The QUndoGroup class is a group of QUndoStack objects. More...

Inheritance diagram for QUndoGroup:

Public Signals
void	activeStackChanged (QUndoStack *stack)

void	canRedoChanged (bool canRedo)

void	canUndoChanged (bool canUndo)

void	cleanChanged (bool clean)

void	indexChanged (int idx)

void	redoTextChanged (const QString &redoText)

void	undoTextChanged (const QString &undoText)

Public Signals inherited from QObject
void	destroyed (QObject *obj=nullptr)

void	objectNameChanged (const QString &objectName)

Public Slots
void	redo ()

void	setActiveStack (QUndoStack *stack)

void	undo ()

Public Slots inherited from QObject
void	deleteLater ()

Public Methods
	QUndoGroup (QObject *parent=nullptr)

	~QUndoGroup ()

QUndoStack *	activeStack () const

void	addStack (QUndoStack *stack)

bool	canRedo () const

bool	canUndo () const

QAction *	createRedoAction (QObject *parent, const QString &prefix=QString ()) const

QAction *	createUndoAction (QObject *parent, const QString &prefix=QString ()) const

bool	isClean () const

QString	redoText () const

void	removeStack (QUndoStack *stack)

QList< QUndoStack * >	stacks () const

QString	undoText () const

Public Methods inherited from QObject
	QObject (QObject *parent=nullptr)

	~QObject ()

bool	blockSignals (bool block)

const QList< QObject * > &	children () const

bool	connect (const QObject *sender, const QString &signalMethod, const QString &location, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	connect (const QObject *sender, const QString &signalMethod, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	disconnect (const QObject *receiver, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod, const QString &location, const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod=QString (), const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QString >	dynamicPropertyNames () const

virtual bool	event (QEvent *event)

virtual bool	eventFilter (QObject watched, QEvent event)

template<typename T >
T	findChild (const QString &childName=QString ()) const

template<class T >
QList< T >	findChildren (const QRegularExpression &regExp, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<class T >
QList< T >	findChildren (const QString &childName=QString (), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

bool	inherits (const QString &className) const

void	installEventFilter (QObject *filterObj)

bool	isWidgetType () const

bool	isWindowType () const

void	killTimer (int id)

const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

QString	objectName () const

QObject *	parent () const

template<class T = QVariant>
T	property (const QString &name) const

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const QString &name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

QThread *	thread () const

Additional Inherited Members
Static Public Methods inherited from QObject
static bool	connect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

static bool	connect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection, const QString &location=QString ())

static bool	connect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...), Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotLambda, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, std::nullptr_t, const QObject receiver, std::nullptr_t)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...))

template<class Sender , class SignalClass , class... SignalArgs, class Receiver >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, std::nullptr_t slotMethod=nullptr)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotMethod)

static QMetaObject &	staticMetaObject ()

static QString	tr (const char text, const char comment=nullptr, std::optional< int > numArg=std::optional< int >())

Protected Methods inherited from QObject
virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const QMetaMethod &signalMethod) const

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signalMethod) const

bool	isSignalConnected (const QMetaMethod &signalMethod) const

int	receivers (const QString &signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Properties inherited from QObject
	objectName

Related Functions inherited from QObject
T	qobject_cast (QObject *object)

	QObjectList

Detailed Description

The QUndoGroup class is a group of QUndoStack objects. For an overview refer to the Undo System documentation.

An application often has multiple undo stacks, one for each opened document. At the same time, an application usually has one undo action and one redo action, which triggers undo or redo in the active document.

QUndoGroup is a group of QUndoStack objects, one of which may be active. It has an undo() and redo() slot, which calls QUndoStack::undo() and QUndoStack::redo() for the active stack. It also has the functions createUndoAction() and createRedoAction(). The actions returned by these functions behave in the same way as those returned by QUndoStack::createUndoAction() and QUndoStack::createRedoAction() of the active stack.

Stacks are added to a group with addStack() and removed with removeStack(). A stack is implicitly added to a group when it is created with the group as its parent QObject.

It is the programmer's responsibility to specify which stack is active by calling QUndoStack::setActive(), usually when the associated document window receives focus. The active stack may also be set with setActiveStack(), and is returned by activeStack().

When a stack is added to a group using addStack(), the group does not take ownership of the stack. This means the stack has to be deleted separately from the group. When a stack is deleted, it is automatically removed from a group. A stack may belong to only one group. Adding it to another group will cause it to be removed from the previous group.

A QUndoGroup is also useful in conjunction with QUndoView. If a QUndoView is set to watch a group using QUndoView::setGroup(), it will update itself to display the active stack.

See also: addStack()

Constructor & Destructor Documentation

QUndoGroup::QUndoGroup ( QObject * parent = nullptr )

explicit

Creates an empty QUndoGroup object with the given parent.

See also: addStack()

QUndoGroup::~QUndoGroup ( )

Destroys the QUndoGroup.

Method Documentation

QUndoStack * QUndoGroup::activeStack ( ) const

Returns the active stack of this group. If none of the stacks are active, or if the group is empty, this method returns a nullptr.

See also: setActiveStack(), QUndoStack::setActive()

void QUndoGroup::activeStackChanged ( QUndoStack * stack )

signal

This signal is emitted whenever the active stack of the group changes. This can happen when setActiveStack() or QUndoStack::setActive() is called, or when the active stack is removed form the group. The stack is the new active stack. If no undo stack is active, stack is a nullptr.

