The QStackedLayout class provides a stack of widgets where only one widget is visible at a time. More...

Inheritance diagram for QStackedLayout:

Public Types
enum	StackingMode

Public Types inherited from QLayout
enum	SizeConstraint

Public Signals
void	currentChanged (int index)

void	widgetRemoved (int index)

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

void	objectNameChanged (const QString &objectName)

Public Slots
void	setCurrentIndex (int index)

void	setCurrentWidget (QWidget *widget)

Public Slots inherited from QObject
void	deleteLater ()

Public Methods
	QStackedLayout ()

	QStackedLayout (QLayout *parentLayout)

	QStackedLayout (QWidget *parent)

	~QStackedLayout ()

void	addItem (QLayoutItem *item) override

int	addWidget (QWidget *widget)

int	count () const override

int	currentIndex () const

QWidget *	currentWidget () const

bool	hasHeightForWidth () const override

int	heightForWidth (int width) const override

int	insertWidget (int index, QWidget *widget)

QLayoutItem *	itemAt (int index) const override

QSize	minimumSize () const override

void	setGeometry (const QRect &rect) override

void	setStackingMode (StackingMode stackingMode)

QSize	sizeHint () const override

StackingMode	stackingMode () const

QLayoutItem *	takeAt (int index) override

QWidget *	widget (int index) const

Public Methods inherited from QLayout
	QLayout ()

	QLayout (QWidget *parent)

bool	activate ()

void	addWidget (QWidget *w)

QMargins	contentsMargins () const

QRect	contentsRect () const

QSizePolicy::ControlTypes	controlTypes () const override

Qt::Orientations	expandingDirections () const override

QRect	geometry () const override

void	getContentsMargins (int left, int top, int right, int bottom) const

virtual int	indexOf (QWidget *widget) const

void	invalidate () override

bool	isEmpty () const override

bool	isEnabled () const

QLayout *	layout () override

int	margin () const

QSize	maximumSize () const override

QWidget *	menuBar () const

QWidget *	parentWidget () const

void	removeItem (QLayoutItem *item)

void	removeWidget (QWidget *widget)

virtual QLayoutItem *	replaceWidget (QWidget from, QWidget to, Qt::FindChildOptions options=Qt::FindChildrenRecursively)

bool	setAlignment (QLayout *layout, Qt::Alignment alignment)

void	setAlignment (Qt::Alignment alignment)

bool	setAlignment (QWidget *widget, Qt::Alignment alignment)

void	setContentsMargins (const QMargins &margins)

void	setContentsMargins (int left, int top, int right, int bottom)

void	setEnabled (bool enable)

void	setMargin (int margin)

void	setMenuBar (QWidget *widget)

void	setSizeConstraint (SizeConstraint constraint)

void	setSpacing (int spacing)

SizeConstraint	sizeConstraint () const

int	spacing () const

void	update ()

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

Public Methods inherited from QLayoutItem
	QLayoutItem (Qt::Alignment alignment=Qt::Alignment ())

virtual	~QLayoutItem ()

Qt::Alignment	alignment () const

virtual int	minimumHeightForWidth (int width) const

void	setAlignment (Qt::Alignment alignment)

virtual QSpacerItem *	spacerItem ()

virtual QWidget *	widget ()

Properties
	count

	currentIndex

	stackingMode

Properties inherited from QLayout
	margin

	sizeConstraint

	spacing

Properties inherited from QObject
	objectName

Additional Inherited Members
Static Public Methods inherited from QLayout
static QSize	closestAcceptableSize (const QWidget *widget, const QSize &size)

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 QLayout
void	addChildLayout (QLayout *layout)

void	addChildWidget (QWidget *widget)

QRect	alignmentRect (const QRect &rect) const

void	childEvent (QChildEvent *event) override

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)

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

	QObjectList

Detailed Description

The QStackedLayout class provides a stack of widgets where only one widget is visible at a time. QStackedLayout can be used to create a user interface similar to the one provided by QTabWidget. There is also a convenience QStackedWidget class built on top of QStackedLayout.

