The QLabel widget provides a text or image display. More...

#include <qlabel.h>

Inheritance diagram for QLabel:

Collaboration diagram for QLabel:

Public Slots
void	setText (const QString &)

void	setPixmap (const QPixmap &)

void	setPicture (const QPicture &)
	Sets the label contents to picture.

void	setNum (int)
	Sets the label contents to plain text containing the textual representation of integer num.

void	setNum (double)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the label contents to plain text containing the textual representation of double num.

void	clear ()
	Clears any label contents.

Public Slots inherited from QWidget
void	setEnabled (bool)

void	setDisabled (bool)
	Disables widget input events if disable is true; otherwise enables input events.

void	setWindowModified (bool)

void	setWindowTitle (const QString &)

void	setStyleSheet (const QString &styleSheet)

void	setFocus ()
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Gives the keyboard input focus to this widget (or its focus proxy) if this widget or one of its parents is the \l{isActiveWindow()}{active window}.

void	update ()
	Updates the widget unless updates are disabled or the widget is hidden.

void	repaint ()
	Repaints the widget directly by calling paintEvent() immediately, unless updates are disabled or the widget is hidden.

virtual void	setVisible (bool visible)

void	setHidden (bool hidden)
	Convenience function, equivalent to setVisible(!hidden).

void	show ()
	Shows the widget and its child widgets.

void	hide ()
	Hides the widget.

void	showMinimized ()
	Shows the widget minimized, as an icon.

void	showMaximized ()
	Shows the widget maximized.

void	showFullScreen ()
	Shows the widget in full-screen mode.

void	showNormal ()
	Restores the widget after it has been maximized or minimized.

bool	close ()
	Closes this widget.

void	raise ()
	Raises this widget to the top of the parent widget's stack.

void	lower ()
	Lowers the widget to the bottom of the parent widget's stack.

Public Slots inherited from QObject
void	deleteLater ()
	\threadsafe

Signals
void	linkActivated (const QString &link)

void	linkHovered (const QString &link)

Signals inherited from QWidget
void	windowTitleChanged (const QString &title)
	This signal is emitted when the window's title has changed, with the new title as an argument.

void	windowIconChanged (const QIcon &icon)
	This signal is emitted when the window's icon has changed, with the new icon as an argument.

void	windowIconTextChanged (const QString &iconText)
	This signal is emitted when the window's icon text has changed, with the new iconText as an argument.

void	customContextMenuRequested (const QPoint &pos)
	This signal is emitted when the widget's \l contextMenuPolicy is Qt::CustomContextMenu, and the user has requested a context menu on the widget.

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
	QLabel (QWidget *parent=nullptr, Qt::WindowFlags f=Qt::WindowFlags())
	Constructs an empty label.

	QLabel (const QString &text, QWidget *parent=nullptr, Qt::WindowFlags f=Qt::WindowFlags())
	Constructs a label that displays the text, text.

	~QLabel ()
	Destroys the label.

QString	text () const

QPixmap	pixmap () const

QPicture	picture () const

Qt::TextFormat	textFormat () const

void	setTextFormat (Qt::TextFormat)

QTextDocument::ResourceProvider	resourceProvider () const

void	setResourceProvider (const QTextDocument::ResourceProvider &provider)

Qt::Alignment	alignment () const

void	setAlignment (Qt::Alignment)

void	setWordWrap (bool on)

bool	wordWrap () const

int	indent () const

void	setIndent (int)

int	margin () const

void	setMargin (int)

bool	hasScaledContents () const

void	setScaledContents (bool)

QSize	sizeHint () const override
	\reimp

QSize	minimumSizeHint () const override
	\reimp

void	setBuddy (QWidget *)
	Sets this label's buddy to buddy.

QWidget *	buddy () const
	Returns this label's buddy, or nullptr if no buddy is currently set.

int	heightForWidth (int) const override
	\reimp

bool	openExternalLinks () const

void	setOpenExternalLinks (bool open)

void	setTextInteractionFlags (Qt::TextInteractionFlags flags)

Qt::TextInteractionFlags	textInteractionFlags () const

void	setSelection (int, int)
	Selects text from position start and for length characters.

bool	hasSelectedText () const

QString	selectedText () const

int	selectionStart () const
	selectionStart() returns the index of the first selected character in the label or -1 if no text is selected.

Public Member Functions inherited from QFrame
	QFrame (QWidget *parent=nullptr, Qt::WindowFlags f=Qt::WindowFlags())
	Constructs a frame widget with frame style \l NoFrame and a 1-pixel frame width.

	~QFrame ()
	Destroys the frame.

int	frameStyle () const
	Returns the frame style.

void	setFrameStyle (int)
	Sets the frame style to style.

int	frameWidth () const

Shape	frameShape () const

void	setFrameShape (Shape)

Shadow	frameShadow () const

void	setFrameShadow (Shadow)

int	lineWidth () const

void	setLineWidth (int)

int	midLineWidth () const

void	setMidLineWidth (int)

QRect	frameRect () const

void	setFrameRect (const QRect &)

Public Member Functions inherited from QWidget
	QWidget (QWidget *parent=nullptr, Qt::WindowFlags f=Qt::WindowFlags())
	Constructs a widget which is a child of parent, with widget flags set to f.

	~QWidget ()
	Destroys the widget.

int	devType () const override

WId	winId () const
	Returns the window system identifier of the widget.

void	createWinId ()

WId	internalWinId () const

WId	effectiveWinId () const

QStyle *	style () const

void	setStyle (QStyle *)
	Sets the widget's GUI style to style.

bool	isWindow () const
	Returns `true` if the widget is an independent window, otherwise returns `false`.

bool	isModal () const

Qt::WindowModality	windowModality () const

void	setWindowModality (Qt::WindowModality windowModality)

bool	isEnabled () const

bool	isEnabledTo (const QWidget *) const
	Returns `true` if this widget would become enabled if ancestor is enabled; otherwise returns `false`.

QRect	frameGeometry () const

const QRect &	geometry () const

QRect	normalGeometry () const

int	x () const

int	y () const

QPoint	pos () const

QSize	frameSize () const

QSize	size () const

int	width () const

int	height () const

QRect	rect () const

QRect	childrenRect () const

QRegion	childrenRegion () const

QSize	minimumSize () const

QSize	maximumSize () const

int	minimumWidth () const

int	minimumHeight () const

int	maximumWidth () const

int	maximumHeight () const

void	setMinimumSize (const QSize &)

void	setMinimumSize (int minw, int minh)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This function corresponds to setMinimumSize(QSize(minw, minh)).

void	setMaximumSize (const QSize &)

void	setMaximumSize (int maxw, int maxh)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This function corresponds to setMaximumSize(QSize(maxw, maxh)).

void	setMinimumWidth (int minw)

void	setMinimumHeight (int minh)

void	setMaximumWidth (int maxw)

void	setMaximumHeight (int maxh)

QSize	sizeIncrement () const

void	setSizeIncrement (const QSize &)

void	setSizeIncrement (int w, int h)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the x (width) size increment to w and the y (height) size increment to h.

