A cache for images / pictures derived from SVG files. More...

#include <qgssvgcache.h>

Inheritance diagram for QgsSvgCache:

[legend]

Signals
void	remoteSvgFetched (const QString &url)
	Emitted when the cache has finished retrieving an SVG file from a remote url.

Q_DECL_DEPRECATED void	statusChanged (const QString &statusQString)
	Emit a signal to be caught by qgisapp and display a msg on status bar.

Signals inherited from QgsAbstractContentCacheBase
void	remoteContentFetched (const QString &url)
	Emitted when the cache has finished retrieving content from a remote url.

Public Member Functions
	QgsSvgCache (QObject *parent=nullptr)
	Constructor for QgsSvgCache.

void	containsParams (const QString &path, bool &hasFillParam, bool &hasDefaultFillParam, QColor &defaultFillColor, bool &hasFillOpacityParam, bool &hasDefaultFillOpacity, double &defaultFillOpacity, bool &hasStrokeParam, bool &hasDefaultStrokeColor, QColor &defaultStrokeColor, bool &hasStrokeWidthParam, bool &hasDefaultStrokeWidth, double &defaultStrokeWidth, bool &hasStrokeOpacityParam, bool &hasDefaultStrokeOpacity, double &defaultStrokeOpacity, bool blocking=false) const
	Tests if an SVG file contains parameters for fill, stroke color, stroke width.

void	containsParams (const QString &path, bool &hasFillParam, QColor &defaultFillColor, bool &hasStrokeParam, QColor &defaultStrokeColor, bool &hasStrokeWidthParam, double &defaultStrokeWidth, bool blocking=false) const
	Tests if an SVG file contains parameters for fill, stroke color, stroke width.

QByteArray	getImageData (const QString &path, bool blocking=false) const
	Gets the SVG content corresponding to the given path.

QImage	svgAsImage (const QString &path, double size, const QColor &fill, const QColor &stroke, double strokeWidth, double widthScaleFactor, bool &fitsInCache, double fixedAspectRatio=0, bool blocking=false, const QMap< QString, QString > &parameters=QMap< QString, QString >())
	Returns an SVG drawing as a QImage.

QPicture	svgAsPicture (const QString &path, double size, const QColor &fill, const QColor &stroke, double strokeWidth, double widthScaleFactor, bool forceVectorOutput=false, double fixedAspectRatio=0, bool blocking=false, const QMap< QString, QString > &parameters=QMap< QString, QString >())
	Returns an SVG drawing as a QPicture.

QByteArray	svgContent (const QString &path, double size, const QColor &fill, const QColor &stroke, double strokeWidth, double widthScaleFactor, double fixedAspectRatio=0, bool blocking=false, const QMap< QString, QString > &parameters=QMap< QString, QString >(), bool *isMissingImage=nullptr)
	Gets the SVG content corresponding to the given path.

QSizeF	svgViewboxSize (const QString &path, double size, const QColor &fill, const QColor &stroke, double strokeWidth, double widthScaleFactor, double fixedAspectRatio=0, bool blocking=false, const QMap< QString, QString > &parameters=QMap< QString, QString >())
	Calculates the viewbox size of a (possibly cached) SVG file.

Public Member Functions inherited from QgsAbstractContentCache< QgsSvgCacheEntry >
	QgsAbstractContentCache (QObject *parent=nullptr, const QString &typeString=QString(), long maxCacheSize=20000000, int fileModifiedCheckTimeout=30000)
	Constructor for QgsAbstractContentCache, with the specified parent object.

	~QgsAbstractContentCache () override

Public Member Functions inherited from QgsAbstractContentCacheBase
	QgsAbstractContentCacheBase (QObject *parent)
	Constructor for QgsAbstractContentCacheBase, with the specified parent object.

Protected Member Functions
bool	checkReply (QNetworkReply *reply, const QString &path) const override
	Runs additional checks on a network reply to ensure that the reply content is consistent with that required by the cache.

Protected Member Functions inherited from QgsAbstractContentCache< QgsSvgCacheEntry >
QgsSvgCacheEntry *	findExistingEntry (QgsSvgCacheEntry *entryTemplate)
	Returns the existing entry from the cache which matches entryTemplate (deleting entryTemplate when done), or if no existing entry is found then entryTemplate is transferred to the cache and returned.

