QVBoxLayout Class Reference

The QVBoxLayout class lines up widgets vertically. More...

#include <qboxlayout.h>

Inheritance diagram for QVBoxLayout:

Collaboration diagram for QVBoxLayout:

Public Member Functions
	QVBoxLayout ()
	Constructs a new vertical box.
	QVBoxLayout (QWidget *parent)
	Constructs a new top-level vertical box with parent parent.
	~QVBoxLayout ()
	Destroys this box layout.
Public Member Functions inherited from QBoxLayout
	QBoxLayout (Direction, QWidget *parent=nullptr)
	Constructs a new QBoxLayout with direction dir and parent widget parent.
	~QBoxLayout ()
	Destroys this box layout.
Direction	direction () const
	Returns the direction of the box.
void	setDirection (Direction)
	Sets the direction of this layout to direction.
void	addSpacing (int size)
	Adds a non-stretchable space (a QSpacerItem) with size size to the end of this box layout.
void	addStretch (int stretch=0)
	Adds a stretchable space (a QSpacerItem) with zero minimum size and stretch factor stretch to the end of this box layout.
void	addSpacerItem (QSpacerItem *spacerItem)
void	addWidget (QWidget *, int stretch=0, Qt::Alignment alignment=Qt::Alignment())
	Adds widget to the end of this box layout, with a stretch factor of stretch and alignment alignment.
void	addLayout (QLayout *layout, int stretch=0)
	Adds layout to the end of the box, with serial stretch factor stretch.
void	addStrut (int)
	Limits the perpendicular dimension of the box (e.g.
void	addItem (QLayoutItem *) override
	\reimp
void	insertSpacing (int index, int size)
	Inserts a non-stretchable space (a QSpacerItem) at position index, with size size.
void	insertStretch (int index, int stretch=0)
	Inserts a stretchable space (a QSpacerItem) at position index, with zero minimum size and stretch factor stretch.
void	insertSpacerItem (int index, QSpacerItem *spacerItem)
void	insertWidget (int index, QWidget *widget, int stretch=0, Qt::Alignment alignment=Qt::Alignment())
	Inserts widget at position index, with stretch factor stretch and alignment alignment.
void	insertLayout (int index, QLayout *layout, int stretch=0)
	Inserts layout at position index, with stretch factor stretch.
void	insertItem (int index, QLayoutItem *)
	Inserts item into this box layout at position index.
int	spacing () const override
	Reimplements QLayout::spacing().
void	setSpacing (int spacing) override
	Reimplements QLayout::setSpacing().
bool	setStretchFactor (QWidget *w, int stretch)
	Sets the stretch factor for widget to stretch and returns true if widget is found in this layout (not including child layouts); otherwise returns false.
bool	setStretchFactor (QLayout *l, int stretch)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the stretch factor for the layout layout to stretch and returns true if layout is found in this layout (not including child layouts); otherwise returns false.
void	setStretch (int index, int stretch)
	Sets the stretch factor at position index.
int	stretch (int index) const
	Returns the stretch factor at position index.
QSize	sizeHint () const override
	\reimp
QSize	minimumSize () const override
	\reimp
QSize	maximumSize () const override
	\reimp
bool	hasHeightForWidth () const override
	\reimp
int	heightForWidth (int) const override
	\reimp
int	minimumHeightForWidth (int) const override
	\reimp
Qt::Orientations	expandingDirections () const override
	\reimp
void	invalidate () override
	Resets cached information.
QLayoutItem *	itemAt (int) const override
	\reimp
QLayoutItem *	takeAt (int) override
	\reimp
int	count () const override
	\reimp
void	setGeometry (const QRect &) override
	\reimp
Public Member Functions inherited from QLayout
	QLayout (QWidget *parent=nullptr)
	Constructs a new top-level QLayout, with parent parent.
	~QLayout ()
virtual int	spacing () const
virtual void	setSpacing (int)
void	setContentsMargins (int left, int top, int right, int bottom)
void	setContentsMargins (const QMargins &margins)
void	unsetContentsMargins ()
void	getContentsMargins (int *left, int *top, int *right, int *bottom) const
QMargins	contentsMargins () const
QRect	contentsRect () const
bool	setAlignment (QWidget *w, Qt::Alignment alignment)
	Sets the alignment for widget w to alignment and returns true if w is found in this layout (not including child layouts); otherwise returns false.
bool	setAlignment (QLayout *l, Qt::Alignment alignment)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the alignment for the layout l to alignment and returns true if l is found in this layout (not including child layouts); otherwise returns false.
void	setSizeConstraint (SizeConstraint)
SizeConstraint	sizeConstraint () const
void	setMenuBar (QWidget *w)
	Tells the geometry manager to place the menu bar widget at the top of parentWidget(), outside QWidget::contentsMargins().
QWidget *	menuBar () const
	Returns the menu bar set for this layout, or \nullptr if no menu bar is set.