See also: setActiveStack(), QUndoStack::setActive()

void QUndoGroup::addStack ( QUndoStack * stack )

Adds stack to this group. The group does not take ownership of the stack. Another way of adding a stack to a group is by specifying the group as the stack's parent QObject in QUndoStack::QUndoStack(). In this case, the stack is deleted when the group is deleted, in the usual manner of QObjects.

See also: removeStack(), stacks(), QUndoStack::QUndoStack()

bool QUndoGroup::canRedo ( ) const

Returns the value of the active stack's QUndoStack::canRedo().

If none of the stacks are active, or if the group is empty, this function returns false.

See also: canUndo(), setActiveStack()

void QUndoGroup::canRedoChanged ( bool canRedo )

signal

This signal is emitted whenever the active stack emits QUndoStack::canRedoChanged() or the active stack changes. The canRedo is the new state, or false if the active undo stack is a nullptr.

See also: QUndoStack::canRedoChanged(), setActiveStack()

bool QUndoGroup::canUndo ( ) const

Returns the value of the active stack's QUndoStack::canUndo(). If none of the stacks are active, or if the group is empty, this method returns false.

See also: canRedo(), setActiveStack()

void QUndoGroup::canUndoChanged ( bool canUndo )

signal

This signal is emitted whenever the active stack emits QUndoStack::canUndoChanged() or the active stack changes. The canUndo is the new state or false if the active undo stack is a nullptr.

See also: QUndoStack::canUndoChanged(), setActiveStack()

void QUndoGroup::cleanChanged ( bool clean )

signal

This signal is emitted whenever the active stack emits QUndoStack::cleanChanged() or the active stack changes. The clean is the new state, or true if the active undo stack is a nullptr.

See also: QUndoStack::cleanChanged(), setActiveStack()

QAction * QUndoGroup::createRedoAction	(	QObject *	parent,
		const QString &	prefix = `QString()`
	)		const

Creates an redo QAction object with the given parent.

Triggering this action will cause a call to QUndoStack::redo() on the active stack. The text of this action will always be the text of the command which will be redone in the next call to redo(), prefixed by prefix. If there is no command available for redo, if the group is empty or if none of the stacks are active, this action will be disabled.

If prefix is empty, the default template "Redo %1" is used instead of prefix.

See also: createUndoAction(), canRedo(), QUndoCommand::text()

QAction * QUndoGroup::createUndoAction	(	QObject *	parent,
		const QString &	prefix = `QString()`
	)		const

Creates an undo QAction object with the given parent.

Triggering this action will cause a call to QUndoStack::undo() on the active stack. The text of this action will always be the text of the command which will be undone in the next call to undo(), prefixed by prefix. If there is no command available for undo, if the group is empty or if none of the stacks are active, this action will be disabled.

If prefix is empty, the default template "Undo %1" is used instead of prefix.

See also: createRedoAction(), canUndo(), QUndoCommand::text()

void QUndoGroup::indexChanged ( int idx )

signal

This signal is emitted whenever the active undo stack emits QUndoStack::indexChanged() or the active stack changes. The value for idx is the new current index or 0 if the active undo stack is a nullptr.

See also: QUndoStack::indexChanged(), setActiveStack()

bool QUndoGroup::isClean ( ) const

Returns the value of the active stack's QUndoStack::isClean(). If none of the stacks are active, or if the group is empty, this method returns true.

See also: setActiveStack()

void QUndoGroup::redo ( )

slot

Calls QUndoStack::redo() on the active stack. If none of the stacks are active, or if the group is empty, this function does nothing.

See also: undo(), canRedo(), setActiveStack()

QString QUndoGroup::redoText ( ) const

Returns the value of the active stack's QUndoStack::redoText(). If none of the stacks are active, or if the group is empty, this function returns an empty string.

See also: undoText(), setActiveStack()

void QUndoGroup::redoTextChanged ( const QString & redoText )

signal

This signal is emitted whenever the active undo stack emits QUndoStack::redoTextChanged() or the active stack changes. The redoText is the new state or an empty string if the active stack is a nullptr.

See also: QUndoStack::redoTextChanged(), setActiveStack()

void QUndoGroup::removeStack ( QUndoStack * stack )

Removes stack from this group. If the stack was the active stack in the group, the active stack becomes a nullptr.

See also: addStack(), stacks(), QUndoStack::~QUndoStack()

void QUndoGroup::setActiveStack ( QUndoStack * stack )

slot

Sets the active stack of this group to stack. If the stack is not a member of this group, this method does nothing. The actions returned by createUndoAction() and createRedoAction() will now behave in the same way as those returned by stack's QUndoStack::createUndoAction() and QUndoStack::createRedoAction().

Equivalent to calling QUndoStack::setActive(stack).

See also: QUndoStack::setActive(), activeStack()

QList< QUndoStack * > QUndoGroup::stacks ( ) const

Returns a list of stacks in this group.

See also: addStack(), removeStack()

void QUndoGroup::undo ( )

slot

Calls QUndoStack::undo() on the active stack. If none of the stacks are active, or if the group is empty, this method does nothing.

See also: redo(), canUndo(), setActiveStack()

QString QUndoGroup::undoText ( ) const

Returns the value of the active stack's QUndoStack::undoText(). If none of the stacks are active, or if the group is empty, this method returns an empty string.

See also: redoText(), setActiveStack()

void QUndoGroup::undoTextChanged ( const QString & undoText )

signal

This signal is emitted whenever the active stack emits QUndoStack::undoTextChanged() or the active stack changes. The undoText is the new state, or an empty string if the active undo stack is a nullptr.

See also: QUndoStack::undoTextChanged(), setActiveStack()

Public Signals

Public Slots

Public Methods

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Method Documentation