QByteArray	getContent (const QString &path, const QByteArray &missingContent, const QByteArray &fetchingContent, bool blocking=false) const
	Gets the file content corresponding to the given path.

void	onRemoteContentFetched (const QString &url, bool success) override
	Triggered after remote content (i.e.

void	trimToMaximumSize ()
	Removes the least used cache entries until the maximum cache size is under the predefined size limit.

bool	waitForTaskFinished (QgsNetworkContentFetcherTask *task) const
	Blocks the current thread until the task finishes (or user's preset network timeout expires)

Friends
class	TestQgsSvgCache

Additional Inherited Members
Protected Slots inherited from QgsAbstractContentCacheBase
Protected Attributes inherited from QgsAbstractContentCache< QgsSvgCacheEntry >
long	mMaxCacheSize
	Maximum cache size.

QRecursiveMutex	mMutex

long	mTotalSize
	Estimated total size of all cached content.

Detailed Description

A cache for images / pictures derived from SVG files.

This class supports parameter replacement in SVG files according to the SVG params specification (http://www.w3.org/TR/2009/WD-SVGParamPrimer-20090616/).

Supported parameters are:

param(fill): fill color (with no opacity value)
param(fill-opacity): fill color opacity
param(outline): outline color (with no opacity value)
param(outline-opacity): outline color opacity
param(outline-width): width of outline strokes

E.g:

<circle fill="param(fill-color red)" stroke="param(pen-color black)" stroke-width="param(outline-width 1)"

Note: QgsSvgCache is not usually directly created, but rather accessed through QgsApplication::svgCache().

Definition at line 121 of file qgssvgcache.h.

Constructor & Destructor Documentation

◆ QgsSvgCache()

QgsSvgCache::QgsSvgCache ( QObject * parent = nullptr )

Constructor for QgsSvgCache.

Definition at line 103 of file qgssvgcache.cpp.

Member Function Documentation

◆ checkReply()

bool QgsSvgCache::checkReply	(	QNetworkReply *	reply,
		const QString &	path
	)		const

overrideprotectedvirtual

Runs additional checks on a network reply to ensure that the reply content is consistent with that required by the cache.

Reimplemented from QgsAbstractContentCacheBase.

Definition at line 407 of file qgssvgcache.cpp.

◆ containsParams() [1/2]

void QgsSvgCache::containsParams	(	const QString &	path,
		bool &	hasFillParam,
		bool &	hasDefaultFillParam,
		QColor &	defaultFillColor,
		bool &	hasFillOpacityParam,
		bool &	hasDefaultFillOpacity,
		double &	defaultFillOpacity,
		bool &	hasStrokeParam,
		bool &	hasDefaultStrokeColor,
		QColor &	defaultStrokeColor,
		bool &	hasStrokeWidthParam,
		bool &	hasDefaultStrokeWidth,
		double &	defaultStrokeWidth,
		bool &	hasStrokeOpacityParam,
		bool &	hasDefaultStrokeOpacity,
		double &	defaultStrokeOpacity,
		bool	blocking = `false`
	)		const

Tests if an SVG file contains parameters for fill, stroke color, stroke width.

If yes, possible default values are returned. If there are several default values in the SVG file, only the first one is considered.

Parameters

path	path to SVG file
hasFillParam	will be `true` if fill param present in SVG
hasDefaultFillParam	will be `true` if fill param has a default value specified
defaultFillColor	will be set to default fill color specified in SVG, if present
hasFillOpacityParam	will be `true` if fill opacity param present in SVG
hasDefaultFillOpacity	will be `true` if fill opacity param has a default value specified
defaultFillOpacity	will be set to default fill opacity specified in SVG, if present
hasStrokeParam	will be `true` if stroke param present in SVG
hasDefaultStrokeColor	will be `true` if stroke param has a default value specified
defaultStrokeColor	will be set to default stroke color specified in SVG, if present
hasStrokeWidthParam	will be `true` if stroke width param present in SVG
hasDefaultStrokeWidth	will be `true` if stroke width param has a default value specified
defaultStrokeWidth	will be set to default stroke width specified in SVG, if present
hasStrokeOpacityParam	will be `true` if stroke opacity param present in SVG
hasDefaultStrokeOpacity	will be `true` if stroke opacity param has a default value specified
defaultStrokeOpacity	will be set to default stroke opacity specified in SVG, if present
blocking	forces to wait for loading before returning image (optional).

