Abstract base class for map rendering implementations. More...

#include <qgsmaprendererjob.h>

Inheritance diagram for QgsMapRendererJob:

[legend]

Classes
struct	Error

Public Types
typedef QList< Error >	Errors

Signals
void	finished ()
	emitted when asynchronous rendering is finished (or canceled). More...

Public Member Functions
	QgsMapRendererJob (const QgsMapSettings &settings)

virtual	~QgsMapRendererJob ()

virtual void	cancel ()=0
	Stop the rendering job - does not return until the job has terminated. More...

virtual void	cancelWithoutBlocking ()=0
	Triggers cancellation of the rendering job without blocking. More...

Errors	errors () const
	List of errors that happened during the rendering job - available when the rendering has been finished. More...

virtual bool	isActive () const =0
	Tell whether the rendering job is currently running in background. More...

const QgsMapSettings &	mapSettings () const
	Return map settings with which this job was started. More...

int	renderingTime () const
	Find out how log it took to finish the job (in miliseconds) More...

void	setCache (QgsMapRendererCache *cache)
	Assign a cache to be used for reading and storing rendered images of individual layers. More...

void	setRequestedGeometryCacheForLayers (const QStringList &layerIds)
	Set which vector layers should be cached while rendering. More...

virtual void	start ()=0
	Start the rendering job and immediately return. More...

virtual QgsLabelingResults *	takeLabelingResults ()=0
	Get pointer to internal labeling engine (in order to get access to the results) More...

virtual void	waitForFinished ()=0
	Block until the job has finished. More...

Public Member Functions inherited from QObject
	QObject (QObject *parent)

	QObject (QObject parent, const char name)

virtual	~QObject ()

bool	blockSignals (bool block)

QObject *	child (const char objName, const char inheritsClass, bool recursiveSearch) const

const QObjectList &	children () const

const char *	className () const

bool	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const

void	deleteLater ()

void	destroyed (QObject *obj)

bool	disconnect (const QObject receiver, const char method)

bool	disconnect (const char signal, const QObject receiver, const char *method)

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QByteArray >	dynamicPropertyNames () const

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

T	findChild (const QString &name) const

QList< T >	findChildren (const QRegExp &regExp) const

QList< T >	findChildren (const QString &name) const

bool	inherits (const char *className) const

void	insertChild (QObject *object)

void	installEventFilter (QObject *filterObj)

bool	isA (const char *className) const

bool	isWidgetType () const

void	killTimer (int id)

virtual const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

const char *	name () const

const char *	name (const char *defaultName) const

QString	objectName () const

QObject *	parent () const

QVariant	property (const char *name) const

void	removeChild (QObject *object)

void	removeEventFilter (QObject *obj)

void	setName (const char *name)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const char *name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval)

QThread *	thread () const

Protected Member Functions
void	cleanupJobs (LayerRenderJobs &jobs)

void	logRenderingTime (const LayerRenderJobs &jobs)

bool	needTemporaryImage (QgsMapLayer *ml)

LayerRenderJobs	prepareJobs (QPainter painter, QgsPalLabeling labelingEngine, QgsLabelingEngineV2 *labelingEngine2)

void	updateLayerGeometryCaches ()
	called when rendering has finished to update all layers' geometry caches More...

Protected Member Functions inherited from QObject
bool	checkConnectArgs (const char signal, const QObject object, const char *method)

virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const char *signal)

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const char *signal)

int	receivers (const char *signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Static Protected Member Functions
static QImage	composeImage (const QgsMapSettings &settings, const LayerRenderJobs &jobs)

static void	drawLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext, QgsPalLabeling labelingEngine, QgsLabelingEngineV2 labelingEngine2, QPainter *painter)

static void	drawNewLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext, QgsPalLabeling *labelingEngine)

static void	drawOldLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext)

static bool	reprojectToLayerExtent (const QgsMapLayer ml, const QgsCoordinateTransform ct, QgsRectangle &extent, QgsRectangle &r2)
	Convenience function to project an extent into the layer source CRS, but also split it into two extents if it crosses the +/- 180 degree line. More...

Static Protected Member Functions inherited from QObject
QByteArray	normalizeSignalSlot (const char *signalSlot)

Protected Attributes
QgsMapRendererCache *	mCache

Errors	mErrors

QMap< QString, QgsGeometryCache >	mGeometryCaches
	map of geometry caches More...

QTime	mRenderingStart

int	mRenderingTime

QStringList	mRequestedGeomCacheForLayers
	list of layer IDs for which the geometry cache should be updated More...

QgsMapSettings	mSettings

Additional Inherited Members
Static Public Member Functions inherited from QObject
bool	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

bool	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

QString	tr (const char sourceText, const char disambiguation, int n)

QString	trUtf8 (const char sourceText, const char disambiguation, int n)

Properties inherited from QObject
	objectName

Detailed Description

Abstract base class for map rendering implementations.

The API is designed in a way that rendering is done asynchronously, therefore the caller is not blocked while the rendering is in progress. Non-blocking operation is quite important because the rendering can take considerable amount of time.

