QIcon

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

Inheritance diagram of PySide2.QtGui.QIcon

Synopsis

Functions

  • def actualSize (size[, mode=Normal[, state=Off]])

  • def actualSize (window, size[, mode=Normal[, state=Off]])

  • def addFile (fileName[, size=QSize()[, mode=Normal[, state=Off]]])

  • def addPixmap (pixmap[, mode=Normal[, state=Off]])

  • def availableSizes ([mode=Normal[, state=Off]])

  • def cacheKey ()

  • def isMask ()

  • def isNull ()

  • def name ()

  • def paint (painter, rect[, alignment=Qt.AlignCenter[, mode=Normal[, state=Off]]])

  • def paint (painter, x, y, w, h[, alignment=Qt.AlignCenter[, mode=Normal[, state=Off]]])

  • def pixmap (extent[, mode=Normal[, state=Off]])

  • def pixmap (size[, mode=Normal[, state=Off]])

  • def pixmap (w, h[, mode=Normal[, state=Off]])

  • def pixmap (window, size[, mode=Normal[, state=Off]])

  • def setIsMask (isMask)

  • def swap (other)

Static functions

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 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:

button = QToolButton()
button.setIcon(QIcon("open.xpm"))

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

button.setIcon(QIcon())

Use the supportedImageFormats() and 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.

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 when you draw the icon, choose whichever pixmap is appropriate for the current state of your widget. For example:

def drawIcon(self, painter, pos):
    enabledStatus = QIcon.Normal
    if not isEnabled():
        enabledStatus = QIcon::Disabled

    onOff = QIcon.On
    if not isOn():
        onOff = QIcon.Off

    pixmap = self.icon.pixmap(QSize(22, 22), enabledStatus, onOff)
    painter.drawPixmap(pos, pixmap)

You might also make use of the Active mode, perhaps making your widget Active when the mouse is over the widget (see 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.

../../_images/icon.png

Note

QIcon needs a QGuiApplication instance before the icon is created.

High DPI Icons

There are two ways that QIcon supports high DPI icons: via addFile() and fromTheme() .

addFile() is useful if you have your own custom directory structure and do not need to use the freedesktop.org Icon Theme Specification . Icons created via this approach use Qt’s "@nx" high DPI syntax .

Using fromTheme() is necessary if you plan on following the Icon Theme Specification. To make QIcon use the high DPI version of an image, add an additional entry to the appropriate index.theme file:

[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:

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

See also

GUI Design Handbook: Iconic Label Icons Example

class QIcon

QIcon(engine)

QIcon(other)

QIcon(pixmap)

QIcon(fileName)

param other

QIcon

param fileName

unicode

param engine

QIconEngine

param pixmap

QPixmap

Constructs a null icon.

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

PySide2.QtGui.QIcon.Mode

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

Constant

Description

QIcon.Normal

Display the pixmap when the user is not interacting with the icon, but the functionality represented by the icon is available.

QIcon.Disabled

Display the pixmap when the functionality represented by the icon is not available.

QIcon.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.

QIcon.Selected

Display the pixmap when the item represented by the icon is selected.

PySide2.QtGui.QIcon.State

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

Constant

Description

QIcon.Off

Display the pixmap when the widget is in an “off” state

QIcon.On

Display the pixmap when the widget is in an “on” state

PySide2.QtGui.QIcon.actualSize(window, size[, mode=Normal[, state=Off]])
Parameters
Return type

QSize

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.)

PySide2.QtGui.QIcon.actualSize(size[, mode=Normal[, state=Off]])
Parameters
  • sizeQSize

  • modeMode

  • stateState

Return type

QSize

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()

PySide2.QtGui.QIcon.addFile(fileName[, size=QSize()[, mode=Normal[, state=Off]]])
Parameters
  • fileName – unicode

  • sizeQSize

  • modeMode

  • stateState

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 Resource System overview for details on how to embed images and other resource files in the application’s executable.

Use the supportedImageFormats() and 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() devicePixelRatio()

PySide2.QtGui.QIcon.addPixmap(pixmap[, mode=Normal[, state=Off]])
Parameters

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()

PySide2.QtGui.QIcon.availableSizes([mode=Normal[, state=Off]])
Parameters
Return type

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

PySide2.QtGui.QIcon.cacheKey()
Return type

qint64

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

Cache keys are mostly useful in conjunction with caching.

