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

#include <qundogroup.h>

Inheritance diagram for QUndoGroup:

Public Slots
void	redo ()
	Calls QUndoStack::redo() on the active stack. More...

void	setActiveStack (QUndoStack *stack)
	Sets the active stack of this group to stack. More...

void	undo ()
	Calls QUndoStack::undo() on the active stack. More...

Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...

Signals
void	activeStackChanged (QUndoStack *stack)
	This signal is emitted whenever the active stack of the group changes. More...

void	canRedoChanged (bool canRedo)
	This signal is emitted whenever the active stack emits QUndoStack::canRedoChanged() or the active stack changes. More...

void	canUndoChanged (bool canUndo)
	This signal is emitted whenever the active stack emits QUndoStack::canUndoChanged() or the active stack changes. More...

void	cleanChanged (bool clean)
	This signal is emitted whenever the active stack emits QUndoStack::cleanChanged() or the active stack changes. More...

void	indexChanged (int idx)
	This signal is emitted whenever the active stack emits QUndoStack::indexChanged() or the active stack changes. More...

void	redoTextChanged (const QString &redoText)
	This signal is emitted whenever the active stack emits QUndoStack::redoTextChanged() or the active stack changes. More...

void	undoTextChanged (const QString &undoText)
	This signal is emitted whenever the active stack emits QUndoStack::undoTextChanged() or the active stack changes. More...

Signals inherited from QObject
void	destroyed (QObject *=0)
	This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More...

Public Functions
QUndoStack *	activeStack () const
	Returns the active stack of this group. More...

void	addStack (QUndoStack *stack)
	Adds stack to this group. More...

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

bool	canUndo () const
	Returns the value of the active stack's QUndoStack::canUndo(). More...

QAction *	createRedoAction (QObject *parent, const QString &prefix=QString()) const
	Creates an redo QAction object with parent parent. More...

QAction *	createUndoAction (QObject *parent, const QString &prefix=QString()) const
	Creates an undo QAction object with parent parent. More...

bool	isClean () const
	Returns the value of the active stack's QUndoStack::isClean(). More...

	QUndoGroup (QObject *parent=0)
	Creates an empty QUndoGroup object with parent parent. More...

QString	redoText () const
	Returns the value of the active stack's QUndoStack::redoText(). More...

void	removeStack (QUndoStack *stack)
	Removes stack from this group. More...

QList< QUndoStack * >	stacks () const
	Returns a list of stacks in this group. More...

QString	undoText () const
	Returns the value of the active stack's QUndoStack::undoText(). More...

	~QUndoGroup ()
	Destroys the QUndoGroup. More...

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

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

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

bool	disconnect (const char signal=0, const QObject receiver=0, const char *member=0)

bool	disconnect (const QObject receiver, const char member=0)

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

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

QList< QByteArray >	dynamicPropertyNames () const
	Returns the names of all properties that were dynamically added to the object using setProperty(). More...

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

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

template<typename T >
T	findChild (const QString &aName=QString()) const
	Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More...

template<typename T >
QList< T >	findChildren (const QString &aName=QString()) 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. More...

template<typename T >
QList< T >	findChildren (const QRegExp &re) const

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. More...

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

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

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

virtual const QMetaObject *	metaObject () const
	Returns a pointer to the meta-object of this object. More...

void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children. More...

QString	objectName () const

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

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

Q_INVOKABLE	QObject (QObject *parent=0)
	Constructs an object with parent object parent. More...

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

void	setObjectName (const QString &name)

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

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

void	setUserData (uint id, QObjectUserData *data)

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

int	startTimer (int interval)
	Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More...

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

QObjectUserData *	userData (uint id) const

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

Additional Inherited Members
Static Public Functions inherited from QObject
static bool	connect (const QObject sender, const char signal, const QObject receiver, const char member, Qt::ConnectionType=Qt::AutoConnection)
	Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More...

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

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)
	Disconnects signal in object sender from method in object receiver. More...