Common use case: 0. prepare QgsMapSettings with rendering configuration (extent, layer, map size, ...)

create QgsMapRendererJob subclass with QgsMapSettings instance
connect to job's finished() signal
call start(). Map rendering will start in background, the function immediately returns
at some point, slot connected to finished() signal is called, map rendering is done

It is possible to cancel the rendering job while it is active by calling cancel() function.

The following subclasses are available:

QgsMapRendererSequentialJob - renders map in one background thread to an image
QgsMapRendererParallelJob - renders map in multiple background threads to an image
QgsMapRendererCustomPainterJob - renders map with given QPainter in one background thread

Note: added in 2.4

Definition at line 82 of file qgsmaprendererjob.h.

Member Typedef Documentation

◆ Errors

typedef QList<Error> QgsMapRendererJob::Errors

Definition at line 126 of file qgsmaprendererjob.h.

Constructor & Destructor Documentation

◆ QgsMapRendererJob()

QgsMapRendererJob::QgsMapRendererJob ( const QgsMapSettings & settings )

Definition at line 37 of file qgsmaprendererjob.cpp.

◆ ~QgsMapRendererJob()

virtual QgsMapRendererJob::~QgsMapRendererJob ( )

inlinevirtual

Definition at line 89 of file qgsmaprendererjob.h.

Member Function Documentation

◆ cancel()

virtual void QgsMapRendererJob::cancel ( )

pure virtual

Stop the rendering job - does not return until the job has terminated.

Does nothing if the rendering is not active.

Implemented in QgsMapRendererCustomPainterJob, QgsMapRendererSequentialJob, and QgsMapRendererParallelJob.

◆ cancelWithoutBlocking()

virtual void QgsMapRendererJob::cancelWithoutBlocking ( )

pure virtual

Triggers cancellation of the rendering job without blocking.

The render job will continue to operate until it is able to cancel, at which stage the finished() signal will be emitted. Does nothing if the rendering is not active.

Implemented in QgsMapRendererCustomPainterJob, QgsMapRendererSequentialJob, and QgsMapRendererParallelJob.

◆ cleanupJobs()

void QgsMapRendererJob::cleanupJobs ( LayerRenderJobs & jobs )

protected

Note: not available in python bindings

Definition at line 321 of file qgsmaprendererjob.cpp.

◆ composeImage()

QImage QgsMapRendererJob::composeImage	(	const QgsMapSettings &	settings,
		const LayerRenderJobs &	jobs
	)

staticprotected

Definition at line 357 of file qgsmaprendererjob.cpp.

◆ drawLabeling()

void QgsMapRendererJob::drawLabeling	(	const QgsMapSettings &	settings,
		QgsRenderContext &	renderContext,
		QgsPalLabeling *	labelingEngine,
		QgsLabelingEngineV2 *	labelingEngine2,
		QPainter *	painter
	)

staticprotected

Note: not available in Python bindings

Definition at line 297 of file qgsmaprenderercustompainterjob.cpp.

◆ drawNewLabeling()

void QgsMapRendererJob::drawNewLabeling	(	const QgsMapSettings &	settings,
		QgsRenderContext &	renderContext,
		QgsPalLabeling *	labelingEngine
	)

staticprotected

Definition at line 373 of file qgsmaprenderercustompainterjob.cpp.

◆ drawOldLabeling()

void QgsMapRendererJob::drawOldLabeling	(	const QgsMapSettings &	settings,
		QgsRenderContext &	renderContext
	)

staticprotected

Definition at line 331 of file qgsmaprenderercustompainterjob.cpp.

◆ errors()

QgsMapRendererJob::Errors QgsMapRendererJob::errors ( ) const

List of errors that happened during the rendering job - available when the rendering has been finished.

Definition at line 51 of file qgsmaprendererjob.cpp.

◆ finished

void QgsMapRendererJob::finished ( )

signal

emitted when asynchronous rendering is finished (or canceled).

◆ isActive()

virtual bool QgsMapRendererJob::isActive ( ) const

pure virtual

Tell whether the rendering job is currently running in background.

Implemented in QgsMapRendererCustomPainterJob, QgsMapRendererSequentialJob, and QgsMapRendererParallelJob.

◆ logRenderingTime()

void QgsMapRendererJob::logRenderingTime ( const LayerRenderJobs & jobs )

protected

Note: not available in python bindings

Definition at line 380 of file qgsmaprendererjob.cpp.

◆ mapSettings()

const QgsMapSettings & QgsMapRendererJob::mapSettings ( ) const

Return map settings with which this job was started.

Returns: A QgsMapSettings instance with render settings

Note: added in 2.8

Definition at line 61 of file qgsmaprendererjob.cpp.

◆ needTemporaryImage()

bool QgsMapRendererJob::needTemporaryImage ( QgsMapLayer * ml )

protected

Definition at line 399 of file qgsmaprenderercustompainterjob.cpp.

