QIcon Class

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

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Publié le 27 décembre 2024 - Mis à jour le 27 décembre 2024

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QIcon Class▲

Header: QIcon
CMake:

find_package(Qt6 REQUIRED COMPONENTS Gui)

target_link_libraries(mytarget PRIVATE Qt6::Gui)
qmake: QT += gui
Group: QIcon is part of Painting Classes, shared

Detailed Description▲

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

Creating an icon from image files▲

The simplest way to construct a QIcon is to create one from one or several image files or resources. For example:

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QToolButton *button = new QToolButton;
button-&gt;setIcon(QIcon("open.png"));

QIcon can store several images for different states, and Qt will select the image that is the closest match for the action's current state.

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QIcon openIcon("open.png");
openIcon.addFile("open-disabled.png", QIcon::Disabled);

Qt will generate the required icon styles and sizes when needed, e.g. the pixmap for the QIcon::Disabled state might be generated by graying out one of the provided pixmaps.

To clear the icon, simply set a null icon in its place:

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button-&gt;setIcon(QIcon());

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

Creating an icon from a theme or icon library▲

The most convenient way to construct an icon is by using the fromTheme() factory function. Qt implements access to the native icon library on platforms that support the Freedesktop Icon Theme Specification. Since Qt 6.7, Qt also provides access to the native icon library on macOS, iOS, and Windows 10 and 11. On Android, Qt can access icons from the Material design system as long as the MaterialIcons-Regular font is available on the system, or bundled as a resource at :/qt-project.org/icons/MaterialIcons-Regular.ttf with the application.

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QIcon undoicon = QIcon::fromTheme(QIcon::ThemeIcon::EditUndo);

Applications can use the same theming specification to provide their own icon library. See below for an example theme description and the corresponding directory structure for the image files. Icons from an application-provided theme take precedence over the native icon library.

In addition, it is possible to provide custom icon engines. This allows applications to 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.

Making Classes that Use QIcon▲

If you write your own widgets that have an option to set a small pixmap, consider allowing a QIcon to be set for that pixmap. The Qt class QToolButton is an example of such a widget.

Provide a method to set a QIcon, and paint the QIcon with paint, choosing the appropriate parameters based on the current state of your widget. For example:

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void MyWidget::drawIcon(QPainter *painter, const QRect &amp;rect)
{
    icon.paint(painter, rect, Qt::AlignCenter, isEnabled() ? QIcon::Normal
                                                           : QIcon::Disabled,
                                               isChecked() ? QIcon::On
                                                           : QIcon::Off);
}

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.

You might also make use of the Active mode, perhaps making your widget Active when the mouse is over the widget (see QWidget::enterEvent()), while the mouse is pressed pending the release that will activate the function, or when it is the currently selected item. If the widget can be toggled, the "On" mode might be used to draw a different icon.

QIcon needs a QGuiApplication instance before the icon is created.

High DPI Icons▲

Icons that are provided by the native icon library are usually based on vector graphics, and will automatically be rendered in the appropriate resolution.

When providing your own image files via addFile(), then QIcon will use Qt's "@nx" high DPI syntax. This is useful if you have your own custom directory structure and do not use follow Freedesktop Icon Theme Specification.

When providing an application theme, then you need to follow the Icon Theme Specification to specify which files to use for different resolutions. To make QIcon use the high DPI version of an image, add an additional entry to the appropriate index.theme file:

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[Icon Theme]
Name=Test
Comment=Test Theme

Directories=32x32/actions,32x32@2/actions

[32x32/actions]
Size=32
Context=Actions
Type=Fixed

# High DPI version of the entry above.
[32x32@2/actions]
Size=32
Scale=2
Type=Fixed

Your icon theme directory would then look something like this:

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├── 32x32
│   └── actions
│       └── appointment-new.png
├── 32x32@2
│   └── actions
│       └── appointment-new.png
└── index.theme

Member Type Documentation▲

enum QIcon::Mode▲

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

Constant	Value	Description
QIcon::Normal	0	Display the pixmap when the user is not interacting with the icon, but the functionality represented by the icon is available.
QIcon::Disabled	1	Display the pixmap when the functionality represented by the icon is not available.
QIcon::Active	2	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.
QIcon::Selected	3	Display the pixmap when the item represented by the icon is selected.

enum QIcon::State▲

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

Constant	Value	Description
QIcon::Off	1	Display the pixmap when the widget is in an "off" state
QIcon::On	0	Display the pixmap when the widget is in an "on" state

[since 6.7] enum QIcon::ThemeIcon▲

This enum provides access to icons that are provided by most icon theme implementations.