QSize	baseSize () const

void	setBaseSize (const QSize &)

void	setBaseSize (int basew, int baseh)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This corresponds to setBaseSize(QSize(basew, baseh)).

void	setFixedSize (const QSize &)
	Sets both the minimum and maximum sizes of the widget to s, thereby preventing it from ever growing or shrinking.

void	setFixedSize (int w, int h)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the width of the widget to w and the height to h.

void	setFixedWidth (int w)
	Sets both the minimum and maximum width of the widget to w without changing the heights.

void	setFixedHeight (int h)
	Sets both the minimum and maximum heights of the widget to h without changing the widths.

QPointF	mapToGlobal (const QPointF &) const
	Translates the widget coordinate pos to global screen coordinates.

QPoint	mapToGlobal (const QPoint &) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QPointF	mapFromGlobal (const QPointF &) const
	Translates the global screen coordinate pos to widget coordinates.

QPoint	mapFromGlobal (const QPoint &) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QPointF	mapToParent (const QPointF &) const
	Translates the widget coordinate pos to a coordinate in the parent widget.

QPoint	mapToParent (const QPoint &) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QPointF	mapFromParent (const QPointF &) const
	Translates the parent widget coordinate pos to widget coordinates.

QPoint	mapFromParent (const QPoint &) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QPointF	mapTo (const QWidget *, const QPointF &) const
	Translates the widget coordinate pos to the coordinate system of parent.

QPoint	mapTo (const QWidget *, const QPoint &) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QPointF	mapFrom (const QWidget *, const QPointF &) const
	Translates the widget coordinate pos from the coordinate system of parent to this widget's coordinate system.

QPoint	mapFrom (const QWidget *, const QPoint &) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QWidget *	window () const
	Returns the window for this widget, i.e.

QWidget *	nativeParentWidget () const

QWidget *	topLevelWidget () const

const QPalette &	palette () const

void	setPalette (const QPalette &)

void	setBackgroundRole (QPalette::ColorRole)
	Sets the background role of the widget to role.

QPalette::ColorRole	backgroundRole () const
	Returns the background role of the widget.

void	setForegroundRole (QPalette::ColorRole)
	Sets the foreground role of the widget to role.

QPalette::ColorRole	foregroundRole () const
	Returns the foreground role.

const QFont &	font () const

void	setFont (const QFont &)

QFontMetrics	fontMetrics () const
	Returns the font metrics for the widget's current font.

QFontInfo	fontInfo () const
	Returns the font info for the widget's current font.

QCursor	cursor () const

void	setCursor (const QCursor &)

void	unsetCursor ()

void	setMouseTracking (bool enable)

bool	hasMouseTracking () const

bool	underMouse () const
	Returns `true` if the widget is under the mouse cursor; otherwise returns `false`.

void	setTabletTracking (bool enable)

bool	hasTabletTracking () const

void	setMask (const QBitmap &)
	Causes only the pixels of the widget for which bitmap has a corresponding 1 bit to be visible.

void	setMask (const QRegion &)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Causes only the parts of the widget which overlap region to be visible.

QRegion	mask () const
	Returns the mask currently set on a widget.

void	clearMask ()
	Removes any mask set by setMask().

void	render (QPaintDevice *target, const QPoint &targetOffset=QPoint(), const QRegion &sourceRegion=QRegion(), RenderFlags renderFlags=RenderFlags(DrawWindowBackground\|DrawChildren))

void	render (QPainter *painter, const QPoint &targetOffset=QPoint(), const QRegion &sourceRegion=QRegion(), RenderFlags renderFlags=RenderFlags(DrawWindowBackground\|DrawChildren))
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Renders the widget into the painter's QPainter::device().

Q_INVOKABLE QPixmap	grab (const QRect &rectangle=QRect(QPoint(0, 0), QSize(-1, -1)))

void	grabGesture (Qt::GestureType type, Qt::GestureFlags flags=Qt::GestureFlags())
	Subscribes the widget to a given gesture with specific flags.

void	ungrabGesture (Qt::GestureType type)
	Unsubscribes the widget from a given gesture type.

QString	styleSheet () const

QString	windowTitle () const

void	setWindowIcon (const QIcon &icon)

QIcon	windowIcon () const

void	setWindowIconText (const QString &)

QString	windowIconText () const

void	setWindowRole (const QString &)
	Sets the window's role to role.

QString	windowRole () const
	Returns the window's role, or an empty string.

void	setWindowFilePath (const QString &filePath)

QString	windowFilePath () const

void	setWindowOpacity (qreal level)

qreal	windowOpacity () const

bool	isWindowModified () const

void	setLayoutDirection (Qt::LayoutDirection direction)

Qt::LayoutDirection	layoutDirection () const

void	unsetLayoutDirection ()

void	setLocale (const QLocale &locale)

QLocale	locale () const

void	unsetLocale ()

bool	isRightToLeft () const

bool	isLeftToRight () const

bool	isActiveWindow () const

void	activateWindow ()
	Sets the top-level widget containing this widget to be the active window.

void	clearFocus ()
	Takes keyboard input focus from the widget.

void	setFocus (Qt::FocusReason reason)
	Gives the keyboard input focus to this widget (or its focus proxy) if this widget or one of its parents is the \l{isActiveWindow()}{active window}.

Qt::FocusPolicy	focusPolicy () const

void	setFocusPolicy (Qt::FocusPolicy policy)

bool	hasFocus () const

void	setFocusProxy (QWidget *)
	Sets the widget's focus proxy to widget w.

QWidget *	focusProxy () const
	Returns the focus proxy, or \nullptr if there is no focus proxy.

Qt::ContextMenuPolicy	contextMenuPolicy () const

void	setContextMenuPolicy (Qt::ContextMenuPolicy policy)

void	grabMouse ()
	Grabs the mouse input.

void	grabMouse (const QCursor &)

void	releaseMouse ()
	Releases the mouse grab.

void	grabKeyboard ()
	Grabs the keyboard input.

void	releaseKeyboard ()
	Releases the keyboard grab.

int	grabShortcut (const QKeySequence &key, Qt::ShortcutContext context=Qt::WindowShortcut)
	Adds a shortcut to Qt's shortcut system that watches for the given key sequence in the given context.

void	releaseShortcut (int id)
	Removes the shortcut with the given id from Qt's shortcut system.

void	setShortcutEnabled (int id, bool enable=true)
	If enable is true, the shortcut with the given id is enabled; otherwise the shortcut is disabled.

void	setShortcutAutoRepeat (int id, bool enable=true)

bool	updatesEnabled () const

void	setUpdatesEnabled (bool enable)

void	update (int x, int y, int w, int h)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This version updates a rectangle (x, y, w, h) inside the widget.

void	update (const QRect &)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This version updates a rectangle rect inside the widget.

void	update (const QRegion &)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This version repaints a region rgn inside the widget.

void	repaint (int x, int y, int w, int h)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This version repaints a rectangle (x, y, w, h) inside the widget.

void	repaint (const QRect &)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This version repaints a rectangle rect inside the widget.

void	repaint (const QRegion &)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This version repaints a region rgn inside the widget.

void	stackUnder (QWidget *)
	Places the widget under w in the parent widget's stack.

void	move (int x, int y)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This corresponds to move(QPoint(x, y)).