A QStackedLayout can be populated with a number of child widgets ("pages").

QWidget *firstPageWidget = new QWidget;
QWidget *secondPageWidget = new QWidget;
QWidget *thirdPageWidget = new QWidget;
 
QStackedLayout *stackedLayout = new QStackedLayout;
stackedLayout->addWidget(firstPageWidget);
stackedLayout->addWidget(secondPageWidget);
stackedLayout->addWidget(thirdPageWidget);
 
QVBoxLayout *mainLayout = new QVBoxLayout;
mainLayout->addLayout(stackedLayout);
setLayout(mainLayout);

QStackedLayout provides no intrinsic means for the user to switch page. This is typically done through a QComboBox or a QListWidget that stores the titles of the QStackedLayout's pages.

QComboBox *pageComboBox = new QComboBox;
pageComboBox->addItem(tr("Page 1"));
pageComboBox->addItem(tr("Page 2"));
pageComboBox->addItem(tr("Page 3"));
 
connect(pageComboBox, SIGNAL(activated(int)), stackedLayout, SLOT(setCurrentIndex(int)));

When populating a layout, the widgets are added to an internal list. The indexOf() function returns the index of a widget in that list. The widgets can either be added to the end of the list using the addWidget() function, or inserted at a given index using the insertWidget() function. The removeWidget() function removes the widget at the given index from the layout. The number of widgets contained in the layout, can be obtained using the count() function.

The widget() function returns the widget at a given index position. The index of the widget that is shown on screen is given by currentIndex() and can be changed using setCurrentIndex(). In a similar manner, the currently shown widget can be retrieved using the currentWidget() function, and altered using the setCurrentWidget() function.

Whenever the current widget in the layout changes or a widget is removed from the layout, the currentChanged() and widgetRemoved() signals are emitted respectively.

See also: QStackedWidget, QTabWidget

Member Enumeration Documentation

enum QStackedLayout::StackingMode

This enum specifies how the layout handles its child widgets regarding their visibility.

Constant	Value	Description
`QStackedLayout::StackOne`	`0`	Only the current widget is visible. This is the default.
`QStackedLayout::StackAll`	`1`	All widgets are visible. The current widget is merely raised.

Constructor & Destructor Documentation

QStackedLayout::QStackedLayout ( )

Constructs a QStackedLayout with no parent. This QStackedLayout must be installed on a widget later on to become effective.

See also: addWidget(), insertWidget()

QStackedLayout::QStackedLayout ( QWidget * parent )

explicit

Constructs a new QStackedLayout with the given parent. This layout will install itself on the parent widget and manage the geometry of its children.

QStackedLayout::QStackedLayout ( QLayout * parentLayout )

explicit

Constructs a new QStackedLayout and inserts it into the given parentLayout.

QStackedLayout::~QStackedLayout ( )

Destroys this QStackedLayout. Note that the layout's widgets are not destroyed.

Method Documentation

void QStackedLayout::addItem ( QLayoutItem * item )

overridevirtual

Implements QLayout::addItem()

int QStackedLayout::addWidget ( QWidget * widget )

Adds the given widget to the end of this layout and returns the index position of the widget. If the QStackedLayout is empty before this function is called, the given widget becomes the current widget.

See also: insertWidget(), removeWidget(), setCurrentWidget()

int QStackedLayout::count ( ) const

overridevirtual

Must be implemented in subclasses to return the number of items in the layout.

See also: itemAt()

Implements QLayout::count()

void QStackedLayout::currentChanged ( int index )

signal

This signal is emitted whenever the current widget in the layout changes. The index specifies the index of the new current widget, or -1 if there is not a new one (for example, if there are no widgets in the QStackedLayout)

See also: currentWidget(), setCurrentWidget()

int QStackedLayout::currentIndex ( ) const

Returns the value of the property.

QWidget * QStackedLayout::currentWidget ( ) const

Returns the current widget or nullptr if there are no widgets in this layout.