Constant	Value	Description
QIcon::ThemeIcon::AddressBookNew	0	The icon for the action to create a new address book.
QIcon::ThemeIcon::ApplicationExit	1	The icon for exiting an application.
QIcon::ThemeIcon::AppointmentNew	2	The icon for the action to create a new appointment.
QIcon::ThemeIcon::CallStart	3	The icon for initiating or accepting a call.
QIcon::ThemeIcon::CallStop	4	The icon for stopping a current call.
QIcon::ThemeIcon::ContactNew	5	The icon for the action to create a new contact.
QIcon::ThemeIcon::DocumentNew	6	The icon for the action to create a new document.
QIcon::ThemeIcon::DocumentOpen	7	The icon for the action to open a document.
QIcon::ThemeIcon::DocumentOpenRecent	8	The icon for the action to open a document that was recently opened.
QIcon::ThemeIcon::DocumentPageSetup	9	The icon for the page setup action.
QIcon::ThemeIcon::DocumentPrint	10	The icon for the print action.
QIcon::ThemeIcon::DocumentPrintPreview	11	The icon for the print preview action.
QIcon::ThemeIcon::DocumentProperties	12	The icon for the action to view the properties of a document.
QIcon::ThemeIcon::DocumentRevert	13	The icon for the action of reverting to a previous version of a document.
QIcon::ThemeIcon::DocumentSave	14	The icon for the save action.
QIcon::ThemeIcon::DocumentSaveAs	15	The icon for the save as action.
QIcon::ThemeIcon::DocumentSend	16	The icon for the send action.
QIcon::ThemeIcon::EditClear	17	The icon for the clear action.
QIcon::ThemeIcon::EditCopy	18	The icon for the copy action.
QIcon::ThemeIcon::EditCut	19	The icon for the cut action.
QIcon::ThemeIcon::EditDelete	20	The icon for the delete action.
QIcon::ThemeIcon::EditFind	21	The icon for the find action.
QIcon::ThemeIcon::EditPaste	22	The icon for the paste action.
QIcon::ThemeIcon::EditRedo	23	The icon for the redo action.
QIcon::ThemeIcon::EditSelectAll	24	The icon for the select all action.
QIcon::ThemeIcon::EditUndo	25	The icon for the undo action.
QIcon::ThemeIcon::FolderNew	26	The icon for creating a new folder.
QIcon::ThemeIcon::FormatIndentLess	27	The icon for the decrease indent formatting action.
QIcon::ThemeIcon::FormatIndentMore	28	The icon for the increase indent formatting action.
QIcon::ThemeIcon::FormatJustifyCenter	29	The icon for the center justification formatting action.
QIcon::ThemeIcon::FormatJustifyFill	30	The icon for the fill justification formatting action.
QIcon::ThemeIcon::FormatJustifyLeft	31	The icon for the left justification formatting action.
QIcon::ThemeIcon::FormatJustifyRight	32	The icon for the right justification action.
QIcon::ThemeIcon::FormatTextDirectionLtr	33	The icon for the left-to-right text formatting action.
QIcon::ThemeIcon::FormatTextDirectionRtl	34	The icon for the right-to-left formatting action.
QIcon::ThemeIcon::FormatTextBold	35	The icon for the bold text formatting action.
QIcon::ThemeIcon::FormatTextItalic	36	The icon for the italic text formatting action.
QIcon::ThemeIcon::FormatTextUnderline	37	The icon for the underlined text formatting action.
QIcon::ThemeIcon::FormatTextStrikethrough	38	The icon for the strikethrough text formatting action.
QIcon::ThemeIcon::GoDown	39	The icon for the go down in a list action.
QIcon::ThemeIcon::GoHome	40	The icon for the go to home location action.
QIcon::ThemeIcon::GoNext	41	The icon for the go to the next item in a list action.
QIcon::ThemeIcon::GoPrevious	42	The icon for the go to the previous item in a list action.
QIcon::ThemeIcon::GoUp	43	The icon for the go up in a list action.
QIcon::ThemeIcon::HelpAbout	44	The icon for the About item in the Help menu.
QIcon::ThemeIcon::HelpFaq	45	The icon for the FAQ item in the Help menu.
QIcon::ThemeIcon::InsertImage	46	The icon for the insert image action of an application.
QIcon::ThemeIcon::InsertLink	47	The icon for the insert link action of an application.
QIcon::ThemeIcon::InsertText	48	The icon for the insert text action of an application.
QIcon::ThemeIcon::ListAdd	49	The icon for the add to list action.
QIcon::ThemeIcon::ListRemove	50	The icon for the remove from list action.
QIcon::ThemeIcon::MailForward	51	The icon for the forward action.
QIcon::ThemeIcon::MailMarkImportant	52	The icon for the mark as important action.
