Render job implementation that renders maps in stages, allowing different stages (e.g. More...

#include <qgsmaprendererstagedrenderjob.h>

Inheritance diagram for QgsMapRendererStagedRenderJob:

[legend]

Public Types
enum	Flag { RenderLabelsByMapLayer = 0x01 }
	Flags which control the staged render job behavior. More...

typedef QFlags< Flag >	Flags

enum	RenderStage { Symbology , Labels , Finished }
	Represents the stages of a rendering job. More...

Public Types inherited from QgsMapRendererJob
typedef QList< QgsMapRendererJob::Error >	Errors

Public Member Functions
	QgsMapRendererStagedRenderJob (const QgsMapSettings &settings, Flags flags=Flags())
	Constructor for QgsMapRendererStagedRenderJob, using the given map settings.

	~QgsMapRendererStagedRenderJob () override

void	cancel () override
	Stop the rendering job - does not return until the job has terminated.

void	cancelWithoutBlocking () override
	Triggers cancellation of the rendering job without blocking.

QPainter::CompositionMode	currentLayerCompositionMode () const
	Returns the composition mode for the current layer about to be rendered in the next render operation.

QString	currentLayerId () const
	Returns the ID of the current layer about to be rendered in the next render operation.

double	currentLayerOpacity () const
	Returns the opacity for the current layer about to be rendered in the next render operation.

RenderStage	currentStage () const
	Returns the current stage which will be rendered in the next render operation.

bool	isActive () const override
	Tell whether the rendering job is currently running in background.

bool	isFinished () const
	Returns `true` if the job is finished, and nothing remains to render.

bool	nextPart ()
	Iterates to the next part to render.

bool	renderCurrentPart (QPainter *painter)
	Renders the current part of the map to the specified painter.

QgsLabelingResults *	takeLabelingResults () override
	Gets pointer to internal labeling engine (in order to get access to the results).

bool	usedCachedLabels () const override
	Returns `true` if the render job was able to use a cached labeling solution.

void	waitForFinished () override
	Block until the job has finished.

Public Member Functions inherited from QgsMapRendererAbstractCustomPainterJob
	QgsMapRendererAbstractCustomPainterJob (const QgsMapSettings &settings)
	Constructor for QgsMapRendererAbstractCustomPainterJob, using the given map settings.

Public Member Functions inherited from QgsMapRendererJob
	QgsMapRendererJob (const QgsMapSettings &settings)

	~QgsMapRendererJob () override

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

const QgsFeatureFilterProvider *	featureFilterProvider () const
	Returns the feature filter provider used by the QgsRenderContext of each LayerRenderJob.

QgsLabelingEngineFeedback *	labelingEngineFeedback ()
	Returns the associated labeling engine feedback object.

QgsLabelSink *	labelSink () const
	Returns the label sink associated to this rendering job.

QStringList	layersRedrawnFromCache () const
	Returns a list of the layer IDs for all layers which were redrawn from cached images.

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

QHash< QgsMapLayer *, int >	perLayerRenderingTime () const
	Returns the render time (in ms) per layer.

int	renderingTime () const
	Returns the total time it took to finish the job (in milliseconds).

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

void	setFeatureFilterProvider (const QgsFeatureFilterProvider *f)
	Set the feature filter provider used by the QgsRenderContext of each LayerRenderJob.

void	setLabelSink (QgsLabelSink *sink)
	Assigns the label sink which will take over responsibility for handling labels during the rendering job.

void	setLayerRenderingTimeHints (const QHash< QString, int > &hints)
	Sets approximate render times (in ms) for map layers.

void	start ()
	Start the rendering job and immediately return.

QgsRenderedItemResults *	takeRenderedItemResults ()
	Takes the rendered item results from the map render job and returns them.

Additional Inherited Members
Signals inherited from QgsMapRendererJob
void	finished ()
	emitted when asynchronous rendering is finished (or canceled).

void	layerRendered (const QString &layerId)
	Emitted when a layer has completed rendering.

void	layerRenderingStarted (const QString &layerId)
	Emitted just before rendering starts for a particular layer.

void	renderingLayersFinished ()
	Emitted when the layers are rendered.

Static Public Attributes inherited from QgsMapRendererJob
static const QString	ELEVATION_MAP_CACHE_PREFIX
	QgsMapRendererCache prefix string for cached elevation map image.

static const QString	LABEL_CACHE_ID
	QgsMapRendererCache ID string for cached label image.

static const QString	LABEL_PREVIEW_CACHE_ID
	QgsMapRendererCache ID string for cached label image during preview compositions only.

static const QgsSettingsEntryBool *	settingsLogCanvasRefreshEvent = new QgsSettingsEntryBool( QStringLiteral( "logCanvasRefreshEvent" ), QgsSettingsTree::sTreeMap, false )
	Settings entry log canvas refresh event.

static const QgsSettingsEntryString *	settingsMaskBackend = new QgsSettingsEntryString( QStringLiteral( "mask-backend" ), QgsSettingsTree::sTreeMap, QString(), QStringLiteral( "Backend engine to use for selective masking" ) )
	Settings entry for mask painting backend engine.

Protected Member Functions inherited from QgsMapRendererAbstractCustomPainterJob
void	preparePainter (QPainter *painter, const QColor &backgroundColor=Qt::transparent)
	Prepares the given painter ready for a map render.

