QGIS API Documentation 2.99.0-Master (8ec3eaf)
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 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 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 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...|
|Protected Member Functions inherited from QgsMapRendererJob|
|void||cleanupJobs (LayerRenderJobs &jobs)|
|void||logRenderingTime (const LayerRenderJobs &jobs)|
|bool||needTemporaryImage (QgsMapLayer *ml)|
|LayerRenderJobs||prepareJobs (QPainter *painter, QgsLabelingEngine *labelingEngine2)|
|called when rendering has finished to update all layers' geometry caches More...|
|static void||staticRender (QgsMapRendererCustomPainterJob *self)|
|Static Protected Member Functions inherited from QgsMapRendererJob|
|static QImage||composeImage (const QgsMapSettings &settings, const LayerRenderJobs &jobs)|
|static void||drawLabeling (const QgsMapSettings &settings, QgsRenderContext &renderContext, QgsLabelingEngine *labelingEngine2, QPainter *painter)|
|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...|
|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...|
|Protected Attributes inherited from QgsMapRendererJob|
|QMap< QString, QgsGeometryCache >||mGeometryCaches|
|map of geometry caches More...|
|list of layer IDs for which the geometry cache should be updated More...|
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,|
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::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.