QgsMapRendererCustomPainterJob Class Reference

Job implementation that renders everything sequentially using a custom painter. More...

#include <qgsmaprenderercustompainterjob.h>

Inheritance diagram for QgsMapRendererCustomPainterJob:

Public Member Functions
	QgsMapRendererCustomPainterJob (const QgsMapSettings &settings, QPainter *painter)
	~QgsMapRendererCustomPainterJob ()
virtual void	start ()
	Start the rendering job and immediately return.
virtual void	cancel ()
	Stop the rendering job - does not return until the job has terminated.
virtual void	waitForFinished ()
	Block until the job has finished.
virtual bool	isActive () const
	Tell whether the rendering job is currently running in background.
virtual QgsLabelingResults *	takeLabelingResults ()
	Get pointer to internal labeling engine (in order to get access to the results)
const LayerRenderJobs &	jobs () const
void	waitForFinishedWithEventLoop (QEventLoop::ProcessEventsFlags flags=QEventLoop::AllEvents)
	Wait for the job to be finished - and keep the thread's event loop running while waiting.
void	renderSynchronously ()
	Render the map synchronously in this thread.
Public Member Functions inherited from QgsMapRendererJob
	QgsMapRendererJob (const QgsMapSettings &settings)
virtual	~QgsMapRendererJob ()
Errors	errors () const
	List of errors that happened during the rendering job - available when the rendering has been finished.
void	setCache (QgsMapRendererCache *cache)
	Assign a cache to be used for reading and storing rendered images of individual layers.
void	setRequestedGeometryCacheForLayers (const QStringList &layerIds)
	Set which vector layers should be cached while rendering.
int	renderingTime () const
	Find out how log it took to finish the job (in miliseconds)

Protected Slots
void	futureFinished ()

Protected Member Functions
void	doRender ()
Protected Member Functions inherited from QgsMapRendererJob
LayerRenderJobs	prepareJobs (QPainter *painter, QgsPalLabeling *labelingEngine)
void	cleanupJobs (LayerRenderJobs &jobs)
bool	needTemporaryImage (QgsMapLayer *ml)
void	updateLayerGeometryCaches ()
	called when rendering has finished to update all layers' geometry caches

Static Protected Member Functions
static void	staticRender (QgsMapRendererCustomPainterJob *self)
Static Protected Member Functions inherited from QgsMapRendererJob
static bool	reprojectToLayerExtent (const QgsCoordinateTransform *ct, bool layerCrsGeographic, 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.
static QImage	composeImage (const QgsMapSettings &settings, const LayerRenderJobs &jobs)
static void	drawLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext, QgsPalLabeling *labelingEngine, QPainter *painter)
static void	drawOldLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext)
static void	drawNewLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext, QgsPalLabeling *labelingEngine)

Additional Inherited Members
Public Types inherited from QgsMapRendererJob
typedef QList< Error >	Errors
Signals inherited from QgsMapRendererJob
void	finished ()
	emitted when asynchronous rendering is finished (or canceled).
Protected Attributes inherited from QgsMapRendererJob
QgsMapSettings	mSettings
Errors	mErrors
QgsMapRendererCache *	mCache
QStringList	mRequestedGeomCacheForLayers
	list of layer IDs for which the geometry cache should be updated
QMap< QString, QgsGeometryCache >	mGeometryCaches
	map of geometry caches
QTime	mRenderingStart
int	mRenderingTime

Detailed Description

Job implementation that renders everything sequentially using a custom painter.

Also supports synchronous rendering in main thread for cases when rendering in background is not an option because of some technical limitations (e.g. printing to printer on some platforms).

Note

added in 2.4

Constructor & Destructor Documentation

QgsMapRendererCustomPainterJob::QgsMapRendererCustomPainterJob	(	const QgsMapSettings &	settings,
		QPainter *	painter
	)

QgsMapRendererCustomPainterJob::~QgsMapRendererCustomPainterJob

(

)

Member Function Documentation

void QgsMapRendererCustomPainterJob::cancel ( )

virtual

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

Does nothing if the rendering is not active.

Implements QgsMapRendererJob.

void QgsMapRendererCustomPainterJob::doRender ( )

protected

void QgsMapRendererCustomPainterJob::futureFinished ( )

protectedslot

bool QgsMapRendererCustomPainterJob::isActive ( ) const

virtual

Tell whether the rendering job is currently running in background.

Implements QgsMapRendererJob.

const LayerRenderJobs& QgsMapRendererCustomPainterJob::jobs ( ) const

inline

Note

not available in python bindings

void QgsMapRendererCustomPainterJob::renderSynchronously

(

)

Render the map synchronously in this thread.

The function does not return until the map is completely rendered.

This is an alternative to ordinary API (using start() + waiting for finished() signal). Users are discouraged to use this method unless they have a strong reason for doing it. The synchronous rendering blocks the main thread, making the application unresponsive. Also, it is not possible to cancel rendering while it is in progress.

void QgsMapRendererCustomPainterJob::start ( )

virtual

Start the rendering job and immediately return.

Does nothing if the rendering is already in progress.

Implements QgsMapRendererJob.

void QgsMapRendererCustomPainterJob::staticRender ( QgsMapRendererCustomPainterJob *  self )

staticprotected

QgsLabelingResults * QgsMapRendererCustomPainterJob::takeLabelingResults ( )

virtual

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

Implements QgsMapRendererJob.

void QgsMapRendererCustomPainterJob::waitForFinished ( )

virtual

Block until the job has finished.

Implements QgsMapRendererJob.

void QgsMapRendererCustomPainterJob::waitForFinishedWithEventLoop

(

QEventLoop::ProcessEventsFlags

flags = QEventLoop::AllEvents

)

Wait for the job to be finished - and keep the thread's event loop running while waiting.

With a call to waitForFinished(), the waiting is done with a synchronization primitive and does not involve processing of messages. That may cause issues to code which requires some events to be handled in the main thread. Some plugins hooking into the rendering pipeline may require this in order to work properly - for example, OpenLayers plugin which uses a QWebPage in the main thread.

Ideally the "wait for finished" method should not be used at all. The code triggering rendering should not need to actively wait for rendering to finish.

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

• /tmp/buildd/qgis-2.6.0+wheezy1/src/core/qgsmaprenderercustompainterjob.h
• /tmp/buildd/qgis-2.6.0+wheezy1/src/core/qgsmaprenderercustompainterjob.cpp