QIcon::ThemeIcon::MailMarkRead	53	The icon for the mark as read action.
QIcon::ThemeIcon::MailMarkUnread	54	The icon for the mark as unread action.
QIcon::ThemeIcon::MailMessageNew	55	The icon for the compose new mail action.
QIcon::ThemeIcon::MailReplyAll	56	The icon for the reply to all action.
QIcon::ThemeIcon::MailReplySender	57	The icon for the reply to sender action.
QIcon::ThemeIcon::MailSend	58	The icon for the send action.
QIcon::ThemeIcon::MediaEject	59	The icon for the eject action of a media player or file manager.
QIcon::ThemeIcon::MediaPlaybackPause	60	The icon for the pause action of a media player.
QIcon::ThemeIcon::MediaPlaybackStart	61	The icon for the start playback action of a media player.
QIcon::ThemeIcon::MediaPlaybackStop	62	The icon for the stop action of a media player.
QIcon::ThemeIcon::MediaRecord	63	The icon for the record action of a media application.
QIcon::ThemeIcon::MediaSeekBackward	64	The icon for the seek backward action of a media player.
QIcon::ThemeIcon::MediaSeekForward	65	The icon for the seek forward action of a media player.
QIcon::ThemeIcon::MediaSkipBackward	66	The icon for the skip backward action of a media player.
QIcon::ThemeIcon::MediaSkipForward	67	The icon for the skip forward action of a media player.
QIcon::ThemeIcon::ObjectRotateLeft	68	The icon for the rotate left action performed on an object.
QIcon::ThemeIcon::ObjectRotateRight	69	The icon for the rotate right action performed on an object.
QIcon::ThemeIcon::ProcessStop	70	The icon for the stop action in applications with actions that may take a while to process, such as web page loading in a browser.
QIcon::ThemeIcon::SystemLockScreen	71	The icon for the lock screen action.
QIcon::ThemeIcon::SystemLogOut	72	The icon for the log out action.
QIcon::ThemeIcon::SystemSearch	73	The icon for the search action.
QIcon::ThemeIcon::SystemReboot	74	The icon for the reboot action.
QIcon::ThemeIcon::SystemShutdown	75	The icon for the shutdown action.
QIcon::ThemeIcon::ToolsCheckSpelling	76	The icon for the check spelling action.
QIcon::ThemeIcon::ViewFullscreen	77	The icon for the fullscreen action.
QIcon::ThemeIcon::ViewRefresh	78	The icon for the refresh action.
QIcon::ThemeIcon::ViewRestore	79	The icon for leaving the fullscreen view.
QIcon::ThemeIcon::WindowClose	80	The icon for the close window action.
QIcon::ThemeIcon::WindowNew	81	The icon for the new window action.
QIcon::ThemeIcon::ZoomFitBest	82	The icon for the best fit action.
QIcon::ThemeIcon::ZoomIn	83	The icon for the zoom in action.
QIcon::ThemeIcon::ZoomOut	84	The icon for the zoom out action.
QIcon::ThemeIcon::AudioCard	85	The icon for the audio rendering device.
QIcon::ThemeIcon::AudioInputMicrophone	86	The icon for the microphone audio input device.
QIcon::ThemeIcon::Battery	87	The icon for the system battery device.
QIcon::ThemeIcon::CameraPhoto	88	The icon for a digital still camera devices.
QIcon::ThemeIcon::CameraVideo	89	The icon for a video camera device.
QIcon::ThemeIcon::CameraWeb	90	The icon for a web camera device.
QIcon::ThemeIcon::Computer	91	The icon for the computing device as a whole.
QIcon::ThemeIcon::DriveHarddisk	92	The icon for hard disk drives.
QIcon::ThemeIcon::DriveOptical	93	The icon for optical media drives such as CD and DVD.
QIcon::ThemeIcon::InputGaming	94	The icon for the gaming input device.
QIcon::ThemeIcon::InputKeyboard	95	The icon for the keyboard input device.
QIcon::ThemeIcon::InputMouse	96	The icon for the mousing input device.
QIcon::ThemeIcon::InputTablet	97	The icon for graphics tablet input devices.
QIcon::ThemeIcon::MediaFlash	98	The icon for flash media, such as a memory stick.
QIcon::ThemeIcon::MediaOptical	99	The icon for physical optical media such as CD and DVD.
QIcon::ThemeIcon::MediaTape	100	The icon for generic physical tape media.
QIcon::ThemeIcon::MultimediaPlayer	101	The icon for generic multimedia playing devices.
QIcon::ThemeIcon::NetworkWired	102	The icon for wired network connections.
QIcon::ThemeIcon::NetworkWireless	103	The icon for wireless network connections.
QIcon::ThemeIcon::Phone	104	The icon for phone devices.
QIcon::ThemeIcon::Printer	105	The icon for a printer device.
QIcon::ThemeIcon::Scanner	106	The icon for a scanner device.
