The QIcon class provides scalable icons in different modes and states. More...

#include <qicon.h>

Public Types
enum	Mode { Normal , Disabled , Active , Selected }

enum	State { On , Off }

typedef QIconPrivate *	DataPtr

Public Member Functions
	QIcon () noexcept

	QIcon (const QPixmap &pixmap)

	QIcon (const QIcon &other)

	QIcon (QIcon &&other) noexcept

	QIcon (const QString &fileName)

	QIcon (QIconEngine *engine)

	~QIcon ()

QIcon &	operator= (const QIcon &other)

void	swap (QIcon &other) noexcept

bool	operator== (const QIcon &) const =delete

bool	operator!= (const QIcon &) const =delete

	operator QVariant () const

QPixmap	pixmap (const QSize &size, Mode mode=Normal, State state=Off) const

QPixmap	pixmap (int w, int h, Mode mode=Normal, State state=Off) const

QPixmap	pixmap (int extent, Mode mode=Normal, State state=Off) const

QPixmap	pixmap (const QSize &size, qreal devicePixelRatio, Mode mode=Normal, State state=Off) const

QSize	actualSize (const QSize &size, Mode mode=Normal, State state=Off) const

QString	name () const

void	paint (QPainter *painter, const QRect &rect, Qt::Alignment alignment=Qt::AlignCenter, Mode mode=Normal, State state=Off) const

void	paint (QPainter *painter, int x, int y, int w, int h, Qt::Alignment alignment=Qt::AlignCenter, Mode mode=Normal, State state=Off) const

bool	isNull () const

bool	isDetached () const

void	detach ()

qint64	cacheKey () const

void	addPixmap (const QPixmap &pixmap, Mode mode=Normal, State state=Off)

void	addFile (const QString &fileName, const QSize &size=QSize(), Mode mode=Normal, State state=Off)

QList< QSize >	availableSizes (Mode mode=Normal, State state=Off) const

void	setIsMask (bool isMask)

bool	isMask () const

DataPtr &	data_ptr ()

Static Public Member Functions
static QIcon	fromTheme (const QString &name)

static QIcon	fromTheme (const QString &name, const QIcon &fallback)

static bool	hasThemeIcon (const QString &name)

static QStringList	themeSearchPaths ()

static void	setThemeSearchPaths (const QStringList &searchpath)

static QStringList	fallbackSearchPaths ()

static void	setFallbackSearchPaths (const QStringList &paths)

static QString	themeName ()

static void	setThemeName (const QString &path)

static QString	fallbackThemeName ()

static void	setFallbackThemeName (const QString &name)

Friends
Q_GUI_EXPORT QDataStream &	operator<< (QDataStream &, const QIcon &)

Q_GUI_EXPORT QDataStream &	operator>> (QDataStream &, QIcon &)

Related Functions
(Note that these are not member functions.)
QDataStream &	operator<< (QDataStream &stream, const QIcon &icon)

QDataStream &	operator>> (QDataStream &stream, QIcon &icon)

Detailed Description

The QIcon class provides scalable icons in different modes and states.

\inmodule QtGui

A QIcon can generate smaller, larger, active, and disabled pixmaps from the set of pixmaps it is given. Such pixmaps are used by Qt widgets to show an icon representing a particular action.

The simplest use of QIcon is to create one from a QPixmap file or resource, and then use it, allowing Qt to work out all the required icon styles and sizes. For example:

To undo a QIcon, simply set a null icon in its place:

Use the QImageReader::supportedImageFormats() and QImageWriter::supportedImageFormats() functions to retrieve a complete list of the supported file formats.

When you retrieve a pixmap using pixmap(QSize, Mode, State), and no pixmap for this given size, mode and state has been added with addFile() or addPixmap(), then QIcon will generate one on the fly. This pixmap generation happens in a QIconEngine. The default engine scales pixmaps down if required, but never up, and it uses the current style to calculate a disabled appearance. By using custom icon engines, you can customize every aspect of generated icons. With QIconEnginePlugin it is possible to register different icon engines for different file suffixes, making it possible for third parties to provide additional icon engines to those included with Qt.

Note: Since Qt 4.2, an icon engine that supports SVG is included.

Definition at line 55 of file qicon.h.

Member Typedef Documentation

◆ DataPtr

QIcon::DataPtr

Definition at line 142 of file qicon.h.

