This allows the fixup() function the opportunity of performing some magic to make an \l Invalid string \l Acceptable.

A validator has a locale, set with setLocale(). It is typically used to parse localized data. For example, QIntValidator and QDoubleValidator use it to parse localized representations of integers and doubles.

QValidator is typically used with QLineEdit, QSpinBox and QComboBox.

See also: QIntValidator, QDoubleValidator, QRegularExpressionValidator, {Line Edits Example}

Definition at line 23 of file qvalidator.h.

Member Enumeration Documentation

◆ State

enum QValidator::State

This enum type defines the states in which a validated string can exist.

\value Invalid The string is clearly invalid. \value Intermediate The string is a plausible intermediate value. \value Acceptable The string is acceptable as a final result; i.e. it is valid.

Enumerator
Invalid
Intermediate
Acceptable

Definition at line 30 of file qvalidator.h.

Constructor & Destructor Documentation

◆ QValidator() [1/3]

QValidator::QValidator ( QObject * parent = nullptr )

explicit

Sets up the validator.

The parent parameter is passed on to the QObject constructor.

Definition at line 175 of file qvalidator.cpp.

◆ ~QValidator()

QValidator::~QValidator ( )

Destroys the validator, freeing any storage and other resources used.

Definition at line 185 of file qvalidator.cpp.

◆ QValidator() [2/3]

QValidator::QValidator	(	QObjectPrivate &	d,
		QObject *	parent )

protected

Definition at line 495 of file qvalidator.cpp.

◆ QValidator() [3/3]

QValidator::QValidator	(	QValidatorPrivate &	d,
		QObject *	parent )

protected

Definition at line 503 of file qvalidator.cpp.

Member Function Documentation

◆ changed

void QValidator::changed ( )

signal

This signal is emitted when any property that may affect the validity of a string has changed.

Referenced by setLocale(), QDoubleValidator::setNotation(), QDoubleValidator::setRange(), and QIntValidator::setRange().

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◆ fixup()

void QValidator::fixup ( QString & input ) const

virtual

This function attempts to change input to be valid according to this validator's rules.

It need not result in a valid string: callers of this function must re-test afterwards; the default does nothing.

Reimplementations of this function can change input even if they do not produce a valid string. For example, an ISBN validator might want to delete every character except digits and "-", even if the result is still not a valid ISBN; a surname validator might want to remove whitespace from the start and end of the string, even if the resulting string is not in the list of accepted surnames.

Reimplemented in QSpinBoxValidator, QIntValidator, and QDoubleValidator.

Definition at line 250 of file qvalidator.cpp.

Referenced by QWidgetLineControl::fixup().

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◆ locale()

QLocale QValidator::locale ( ) const

Returns the locale for the validator.

The locale is by default initialized to the same as QLocale().

See also: setLocale(); QLocale::QLocale()

Definition at line 195 of file qvalidator.cpp.

References d.

Referenced by QIntValidator::fixup(), QDoubleValidator::fixup(), setLocale(), QIntValidator::validate(), and QDoubleValidator::validate().

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◆ setLocale()

void QValidator::setLocale ( const QLocale & locale )

Sets the locale that will be used for the validator.

Unless setLocale has been called, the validator will use the default locale set with QLocale::setDefault(). If a default locale has not been set, it is the operating system's locale.

See also: locale(), QLocale::setDefault()

Definition at line 209 of file qvalidator.cpp.

References changed(), d, emit, and locale().

Referenced by src_gui_util_qvalidator::Wrapper::wrapper3().

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◆ validate()

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

pure virtual

This virtual function returns \l Invalid if input is invalid according to this validator's rules, \l Intermediate if it is likely that a little more editing will make the input acceptable (e.g.

the user types "4" into a widget which accepts integers between 10 and 99), and \l Acceptable if the input is valid.

The function can change both input and pos (the cursor position) if required.

Implemented in QIntValidator, QDoubleValidator, and QSpinBoxValidator.

Referenced by QWidgetLineControl::fixup().

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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

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ State

Constructor & Destructor Documentation

◆ QValidator() [1/3]

◆ ~QValidator()

◆ QValidator() [2/3]

◆ QValidator() [3/3]

Member Function Documentation

◆ changed

◆ fixup()

◆ locale()

◆ setLocale()

◆ validate()