Note: Available in Python bindings as containsParamsV3

Warning: The blocking parameter must NEVER be true from GUI based applications (like the main QGIS application) or crashes will result. Only for use in external scripts or QGIS server.

Definition at line 250 of file qgssvgcache.cpp.

◆ containsParams() [2/2]

void QgsSvgCache::containsParams	(	const QString &	path,
		bool &	hasFillParam,
		QColor &	defaultFillColor,
		bool &	hasStrokeParam,
		QColor &	defaultStrokeColor,
		bool &	hasStrokeWidthParam,
		double &	defaultStrokeWidth,
		bool	blocking = `false`
	)		const

Tests if an SVG file contains parameters for fill, stroke color, stroke width.

If yes, possible default values are returned. If there are several default values in the SVG file, only the first one is considered. Blocking forces to wait for loading before returning image (optional). WARNING: the blocking parameter must NEVER be true from GUI based applications (like the main QGIS application) or crashes will result. Only for use in external scripts or QGIS server.

Definition at line 229 of file qgssvgcache.cpp.

◆ getImageData()

QByteArray QgsSvgCache::getImageData	(	const QString &	path,
		bool	blocking = `false`
	)		const

Gets the SVG content corresponding to the given path.

path may be a local file, remote (HTTP) url, or a base 64 encoded string (with a "base64:" prefix).

The class default missingContent byte array is returned if the path could not be resolved or is broken. If the path corresponds to a remote URL, then class default fetchingContent will be returned while the content is in the process of being fetched. The blocking boolean forces to wait for loading before returning result. The content is loaded in the same thread to ensure provided the remote content.

Warning: The blocking parameter must NEVER be true from GUI based applications (like the main QGIS application) or crashes will result. Only for use in external scripts or QGIS server.

Definition at line 402 of file qgssvgcache.cpp.

◆ remoteSvgFetched

void QgsSvgCache::remoteSvgFetched ( const QString & url )

signal

Emitted when the cache has finished retrieving an SVG file from a remote url.

Since: QGIS 3.2

◆ statusChanged

Q_DECL_DEPRECATED void QgsSvgCache::statusChanged ( const QString & statusQString )

signal

Emit a signal to be caught by qgisapp and display a msg on status bar.

Deprecated:: Deprecated since QGIS 3.6 – no longer emitted.

◆ svgAsImage()

QImage QgsSvgCache::svgAsImage	(	const QString &	path,
		double	size,
		const QColor &	fill,
		const QColor &	stroke,
		double	strokeWidth,
		double	widthScaleFactor,
		bool &	fitsInCache,
		double	fixedAspectRatio = `0`,
		bool	blocking = `false`,
		const QMap< QString, QString > &	parameters = `QMap<QString, QString>()`
	)

Returns an SVG drawing as a QImage.

Parameters

path	Absolute path to SVG file.
size	size of cached image
fill	color of fill
stroke	color of stroke
strokeWidth	width of stroke
widthScaleFactor	width scale factor
fitsInCache
fixedAspectRatio	fixed aspect ratio (optional)
blocking	forces to wait for loading before returning image (optional).
parameters	is a map of parameters to dynamically replace content in SVG.

Warning: The blocking parameter must NEVER be true from GUI based applications (like the main QGIS application) or crashes will result. Only for use in external scripts or QGIS server.

Definition at line 126 of file qgssvgcache.cpp.

◆ svgAsPicture()

QPicture QgsSvgCache::svgAsPicture	(	const QString &	path,
		double	size,
		const QColor &	fill,
		const QColor &	stroke,
		double	strokeWidth,
		double	widthScaleFactor,
		bool	forceVectorOutput = `false`,
		double	fixedAspectRatio = `0`,
		bool	blocking = `false`,
		const QMap< QString, QString > &	parameters = `QMap<QString, QString>()`
	)

Returns an SVG drawing as a QPicture.