Member Enumeration Documentation

◆ Mode

enum QIcon::Mode

This enum type describes the mode for which a pixmap is intended to be used. The currently defined modes are:

\value Normal Display the pixmap when the user is not interacting with the icon, but the functionality represented by the icon is available. \value Disabled Display the pixmap when the functionality represented by the icon is not available. \value Active Display the pixmap when the functionality represented by the icon is available and the user is interacting with the icon, for example, moving the mouse over it or clicking it. \value Selected Display the pixmap when the item represented by the icon is selected.

Enumerator
Normal
Disabled
Active
Selected

Definition at line 58 of file qicon.h.

◆ State

enum QIcon::State

This enum describes the state for which a pixmap is intended to be used. The state can be:

\value Off Display the pixmap when the widget is in an "off" state \value On Display the pixmap when the widget is in an "on" state

Enumerator
On
Off

Definition at line 59 of file qicon.h.

Constructor & Destructor Documentation

◆ QIcon() [1/6]

QIcon::QIcon ( )

noexcept

Constructs a null icon.

Definition at line 677 of file qicon.cpp.

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◆ QIcon() [2/6]

QIcon::QIcon ( const QPixmap & pixmap )

Constructs an icon from a pixmap.

Definition at line 685 of file qicon.cpp.

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◆ QIcon() [3/6]

QIcon::QIcon ( const QIcon & other )

Constructs a copy of other. This is very fast.

Definition at line 694 of file qicon.cpp.

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◆ QIcon() [4/6]

QIcon::QIcon ( QIcon && other )

inlinenoexcept

Move-constructs a QIcon instance, making it point to the same object that other was pointing to.

Definition at line 64 of file qicon.h.

◆ QIcon() [5/6]

QIcon::QIcon ( const QString & fileName )

explicit

Constructs an icon from the file with the given fileName. The file will be loaded on demand.

If fileName contains a relative path (e.g. the filename only) the relevant file must be found relative to the runtime working directory.

The file name can refer to an actual file on disk or to one of the application's embedded resources. See the \l{resources.html}{Resource System} overview for details on how to embed images and other resource files in the application's executable.

Use the QImageReader::supportedImageFormats() and QImageWriter::supportedImageFormats() functions to retrieve a complete list of the supported file formats.

Definition at line 726 of file qicon.cpp.

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◆ QIcon() [6/6]

QIcon::QIcon ( QIconEngine * engine )

explicit

Creates an icon with a specific icon engine. The icon takes ownership of the engine.

Definition at line 737 of file qicon.cpp.

◆ ~QIcon()

QIcon::~QIcon ( )

Destroys the icon.

Definition at line 745 of file qicon.cpp.

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Member Function Documentation

◆ actualSize()

QSize QIcon::actualSize	(	const QSize &	size,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Returns the actual size of the icon for the requested size, mode, and state. The result might be smaller than requested, but never larger. The returned size is in device-independent pixels (This is relevant for high-dpi pixmaps.)

See also: pixmap(), paint()

Definition at line 909 of file qicon.cpp.

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◆ addFile()

void QIcon::addFile	(	const QString &	fileName,
		const QSize &	size = `QSize()`,
		Mode	mode = `Normal`,
		State	state = `Off`
	)

Adds an image from the file with the given fileName to the icon, as a specialization for size, mode and state. The file will be loaded on demand. Note: custom icon engines are free to ignore additionally added pixmaps.

If fileName contains a relative path (e.g. the filename only) the relevant file must be found relative to the runtime working directory.

The file name can refer to an actual file on disk or to one of the application's embedded resources. See the \l{resources.html}{Resource System} overview for details on how to embed images and other resource files in the application's executable.

Use the QImageReader::supportedImageFormats() and QImageWriter::supportedImageFormats() functions to retrieve a complete list of the supported file formats.

If a high resolution version of the image exists (identified by the suffix @2x on the base name), it is automatically loaded and added with the {device pixel ratio} set to a value of 2. This can be disabled by setting the environment variable QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING (see QImageReader).

Note: When you add a non-empty filename to a QIcon, the icon becomes non-null, even if the file doesn't exist or points to a corrupt file.

See also: addPixmap(), QPixmap::devicePixelRatio()

Definition at line 1096 of file qicon.cpp.