void	move (const QPoint &)

void	resize (int w, int h)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This corresponds to resize(QSize(w, h)).

void	resize (const QSize &)

void	setGeometry (int x, int y, int w, int h)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This corresponds to setGeometry(QRect(x, y, w, h)).

void	setGeometry (const QRect &)

QByteArray	saveGeometry () const

bool	restoreGeometry (const QByteArray &geometry)

void	adjustSize ()
	Adjusts the size of the widget to fit its contents.

bool	isVisible () const

bool	isVisibleTo (const QWidget *) const
	Returns `true` if this widget would become visible if ancestor is shown; otherwise returns `false`.

bool	isHidden () const
	Returns `true` if the widget is hidden, otherwise returns `false`.

bool	isMinimized () const

bool	isMaximized () const

bool	isFullScreen () const

Qt::WindowStates	windowState () const
	Returns the current window state.

void	setWindowState (Qt::WindowStates state)
	Sets the window state to windowState.

void	overrideWindowState (Qt::WindowStates state)

QSizePolicy	sizePolicy () const

void	setSizePolicy (QSizePolicy)

void	setSizePolicy (QSizePolicy::Policy horizontal, QSizePolicy::Policy vertical)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the size policy of the widget to horizontal and vertical, with standard stretch and no height-for-width.

virtual bool	hasHeightForWidth () const

QRegion	visibleRegion () const
	Returns the unobscured region where paint events can occur.

void	setContentsMargins (int left, int top, int right, int bottom)
	Sets the margins around the contents of the widget to have the sizes left, top, right, and bottom.

void	setContentsMargins (const QMargins &margins)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

QMargins	contentsMargins () const
	The contentsMargins function returns the widget's contents margins.

QRect	contentsRect () const
	Returns the area inside the widget's margins.

QLayout *	layout () const
	Returns the layout manager that is installed on this widget, or \nullptr if no layout manager is installed.

void	setLayout (QLayout *)
	Sets the layout manager for this widget to layout.

void	updateGeometry ()
	Notifies the layout system that this widget has changed and may need to change geometry.

void	setParent (QWidget *parent)
	Sets the parent of the widget to parent, and resets the window flags.

void	setParent (QWidget *parent, Qt::WindowFlags f)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This function also takes widget flags, f as an argument.

void	scroll (int dx, int dy)
	Scrolls the widget including its children dx pixels to the right and dy downward.

void	scroll (int dx, int dy, const QRect &)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.This version only scrolls r and does not move the children of the widget.

QWidget *	focusWidget () const
	Returns the last child of this widget that setFocus had been called on.

QWidget *	nextInFocusChain () const
	Returns the next widget in this widget's focus chain.

QWidget *	previousInFocusChain () const
	The previousInFocusChain function returns the previous widget in this widget's focus chain.

bool	acceptDrops () const

void	setAcceptDrops (bool on)

void	addAction (QAction *action)
	Appends the action action to this widget's list of actions.

void	addActions (const QList< QAction * > &actions)
	Appends the actions actions to this widget's list of actions.

void	insertActions (QAction before, const QList< QAction > &actions)
	Inserts the actions actions to this widget's list of actions, before the action before.

void	insertAction (QAction before, QAction action)
	Inserts the action action to this widget's list of actions, before the action before.

void	removeAction (QAction *action)
	Removes the action action from this widget's list of actions.

QList< QAction * >	actions () const
	Returns the (possibly empty) list of this widget's actions.

QAction *	addAction (const QString &text)

QAction *	addAction (const QIcon &icon, const QString &text)

QAction *	addAction (const QString &text, const QObject receiver, const char member, Qt::ConnectionType type=Qt::AutoConnection)

QAction *	addAction (const QIcon &icon, const QString &text, const QObject receiver, const char member, Qt::ConnectionType type=Qt::AutoConnection)

template<typename... Args, typename = compatible_action_slot_args<Args...>>
QAction *	addAction (const QString &text, Args &&...args)

template<typename... Args, typename = compatible_action_slot_args<Args...>>
QAction *	addAction (const QIcon &icon, const QString &text, Args &&...args)

QWidget *	parentWidget () const
	Returns the parent of this widget, or \nullptr if it does not have any parent widget.

void	setWindowFlags (Qt::WindowFlags type)

Qt::WindowFlags	windowFlags () const
	Window flags are a combination of a type (e.g.

void	setWindowFlag (Qt::WindowType, bool on=true)

void	overrideWindowFlags (Qt::WindowFlags type)
	Sets the window flags for the widget to flags, without telling the window system.

Qt::WindowType	windowType () const
	Returns the window type of this widget.

QWidget *	childAt (int x, int y) const
	Returns the visible child widget at the position ({x}, {y}) in the widget's coordinate system.

QWidget *	childAt (const QPoint &p) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns the visible child widget at point p in the widget's own coordinate system.

void	setAttribute (Qt::WidgetAttribute, bool on=true)
	Sets the attribute attribute on this widget if on is true; otherwise clears the attribute.

bool	testAttribute (Qt::WidgetAttribute) const
	Returns `true` if attribute attribute is set on this widget; otherwise returns `false`.

QPaintEngine *	paintEngine () const override
	Returns the widget's paint engine.

void	ensurePolished () const
	Ensures that the widget and its children have been polished by QStyle (i.e., have a proper font and palette).

bool	isAncestorOf (const QWidget *child) const
	Returns `true` if this widget is a parent, (or grandparent and so on to any level), of the given child, and both widgets are within the same window; otherwise returns `false`.

bool	autoFillBackground () const

void	setAutoFillBackground (bool enabled)

QBackingStore *	backingStore () const

QWindow *	windowHandle () const
	If this is a native widget, return the associated QWindow.

QScreen *	screen () const
	Returns the screen the widget is on.

void	setScreen (QScreen *)
	Sets the screen on which the widget should be shown to screen.

virtual QVariant	inputMethodQuery (Qt::InputMethodQuery) const
	This method is only relevant for input widgets.

Qt::InputMethodHints	inputMethodHints () const

void	setInputMethodHints (Qt::InputMethodHints hints)

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	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`.

Public Member Functions inherited from QPaintDevice
virtual	~QPaintDevice ()

bool	paintingActive () const

int	width () const

int	height () const

int	widthMM () const

int	heightMM () const

int	logicalDpiX () const

int	logicalDpiY () const

int	physicalDpiX () const

int	physicalDpiY () const

qreal	devicePixelRatio () const

qreal	devicePixelRatioF () const

int	colorCount () const

int	depth () const

Protected Member Functions
bool	event (QEvent *e) override
	\reimp

void	keyPressEvent (QKeyEvent *ev) override
	\reimp

void	paintEvent (QPaintEvent *) override
	\reimp

void	changeEvent (QEvent *) override
	\reimp

void	mousePressEvent (QMouseEvent *ev) override
	\reimp

void	mouseMoveEvent (QMouseEvent *ev) override
	\reimp

void	mouseReleaseEvent (QMouseEvent *ev) override
	\reimp

void	contextMenuEvent (QContextMenuEvent *ev) override
	\reimp

void	focusInEvent (QFocusEvent *ev) override
	\reimp

void	focusOutEvent (QFocusEvent *ev) override
	\reimp

bool	focusNextPrevChild (bool next) override
	\reimp

Protected Member Functions inherited from QFrame
void	drawFrame (QPainter *)