◆ prepareJobs()

LayerRenderJobs QgsMapRendererJob::prepareJobs	(	QPainter *	painter,
		QgsPalLabeling *	labelingEngine,
		QgsLabelingEngineV2 *	labelingEngine2
	)

protected

Note: not available in python bindings

Definition at line 171 of file qgsmaprendererjob.cpp.

◆ renderingTime()

int QgsMapRendererJob::renderingTime ( ) const

inline

Find out how log it took to finish the job (in miliseconds)

Definition at line 141 of file qgsmaprendererjob.h.

◆ reprojectToLayerExtent()

bool QgsMapRendererJob::reprojectToLayerExtent	(	const QgsMapLayer *	ml,
		const QgsCoordinateTransform *	ct,
		QgsRectangle &	extent,
		QgsRectangle &	r2
	)

staticprotected

Convenience function to project an extent into the layer source CRS, but also split it into two extents if it crosses the +/- 180 degree line.

Modifies the given extent to be in the source CRS coordinates, and if it was split, returns true, and also sets the contents of the r2 parameter

Definition at line 67 of file qgsmaprendererjob.cpp.

◆ setCache()

void QgsMapRendererJob::setCache ( QgsMapRendererCache * cache )

Assign a cache to be used for reading and storing rendered images of individual layers.

Does not take ownership of the object.

Definition at line 56 of file qgsmaprendererjob.cpp.

◆ setRequestedGeometryCacheForLayers()

void QgsMapRendererJob::setRequestedGeometryCacheForLayers ( const QStringList & layerIds )

inline

Set which vector layers should be cached while rendering.

Note: The way how geometries are cached is really suboptimal - this method may be removed in future releases

Definition at line 138 of file qgsmaprendererjob.h.

◆ start()

virtual void QgsMapRendererJob::start ( )

pure virtual

Start the rendering job and immediately return.

Does nothing if the rendering is already in progress.

Implemented in QgsMapRendererCustomPainterJob, QgsMapRendererSequentialJob, and QgsMapRendererParallelJob.

◆ takeLabelingResults()

virtual QgsLabelingResults* QgsMapRendererJob::takeLabelingResults ( )

pure virtual

Get pointer to internal labeling engine (in order to get access to the results)

Implemented in QgsMapRendererCustomPainterJob, QgsMapRendererSequentialJob, and QgsMapRendererParallelJob.

◆ updateLayerGeometryCaches()

void QgsMapRendererJob::updateLayerGeometryCaches ( )

protected

called when rendering has finished to update all layers' geometry caches

Definition at line 386 of file qgsmaprenderercustompainterjob.cpp.

◆ waitForFinished()

virtual void QgsMapRendererJob::waitForFinished ( )

pure virtual

Block until the job has finished.

Implemented in QgsMapRendererCustomPainterJob, QgsMapRendererSequentialJob, and QgsMapRendererParallelJob.

Member Data Documentation

◆ mCache

QgsMapRendererCache* QgsMapRendererJob::mCache

protected

Definition at line 189 of file qgsmaprendererjob.h.

◆ mErrors

Errors QgsMapRendererJob::mErrors

protected

Definition at line 187 of file qgsmaprendererjob.h.

◆ mGeometryCaches

QMap<QString, QgsGeometryCache> QgsMapRendererJob::mGeometryCaches

protected

map of geometry caches

Definition at line 194 of file qgsmaprendererjob.h.

◆ mRenderingStart

QTime QgsMapRendererJob::mRenderingStart

protected

Definition at line 196 of file qgsmaprendererjob.h.

◆ mRenderingTime

int QgsMapRendererJob::mRenderingTime

protected

Definition at line 197 of file qgsmaprendererjob.h.

◆ mRequestedGeomCacheForLayers

QStringList QgsMapRendererJob::mRequestedGeomCacheForLayers

protected

list of layer IDs for which the geometry cache should be updated

Definition at line 192 of file qgsmaprendererjob.h.

◆ mSettings

QgsMapSettings QgsMapRendererJob::mSettings

protected

Definition at line 186 of file qgsmaprendererjob.h.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaprendererjob.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaprenderercustompainterjob.cpp
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaprendererjob.cpp

Classes

Public Types

Signals

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Errors

Constructor & Destructor Documentation

◆ QgsMapRendererJob()

◆ ~QgsMapRendererJob()

Member Function Documentation

◆ cancel()

◆ cancelWithoutBlocking()

◆ cleanupJobs()

◆ composeImage()

◆ drawLabeling()

◆ drawNewLabeling()

◆ drawOldLabeling()

◆ errors()

◆ finished

◆ isActive()

◆ logRenderingTime()

◆ mapSettings()

◆ needTemporaryImage()

◆ prepareJobs()

◆ renderingTime()

◆ reprojectToLayerExtent()

◆ setCache()

◆ setRequestedGeometryCacheForLayers()

◆ start()

◆ takeLabelingResults()

◆ updateLayerGeometryCaches()

◆ waitForFinished()

Member Data Documentation

◆ mCache

◆ mErrors

◆ mGeometryCaches

◆ mRenderingStart

◆ mRenderingTime

◆ mRequestedGeomCacheForLayers

◆ mSettings