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◆ addPixmap()

void QIcon::addPixmap	(	const QPixmap &	pixmap,
		Mode	mode = `Normal`,
		State	state = `Off`
	)

Adds pixmap to the icon, as a specialization for mode and state.

Custom icon engines are free to ignore additionally added pixmaps.

See also: addFile()

Definition at line 1043 of file qicon.cpp.

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◆ availableSizes()

QList< QSize > QIcon::availableSizes	(	Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Since: 4.5

Returns a list of available icon sizes for the specified mode and state.

Definition at line 1127 of file qicon.cpp.

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◆ cacheKey()

qint64 QIcon::cacheKey ( ) const

Returns a number that identifies the contents of this QIcon object. Distinct QIcon objects can have the same key if they refer to the same contents.

Since: 4.3

The cacheKey() will change when the icon is altered via addPixmap() or addFile().

Cache keys are mostly useful in conjunction with caching.

See also: QPixmap::cacheKey()

Definition at line 802 of file qicon.cpp.

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◆ data_ptr()

DataPtr & QIcon::data_ptr ( )

inline

Definition at line 143 of file qicon.h.

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◆ detach()

void QIcon::detach ( )

Definition at line 1016 of file qicon.cpp.

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◆ fallbackSearchPaths()

QStringList QIcon::fallbackSearchPaths ( )

static

Since: 5.11

Returns the fallback search paths for icons.

The default value will depend on the platform.

See also: setFallbackSearchPaths(), themeSearchPaths()

Definition at line 1192 of file qicon.cpp.

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◆ fallbackThemeName()

QString QIcon::fallbackThemeName ( )

static

Since: 5.12

Returns the name of the fallback icon theme.

On X11, if not set, the fallback icon theme depends on your desktop settings. On other platforms it is not set by default.

See also: setFallbackThemeName(), themeName()

Definition at line 1255 of file qicon.cpp.

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◆ fromTheme() [1/2]

QIcon QIcon::fromTheme ( const QString & name )

static

Since: 4.6

Returns the QIcon corresponding to name in the current icon theme.

The latest version of the freedesktop icon specification and naming specification can be obtained here:

\list

To fetch an icon from the current icon theme:

Note: By default, only X11 will support themed icons. In order to use themed icons on Mac and Windows, you will have to bundle a compliant theme in one of your themeSearchPaths() and set the appropriate themeName().; Qt will make use of GTK's icon-theme.cache if present to speed up the lookup. These caches can be generated using gtk-update-icon-cache: \l{https://developer.gnome.org/gtk3/stable/gtk-update-icon-cache.html}.; If an icon can't be found in the current theme, then it will be searched in fallbackSearchPaths() as an unthemed icon.

See also: themeName(), setThemeName(), themeSearchPaths(), fallbackSearchPaths()

Definition at line 1311 of file qicon.cpp.

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◆ fromTheme() [2/2]

QIcon QIcon::fromTheme	(	const QString &	name,
		const QIcon &	fallback
	)

static

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

Returns the QIcon corresponding to name in the current icon theme. If no such icon is found in the current theme fallback is returned instead.

If you want to provide a guaranteed fallback for platforms that do not support theme icons, you can use the second argument:

Definition at line 1344 of file qicon.cpp.

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◆ hasThemeIcon()

bool QIcon::hasThemeIcon ( const QString & name )

static

Since: 4.6

Returns true if there is an icon available for name in the current icon theme, otherwise returns false.

See also: themeSearchPaths(), fromTheme(), setThemeName()

Definition at line 1362 of file qicon.cpp.

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◆ isDetached()

bool QIcon::isDetached ( ) const

Definition at line 1009 of file qicon.cpp.

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◆ isMask()

bool QIcon::isMask ( ) const

Since: 5.6

Returns true if this icon has been marked as a mask image. Certain platforms render mask icons differently (for example, menu icons on \macos).

See also: setIsMask()

Definition at line 1393 of file qicon.cpp.

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◆ isNull()

bool QIcon::isNull ( ) const

Returns true if the icon is empty; otherwise returns false.

An icon is empty if it has neither a pixmap nor a filename.

Note: Even a non-null icon might not be able to create valid pixmaps, eg. if the file does not exist or cannot be read.

Definition at line 1002 of file qicon.cpp.

