QIconEngine ClassThe QIconEngine class provides an abstract base class for QIcon renderers. More... #include <QIconEngine>
Public Types
Public Functions
Detailed DescriptionThe 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. See also QIconEnginePlugin. Member Type Documentation
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Constant | Value | Description |
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QIconEngine::AvailableSizesHook | 1 | Allows to query the sizes of the contained pixmaps for pixmap-based engines. The data argument of the virtual_hook() function is a AvailableSizesArgument pointer that should be filled with icon sizes. Engines that work in terms of a scalable, vectorial format normally return an empty list. |
QIconEngine::IconNameHook | 2 | Allows to query the name used to create the icon, for example when instantiating an icon using QIcon::fromTheme(). |
This enum was introduced or modified in Qt 4.5.
See also virtual_hook().
Destroys the icon engine.
Returns the actual size of the icon the engine provides for the requested size, mode and state. The default implementation returns the given size.
Called by QIcon::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.
Called by QIcon::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.
Returns sizes of all images that are contained in the engine for the specific mode and state.
Note: This is a helper method and the actual work is done by virtual_hook() method, hence this method depends on icon engine support and may not work with all icon engines.
This function was introduced in Qt 4.5.
Reimplement this method to return a clone of this icon engine.
Returns the name used to create the engine, if available.
Note: This is a helper method and the actual work is done by virtual_hook() method, hence this method depends on icon engine support and may not work with all icon engines.
This function was introduced in Qt 4.7.
Returns a key that identifies this icon engine.
Uses the given painter to paint the icon with the required mode and state into the rectangle rect.
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.
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.
Additional method to allow extending QIconEngine without adding new virtual methods (and without breaking binary compatibility). The actual action and format of data depends on id argument which is in fact a constant from IconEngineHook enum.
This function was introduced in Qt 4.5.
See also IconEngineHook.
Writes the contents of this engine to the QDataStream out. Returns true if the contents were written; otherwise returns false.
QIconEngine's default implementation always return false.