Protected Member Functions inherited from QgsMapRendererJob
void	cleanupJobs (std::vector< LayerRenderJob > &jobs)

void	cleanupLabelJob (LabelRenderJob &job)
	Handles clean up tasks for a label job, including deletion of images and storing cached label results.

void	cleanupSecondPassJobs (std::vector< LayerRenderJob > &jobs)

void	initSecondPassJobs (std::vector< LayerRenderJob > &secondPassJobs, LabelRenderJob &labelJob) const
	Initialize secondPassJobs according to what have been rendered (mask clipping path e.g.) in first pass jobs and labelJob.

void	logRenderingTime (const std::vector< LayerRenderJob > &jobs, const std::vector< LayerRenderJob > &secondPassJobs, const LabelRenderJob &labelJob)

QList< QPointer< QgsMapLayer > >	participatingLabelLayers (QgsLabelingEngine *engine)
	Returns a list of the layers participating in the map labeling.

std::vector< LayerRenderJob >	prepareJobs (QPainter painter, QgsLabelingEngine labelingEngine2, bool deferredPainterSet=false)
	Creates a list of layer rendering jobs and prepares them for later render.

bool	prepareLabelCache () const
	Prepares the cache for storing the result of labeling.

LabelRenderJob	prepareLabelingJob (QPainter painter, QgsLabelingEngine labelingEngine2, bool canUseLabelCache=true)
	Prepares a labeling job.

std::vector< LayerRenderJob >	prepareSecondPassJobs (std::vector< LayerRenderJob > &firstPassJobs, LabelRenderJob &labelJob)
	Prepares jobs for a second pass, if selective masks exist (from labels or symbol layers).

Static Protected Member Functions inherited from QgsMapRendererJob
static QImage	composeImage (const QgsMapSettings &settings, const std::vector< LayerRenderJob > &jobs, const LabelRenderJob &labelJob, const QgsMapRendererCache *cache=nullptr)

static void	composeSecondPass (std::vector< LayerRenderJob > &secondPassJobs, LabelRenderJob &labelJob, bool forceVector=false)
	Compose second pass images into first pass images.

static Q_DECL_DEPRECATED void	drawLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext, QgsLabelingEngine labelingEngine2, QPainter painter)

static void	drawLabeling (QgsRenderContext &renderContext, QgsLabelingEngine labelingEngine2, QPainter painter)

static QgsElevationMap	layerElevationToBeComposed (const QgsMapSettings &settings, const LayerRenderJob &job, const QgsMapRendererCache *cache)

static QImage	layerImageToBeComposed (const QgsMapSettings &settings, const LayerRenderJob &job, const QgsMapRendererCache *cache)

Protected Attributes inherited from QgsMapRendererJob
QList< QPointer< QgsMapLayer > >	mAdditionalLabelLayers
	Additional layers participating in labeling problem.

QgsMapRendererCache *	mCache = nullptr

Errors	mErrors

QHash< QString, int >	mLayerRenderingTimeHints
	Approximate expected layer rendering time per layer, by layer ID.

QStringList	mLayersRedrawnFromCache

QHash< QgsWeakMapLayerPointer, int >	mPerLayerRenderingTime
	Render time (in ms) per layer, by layer ID.

bool	mRecordRenderingTime = true
	`true` if layer rendering time should be recorded.

std::unique_ptr< QgsRenderedItemResults >	mRenderedItemResults

QElapsedTimer	mRenderingStart

int	mRenderingTime = 0

QgsMapSettings	mSettings

Detailed Description

Render job implementation that renders maps in stages, allowing different stages (e.g.

individual map layers) to be rendered to different paint devices.

Since: QGIS 3.10

Definition at line 32 of file qgsmaprendererstagedrenderjob.h.

Member Typedef Documentation

◆ Flags

typedef QFlags< Flag > QgsMapRendererStagedRenderJob::Flags

Definition at line 44 of file qgsmaprendererstagedrenderjob.h.

Member Enumeration Documentation

◆ Flag

enum QgsMapRendererStagedRenderJob::Flag

Flags which control the staged render job behavior.

Enumerator
RenderLabelsByMapLayer	Labels should be rendered in individual stages by map layer. This allows separation of labels belonging to different layers, but may affect label stacking order as the order will become layer-dependent, instead of per-label-dependent.

Definition at line 40 of file qgsmaprendererstagedrenderjob.h.

◆ RenderStage

enum QgsMapRendererStagedRenderJob::RenderStage

Represents the stages of a rendering job.

Enumerator
Symbology	Rendering layer symbology.
Labels	Rendering labels.
Finished	Rendering is finished.

Definition at line 49 of file qgsmaprendererstagedrenderjob.h.

Constructor & Destructor Documentation

◆ QgsMapRendererStagedRenderJob()

QgsMapRendererStagedRenderJob::QgsMapRendererStagedRenderJob	(	const QgsMapSettings &	settings,
		Flags	flags = `Flags()`
	)

Constructor for QgsMapRendererStagedRenderJob, using the given map settings.

The optional flags argument can be used to control the staged render job behavior.

Definition at line 26 of file qgsmaprendererstagedrenderjob.cpp.

◆ ~QgsMapRendererStagedRenderJob()

QgsMapRendererStagedRenderJob::~QgsMapRendererStagedRenderJob ( )

override

Definition at line 32 of file qgsmaprendererstagedrenderjob.cpp.

Member Function Documentation

◆ cancel()

void QgsMapRendererStagedRenderJob::cancel ( )

overridevirtual

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

Does nothing if the rendering is not active.

Implements QgsMapRendererJob.

Definition at line 66 of file qgsmaprendererstagedrenderjob.cpp.

◆ cancelWithoutBlocking()

void QgsMapRendererStagedRenderJob::cancelWithoutBlocking ( )

overridevirtual

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.

Implements QgsMapRendererJob.

Definition at line 70 of file qgsmaprendererstagedrenderjob.cpp.