QIconEngine¶

PyQt6.QtGui.QIconEngine

Description¶

The QIconEngine class provides an abstract base class for QIcon renderers.

An icon engine provides the rendering functions for a QIcon. Each icon has a corresponding icon engine that is responsible for drawing the icon with a requested size, mode and state.

The icon is rendered by the paint() function, and the icon can additionally be obtained as a pixmap with the pixmap() function (the default implementation simply uses paint() to achieve this). The addPixmap() function can be used to add new pixmaps to the icon engine, and is used by QIcon to add specialized custom pixmaps.

The paint(), pixmap(), and addPixmap() functions are all virtual, and can therefore be reimplemented in subclasses of QIconEngine.

Classes¶

ScaledPixmapArgument

Enums¶

IconEngineHook

These enum values are used for virtual_hook() to allow additional queries to icon engine without breaking binary compatibility.

Methods¶

__init__(): Constructs the icon engine.

__init__(QIconEngine): TODO

actualSize(QSize, Mode, State) → QSize

Returns the actual size of the icon the engine provides for the requested size, mode and state. The default implementation returns the given size.

The returned size is in device-independent pixels (This is relevant for high-dpi pixmaps).

addFile(Optional[str], QSize, Mode, State): Called by addFile(). Adds a specialized pixmap from the file with the given fileName, size, mode and state. The default pixmap-based engine stores any supplied file names, and it loads the pixmaps on demand instead of using scaled pixmaps if the size of a pixmap matches the size of icon requested. Custom icon engines that implement scalable vector formats are free to ignores any extra files.

addPixmap(QPixmap, Mode, State): Called by addPixmap(). Adds a specialized pixmap for the given mode and state. The default pixmap-based engine stores any supplied pixmaps, and it uses them instead of scaled pixmaps if the size of a pixmap matches the size of icon requested. Custom icon engines that implement scalable vector formats are free to ignores any extra pixmaps.

availableSizes(mode: Mode = Normal, state: State = Off) → list[QSize]: Returns sizes of all images that are contained in the engine for the specific mode and state.

clone() → QIconEngine: TODO

iconName() → str: Returns the name used to create the engine, if available.

isNull() → bool

Returns true if this icon engine represent a null QIcon.

Note: This is a helper method and the actual work is done by the virtual_hook() method, hence this method depends on icon engine support and may not work with all icon engines.

key() → str: Returns a key that identifies this icon engine.

paint(QPainter, QRect, Mode, State): TODO

pixmap(QSize, Mode, State) → QPixmap: Returns the icon as a pixmap with the required size, mode, and state. The default implementation creates a new pixmap and calls paint() to fill it.

read(QDataStream) → bool

Reads icon engine contents from the QDataStream in. Returns true if the contents were read; otherwise returns false.

QIconEngine’s default implementation always return false.

scaledPixmap(QSize, Mode, State, float) → QPixmap

Returns a pixmap for the given size, mode, state and scale.

The scale argument is typically equal to the device pixel ratio of the display.

Note: This is a helper method and the actual work is done by the virtual_hook() method, hence this method depends on icon engine support and may not work with all icon engines.

Note: Some engines may cast scale to an integer.

Member	Value	Description
IsNullHook	3	Allow to query if this engine represents a null icon. The data argument of the virtual_hook() is a pointer to a bool that can be set to true if the icon is null. This enum value was added in Qt 5.7.
ScaledPixmapHook	4	Provides a way to get a pixmap that is scaled according to the given scale (typically equal to the device pixel ratio). The data argument of the virtual_hook() function is a ScaledPixmapArgument pointer that contains both the input and output arguments. This enum value was added in Qt 5.9.