QGIS API Documentation 2.99.0-Master (bdf46d7)
Job implementation that renders everything sequentially using a custom painter. More...
|QgsMapRendererCustomPainterJob (const QgsMapSettings &settings, QPainter *painter)|
|virtual void||cancel () override|
|Stop the rendering job - does not return until the job has terminated. More...|
|virtual void||cancelWithoutBlocking () override|
|Triggers cancelation of the rendering job without blocking. More...|
|virtual bool||isActive () const override|
|Tell whether the rendering job is currently running in background. More...|
|const LayerRenderJobs &||jobs () const|
|Render the map synchronously in this thread. More...|
|virtual void||start () override|
|Start the rendering job and immediately return. More...|
|virtual QgsLabelingResults *||takeLabelingResults () override|
|Get pointer to internal labeling engine (in order to get access to the results). More...|
|virtual bool||usedCachedLabels () const override|
|Returns true if the render job was able to use a cached labeling solution. More...|
|virtual void||waitForFinished () override|
|Block until the job has finished. More...|
|void||waitForFinishedWithEventLoop (QEventLoop::ProcessEventsFlags flags=QEventLoop::AllEvents)|
|Wait for the job to be finished - and keep the thread's event loop running while waiting. More...|
|Public Member Functions inherited from QgsMapRendererJob|
|QgsMapRendererJob (const QgsMapSettings &settings)|
|Errors||errors () const|
|List of errors that happened during the rendering job - available when the rendering has been finished. More...|
|const QgsFeatureFilterProvider *||featureFilterProvider () const|
|const QgsMapSettings &||mapSettings () const|
|Return map settings with which this job was started. More...|
|int||renderingTime () const|
|Find out how long it took to finish the job (in milliseconds) More...|
|void||setCache (QgsMapRendererCache *cache)|
|Assign a cache to be used for reading and storing rendered images of individual layers. More...|
|void||setFeatureFilterProvider (const QgsFeatureFilterProvider *f)|
|void||setRequestedGeometryCacheForLayers (const QStringList &layerIds)|
|Set which vector layers should be cached while rendering. More...|
|Public Types inherited from QgsMapRendererJob|
|typedef QList< Error >||Errors|
|Signals inherited from QgsMapRendererJob|
|emitted when asynchronous rendering is finished (or canceled). More...|
|Emitted when the layers are rendered. More...|
|Static Public Attributes inherited from QgsMapRendererJob|
|static const QString||LABEL_CACHE_ID|
|QgsMapRendererCache ID string for cached label image. More...|
|Protected Member Functions inherited from QgsMapRendererJob|
|void||cleanupJobs (LayerRenderJobs &jobs)|
|void||cleanupLabelJob (LabelRenderJob &job)|
|Handles clean up tasks for a label job, including deletion of images and storing cached label results. More...|
|void||logRenderingTime (const LayerRenderJobs &jobs, const LabelRenderJob &labelJob)|
|LayerRenderJobs||prepareJobs (QPainter *painter, QgsLabelingEngine *labelingEngine2)|
|bool||prepareLabelCache () const|
|Prepares the cache for storing the result of labeling. More...|
|LabelRenderJob||prepareLabelingJob (QPainter *painter, QgsLabelingEngine *labelingEngine2, bool canUseLabelCache=true)|
|Prepares a labeling job. More...|
|Static Protected Member Functions inherited from QgsMapRendererJob|
|static QImage||composeImage (const QgsMapSettings &settings, const LayerRenderJobs &jobs, const LabelRenderJob &labelJob)|
|static void||drawLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext, QgsLabelingEngine *labelingEngine2, QPainter *painter)|
|Protected Attributes inherited from QgsMapRendererJob|
|QgsMapRendererCache *||mCache = nullptr|
|int||mRenderingTime = 0|
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).
|QgsMapRendererCustomPainterJob::QgsMapRendererCustomPainterJob||(||const QgsMapSettings &||settings,|
Triggers cancelation 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.
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.
Returns true if the render job was able to use a cached labeling solution.
If so, any previously stored labeling results (see takeLabelingResults()) should be retained.
|void QgsMapRendererCustomPainterJob::waitForFinishedWithEventLoop||(||QEventLoop::ProcessEventsFlags||flags = ||)|
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.