QWidget *	parentWidget () const
	Returns the parent widget of this layout, or \nullptr if this layout is not installed on any widget.
void	invalidate () override
	\reimp
QRect	geometry () const override
	\reimp
bool	activate ()
	Redoes the layout for parentWidget() if necessary.
void	update ()
	Updates the layout for parentWidget().
void	addWidget (QWidget *w)
	Adds widget w to this layout in a manner specific to the layout.
virtual void	addItem (QLayoutItem *)=0
	Implemented in subclasses to add an item.
void	removeWidget (QWidget *w)
	Removes the widget widget from the layout.
void	removeItem (QLayoutItem *)
	Removes the layout item item from the layout.
Qt::Orientations	expandingDirections () const override
	Returns whether this layout can make use of more space than sizeHint().
QSize	minimumSize () const override
	Returns the minimum size of this layout.
QSize	maximumSize () const override
	Returns the maximum size of this layout.
virtual void	setGeometry (const QRect &) override
	\reimp
virtual QLayoutItem *	itemAt (int index) const =0
	Must be implemented in subclasses to return the layout item at index.
virtual QLayoutItem *	takeAt (int index)=0
	Must be implemented in subclasses to remove the layout item at index from the layout, and return the item.
virtual int	indexOf (const QWidget *) const
	Searches for widget widget in this layout (not including child layouts).
virtual int	indexOf (const QLayoutItem *) const
virtual int	count () const =0
	Must be implemented in subclasses to return the number of items in the layout.
bool	isEmpty () const override
	\reimp
QSizePolicy::ControlTypes	controlTypes () const override
	\reimp
virtual QLayoutItem *	replaceWidget (QWidget *from, QWidget *to, Qt::FindChildOptions options=Qt::FindChildrenRecursively)
int	totalMinimumHeightForWidth (int w) const
int	totalHeightForWidth (int w) const
QSize	totalMinimumSize () const
QSize	totalMaximumSize () const
QSize	totalSizeHint () const
QLayout *	layout () override
	\reimp
void	setEnabled (bool)
	Enables this layout if enable is true, otherwise disables it.
bool	isEnabled () const
	Returns true if the layout is enabled; otherwise returns false.
void	setAlignment (Qt::Alignment a)
	Sets the alignment of this item to alignment.
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.
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children.
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::milliseconds time, Qt::TimerType timerType=Qt::CoarseTimer)
void	killTimer (int id)
	Kills the timer with timer identifier, id.
template<typename T >
T	findChild (const QString &aName=QString(), 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 (const QString &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 >
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.
Public Member Functions inherited from QLayoutItem
	QLayoutItem (Qt::Alignment alignment=Qt::Alignment())
	Constructs a layout item with an alignment.
virtual	~QLayoutItem ()
	Destroys the QLayoutItem.
virtual QSize	sizeHint () const =0
	Implemented in subclasses to return the preferred size of this item.
virtual QSize	minimumSize () const =0
	Implemented in subclasses to return the minimum size of this item.
virtual QSize	maximumSize () const =0
	Implemented in subclasses to return the maximum size of this item.
virtual Qt::Orientations	expandingDirections () const =0
	Returns whether this layout item can make use of more space than sizeHint().
virtual void	setGeometry (const QRect &)=0
	Implemented in subclasses to set this item's geometry to r.
virtual QRect	geometry () const =0
	Returns the rectangle covered by this layout item.
virtual bool	isEmpty () const =0
	Implemented in subclasses to return whether this item is empty, i.e.
virtual bool	hasHeightForWidth () const
	Returns true if this layout's preferred height depends on its width; otherwise returns false.
virtual int	heightForWidth (int) const
	Returns the preferred height for this layout item, given the width, which is not used in this default implementation.
virtual int	minimumHeightForWidth (int) const
	Returns the minimum height this widget needs for the given width, w.
virtual void	invalidate ()
	Invalidates any cached information in this layout item.
virtual QWidget *	widget () const
	If this item manages a QWidget, returns that widget.
virtual QLayout *	layout ()
	If this item is a QLayout, it is returned as a QLayout; otherwise \nullptr is returned.
virtual QSpacerItem *	spacerItem ()
	If this item is a QSpacerItem, it is returned as a QSpacerItem; otherwise \nullptr is returned.
Qt::Alignment	alignment () const
	Returns the alignment of this item.
void	setAlignment (Qt::Alignment a)
	Sets the alignment of this item to alignment.
virtual QSizePolicy::ControlTypes	controlTypes () const
	Returns the control type(s) for the layout item.