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

static uint	registerUserData ()

static QString	tr (const char sourceText, const char comment=0, int n=-1)

static QString	trUtf8 (const char sourceText, const char comment=0, int n=-1)

Static Public Variables inherited from QObject
static const QMetaObject	staticMetaObject
	This variable stores the meta-object for the class. More...

Protected Functions inherited from QObject
virtual void	childEvent (QChildEvent *)
	This event handler can be reimplemented in a subclass to receive child events. More...

virtual void	connectNotify (const char *signal)
	This virtual function is called when something has been connected to signal in this object. More...

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

virtual void	disconnectNotify (const char *signal)
	This virtual function is called when something has been disconnected from signal in this object. More...

	QObject (QObjectPrivate &dd, QObject *parent=0)

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

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 0. More...

int	senderSignalIndex () const

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

Protected Variables inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Static Protected Variables inherited from QObject
static const QMetaObject	staticQtMetaObject

Related Functions inherited from QObject
T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

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

QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QRegExp &regExp)()

T *	qobject_cast (QObject *object)

	QObjectList

void *	qt_find_obj_child (QObject parent, const char type, const QString &name)
	Returns a pointer to the object named name that inherits type and with a given parent. More...

Detailed Description

The QUndoGroup class is a group of QUndoStack objects.

Since: 4.2

For an overview of the Qt's undo framework, see the overview.

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.

Definition at line 60 of file qundogroup.h.

Constructors and Destructors

◆ QUndoGroup()

QUndoGroup::QUndoGroup ( QObject * parent = 0 )

explicit

Creates an empty QUndoGroup object with parent parent.

See also: addStack()

Definition at line 106 of file qundogroup.cpp.

     : QObject(*new QUndoGroupPrivate(), parent)
 {
 }

◆ ~QUndoGroup()

QUndoGroup::~QUndoGroup ( )

Destroys the QUndoGroup.

Definition at line 114 of file qundogroup.cpp.

 {
     // Ensure all QUndoStacks no longer refer to this group.
     Q_D(QUndoGroup);
     QList<QUndoStack *>::iterator it = d->stack_list.begin();
     QList<QUndoStack *>::iterator end = d->stack_list.end();
     while (it != end) {
         (*it)->d_func()->group = 0;
         ++it;
     }
 }

Functions

◆ activeStack()

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 function returns 0.

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

Definition at line 255 of file qundogroup.cpp.

 {
     Q_D(const QUndoGroup);
     return d->active;
 }

◆ activeStackChanged

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. stack is the new active stack. If no stack is active, stack is 0.

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

Referenced by setActiveStack().

◆ addStack()

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()

Definition at line 135 of file qundogroup.cpp.

 {
     Q_D(QUndoGroup);
 
     if (d->stack_list.contains(stack))
         return;
     d->stack_list.append(stack);
 
     if (QUndoGroup *other = stack->d_func()->group)
         other->removeStack(stack);
     stack->d_func()->group = this;
 }

◆ canRedo()

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()

Definition at line 318 of file qundogroup.cpp.

Referenced by createRedoAction().

 {
     Q_D(const QUndoGroup);
     return d->active != 0 && d->active->canRedo();
 }

◆ canRedoChanged

void QUndoGroup::canRedoChanged ( bool canRedo )

signal

This signal is emitted whenever the active stack emits QUndoStack::canRedoChanged() or the active stack changes.

canRedo is the new state, or false if the active stack is 0.

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

Referenced by createRedoAction(), and setActiveStack().

◆ canUndo()

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 function returns false.

See also: canRedo() setActiveStack()

Definition at line 303 of file qundogroup.cpp.

Referenced by createUndoAction().

 {
     Q_D(const QUndoGroup);
     return d->active != 0 && d->active->canUndo();
 }

◆ canUndoChanged

void QUndoGroup::canUndoChanged ( bool canUndo )

signal

This signal is emitted whenever the active stack emits QUndoStack::canUndoChanged() or the active stack changes.

canUndo is the new state, or false if the active stack is 0.

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

Referenced by createUndoAction(), and setActiveStack().