QIcon::ThemeIcon::VideoDisplay	107	The icon for the monitor that video gets displayed on.
QIcon::ThemeIcon::AppointmentMissed	108	The icon for when an appointment was missed.
QIcon::ThemeIcon::AppointmentSoon	109	The icon for when an appointment will occur soon.
QIcon::ThemeIcon::AudioVolumeHigh	110	The icon used to indicate high audio volume.
QIcon::ThemeIcon::AudioVolumeLow	111	The icon used to indicate low audio volume.
QIcon::ThemeIcon::AudioVolumeMedium	112	The icon used to indicate medium audio volume.
QIcon::ThemeIcon::AudioVolumeMuted	113	The icon used to indicate the muted state for audio playback.
QIcon::ThemeIcon::BatteryCaution	114	The icon used when the battery is below 40%.
QIcon::ThemeIcon::BatteryLow	115	The icon used when the battery is below 20%.
QIcon::ThemeIcon::DialogError	116	The icon used when a dialog is opened to explain an error condition to the user.
QIcon::ThemeIcon::DialogInformation	117	The icon used when a dialog is opened to give information to the user that may be pertinent to the requested action.
QIcon::ThemeIcon::DialogPassword	118	The icon used when a dialog requesting the authentication credentials for a user is opened.
QIcon::ThemeIcon::DialogQuestion	119	The icon used when a dialog is opened to ask a simple question to the user.
QIcon::ThemeIcon::DialogWarning	120	The icon used when a dialog is opened to warn the user of impending issues with the requested action.
QIcon::ThemeIcon::FolderDragAccept	121	The icon used for a folder while an acceptable object is being dragged onto it.
QIcon::ThemeIcon::FolderOpen	122	The icon used for folders, while their contents are being displayed within the same window.
QIcon::ThemeIcon::FolderVisiting	123	The icon used for folders, while their contents are being displayed in another window.
QIcon::ThemeIcon::ImageLoading	124	The icon used while another image is being loaded.
QIcon::ThemeIcon::ImageMissing	125	The icon used when another image could not be loaded.
QIcon::ThemeIcon::MailAttachment	126	The icon for a message that contains attachments.
QIcon::ThemeIcon::MailUnread	127	The icon for an unread message.
QIcon::ThemeIcon::MailRead	128	The icon for a read message.
QIcon::ThemeIcon::MailReplied	129	The icon for a message that has been replied to.
QIcon::ThemeIcon::MediaPlaylistRepeat	130	The icon for the repeat mode of a media player.
QIcon::ThemeIcon::MediaPlaylistShuffle	131	The icon for the shuffle mode of a media player.
QIcon::ThemeIcon::NetworkOffline	132	The icon used to indicate that the device is not connected to the network.
QIcon::ThemeIcon::PrinterPrinting	133	The icon used while a print job is successfully being spooled to a printing device.
QIcon::ThemeIcon::SecurityHigh	134	The icon used to indicate that the security level of an item is known to be high.
QIcon::ThemeIcon::SecurityLow	135	The icon used to indicate that the security level of an item is known to be low.
QIcon::ThemeIcon::SoftwareUpdateAvailable	136	The icon used to indicate that an update is available.
QIcon::ThemeIcon::SoftwareUpdateUrgent	137	The icon used to indicate that an urgent update is available.
QIcon::ThemeIcon::SyncError	138	The icon used when an error occurs while attempting to synchronize data across devices.
QIcon::ThemeIcon::SyncSynchronizing	139	The icon used while data is successfully synchronizing across devices.
QIcon::ThemeIcon::UserAvailable	140	The icon used to indicate that a user is available.
QIcon::ThemeIcon::UserOffline	141	The icon used to indicate that a user is not available.
QIcon::ThemeIcon::WeatherClear	142	The icon used to indicate that the sky is clear.
QIcon::ThemeIcon::WeatherClearNight	143	The icon used to indicate that the sky is clear during the night.
QIcon::ThemeIcon::WeatherFewClouds	144	The icon used to indicate that the sky is partly cloudy.
QIcon::ThemeIcon::WeatherFewCloudsNight	145	The icon used to indicate that the sky is partly cloudy during the night.
QIcon::ThemeIcon::WeatherFog	146	The icon used to indicate that the weather is foggy.
QIcon::ThemeIcon::WeatherShowers	147	The icon used to indicate that rain showers are occurring.
QIcon::ThemeIcon::WeatherSnow	148	The icon used to indicate that snow is falling.
QIcon::ThemeIcon::WeatherStorm	149	The icon used to indicate that the weather is stormy.