	QFrame (QFramePrivate &dd, QWidget *parent=nullptr, Qt::WindowFlags f=Qt::WindowFlags())

virtual void	initStyleOption (QStyleOptionFrame *option) const

Protected Member Functions inherited from QWidget
bool	event (QEvent *event) override
	This is the main event handler; it handles event event.

virtual void	mouseDoubleClickEvent (QMouseEvent *event)
	This event handler, for event event, can be reimplemented in a subclass to receive mouse double click events for the widget.

virtual void	keyReleaseEvent (QKeyEvent *event)
	This event handler, for event event, can be reimplemented in a subclass to receive key release events for the widget.

virtual void	enterEvent (QEnterEvent *event)
	This event handler can be reimplemented in a subclass to receive widget enter events which are passed in the event parameter.

virtual void	leaveEvent (QEvent *event)
	This event handler can be reimplemented in a subclass to receive widget leave events which are passed in the event parameter.

virtual void	moveEvent (QMoveEvent *event)
	This event handler can be reimplemented in a subclass to receive widget move events which are passed in the event parameter.

virtual void	resizeEvent (QResizeEvent *event)
	This event handler can be reimplemented in a subclass to receive widget resize events which are passed in the event parameter.

virtual void	closeEvent (QCloseEvent *event)
	This event handler is called with the given event when Qt receives a window close request for a top-level widget from the window system.

virtual void	actionEvent (QActionEvent *event)
	This event handler is called with the given event whenever the widget's actions are changed.

virtual void	showEvent (QShowEvent *event)
	This event handler can be reimplemented in a subclass to receive widget show events which are passed in the event parameter.

virtual void	hideEvent (QHideEvent *event)
	This event handler can be reimplemented in a subclass to receive widget hide events.

virtual bool	nativeEvent (const QByteArray &eventType, void message, qintptr result)
	This special event handler can be reimplemented in a subclass to receive native platform events identified by eventType which are passed in the message parameter.

int	metric (PaintDeviceMetric) const override
	Internal implementation of the virtual QPaintDevice::metric() function.

void	initPainter (QPainter *painter) const override
	Initializes the painter pen, background and font to the same as the given widget's.

QPaintDevice *	redirected (QPoint *offset) const override

QPainter *	sharedPainter () const override

virtual void	inputMethodEvent (QInputMethodEvent *)
	This event handler, for event event, can be reimplemented in a subclass to receive Input Method composition events.

void	create (WId=0, bool initializeWindow=true, bool destroyOldWindow=true)
	Creates a new widget window.

void	destroy (bool destroyWindow=true, bool destroySubWindows=true)
	Frees up window system resources.

bool	focusNextChild ()
	Finds a new widget to give the keyboard focus to, as appropriate for \uicontrol Tab, and returns `true` if it can find a new widget, or false if it can't.

bool	focusPreviousChild ()
	Finds a new widget to give the keyboard focus to, as appropriate for \uicontrol Shift+Tab, and returns `true` if it can find a new widget, or false if it can't.

	QWidget (QWidgetPrivate &d, QWidget *parent, Qt::WindowFlags f)

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 Member Functions inherited from QPaintDevice
	QPaintDevice () noexcept

Properties
QString	text
	the label's text

Qt::TextFormat	textFormat
	the label's text format

QPixmap	pixmap
	the label's pixmap.

bool	scaledContents
	whether the label will scale its contents to fill all available space.

Qt::Alignment	alignment
	the alignment of the label's contents

bool	wordWrap
	the label's word-wrapping policy

int	margin
	the width of the margin

int	indent
	the label's text indent in pixels

bool	openExternalLinks

Qt::TextInteractionFlags	textInteractionFlags

bool	hasSelectedText
	whether there is any text selected

QString	selectedText
	the selected text

Properties inherited from QFrame
Shape	frameShape
	the frame shape value from the frame style

Shadow	frameShadow
	the frame shadow value from the frame style

int	lineWidth
	the line width

int	midLineWidth
	the width of the mid-line

int	frameWidth
	the width of the frame that is drawn.

QRect	frameRect
	the frame's rectangle

Properties inherited from QWidget
bool	modal
	whether the widget is a modal widget

Qt::WindowModality	windowModality
	which windows are blocked by the modal widget

bool	enabled
	whether the widget is enabled

QRect	geometry
	the geometry of the widget relative to its parent and excluding the window frame

QRect	frameGeometry
	geometry of the widget relative to its parent including any window frame

QRect	normalGeometry
	the geometry of the widget as it will appear when shown as a normal (not maximized or full screen) top-level widget

int	x
	the x coordinate of the widget relative to its parent including any window frame

int	y
	the y coordinate of the widget relative to its parent and including any window frame

QPoint	pos
	the position of the widget within its parent widget

QSize	frameSize
	the size of the widget including any window frame

QSize	size
	the size of the widget excluding any window frame

int	width
	the width of the widget excluding any window frame

int	height
	the height of the widget excluding any window frame

QRect	rect
	the internal geometry of the widget excluding any window frame

QRect	childrenRect
	the bounding rectangle of the widget's children

QRegion	childrenRegion
	the combined region occupied by the widget's children

QSizePolicy	sizePolicy
	the default layout behavior of the widget

QSize	minimumSize
	the widget's minimum size

QSize	maximumSize
	the widget's maximum size in pixels

int	minimumWidth
	the widget's minimum width in pixels

int	minimumHeight
	the widget's minimum height in pixels

int	maximumWidth
	the widget's maximum width in pixels

int	maximumHeight
	the widget's maximum height in pixels

QSize	sizeIncrement
	the size increment of the widget

QSize	baseSize
	the base size of the widget

QPalette	palette
	the widget's palette

QFont	font
	the font currently set for the widget

QCursor	cursor
	the cursor shape for this widget

bool	mouseTracking
	whether mouse tracking is enabled for the widget

bool	tabletTracking
	whether tablet tracking is enabled for the widget

bool	isActiveWindow
	whether this widget's window is the active window

Qt::FocusPolicy	focusPolicy
	the way the widget accepts keyboard focus

bool	focus
	whether this widget (or its focus proxy) has the keyboard input focus

Qt::ContextMenuPolicy	contextMenuPolicy
	how the widget shows a context menu

bool	updatesEnabled
	whether updates are enabled

bool	visible
	whether the widget is visible

bool	minimized
	whether this widget is minimized (iconified)

bool	maximized
	whether this widget is maximized

bool	fullScreen
	whether the widget is shown in full screen mode

QSize	sizeHint
	the recommended size for the widget

QSize	minimumSizeHint
	the recommended minimum size for the widget

bool	acceptDrops
	whether drop events are enabled for this widget

QString	windowTitle
	the window title (caption)

QIcon	windowIcon
	the widget's icon

QString	windowIconText
	the text to be displayed on the icon of a minimized window

double	windowOpacity
	The level of opacity for the window.

bool	windowModified
	whether the document shown in the window has unsaved changes

Qt::LayoutDirection	layoutDirection
	the layout direction for this widget.

bool	autoFillBackground
	whether the widget background is filled automatically

QString	styleSheet
	the widget's style sheet

QLocale	locale
	the widget's locale

QString	windowFilePath
	the file path associated with a widget

Qt::InputMethodHints	inputMethodHints
	What input method specific hints the widget has.