◆ cleanChanged

void QUndoGroup::cleanChanged ( bool clean )

signal

This signal is emitted whenever the active stack emits QUndoStack::cleanChanged() or the active stack changes.

clean is the new state, or true if the active stack is 0.

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

Referenced by setActiveStack().

◆ createRedoAction()

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

Creates an redo QAction object with parent 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. Before Qt 4.8, the prefix "Redo" was used by default.

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

Definition at line 417 of file qundogroup.cpp.

 {
     QUndoAction *result = new QUndoAction(prefix, parent);
     if (prefix.isEmpty())
         result->setTextFormat(tr("Redo %1"), tr("Redo", "Default text for redo action"));
 
     result->setEnabled(canRedo());
     result->setPrefixedText(redoText());
     connect(this, SIGNAL(canRedoChanged(bool)),
             result, SLOT(setEnabled(bool)));
     connect(this, SIGNAL(redoTextChanged(QString)),
             result, SLOT(setPrefixedText(QString)));
     connect(result, SIGNAL(triggered()), this, SLOT(redo()));
     return result;
 }

◆ createUndoAction()

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

Creates an undo QAction object with parent 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. Before Qt 4.8, the prefix "Undo" was used by default.

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

Definition at line 386 of file qundogroup.cpp.

 {
     QUndoAction *result = new QUndoAction(prefix, parent);
     if (prefix.isEmpty())
         result->setTextFormat(tr("Undo %1"), tr("Undo", "Default text for undo action"));
 
     result->setEnabled(canUndo());
     result->setPrefixedText(undoText());
     connect(this, SIGNAL(canUndoChanged(bool)),
             result, SLOT(setEnabled(bool)));
     connect(this, SIGNAL(undoTextChanged(QString)),
             result, SLOT(setPrefixedText(QString)));
     connect(result, SIGNAL(triggered()), this, SLOT(undo()));
     return result;
 }

◆ indexChanged

void QUndoGroup::indexChanged ( int idx )

signal

This signal is emitted whenever the active stack emits QUndoStack::indexChanged() or the active stack changes.

idx is the new current index, or 0 if the active stack is 0.

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

Referenced by setActiveStack().

◆ isClean()

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 function returns true.

See also: setActiveStack()

Definition at line 363 of file qundogroup.cpp.

 {
     Q_D(const QUndoGroup);
     return d->active == 0 || d->active->isClean();
 }

◆ redo

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()

Definition at line 287 of file qundogroup.cpp.

Referenced by createRedoAction().

 {
     Q_D(QUndoGroup);
     if (d->active != 0)
         d->active->redo();
 }

◆ redoText()

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()

Definition at line 348 of file qundogroup.cpp.

Referenced by createRedoAction().

 {
     Q_D(const QUndoGroup);
     return d->active == 0 ? QString() : d->active->redoText();
 }

◆ redoTextChanged

void QUndoGroup::redoTextChanged ( const QString & redoText )

signal

This signal is emitted whenever the active stack emits QUndoStack::redoTextChanged() or the active stack changes.

redoText is the new state, or an empty string if the active stack is 0.

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

Referenced by createRedoAction(), and setActiveStack().

◆ removeStack()

void QUndoGroup::removeStack ( QUndoStack * stack )

Removes stack from this group.

If the stack was the active stack in the group, the active stack becomes 0.

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

Definition at line 155 of file qundogroup.cpp.

 {
     Q_D(QUndoGroup);
 
     if (d->stack_list.removeAll(stack) == 0)
         return;
     if (stack == d->active)
         setActiveStack(0);
     stack->d_func()->group = 0;
 }

◆ setActiveStack

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 function does nothing.

Synonymous with calling QUndoStack::setActive() on stack.

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().

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

Definition at line 192 of file qundogroup.cpp.

Referenced by removeStack().

