QGraphicsSvgItem ¶

概要 ¶

详细描述 ¶

QGraphicsSvgItem provides a way of rendering SVG files onto QGraphicsView . QGraphicsSvgItem can be created by passing the SVG file to be rendered to its constructor or by explicit setting a shared QSvgRenderer on it.

Note that setting QSvgRenderer 在 QGraphicsSvgItem doesn’t make the item take ownership of the renderer, therefore if using setSharedRenderer() method one has to make sure that the lifetime of the QSvgRenderer object will be at least as long as that of the QGraphicsSvgItem .

QGraphicsSvgItem provides a way of rendering only parts of the SVG files via the setElementId 。若 setElementId() method is called, only the SVG element (and its children) with the passed id will be renderer. This provides a convenient way of selectively rendering large SVG files that contain a number of discrete elements. For example the following code renders only jokers from a SVG file containing a whole card deck:

QSvgRenderer *renderer = new QSvgRenderer(QLatin1String("SvgCardDeck.svg"));
QGraphicsSvgItem *black = new QGraphicsSvgItem();
QGraphicsSvgItem *red   = new QGraphicsSvgItem();
black->setSharedRenderer(renderer);
black->setElementId(QLatin1String("black_joker"));
red->setSharedRenderer(renderer);
red->setElementId(QLatin1String("red_joker"));
											

Size of the item can be set via direct manipulation of the items transformation matrix.

By default the SVG rendering is cached using DeviceCoordinateCache mode to speedup the display of items. Caching can be disabled by passing NoCache 到 setCacheMode() 方法。

另请参阅

QSvgWidget Qt SVG C++ 类 QGraphicsItem QGraphicsView

class QGraphicsSvgItem ( [ parentItem=None ] ) ¶

QGraphicsSvgItem(fileName[, parentItem=None])

param fileName

unicode

param parentItem

QGraphicsItem

构造新的 SVG 项采用给定 parent .

构造新的项采用给定 parent and loads the contents of the SVG file with the specified fileName .

PySide2.QtSvg.QGraphicsSvgItem. elementId ( ) ¶

返回类型

unicode

Returns the XML ID the element that is currently being rendered. Returns an empty string if the whole file is being rendered.

另请参阅

setElementId()

PySide2.QtSvg.QGraphicsSvgItem. isCachingEnabled ( ) ¶

返回类型

bool

使用 cacheMode() 代替。

PySide2.QtSvg.QGraphicsSvgItem. maximumCacheSize ( ) ¶

返回类型

QSize

Returns the current maximum size of the device coordinate cache for this item. If the item is cached using DeviceCoordinateCache mode, caching is bypassed if the extension of the item in device coordinates is larger than the maximum size.

The default maximum cache size is 1024x768. cacheLimit() gives the cumulative bounds of the whole cache, whereas refers to a maximum cache size for this particular item.

另请参阅

setMaximumCacheSize() cacheMode()

PySide2.QtSvg.QGraphicsSvgItem. renderer ( ) ¶

返回类型

QSvgRenderer

Returns the currently use QSvgRenderer .

PySide2.QtSvg.QGraphicsSvgItem. setCachingEnabled ( arg__1 ) ¶

参数

arg__1 – bool

使用 setCacheMode() instead. Passing true to this function is equivalent to setCacheMode ( DeviceCoordinateCache ).

另请参阅

isCachingEnabled()

PySide2.QtSvg.QGraphicsSvgItem. setElementId ( id ) ¶

参数

id – unicode

Sets the XML ID of the element to id .

另请参阅

elementId()

PySide2.QtSvg.QGraphicsSvgItem. setMaximumCacheSize ( size ) ¶

参数

size – QSize

Sets the maximum device coordinate cache size of the item to size . If the item is cached using DeviceCoordinateCache mode, caching is bypassed if the extension of the item in device coordinates is larger than size .

The cache corresponds to the QPixmap which is used to cache the results of the rendering. Use setCacheLimit() to set limitations on the whole cache and use when setting cache size for individual items.

另请参阅

maximumCacheSize() cacheMode()

PySide2.QtSvg.QGraphicsSvgItem. setSharedRenderer ( renderer ) ¶

参数

renderer – QSvgRenderer

集 renderer to be a shared QSvgRenderer on the item. By using this method one can share the same QSvgRenderer on a number of items. This means that the SVG file will be parsed only once. QSvgRenderer passed to this method has to exist for as long as this item is used.