See also

cacheKey()

static PySide2.QtGui.QIcon.fallbackSearchPaths()
Return type

list of strings

Returns the fallback search paths for icons.

The default value will depend on the platform.

static PySide2.QtGui.QIcon.fallbackThemeName()
Return type

unicode

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.

static PySide2.QtGui.QIcon.fromTheme(name)
Parameters

name – unicode

Return type

QIcon

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:

To fetch an icon from the current icon theme:

undoicon = QIcon.fromTheme("edit-undo")

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() .

Note

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: https://developer.gnome.org/gtk3/stable/gtk-update-icon-cache.html.

Note

If an icon can’t be found in the current theme, then it will be searched in fallbackSearchPaths() as an unthemed icon.

static PySide2.QtGui.QIcon.fromTheme(name, fallback)
Parameters
  • name – unicode

  • fallbackQIcon

Return type

QIcon

This is an overloaded function.

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:

undoicon = QIcon.fromTheme("edit-undo", QIcon(":/undo.png"))
static PySide2.QtGui.QIcon.hasThemeIcon(name)
Parameters

name – unicode

Return type

bool

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

PySide2.QtGui.QIcon.isMask()
Return type

bool

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()

PySide2.QtGui.QIcon.isNull()
Return type

bool

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.

PySide2.QtGui.QIcon.name()
Return type

unicode

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() or icons using a QIconEngine which supports the IconNameHook .

PySide2.QtGui.QIcon.paint(painter, rect[, alignment=Qt.AlignCenter[, mode=Normal[, state=Off]]])
Parameters
  • painterQPainter

  • rectQRect

  • alignmentAlignment

  • modeMode

  • stateState

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

PySide2.QtGui.QIcon.paint(painter, x, y, w, h[, alignment=Qt.AlignCenter[, mode=Normal[, state=Off]]])
Parameters
  • painterQPainter

  • xint

  • yint

  • wint

  • hint

  • alignmentAlignment

  • modeMode

  • stateState

This is an overloaded function.

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

PySide2.QtGui.QIcon.pixmap(w, h[, mode=Normal[, state=Off]])
Parameters
  • wint

  • hint

  • modeMode

  • stateState

Return type

QPixmap

This is an overloaded function.

Returns a pixmap of size QSize (w , h ). The pixmap might be smaller than requested, but never larger.

Setting the AA_UseHighDpiPixmaps application attribute enables this function to return pixmaps that are larger than the requested size. Such images will have a devicePixelRatio larger than 1.

PySide2.QtGui.QIcon.pixmap(extent[, mode=Normal[, state=Off]])
Parameters
  • extentint

  • modeMode

  • stateState

Return type

QPixmap

This is an overloaded function.

Returns a pixmap of size QSize (extent , extent ). The pixmap might be smaller than requested, but never larger.

Setting the AA_UseHighDpiPixmaps application attribute enables this function to return pixmaps that are larger than the requested size. Such images will have a devicePixelRatio larger than 1.

PySide2.QtGui.QIcon.pixmap(size[, mode=Normal[, state=Off]])
Parameters
  • sizeQSize

  • modeMode

  • stateState

Return type

QPixmap

PySide2.QtGui.QIcon.pixmap(window, size[, mode=Normal[, state=Off]])
Parameters
Return type

QPixmap

static PySide2.QtGui.QIcon.setFallbackSearchPaths(paths)
Parameters

paths – list of strings

Sets the fallback search paths for icons to paths .

Note

To add some path without replacing existing ones:

QIcon::setFallbackSearchPaths(QIcon::fallbackSearchPaths() << "my/search/path");
static PySide2.QtGui.QIcon.setFallbackThemeName(name)
Parameters

name – unicode

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.

PySide2.QtGui.QIcon.setIsMask(isMask)
Parameters

isMaskbool

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()

static PySide2.QtGui.QIcon.setThemeName(path)
Parameters

path – unicode

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.

static PySide2.QtGui.QIcon.setThemeSearchPaths(searchpath)
Parameters

searchpath – list of strings

Sets the search paths for icon themes to paths .

PySide2.QtGui.QIcon.swap(other)
Parameters

otherQIcon

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

static PySide2.QtGui.QIcon.themeName()
Return type

unicode

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.

static PySide2.QtGui.QIcon.themeSearchPaths()
Return type

list of strings

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.