QGIS API Documentation 3.41.0-Master (d5b93354e9c)
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Public Member Functions | List of all members
QgsMapRendererQImageJob Class Referenceabstract

Intermediate base class adding functionality that allows client to query the rendered image. More...

#include <qgsmaprendererjob.h>

Inheritance diagram for QgsMapRendererQImageJob:
Inheritance graph
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Public Member Functions

 QgsMapRendererQImageJob (const QgsMapSettings &settings)
 
virtual QImage renderedImage ()=0
 Gets a preview/resulting image.
 
- Public Member Functions inherited from QgsMapRendererJob
 QgsMapRendererJob (const QgsMapSettings &settings)
 
 ~QgsMapRendererJob () override
 
virtual void cancel ()=0
 Stop the rendering job - does not return until the job has terminated.
 
virtual void cancelWithoutBlocking ()=0
 Triggers cancellation of the rendering job without blocking.
 
Errors errors () const
 List of errors that happened during the rendering job - available when the rendering has been finished.
 
const QgsFeatureFilterProviderfeatureFilterProvider () const
 Returns the feature filter provider used by the QgsRenderContext of each LayerRenderJob.
 
virtual bool isActive () const =0
 Tell whether the rendering job is currently running in background.
 
QgsLabelingEngineFeedbacklabelingEngineFeedback ()
 Returns the associated labeling engine feedback object.
 
QgsLabelSinklabelSink () 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 QgsMapSettingsmapSettings () 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.
 
virtual QgsLabelingResultstakeLabelingResults ()=0
 Gets pointer to internal labeling engine (in order to get access to the results).
 
QgsRenderedItemResultstakeRenderedItemResults ()
 Takes the rendered item results from the map render job and returns them.
 
virtual bool usedCachedLabels () const =0
 Returns true if the render job was able to use a cached labeling solution.
 
virtual void waitForFinished ()=0
 Block until the job has finished.
 

Additional Inherited Members

- Public Types inherited from QgsMapRendererJob
typedef QList< QgsMapRendererJob::ErrorErrors
 
- 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 QgsSettingsEntryBoolsettingsLogCanvasRefreshEvent = new QgsSettingsEntryBool( QStringLiteral( "logCanvasRefreshEvent" ), QgsSettingsTree::sTreeMap, false )
 Settings entry log canvas refresh event.
 
static const QgsSettingsEntryStringsettingsMaskBackend = 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 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.
 
QgsMapRendererCachemCache = 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< QgsRenderedItemResultsmRenderedItemResults
 
QElapsedTimer mRenderingStart
 
int mRenderingTime = 0
 
QgsMapSettings mSettings
 

Detailed Description

Intermediate base class adding functionality that allows client to query the rendered image.

The image can be queried even while the rendering is still in progress to get intermediate result

Definition at line 705 of file qgsmaprendererjob.h.

Constructor & Destructor Documentation

◆ QgsMapRendererQImageJob()

QgsMapRendererQImageJob::QgsMapRendererQImageJob ( const QgsMapSettings settings)

Member Function Documentation

◆ renderedImage()

virtual QImage QgsMapRendererQImageJob::renderedImage ( )
pure virtual

Gets a preview/resulting image.

Implemented in QgsMapRendererParallelJob, and QgsMapRendererSequentialJob.


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