Properties inherited from QObject
QString	objectName
	the name of this object

Friends
class	QTipLabel

class	QMessageBoxPrivate

class	QBalloonTip

Additional Inherited Members
Public Types inherited from QFrame
enum	Shape { NoFrame = 0 , Box = 0x0001 , Panel = 0x0002 , WinPanel = 0x0003 , HLine = 0x0004 , VLine = 0x0005 , StyledPanel = 0x0006 }
	This enum type defines the shapes of frame available. More...

enum	Shadow { Plain = 0x0010 , Raised = 0x0020 , Sunken = 0x0030 }
	This enum type defines the types of shadow that are used to give a 3D effect to frames. More...

enum	StyleMask { Shadow_Mask = 0x00f0 , Shape_Mask = 0x000f }
	This enum defines two constants that can be used to extract the two components of frameStyle(): More...

Public Types inherited from QWidget
enum	RenderFlag { DrawWindowBackground = 0x1 , DrawChildren = 0x2 , IgnoreMask = 0x4 }
	This enum describes how to render the widget when calling QWidget::render(). More...

Public Types inherited from QPaintDevice
enum	PaintDeviceMetric { PdmWidth = 1 , PdmHeight , PdmWidthMM , PdmHeightMM , PdmNumColors , PdmDepth , PdmDpiX , PdmDpiY , PdmPhysicalDpiX , PdmPhysicalDpiY , PdmDevicePixelRatio , PdmDevicePixelRatioScaled }

Static Public Member Functions inherited from QWidget
static void	setTabOrder (QWidget , QWidget )
	Puts the second widget after the first widget in the focus order.

static void	setTabOrder (std::initializer_list< QWidget * > widgets)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

static QWidget *	mouseGrabber ()
	Returns the widget that is currently grabbing the mouse input.

static QWidget *	keyboardGrabber ()
	Returns the widget that is currently grabbing the keyboard input.

static QWidget *	find (WId)
	Returns a pointer to the widget with window identifier/handle id.

static QWidget *	createWindowContainer (QWindow window, QWidget parent=nullptr, Qt::WindowFlags flags=Qt::WindowFlags())
	Creates a QWidget that makes it possible to embed window into a QWidget-based application.

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)

Static Public Member Functions inherited from QPaintDevice
static qreal	devicePixelRatioFScale ()

Protected Slots inherited from QWidget
void	updateMicroFocus (Qt::InputMethodQuery query=Qt::ImQueryAll)
	Updates the widget's micro focus and informs input methods that the state specified by query has changed.

Protected Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Protected Attributes inherited from QPaintDevice
ushort	painters

Related Symbols inherited from QWidget
	setupUi (QWidget *widget)
	\macro QWIDGETSIZE_MAX

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 QLabel widget provides a text or image display.

\inmodule QtWidgets

QLabel is used for displaying text or an image. No user interaction functionality is provided. The visual appearance of the label can be configured in various ways, and it can be used for specifying a focus mnemonic key for another widget.

A QLabel can contain any of the following content types:

\table \header

Content
Setting \row
Plain text
Pass a QString to setText(). \row
Rich text
Pass a QString that contains rich text to setText(). \row
A pixmap
Pass a QPixmap to setPixmap(). \row
A movie
Pass a QMovie to setMovie(). \row
A number
Pass an int or a double to setNum(), which converts the number to plain text. \row
Nothing
The same as an empty plain text. This is the default. Set by clear(). \endtable

Warning: When passing a QString to the constructor or calling setText(), make sure to sanitize your input, as QLabel tries to guess whether it displays the text as plain text or as rich text, a subset of HTML 4 markup. You may want to call setTextFormat() explicitly, e.g. in case you expect the text to be in plain format but cannot control the text source (for instance when displaying data loaded from the Web).

When the content is changed using any of these functions, any previous content is cleared.

By default, labels display \l{alignment}{left-aligned, vertically-centered} text and images, where any tabs in the text to be displayed are \l{Qt::TextExpandTabs}{automatically expanded}. However, the look of a QLabel can be adjusted and fine-tuned in several ways.

The positioning of the content within the QLabel widget area can be tuned with setAlignment() and setIndent(). Text content can also wrap lines along word boundaries with setWordWrap(). For example, this code sets up a sunken panel with a two-line text in the bottom right corner (both lines being flush with the right side of the label):

QLabel *label = new QLabel(this);
label->setFrameStyle(QFrame::Panel | QFrame::Sunken);
label->setText("first line\nsecond line");
label->setAlignment(Qt::AlignBottom | Qt::AlignRight);

The properties and functions QLabel inherits from QFrame can also be used to specify the widget frame to be used for any given label.

A QLabel is often used as a label for an interactive widget. For this use QLabel provides a useful mechanism for adding an mnemonic (see QKeySequence) that will set the keyboard focus to the other widget (called the QLabel's "buddy"). For example:

QLineEdit *phoneEdit = new QLineEdit(this);
QLabel *phoneLabel = new QLabel("&Phone:", this);
phoneLabel->setBuddy(phoneEdit);

In this example, keyboard focus is transferred to the label's buddy (the QLineEdit) when the user presses Alt+P. If the buddy was a button (inheriting from QAbstractButton), triggering the mnemonic would emulate a button click.

See also: QLineEdit, QTextEdit, QPixmap, QMovie

Definition at line 19 of file qlabel.h.

Constructor & Destructor Documentation

◆ QLabel() [1/2]

QLabel::QLabel	(	QWidget *	parent = nullptr,
		Qt::WindowFlags	f = Qt::WindowFlags() )

explicit

Constructs an empty label.

The parent and widget flag f, arguments are passed to the QFrame constructor.

See also: setAlignment(), setFrameStyle(), setIndent()

Definition at line 191 of file qlabel.cpp.

References d.

◆ QLabel() [2/2]

QLabel::QLabel	(	const QString &	text,
		QWidget *	parent = nullptr,
		Qt::WindowFlags	f = Qt::WindowFlags() )

explicit

Constructs a label that displays the text, text.

The parent and widget flag f, arguments are passed to the QFrame constructor.

See also: setText(), setAlignment(), setFrameStyle(), setIndent()

Definition at line 206 of file qlabel.cpp.

References setText(), and text.

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◆ ~QLabel()

QLabel::~QLabel ( )

Destroys the label.

Definition at line 218 of file qlabel.cpp.

References d.

Member Function Documentation

◆ alignment()

Qt::Alignment QLabel::alignment ( ) const

Definition at line 454 of file qlabel.cpp.

References Qt::AlignHorizontal_Mask, Qt::AlignVertical_Mask, and d.

◆ buddy()

QWidget * QLabel::buddy ( ) const

Returns this label's buddy, or nullptr if no buddy is currently set.

See also: setBuddy()

Definition at line 1201 of file qlabel.cpp.

References d.

Referenced by setBuddy().