This enum was introduced or modified in Qt 6.7.

Member Function Documentation▲

[static, since 6.7] QIcon QIcon::fromTheme(QIcon::ThemeIcon icon)▲

[static, since 6.7] QIcon QIcon::fromTheme(QIcon::ThemeIcon icon, const QIcon &fallback)

This is an overloaded function.

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

If the current theme does not provide an icon for icon, the fallback icon theme is consulted, before falling back to looking up standalone icon files in the fallback icon search path. Finally, the platform's native icon library is consulted.

If no icon is found and a fallback is provided, fallback is returned. This is useful to provide a guaranteed fallback, regardless of whether the current set of icon themes and fallbacks paths support the requested icon.

If no icon is found and no fallback is provided, a default constructed, empty QIcon is returned.

This function was introduced in Qt 6.7.

QIcon::QIcon()▲

Constructs a null icon.

QIcon::QIcon(const QPixmap &pixmap)▲

Constructs an icon from a pixmap.

[explicit] QIcon::QIcon(const QString &fileName)▲

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 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.

[explicit] QIcon::QIcon(QIconEngine *engine)▲

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

QIcon::QIcon(const QIcon &other)▲

Constructs a copy of other. This is very fast.

QIcon::QIcon(QIcon &&other)▲

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

QIcon::~QIcon()▲

Destroys the icon.

QSize QIcon::actualSize(const QSize &size, QIcon::Mode mode = Normal, QIcon::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.)

void QIcon::addFile(const QString &fileName, const QSize &size = QSize(), QIcon::Mode mode = Normal, QIcon::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.

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).

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.

void QIcon::addPixmap(const QPixmap &pixmap, QIcon::Mode mode = Normal, QIcon::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.