Parameters

path	Absolute path to SVG file.
size	size of cached image
fill	color of fill
stroke	color of stroke
strokeWidth	width of stroke
widthScaleFactor	width scale factor
forceVectorOutput
fixedAspectRatio	fixed aspect ratio (optional)
blocking	forces to wait for loading before returning image (optional)
parameters	is a map of parameters to dynamically replace content in SVG.

Note: The returned QPicture contains the SVG file centered over the picture origin. I.e. if it is rendered using QPainter::drawPicture( QPointF( 5, 10 ), picture ) it will be drawn centered over the point (5, 10). Appropriate translation to the destination painter based on the picture's boundingRect may need to be applied if rendering the SVG using the top-left or other reference point is desired.

Warning: The blocking parameter must NEVER be true from GUI based applications (like the main QGIS application) or crashes will result. Only for use in external scripts or QGIS server.

Definition at line 186 of file qgssvgcache.cpp.

◆ svgContent()

QByteArray QgsSvgCache::svgContent	(	const QString &	path,
		double	size,
		const QColor &	fill,
		const QColor &	stroke,
		double	strokeWidth,
		double	widthScaleFactor,
		double	fixedAspectRatio = `0`,
		bool	blocking = `false`,
		const QMap< QString, QString > &	parameters = `QMap<QString, QString>()`,
		bool *	isMissingImage = `nullptr`
	)

Gets the SVG content corresponding to the given path.

path may be a local file, remote (HTTP) url, or a base 64 encoded string (with a "base64:" prefix).

The parameters size, strokeWidth for width of stroke, widthScaleFactor for width scale factor, fill for color of fill, stroke for color of stroke and fixedAspectRatio for fixed aspect ratio (optional) are needed to get the entry from cache or creates a new entry if it does not exist already.

The blocking boolean forces to wait for loading before returning image. The content is loaded in the same thread to ensure provided the image.

Warning: The blocking parameter must NEVER be true from GUI based applications (like the main QGIS application) or crashes will result. Only for use in external scripts or QGIS server.

Definition at line 210 of file qgssvgcache.cpp.

◆ svgViewboxSize()

QSizeF QgsSvgCache::svgViewboxSize	(	const QString &	path,
		double	size,
		const QColor &	fill,
		const QColor &	stroke,
		double	strokeWidth,
		double	widthScaleFactor,
		double	fixedAspectRatio = `0`,
		bool	blocking = `false`,
		const QMap< QString, QString > &	parameters = `QMap<QString, QString>()`
	)

Calculates the viewbox size of a (possibly cached) SVG file.

Parameters

path	Absolute path to SVG file.
size	size of cached image
fill	color of fill
stroke	color of stroke
strokeWidth	width of stroke
widthScaleFactor	width scale factor
fixedAspectRatio	fixed aspect ratio (optional)
blocking	forces to wait for loading before returning image (optional).
parameters	is a map of parameters to dynamically replace content in SVG.

Returns: viewbox size set in SVG file

Warning: The blocking parameter must NEVER be true from GUI based applications (like the main QGIS application) or crashes will result. Only for use in external scripts or QGIS server.

Definition at line 220 of file qgssvgcache.cpp.

Friends And Related Symbol Documentation

◆ TestQgsSvgCache

friend class TestQgsSvgCache

friend

Definition at line 338 of file qgssvgcache.h.

The documentation for this class was generated from the following files:

/home/fischer/src/qgis-3.38/src/core/symbology/qgssvgcache.h
/home/fischer/src/qgis-3.38/src/core/symbology/qgssvgcache.cpp

Signals

Public Member Functions

Protected Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsSvgCache()

Member Function Documentation

◆ checkReply()

◆ containsParams() [1/2]

◆ containsParams() [2/2]

◆ getImageData()

◆ remoteSvgFetched

◆ statusChanged

◆ svgAsImage()

◆ svgAsPicture()

◆ svgContent()

◆ svgViewboxSize()

Friends And Related Symbol Documentation

◆ TestQgsSvgCache