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◆ changeEvent()

void QLabel::changeEvent ( QEvent * ev )

overrideprotectedvirtual

\reimp

Reimplemented from QFrame.

Definition at line 1418 of file qlabel.cpp.

References QEvent::ApplicationFontChange, QFrame::changeEvent(), QEvent::ContentsRectChange, d, QWidget::font, QEvent::FontChange, QWidget::palette, and QEvent::PaletteChange.

bool QLabel::hasScaledContents ( ) const

Definition at line 1445 of file qlabel.cpp.

References d.

◆ hasSelectedText()

bool QLabel::hasSelectedText ( ) const

Definition at line 767 of file qlabel.cpp.

References d.

◆ heightForWidth()

int QLabel::heightForWidth ( int w ) const

overridevirtual

\reimp

Reimplemented from QWidget.

Definition at line 650 of file qlabel.cpp.

References d, and QWidget::heightForWidth().

Referenced by QWizardHeader::setup().

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◆ indent()

int QLabel::indent ( ) const

Definition at line 517 of file qlabel.cpp.

References d.

◆ keyPressEvent()

void QLabel::keyPressEvent ( QKeyEvent * ev )

overrideprotectedvirtual

\reimp

Reimplemented from QWidget.

Definition at line 948 of file qlabel.cpp.

References d.

◆ linkActivated

void QLabel::linkActivated ( const QString & link )

signal

Since: 4.2

This signal is emitted when the user clicks a link. The URL referred to by the anchor is passed in link.

See also: linkHovered()

Referenced by QLabelPrivate::ensureTextControl().

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◆ linkHovered

void QLabel::linkHovered ( const QString & link )

signal

Since: 4.2

This signal is emitted when the user hovers over a link. The URL referred to by the anchor is passed in link.

See also: linkActivated()

◆ margin()

int QLabel::margin ( ) const

Definition at line 535 of file qlabel.cpp.

References d.

◆ minimumSizeHint()

QSize QLabel::minimumSizeHint ( ) const

overridevirtual

\reimp

Reimplemented from QWidget.

Reimplemented in QWatermarkLabel.

Definition at line 831 of file qlabel.cpp.

References d, QWidget::ensurePolished(), QSize::height(), QWIDGETSIZE_MAX, QSize::rheight(), QSize::rwidth(), and QWidget::sizePolicy.

Referenced by QPrintPreviewDialogPrivate::init(), and sizeHint().

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◆ mouseMoveEvent()

void QLabel::mouseMoveEvent ( QMouseEvent * ev )

overrideprotectedvirtual

\reimp

Reimplemented from QWidget.

Reimplemented in QTipLabel.

Definition at line 867 of file qlabel.cpp.

References d.

Referenced by QTipLabel::mouseMoveEvent().

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◆ mousePressEvent()

void QLabel::mousePressEvent ( QMouseEvent * ev )

overrideprotectedvirtual

\reimp

Reimplemented from QWidget.

Definition at line 859 of file qlabel.cpp.

References d.

◆ mouseReleaseEvent()

void QLabel::mouseReleaseEvent ( QMouseEvent * ev )

overrideprotectedvirtual

\reimp

Reimplemented from QWidget.

Definition at line 875 of file qlabel.cpp.

References d.

◆ openExternalLinks()

bool QLabel::openExternalLinks ( ) const

Definition at line 673 of file qlabel.cpp.

References d.

◆ paintEvent()

void QLabel::paintEvent ( QPaintEvent * )

overrideprotectedvirtual

\reimp

Reimplemented from QFrame.

Reimplemented in QTipLabel.

Definition at line 1001 of file qlabel.cpp.

References QRect::adjust(), Qt::AlignBottom, Qt::AlignHCenter, Qt::AlignRight, Qt::AlignVCenter, QWidget::contentsRect(), context, d, QPaintDevice::devicePixelRatio(), QIcon::Disabled, dpr(), QFrame::drawFrame(), QStyle::drawItemPixmap(), QStyle::drawItemText(), QPainter::drawPicture(), fmt, QWidget::foregroundRole(), QPixmap::fromImage(), QStyle::generatedIconPixmap(), QRect::height(), Qt::IgnoreAspectRatio, QStyleOption::initFrom(), QWidget::isEnabled(), QWidget::layoutDirection, Qt::LeftToRight, opt, painter, QStyleOption::palette, pix, qt_styleSheet(), QPainter::restore(), QPainter::save(), QPainter::scale(), QImage::scaled(), QPainter::setClipRect(), QTextCharFormat::setFontUnderline(), QStyle::SH_UnderlineShortcut, QRect::size(), Qt::SmoothTransformation, QWidget::style(), QStyle::styleHint(), QPalette::Text, QPalette::text(), Qt::TextForceLeftToRight, Qt::TextForceRightToLeft, Qt::TextHideMnemonic, Qt::TextShowMnemonic, QRectF::toAlignedRect(), QPainter::translate(), QStyle::visualAlignment(), QRect::width(), QRect::x(), and QRect::y().

Referenced by QTipLabel::paintEvent().

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◆ picture()

QPicture QLabel::picture ( ) const

Deprecated: Use the overload without argument instead.

Since: 5.15

Returns the label's picture.

Previously, Qt provided a version of picture() which returned the picture by-pointer. That version is now removed. This overload allowed to explicitly differentiate between the by-pointer function and the by-value.

Since: 6.0

Returns the label's picture.

Definition at line 173 of file qlabel.cpp.

References d.

Referenced by setPicture().

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◆ pixmap()

QPixmap QLabel::pixmap ( ) const

Definition at line 350 of file qlabel.cpp.

References d, and QWidget::QPixmap.

◆ resourceProvider()

QTextDocument::ResourceProvider QLabel::resourceProvider ( ) const

Since: 6.1

Returns the resource provider for rich text of this label.

Definition at line 1394 of file qlabel.cpp.

References d.

◆ selectedText()

QString QLabel::selectedText ( ) const

Definition at line 791 of file qlabel.cpp.

References d.

◆ selectionStart()

int QLabel::selectionStart ( ) const

selectionStart() returns the index of the first selected character in the label or -1 if no text is selected.

See also: selectedText()

{Note:} The textInteractionFlags set on the label need to include either TextSelectableByMouse or TextSelectableByKeyboard.

Since: 4.7

Definition at line 810 of file qlabel.cpp.

References d.

◆ setAlignment()

void QLabel::setAlignment ( Qt::Alignment alignment )

Definition at line 442 of file qlabel.cpp.

References Qt::AlignHorizontal_Mask, alignment, Qt::AlignVertical_Mask, and d.

Referenced by DragWidget::DragWidget(), QtPrivate::QColorShower::QColorShower(), QTipLabel::QTipLabel(), QWizardHeader::QWizardHeader(), and QWizardPrivate::recreateLayout().

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◆ setBuddy()

void QLabel::setBuddy ( QWidget * buddy )

Sets this label's buddy to buddy.

When the user presses the shortcut key indicated by this label, the keyboard focus is transferred to the label's buddy widget.

The buddy mechanism is only available for QLabels that contain text in which one character is prefixed with an ampersand, '&'. This character is set as the shortcut key. See the \l QKeySequence::mnemonic() documentation for details (to display an actual ampersand, use '&&').