Additional Inherited Members
Public Types inherited from QBoxLayout
enum	Direction {   LeftToRight , RightToLeft , TopToBottom , BottomToTop ,   Down = TopToBottom , Up = BottomToTop }
	This type is used to determine the direction of a box layout. More...
Public Types inherited from QLayout
enum	SizeConstraint {   SetDefaultConstraint , SetNoConstraint , SetMinimumSize , SetFixedSize ,   SetMaximumSize , SetMinAndMaxSize }
	The possible values are: More...
Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe
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.
Static Public Member Functions inherited from QLayout
static QSize	closestAcceptableSize (const QWidget *w, const QSize &s)
	Returns a size that satisfies all size constraints on widget, including heightForWidth() and that is as close as possible to size.
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 QLayout
void	widgetEvent (QEvent *)
void	childEvent (QChildEvent *e) override
	\reimp
void	addChildLayout (QLayout *l)
	This function is called from addLayout() or insertLayout() functions in subclasses to add layout childLayout as a sub-layout.
void	addChildWidget (QWidget *w)
	This function is called from addWidget() functions in subclasses to add w as a managed widget of a layout.
bool	adoptLayout (QLayout *layout)
QRect	alignmentRect (const QRect &) const
	Returns the rectangle that should be covered when the geometry of this layout is set to r, provided that this layout supports setAlignment().
	QLayout (QLayoutPrivate &d, QLayout *, QWidget *)
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
Protected Attributes inherited from QLayoutItem
Qt::Alignment	align
Properties inherited from QLayout
int	spacing
	the spacing between widgets inside the layout
QMargins	contentsMargins
SizeConstraint	sizeConstraint
	the resize mode of the layout
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 QVBoxLayout class lines up widgets vertically.

\inmodule QtWidgets

This class is used to construct vertical box layout objects. See QBoxLayout for details.

The simplest use of the class is like this:

    QWidget *window = new QWidget;

    QPushButton *button1 = new QPushButton("One");

    QPushButton *button2 = new QPushButton("Two");
    QPushButton *button3 = new QPushButton("Three");
    QPushButton *button4 = new QPushButton("Four");
    QPushButton *button5 = new QPushButton("Five");

\codeline

    QVBoxLayout *layout = new QVBoxLayout(window);

    layout->addWidget(button1);
    layout->addWidget(button2);
    layout->addWidget(button3);
    layout->addWidget(button4);
    layout->addWidget(button5);
 

    window->show();

First, we create the widgets we want to add to the layout. Then, we create the QVBoxLayout object, setting window as parent by passing it in the constructor; next we add the widgets to the layout. window will be the parent of the widgets that are added to the layout.

If you don't pass a parent window to the constructor, you can at a later point use QWidget::setLayout() to install the QVBoxLayout object onto window. At that point, the widgets in the layout are reparented to have window as their parent.

Horizontal box layout with five child widgets

See also

QHBoxLayout, QGridLayout, QStackedLayout, {Layout Management}, {Basic Layouts Example}

Definition at line 90 of file qboxlayout.h.

Constructor & Destructor Documentation

QVBoxLayout() [1/2]

QVBoxLayout::QVBoxLayout

(

)

Constructs a new vertical box.

You must add it to another layout.

Definition at line 1309 of file qboxlayout.cpp.

QVBoxLayout() [2/2]

QVBoxLayout::QVBoxLayout ( QWidget *  parent )

explicit

Constructs a new top-level vertical box with parent parent.

The layout is set directly as the top-level layout for parent. There can be only one top-level layout for a widget. It is returned by QWidget::layout().

See also

QWidget::setLayout()

Definition at line 1299 of file qboxlayout.cpp.

~QVBoxLayout()

QVBoxLayout::~QVBoxLayout

(

)

Destroys this box layout.

The layout's widgets aren't destroyed.

Definition at line 1320 of file qboxlayout.cpp.

---

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

• qtbase/src/widgets/kernel/qboxlayout.h
• qtbase/src/widgets/kernel/qboxlayout.cpp