 {
     Q_D(QUndoGroup);
     if (d->active == stack)
         return;
 
     if (d->active != 0) {
         disconnect(d->active, SIGNAL(canUndoChanged(bool)),
                     this, SIGNAL(canUndoChanged(bool)));
         disconnect(d->active, SIGNAL(undoTextChanged(QString)),
                     this, SIGNAL(undoTextChanged(QString)));
         disconnect(d->active, SIGNAL(canRedoChanged(bool)),
                     this, SIGNAL(canRedoChanged(bool)));
         disconnect(d->active, SIGNAL(redoTextChanged(QString)),
                     this, SIGNAL(redoTextChanged(QString)));
         disconnect(d->active, SIGNAL(indexChanged(int)),
                     this, SIGNAL(indexChanged(int)));
         disconnect(d->active, SIGNAL(cleanChanged(bool)),
                     this, SIGNAL(cleanChanged(bool)));
     }
 
     d->active = stack;
 
     if (d->active == 0) {
         emit canUndoChanged(false);
         emit undoTextChanged(QString());
         emit canRedoChanged(false);
         emit redoTextChanged(QString());
         emit cleanChanged(true);
         emit indexChanged(0);
     } else {
         connect(d->active, SIGNAL(canUndoChanged(bool)),
                 this, SIGNAL(canUndoChanged(bool)));
         connect(d->active, SIGNAL(undoTextChanged(QString)),
                 this, SIGNAL(undoTextChanged(QString)));
         connect(d->active, SIGNAL(canRedoChanged(bool)),
                 this, SIGNAL(canRedoChanged(bool)));
         connect(d->active, SIGNAL(redoTextChanged(QString)),
                 this, SIGNAL(redoTextChanged(QString)));
         connect(d->active, SIGNAL(indexChanged(int)),
                 this, SIGNAL(indexChanged(int)));
         connect(d->active, SIGNAL(cleanChanged(bool)),
                 this, SIGNAL(cleanChanged(bool)));
         emit canUndoChanged(d->active->canUndo());
         emit undoTextChanged(d->active->undoText());
         emit canRedoChanged(d->active->canRedo());
         emit redoTextChanged(d->active->redoText());
         emit cleanChanged(d->active->isClean());
         emit indexChanged(d->active->index());
     }
 
     emit activeStackChanged(d->active);
 }

◆ stacks()

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

Returns a list of stacks in this group.

See also: addStack() removeStack()

Definition at line 172 of file qundogroup.cpp.

 {
     Q_D(const QUndoGroup);
     return d->stack_list;
 }

◆ undo

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 function does nothing.

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

Definition at line 270 of file qundogroup.cpp.

Referenced by createUndoAction().

 {
     Q_D(QUndoGroup);
     if (d->active != 0)
         d->active->undo();
 }

◆ undoText()

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 function returns an empty string.

See also: redoText() setActiveStack()

Definition at line 333 of file qundogroup.cpp.

Referenced by createUndoAction().

 {
     Q_D(const QUndoGroup);
     return d->active == 0 ? QString() : d->active->undoText();
 }

◆ undoTextChanged

void QUndoGroup::undoTextChanged ( const QString & undoText )

signal

This signal is emitted whenever the active stack emits QUndoStack::undoTextChanged() or the active stack changes.

undoText is the new state, or an empty string if the active stack is 0.

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

Referenced by createUndoAction(), and setActiveStack().

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

/src/gui/util/qundogroup.h
/src/gui/util/qundogroup.cpp

Public Slots

Signals

Public Functions

Additional Inherited Members

Detailed Description

Constructors and Destructors

◆ QUndoGroup()

◆ ~QUndoGroup()

Functions

◆ activeStack()

◆ activeStackChanged

◆ addStack()

◆ canRedo()

◆ canRedoChanged

◆ canUndo()

◆ canUndoChanged

◆ cleanChanged

◆ createRedoAction()

◆ createUndoAction()

◆ indexChanged

◆ isClean()

◆ redo

◆ redoText()

◆ redoTextChanged

◆ removeStack()

◆ setActiveStack

◆ stacks()

◆ undo

◆ undoText()

◆ undoTextChanged