In a dialog, you might create two data entry widgets and a label for each, and set up the geometry layout so each label is just to the left of its data entry widget (its "buddy"), for example:

QLineEdit *nameEdit  = new QLineEdit(this);
QLabel    *nameLabel = new QLabel("&Name:", this);
nameLabel->setBuddy(nameEdit);
QLineEdit *phoneEdit  = new QLineEdit(this);
QLabel    *phoneLabel = new QLabel("&Phone:", this);
phoneLabel->setBuddy(phoneEdit);
// (layout setup not shown)

With the code above, the focus jumps to the Name field when the user presses Alt+N, and to the Phone field when the user presses Alt+P.

To unset a previously set buddy, call this function with buddy set to nullptr.

See also: buddy(), setText(), QShortcut, setAlignment()

Definition at line 1169 of file qlabel.cpp.

References buddy(), QLabelPrivate::buddyDeleted(), QObjectPrivate::connect(), d, QObject::destroyed(), QObjectPrivate::disconnect(), and QWidget::releaseShortcut().

Referenced by QtPrivate::QColorShower::QColorShower(), and QFontDialogPrivate::init().

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◆ setIndent()

void QLabel::setIndent ( int indent )

Definition at line 510 of file qlabel.cpp.

References d, and indent.

Referenced by QTipLabel::QTipLabel(), QFontDialogPrivate::init(), and QWizardPrivate::recreateLayout().

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◆ setMargin()

void QLabel::setMargin ( int margin )

Definition at line 541 of file qlabel.cpp.

References d, and margin.

Referenced by QTipLabel::QTipLabel().

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◆ setNum [1/2]

void QLabel::setNum ( double num )

slot

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Sets the label contents to plain text containing the textual representation of double num.

Any previous content is cleared. Does nothing if the double's string representation is the same as the current contents of the label.

The buddy shortcut, if any, is disabled.

See also: setText(), QString::setNum(), setBuddy()

Definition at line 426 of file qlabel.cpp.

References QString::setNum(), setText(), and str.

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◆ setNum [2/2]

void QLabel::setNum ( int num )

slot

Sets the label contents to plain text containing the textual representation of integer num.

Any previous content is cleared. Does nothing if the integer's string representation is the same as the current contents of the label.

The buddy shortcut, if any, is disabled.

See also: setText(), QString::setNum(), setBuddy()

Definition at line 406 of file qlabel.cpp.

References QString::setNum(), setText(), and str.

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◆ setOpenExternalLinks()

void QLabel::setOpenExternalLinks ( bool open )

Definition at line 679 of file qlabel.cpp.

References d, and open().

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◆ setPicture

void QLabel::setPicture ( const QPicture & picture )

slot

Sets the label contents to picture.

Any previous content is cleared.

The buddy shortcut, if any, is disabled.

See also: picture(), setBuddy()

Definition at line 385 of file qlabel.cpp.

References d, and picture().

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◆ setPixmap

void QLabel::setPixmap ( const QPixmap & pixmap )

slot

Definition at line 339 of file qlabel.cpp.

References QPixmap::cacheKey(), d, and pixmap.

Referenced by FinalWidget::setPixmap(), QWizardHeader::setup(), and QWizardPrivate::updateLayout().

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◆ setResourceProvider()

void QLabel::setResourceProvider ( const QTextDocument::ResourceProvider & provider )

Since: 6.1

Sets the provider of resources for rich text of this label.

Note: The label {does not} take ownership of the provider.

Definition at line 1407 of file qlabel.cpp.

References d.

◆ setScaledContents()

void QLabel::setScaledContents ( bool enable )

Definition at line 1451 of file qlabel.cpp.

References QWidget::contentsRect(), d, and QWidget::update().

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◆ setSelection()

void QLabel::setSelection	(	int	start,
		int	length )

Selects text from position start and for length characters.

See also: selectedText()

{Note:} The textInteractionFlags set on the label need to include either TextSelectableByMouse or TextSelectableByKeyboard.

Since: 4.7

Definition at line 739 of file qlabel.cpp.

References QWidget::cursor, d, and QTextCursor::KeepAnchor.

◆ setText

void QLabel::setText ( const QString & text )

slot

Definition at line 263 of file qlabel.cpp.

References Qt::AutoText, d, Qt::mightBeRichText(), Qt::PlainText, Qt::RichText, QWidget::setMouseTracking(), and text.

Referenced by QLabel(), main(), QtPrivate::QColorShower::retranslateStrings(), QFontDialogPrivate::retranslateStrings(), QTipLabel::reuseTip(), DragWidget::setData(), setNum(), setNum(), setTextFormat(), QWizardHeader::setup(), ClipWindow::updateData(), QWizardPrivate::updateLayout(), and QPrintPreviewDialogPrivate::updatePageNumLabel().

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◆ setTextFormat()

void QLabel::setTextFormat ( Qt::TextFormat format )

Definition at line 1376 of file qlabel.cpp.

References QString::clear(), d, and setText().

Referenced by QWizardHeader::setup(), and QWizardPrivate::updateLayout().

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◆ setTextInteractionFlags()

void QLabel::setTextInteractionFlags ( Qt::TextInteractionFlags flags )

Definition at line 699 of file qlabel.cpp.

References Qt::ClickFocus, d, Qt::LinksAccessibleByKeyboard, Qt::NoFocus, QWidget::setFocusPolicy(), Qt::StrongFocus, Qt::TextSelectableByKeyboard, and Qt::TextSelectableByMouse.

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◆ setWordWrap()

void QLabel::setWordWrap ( bool on )

Definition at line 472 of file qlabel.cpp.

References d, and Qt::TextWordWrap.

Referenced by QWizardHeader::QWizardHeader(), QWizardPrivate::recreateLayout(), and QTipLabel::updateSize().

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◆ sizeHint()

QSize QLabel::sizeHint ( ) const

overridevirtual

\reimp

Reimplemented from QFrame.

Definition at line 820 of file qlabel.cpp.

References d, minimumSizeHint(), and void.

Referenced by QWizardHeader::setup(), and QTipLabel::updateSize().

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◆ text()

QString QLabel::text ( ) const

Definition at line 315 of file qlabel.cpp.

References d.

◆ textFormat()

Qt::TextFormat QLabel::textFormat ( ) const

Definition at line 1370 of file qlabel.cpp.

References d.

◆ textInteractionFlags()

Qt::TextInteractionFlags QLabel::textInteractionFlags ( ) const

Definition at line 723 of file qlabel.cpp.

References d.

◆ wordWrap()

bool QLabel::wordWrap ( ) const

Definition at line 483 of file qlabel.cpp.

References d, and Qt::TextWordWrap.

Friends And Related Symbol Documentation

◆ QBalloonTip

friend class QBalloonTip

friend

Definition at line 135 of file qlabel.h.

◆ QMessageBoxPrivate

friend class QMessageBoxPrivate

friend

Definition at line 134 of file qlabel.h.

◆ QTipLabel

friend class QTipLabel

friend

Definition at line 133 of file qlabel.h.

Property Documentation

◆ alignment

QLabel::alignment

readwrite

the alignment of the label's contents

By default, the contents of the label are left-aligned and vertically-centered.