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◆ name()

QString QIcon::name ( ) const

Since: 4.7

Returns the name used to create the icon, if available.

Depending on the way the icon was created, it may have an associated name. This is the case for icons created with fromTheme().

See also: fromTheme(), QIconEngine::iconName()

Definition at line 1144 of file qicon.cpp.

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◆ operator QVariant()

QIcon::operator QVariant ( ) const

Returns the icon as a QVariant.

Definition at line 784 of file qicon.cpp.

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◆ operator!=()

bool QIcon::operator!= ( const QIcon & ) const

delete

◆ operator=()

QIcon & QIcon::operator= ( const QIcon & other )

Assigns the other icon to this icon and returns a reference to this icon.

Move-assigns other to this QIcon instance.

Since: 5.2

Definition at line 755 of file qicon.cpp.

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◆ operator==()

bool QIcon::operator== ( const QIcon & ) const

delete

◆ paint() [1/2]

void QIcon::paint	(	QPainter *	painter,
		const QRect &	rect,
		Qt::Alignment	alignment = `Qt::AlignCenter`,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Uses the painter to paint the icon with specified alignment, required mode, and state into the rectangle rect.

See also: actualSize(), pixmap()

Definition at line 960 of file qicon.cpp.

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◆ paint() [2/2]

void QIcon::paint	(	QPainter *	painter,
		int	x,
		int	y,
		int	w,
		int	h,
		Qt::Alignment	alignment = `Qt::AlignCenter`,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

inline

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

Paints the icon into the rectangle QRect(x, y, w, h).

Definition at line 99 of file qicon.h.

◆ pixmap() [1/4]

QPixmap QIcon::pixmap	(	const QSize &	size,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Returns a pixmap with the requested size, mode, and state, generating one if necessary. The pixmap might be smaller than requested, but never larger, unless the device-pixel ratio of the returned pixmap is larger than 1.

See also: actualSize(), paint()

Definition at line 817 of file qicon.cpp.

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◆ pixmap() [2/4]

QPixmap QIcon::pixmap	(	const QSize &	size,
		qreal	devicePixelRatio,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

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

Since: 6.0

Returns a pixmap with the requested size, devicePixelRatio, mode, and state, generating one if necessary.

See also: actualSize(), paint()

Definition at line 854 of file qicon.cpp.

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◆ pixmap() [3/4]

QPixmap QIcon::pixmap	(	int	extent,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

inline

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

Returns a pixmap of size QSize(extent, extent). The pixmap might be smaller than requested, but never larger, unless the device-pixel ratio of the returned pixmap is larger than 1.

Definition at line 82 of file qicon.h.

◆ pixmap() [4/4]

QPixmap QIcon::pixmap	(	int	w,
		int	h,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

inline

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

Returns a pixmap of size QSize(w, h). The pixmap might be smaller than requested, but never larger, unless the device-pixel ratio of the returned pixmap is larger than 1.

Definition at line 80 of file qicon.h.

◆ setFallbackSearchPaths()

void QIcon::setFallbackSearchPaths ( const QStringList & paths )

static

Since: 5.11

Sets the fallback search paths for icons to paths.

Note: To add some path without replacing existing ones:

See also: fallbackSearchPaths(), setThemeSearchPaths()

Definition at line 1208 of file qicon.cpp.

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◆ setFallbackThemeName()

void QIcon::setFallbackThemeName ( const QString & name )

static

Since: 5.12

Sets the fallback icon theme to name.

The name should correspond to a directory name in the themeSearchPath() containing an index.theme file describing its contents.

Note: This should be done before creating \l QGuiApplication, to ensure correct initialization.

See also: fallbackThemeName(), themeSearchPaths(), themeName()

Definition at line 1274 of file qicon.cpp.

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◆ setIsMask()

void QIcon::setIsMask ( bool isMask )

Since: 5.6

Indicate that this icon is a mask image(boolean isMask), and hence can potentially be modified based on where it's displayed.

See also: isMask()

Definition at line 1376 of file qicon.cpp.

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◆ setThemeName()

void QIcon::setThemeName ( const QString & name )

static

Since: 4.6

Sets the current icon theme to name.

The name should correspond to a directory name in the themeSearchPath() containing an index.theme file describing its contents.

See also: themeSearchPaths(), themeName()

Definition at line 1224 of file qicon.cpp.

