QGIS API Documentation 3.41.0-Master (25ec5511245)
|
Job implementation that renders everything sequentially using a custom painter. More...
#include <qgsmaprenderercustompainterjob.h>
Public Member Functions | |
QgsMapRendererCustomPainterJob (const QgsMapSettings &settings, QPainter *painter) | |
~QgsMapRendererCustomPainterJob () 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. | |
bool | isActive () const override |
Tell whether the rendering job is currently running in background. | |
const std::vector< LayerRenderJob > & | jobs () const |
void | prepare () |
Prepares the job for rendering synchronously in a background thread. | |
void | renderPrepared () |
Render a pre-prepared job. | |
void | renderSynchronously () |
Render the map synchronously in this thread. | |
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. | |
void | waitForFinishedWithEventLoop (QEventLoop::ProcessEventsFlags flags=QEventLoop::AllEvents) |
Wait for the job to be finished - and keep the thread's event loop running while waiting. | |
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 | |
Public Types inherited from QgsMapRendererJob | |
typedef QList< QgsMapRendererJob::Error > | Errors |
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 |
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).
Definition at line 62 of file qgsmaprenderercustompainterjob.h.
QgsMapRendererCustomPainterJob::QgsMapRendererCustomPainterJob | ( | const QgsMapSettings & | settings, |
QPainter * | painter | ||
) |
Definition at line 63 of file qgsmaprenderercustompainterjob.cpp.
|
override |
Definition at line 72 of file qgsmaprenderercustompainterjob.cpp.
|
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 132 of file qgsmaprenderercustompainterjob.cpp.
|
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 156 of file qgsmaprenderercustompainterjob.cpp.
|
overridevirtual |
Tell whether the rendering job is currently running in background.
Implements QgsMapRendererJob.
Definition at line 190 of file qgsmaprenderercustompainterjob.cpp.
|
inline |
Definition at line 77 of file qgsmaprenderercustompainterjob.h.
void QgsMapRendererCustomPainterJob::prepare | ( | ) |
Prepares the job for rendering synchronously in a background thread.
Must be called from the main thread.
This is an alternative to ordinary API (using start() + waiting for finished() signal), and an alternative to renderSynchronously() (which should only ever be called from the main thread).
Definition at line 225 of file qgsmaprenderercustompainterjob.cpp.
void QgsMapRendererCustomPainterJob::renderPrepared | ( | ) |
Render a pre-prepared job.
Can be safely called in a background thread.
Must be preceded by a call to prepare()
This is an alternative to ordinary API (using start() + waiting for finished() signal), and an alternative to renderSynchronously() (which should only ever be called from the main thread).
Definition at line 233 of file qgsmaprenderercustompainterjob.cpp.
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.
Definition at line 217 of file qgsmaprenderercustompainterjob.cpp.
|
overridevirtual |
Gets pointer to internal labeling engine (in order to get access to the results).
This should not be used if cached labeling was redrawn - see usedCachedLabels().
Implements QgsMapRendererJob.
Definition at line 200 of file qgsmaprenderercustompainterjob.cpp.
|
overridevirtual |
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.
Implements QgsMapRendererJob.
Definition at line 195 of file qgsmaprenderercustompainterjob.cpp.
|
overridevirtual |
Block until the job has finished.
Implements QgsMapRendererJob.
Definition at line 173 of file qgsmaprenderercustompainterjob.cpp.
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.
Definition at line 209 of file qgsmaprenderercustompainterjob.cpp.