See also: text

Definition at line 26 of file qlabel.h.

Referenced by setAlignment().

◆ hasSelectedText

QLabel::hasSelectedText

read

whether there is any text selected

hasSelectedText() returns true if some or all of the text has been selected by the user; otherwise returns false.

By default, this property is false.

See also: selectedText()

{Note:} The textInteractionFlags set on the label need to include either TextSelectableByMouse or TextSelectableByKeyboard.

Since: 4.7

Definition at line 33 of file qlabel.h.

◆ indent

QLabel::indent

readwrite

the label's text indent in pixels

If a label displays text, the indent applies to the left edge if alignment() is Qt::AlignLeft, to the right edge if alignment() is Qt::AlignRight, to the top edge if alignment() is Qt::AlignTop, and to the bottom edge if alignment() is Qt::AlignBottom.

If indent is negative, or if no indent has been set, the label computes the effective indent as follows: If frameWidth() is 0, the effective indent becomes 0. If frameWidth() is greater than 0, the effective indent becomes half the width of the "x" character of the widget's current font().

By default, the indent is -1, meaning that an effective indent is calculating in the manner described above.

See also: alignment, margin, frameWidth(), font()

Definition at line 29 of file qlabel.h.

Referenced by setIndent().

◆ margin

QLabel::margin

readwrite

the width of the margin

The margin is the distance between the innermost pixel of the frame and the outermost pixel of contents.

The default margin is 0.

See also: indent

Definition at line 28 of file qlabel.h.

Referenced by setMargin().

◆ openExternalLinks

QLabel::openExternalLinks

readwrite

Since: 4.2

Specifies whether QLabel should automatically open links using QDesktopServices::openUrl() instead of emitting the linkActivated() signal.

{Note:} The textInteractionFlags set on the label need to include either LinksAccessibleByMouse or LinksAccessibleByKeyboard.

The default value is false.

See also: textInteractionFlags()

Definition at line 30 of file qlabel.h.

◆ pixmap

QLabel::pixmap

readwrite

the label's pixmap.

Setting the pixmap clears any previous content. The buddy shortcut, if any, is disabled.

Definition at line 24 of file qlabel.h.

Referenced by QWatermarkLabel::minimumSizeHint(), FinalWidget::mouseMoveEvent(), FinalWidget::pixmap(), setPixmap(), and QMessageBoxPrivate::setupLayout().

◆ scaledContents

QLabel::scaledContents

readwrite

whether the label will scale its contents to fill all available space.

When enabled and the label shows a pixmap, it will scale the pixmap to fill the available space.

This property's default is false.

Definition at line 25 of file qlabel.h.

◆ selectedText

QLabel::selectedText

read

the selected text

If there is no selected text this property's value is an empty string.

By default, this property contains an empty string.

See also: hasSelectedText()

{Note:} The textInteractionFlags set on the label need to include either TextSelectableByMouse or TextSelectableByKeyboard.

Since: 4.7

Definition at line 34 of file qlabel.h.

◆ text

QLabel::text

readwrite

the label's text

If no text has been set this will return an empty string. Setting the text clears any previous content.

The text will be interpreted either as plain text or as rich text, depending on the text format setting; see setTextFormat(). The default setting is Qt::AutoText; i.e. QLabel will try to auto-detect the format of the text set. See \l {Supported HTML Subset} for the definition of rich text.

If a buddy has been set, the buddy mnemonic key is updated from the new text.

Note that QLabel is well-suited to display small rich text documents, such as small documents that get their document specific settings (font, text color, link color) from the label's palette and font properties. For large documents, use QTextEdit in read-only mode instead. QTextEdit can also provide a scroll bar when necessary.

Note: This function enables mouse tracking if text contains rich text.

See also: setTextFormat(), setBuddy(), alignment

Definition at line 22 of file qlabel.h.

Referenced by QLabel(), QTipLabel::QTipLabel(), QTipLabel::restartExpireTimer(), QTipLabel::reuseTip(), setText(), QTipLabel::tipChanged(), and QTipLabel::updateSize().

◆ textFormat

QLabel::textFormat

readwrite

the label's text format

See the Qt::TextFormat enum for an explanation of the possible options.

The default format is Qt::AutoText.

See also: text()

Definition at line 23 of file qlabel.h.

◆ textInteractionFlags

QLabel::textInteractionFlags

readwrite

Since: 4.2

Specifies how the label should interact with user input if it displays text.

If the flags contain Qt::LinksAccessibleByKeyboard the focus policy is also automatically set to Qt::StrongFocus. If Qt::TextSelectableByKeyboard is set then the focus policy is set to Qt::ClickFocus.

The default value is Qt::LinksAccessibleByMouse.

Definition at line 31 of file qlabel.h.

◆ wordWrap

QLabel::wordWrap

readwrite

the label's word-wrapping policy

If this property is true then label text is wrapped where necessary at word-breaks; otherwise it is not wrapped at all.

By default, word wrap is disabled.

See also: text

Definition at line 27 of file qlabel.h.

Referenced by QTipLabel::updateSize().

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

qtbase/src/widgets/widgets/qlabel.h (7efd3c2718a3d0dd656038ee7cd4eb992a6f2f80)
qtbase/src/widgets/widgets/qlabel.cpp (7efd3c2718a3d0dd656038ee7cd4eb992a6f2f80)

Public Slots

Signals

Public Member Functions

Protected Member Functions

Properties

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QLabel() [1/2]

◆ QLabel() [2/2]

◆ ~QLabel()

Member Function Documentation

◆ alignment()

◆ buddy()

◆ changeEvent()

◆ clear

◆ contextMenuEvent()

◆ event()

◆ focusInEvent()

◆ focusNextPrevChild()

◆ focusOutEvent()

◆ hasScaledContents()

◆ hasSelectedText()

◆ heightForWidth()

◆ indent()

◆ keyPressEvent()

◆ linkActivated

◆ linkHovered

◆ margin()

◆ minimumSizeHint()

◆ mouseMoveEvent()

◆ mousePressEvent()

◆ mouseReleaseEvent()

◆ openExternalLinks()

◆ paintEvent()

◆ picture()

◆ pixmap()

◆ resourceProvider()

◆ selectedText()

◆ selectionStart()

◆ setAlignment()

◆ setBuddy()

◆ setIndent()

◆ setMargin()

◆ setNum [1/2]

◆ setNum [2/2]

◆ setOpenExternalLinks()

◆ setPicture

◆ setPixmap

◆ setResourceProvider()

◆ setScaledContents()

◆ setSelection()

◆ setText

◆ setTextFormat()

◆ setTextInteractionFlags()

◆ setWordWrap()

◆ sizeHint()

◆ text()

◆ textFormat()

◆ textInteractionFlags()

◆ wordWrap()

Friends And Related Symbol Documentation

◆ QBalloonTip

◆ QMessageBoxPrivate

◆ QTipLabel

Property Documentation

◆ alignment

◆ hasSelectedText

◆ indent

◆ margin

◆ openExternalLinks

◆ pixmap

◆ scaledContents

◆ selectedText

◆ text

◆ textFormat

◆ textInteractionFlags

◆ wordWrap