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◆ setThemeSearchPaths()

void QIcon::setThemeSearchPaths ( const QStringList & paths )

static

Since: 4.6

Sets the search paths for icon themes to paths.

See also: themeSearchPaths(), fromTheme(), setThemeName()

Definition at line 1157 of file qicon.cpp.

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◆ swap()

void QIcon::swap ( QIcon & other )

inlinenoexcept

Since: 4.8

Swaps icon other with this icon. This operation is very fast and never fails.

Definition at line 72 of file qicon.h.

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◆ themeName()

QString QIcon::themeName ( )

static

Since: 4.6

Returns the name of the current icon theme.

On X11, the current icon theme depends on your desktop settings. On other platforms it is not set by default.

See also: setThemeName(), themeSearchPaths(), fromTheme(), hasThemeIcon()

Definition at line 1240 of file qicon.cpp.

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◆ themeSearchPaths()

QStringList QIcon::themeSearchPaths ( )

static

Since: 4.6

Returns the search paths for icon themes.

The default value will depend on the platform:

On X11, the search path will use the XDG_DATA_DIRS environment variable if available.

By default all platforms will have the resource directory {:\icons} as a fallback. You can use "rcc -project" to generate a resource file from your icon theme.

See also: setThemeSearchPaths(), fromTheme(), setThemeName()

Definition at line 1178 of file qicon.cpp.

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Friends And Related Function Documentation

◆ operator<< [1/2]

QDataStream & operator<<	(	QDataStream &	stream,
		const QIcon &	icon
	)

friend

Since: 4.2

Writes the given icon to the given stream as a PNG image. If the icon contains more than one image, all images will be written to the stream. Note that writing the stream to a file will not produce a valid image file.

Definition at line 1415 of file qicon.cpp.

◆ operator<<() [2/2]

QDataStream & operator<<	(	QDataStream &	stream,
		const QIcon &	icon
	)

Since: 4.2

Writes the given icon to the given stream as a PNG image. If the icon contains more than one image, all images will be written to the stream. Note that writing the stream to a file will not produce a valid image file.

Definition at line 1415 of file qicon.cpp.

◆ operator>> [1/2]

QDataStream & operator>>	(	QDataStream &	stream,
		QIcon &	icon
	)

friend

Since: 4.2

Reads an image, or a set of images, from the given stream into the given icon.

Definition at line 1454 of file qicon.cpp.

◆ operator>>() [2/2]

QDataStream & operator>>	(	QDataStream &	stream,
		QIcon &	icon
	)

Since: 4.2

Reads an image, or a set of images, from the given stream into the given icon.

Definition at line 1454 of file qicon.cpp.

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

src/gui/image/qicon.h
src/gui/image/qicon.cpp

Public Types

Public Member Functions

Static Public Member Functions

Friends

Related Functions

Detailed Description

Member Typedef Documentation

◆ DataPtr

Member Enumeration Documentation

◆ Mode

◆ State

Constructor & Destructor Documentation

◆ QIcon() [1/6]

◆ QIcon() [2/6]

◆ QIcon() [3/6]

◆ QIcon() [4/6]

◆ QIcon() [5/6]

◆ QIcon() [6/6]

◆ ~QIcon()

Member Function Documentation

◆ actualSize()

◆ addFile()

◆ addPixmap()

◆ availableSizes()

◆ cacheKey()

◆ data_ptr()

◆ detach()

◆ fallbackSearchPaths()

◆ fallbackThemeName()

◆ fromTheme() [1/2]

◆ fromTheme() [2/2]

◆ hasThemeIcon()

◆ isDetached()

◆ isMask()

◆ isNull()

◆ name()

◆ operator QVariant()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ paint() [1/2]

◆ paint() [2/2]

◆ pixmap() [1/4]

◆ pixmap() [2/4]

◆ pixmap() [3/4]

◆ pixmap() [4/4]

◆ setFallbackSearchPaths()

◆ setFallbackThemeName()

◆ setIsMask()

◆ setThemeName()

◆ setThemeSearchPaths()

◆ swap()

◆ themeName()

◆ themeSearchPaths()

Friends And Related Function Documentation

◆ operator<< [1/2]

◆ operator<<() [2/2]

◆ operator>> [1/2]

◆ operator>>() [2/2]