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

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

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.

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

Cache keys are mostly useful in conjunction with caching.

[static] QStringList QIcon::fallbackSearchPaths()▲

Returns the fallback search paths for icons.

The fallback search paths are consulted for standalone icon files if the current icon theme or fallback icon theme do not provide results for an icon lookup.

If not set, the fallback search paths will be defined by the platform.

[static] QString QIcon::fallbackThemeName()▲

Returns the name of the fallback icon theme.

If not set, the fallback icon theme will be defined by the platform.

Platform fallback icon themes are only implemented on Freedesktop based systems at the moment, and the icon theme depends on your desktop settings.

[static] QIcon QIcon::fromTheme(const QString &name)▲

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

If the current theme does not provide an icon for name, the fallback icon theme is consulted, before falling back to looking up standalone icon files in the fallback icon search path. Finally, the platform's native icon library is consulted.

To fetch an icon from the current icon theme:

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QIcon undoicon = QIcon::fromTheme(QIcon::ThemeIcon::EditUndo);

If an icon theme has not been explicitly set via setThemeName() a platform defined icon theme will be used.

[static] QIcon QIcon::fromTheme(const QString &name, const QIcon &fallback)▲

This is an overloaded function.

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

If no icon is found fallback is returned.

This is useful to provide a guaranteed fallback, regardless of whether the current set of icon themes and fallbacks paths support the requested icon.

For example:

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QIcon undoicon = QIcon::fromTheme(QIcon::ThemeIcon::EditUndo, QIcon(":/undo.png"));

[static] bool QIcon::hasThemeIcon(const QString &name)▲

Returns true if there is an icon available for name in the current icon theme or any of the fallbacks, as described by fromTheme(), otherwise returns false.

[static, since 6.7] bool QIcon::hasThemeIcon(QIcon::ThemeIcon icon)▲

This is an overloaded function.

Returns true if there is an icon available for icon in the current icon theme or any of the fallbacks, as described by fromTheme(), otherwise returns false.

This function was introduced in Qt 6.7.

bool QIcon::isMask() const▲

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

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.

QString QIcon::name() const▲

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().

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

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

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

This is an overloaded function.

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

QPixmap QIcon::pixmap(const QSize &size, QIcon::Mode mode = Normal, QIcon::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.

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

This is an overloaded function.

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.

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

This is an overloaded function.

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.

[since 6.0] QPixmap QIcon::pixmap(const QSize &size, qreal devicePixelRatio, QIcon::Mode mode = Normal, QIcon::State state = Off) const▲

This is an overloaded function.

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

This function was introduced in Qt 6.0.

[static] void QIcon::setFallbackSearchPaths(const QStringList &paths)▲

Sets the fallback search paths for icons to paths.

The fallback search paths are consulted for standalone icon files if the current icon theme or fallback icon theme do not provide results for an icon lookup.

For example:

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QIcon::setFallbackSearchPaths(QIcon::fallbackSearchPaths() &lt;&lt; "my/search/path");

[static] void QIcon::setFallbackThemeName(const QString &name)▲

Sets the fallback icon theme to name.

The fallback icon theme is consulted for icons not provided by the current icon theme, or if the current icon theme does not exist.

The name should correspond to theme in the same format as documented by setThemeName(), and will be looked up in themeSearchPaths().

Fallback icon themes should be set before creating QGuiApplication, to ensure correct initialization.

void QIcon::setIsMask(bool isMask)▲

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

[static] void QIcon::setThemeName(const QString &name)▲

Sets the current icon theme to name.

The theme will be will be looked up in themeSearchPaths().

At the moment the only supported icon theme format is the Freedesktop Icon Theme Specification. The name should correspond to a directory name in the themeSearchPath() containing an index.theme file describing its contents.

[static] void QIcon::setThemeSearchPaths(const QStringList &paths)▲

Sets the search paths for icon themes to paths.

The content of paths should follow the theme format documented by setThemeName().

void QIcon::swap(QIcon &other)▲

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

[static] QString QIcon::themeName()▲

Returns the name of the current icon theme.

If not set, the current icon theme will be defined by the platform.