See also: currentIndex(), setCurrentWidget()

bool QStackedLayout::hasHeightForWidth ( ) const

overridevirtual

Returns true if this layout's preferred height depends on its width, otherwise returns false. The default implementation returns false. Override this method in layout managers which support height for width.

See also: heightForWidth(), QWidget::heightForWidth()

Reimplemented from QLayoutItem::hasHeightForWidth()

int QStackedLayout::heightForWidth ( int width ) const

overridevirtual

Returns the preferred height for this layout item, given the width.

The default implementation returns -1, indicating that the preferred height is independent of the width of the item. Using the method hasHeightForWidth() will typically be much faster than calling this method and testing for -1.

Override this method in layout managers which support height for width. The following example shows a typical implementation.

// m_cached_hfw should be declared mutable in MyLayout
 
int MyLayout::heightForWidth(int width) const
{
   if (cache_dirty || cached_width != w) {
 
      int h = calculateHeightForWidth(w);
      m_cached_hfw = h;
 
      return h;
   }
 
   return m_cached_hfw;
}

Caching is strongly recommended; without it layout will take exponential time.

See also: hasHeightForWidth()

Reimplemented from QLayoutItem::heightForWidth()

int QStackedLayout::insertWidget	(	int	index,
		QWidget *	widget
	)

Inserts the given widget at the given index in this QStackedLayout. If index is out of range, the widget is appended (in which case it is the actual index of the widget that is returned).

If the QStackedLayout is empty before this function is called, the given widget becomes the current widget.

Inserting a new widget at an index less than or equal to the current index will increment the current index, but keep the current widget.

See also: addWidget(), removeWidget(), setCurrentWidget()

QLayoutItem * QStackedLayout::itemAt ( int index ) const

overridevirtual

Implements QLayout::itemAt()

QSize QStackedLayout::minimumSize ( ) const

overridevirtual

Returns the value of the property.

Reimplemented from QLayout::minimumSize()

void QStackedLayout::setCurrentIndex ( int index )

slot

Sets the value of the property to index.

void QStackedLayout::setCurrentWidget ( QWidget * widget )

slot

Sets the current widget to be the specified widget. The new current widget must already be contained in this stacked layout.

See also: setCurrentIndex(), currentWidget()

void QStackedLayout::setGeometry ( const QRect & rect )

overridevirtual

Sets the value of the property to rect.

Reimplemented from QLayout::setGeometry()

void QStackedLayout::setStackingMode ( StackingMode stackingMode )

Sets the value of the property to stackingMode.

QSize QStackedLayout::sizeHint ( ) const

overridevirtual

Implements QLayoutItem::sizeHint()

StackingMode QStackedLayout::stackingMode ( ) const

Returns the value of the property.

QLayoutItem * QStackedLayout::takeAt ( int index )

overridevirtual

Implements QLayout::takeAt()

QWidget * QStackedLayout::widget ( int index ) const

Returns the widget at the given index or nullptr if there is no widget at the given position.

See also: currentWidget(), indexOf()

void QStackedLayout::widgetRemoved ( int index )

signal

This signal is emitted whenever a widget is removed from the layout. The widget's index is passed as parameter.

See also: removeWidget()

Property Documentation

QStackedLayout::count

This property holds the number of widgets contained in the layout.

See also: currentIndex(), widget()

Properties	Class Methods
read	count

QStackedLayout::currentIndex

This property holds the index position of the widget that is visible. The current index is -1 if there is no current widget.

See also: currentWidget(), indexOf()

Properties	Class Methods
read	currentIndex
write	setCurrentIndex
notify	currentChanged

QStackedLayout::stackingMode

This property determines the way visibility of child widgets are handled.

The default value is StackOne. Setting the property to StackAll allows you to make use of the layout for overlay widgets that do additional drawing on top of other widgets, for example, graphical editors.

Properties	Class Methods
read	stackingMode
write	setStackingMode

Public Types

Public Signals

Public Slots

Public Methods

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation

Property Documentation