Platform icon themes are only implemented on Freedesktop based systems at the moment, and the icon theme depends on your desktop settings.

[static] QStringList QIcon::themeSearchPaths()▲

Returns the search paths for icon themes.

The default search paths will be defined by the platform. All platforms will also have the resource directory :\icons as a fallback.

QVariant QIcon::operator QVariant() const▲

Returns the icon as a QVariant.

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

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

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

Move-assigns other to this QIcon instance.

Related Non-Members▲

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

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.

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

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

Obsolete Members for QIcon▲

The following members of class QIcon are deprecated. We strongly advise against using them in new code.

Obsolete Member Function Documentation▲

QSize QIcon::actualSize(QWindow *window, const QSize &size, QIcon::Mode mode = Normal, QIcon::State state = Off) const▲

This function is deprecated since 6.0. We strongly advise against using it in new code.

Use actualSize(size) instead.

Returns the actual size of the icon for the requested window size, mode, and state.

The pixmap can be smaller than the requested size. The returned size is in device-independent pixels (This is relevant for high-dpi pixmaps.)

QPixmap QIcon::pixmap(QWindow *window, const QSize &size, QIcon::Mode mode = Normal, QIcon::State state = Off) const▲

This function is deprecated since 6.0. We strongly advise against using it in new code.

Use pixmap(size, devicePixelRatio) instead.

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

The pixmap can be smaller than the requested size. If window is on a high-dpi display the pixmap can be larger. In that case it will have a devicePixelRatio larger than 1.

QIcon Class

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QIcon Class▲

Detailed Description▲

Creating an icon from image files▲

Creating an icon from a theme or icon library▲

Making Classes that Use QIcon▲

High DPI Icons▲

Member Type Documentation▲

enum QIcon::Mode▲

enum QIcon::State▲

[since 6.7] enum QIcon::ThemeIcon▲

See Also▲

Member Function Documentation▲

[static, since 6.7] QIcon QIcon::fromTheme(QIcon::ThemeIcon icon)▲

QIcon::QIcon()▲

QIcon::QIcon(const QPixmap &pixmap)▲

[explicit] QIcon::QIcon(const QString &fileName)▲

[explicit] QIcon::QIcon(QIconEngine *engine)▲

QIcon::QIcon(const QIcon &other)▲

QIcon::QIcon(QIcon &&other)▲

QIcon::~QIcon()▲

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

See Also▲

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

See Also▲

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

See Also▲

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

qint64 QIcon::cacheKey() const▲

See Also▲

[static] QStringList QIcon::fallbackSearchPaths()▲

See Also▲

[static] QString QIcon::fallbackThemeName()▲

See Also▲

[static] QIcon QIcon::fromTheme(const QString &name)▲

See Also▲

[static] QIcon QIcon::fromTheme(const QString &name, const QIcon &fallback)▲

See Also▲

[static] bool QIcon::hasThemeIcon(const QString &name)▲

See Also▲

[static, since 6.7] bool QIcon::hasThemeIcon(QIcon::ThemeIcon icon)▲

See Also▲

bool QIcon::isMask() const▲

See Also▲

bool QIcon::isNull() const▲

QString QIcon::name() const▲

See Also▲

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

See Also▲

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

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

See Also▲

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

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

[since 6.0] QPixmap QIcon::pixmap(const QSize &size, qreal devicePixelRatio, QIcon::Mode mode = Normal, QIcon::State state = Off) const▲

See Also▲

[static] void QIcon::setFallbackSearchPaths(const QStringList &paths)▲

See Also▲

[static] void QIcon::setFallbackThemeName(const QString &name)▲

See Also▲

void QIcon::setIsMask(bool isMask)▲

See Also▲

[static] void QIcon::setThemeName(const QString &name)▲

See Also▲

[static] void QIcon::setThemeSearchPaths(const QStringList &paths)▲

See Also▲

void QIcon::swap(QIcon &other)▲

[static] QString QIcon::themeName()▲

See Also▲

[static] QStringList QIcon::themeSearchPaths()▲

See Also▲

QVariant QIcon::operator QVariant() const▲

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

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

Related Non-Members▲

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

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