[feature][api] Allow a custom label sink to be used with map renderer…

… jobs
qgis · Dec 28, 2021 · 4dbcd38 · 4dbcd38
1 parent 5831c43
commit 4dbcd38
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Showing 10 changed files with 131 additions and 10 deletions.
diff --git a/python/core/auto_generated/maprenderer/qgsmaprendererjob.sip.in b/python/core/auto_generated/maprenderer/qgsmaprendererjob.sip.in
@@ -12,7 +12,6 @@
 
 
 
-
 class QgsMapRendererJob : QObject /Abstract/
 {
 %Docstring(signature="appended")
@@ -158,6 +157,8 @@ Assign a cache to be used for reading and storing rendered images of individual
 Does not take ownership of the object.
 %End
 
+
+
     int renderingTime() const;
 %Docstring
 Returns the total time it took to finish the job (in milliseconds).

diff --git a/python/core/auto_generated/qgsrendercontext.sip.in b/python/core/auto_generated/qgsrendercontext.sip.in
@@ -352,6 +352,7 @@ exactly 2mm thick when a map is rendered at 1:1000, or 1mm thick when rendered a
 %End
 
 
+
     QColor selectionColor() const;
 %Docstring
 Returns the color to use when rendering selected features.
@@ -539,6 +540,7 @@ of any faster raster shortcuts.
 %End
 
 
+
     void setSelectionColor( const QColor &color );
 %Docstring
 Sets the ``color`` to use when rendering selected features.

diff --git a/src/analysis/processing/qgsalgorithmvectorize.cpp b/src/analysis/processing/qgsalgorithmvectorize.cpp
@@ -113,7 +113,7 @@ QVariantMap QgsVectorizeAlgorithmBase::processAlgorithm( const QVariantMap &para
       for ( int column = 0; column < iterCols; column++ )
       {
         const double value = rasterBlock->valueAndNoData( row, column, isNoData );
-        if ( !isNoData )
+        if ( !isNoData && !qgsDoubleNear( value, 0.0 ) )
         {
           const QgsGeometry pixelRectGeometry = createGeometryForPixel( currentX, currentY, mRasterUnitsPerPixelX, mRasterUnitsPerPixelY );
 

diff --git a/src/core/maprenderer/qgsmaprendererjob.cpp b/src/core/maprenderer/qgsmaprendererjob.cpp
@@ -495,6 +495,7 @@ std::vector<LayerRenderJob> QgsMapRendererJob::prepareJobs( QPainter *painter, Q
     job.context()->expressionContext().appendScope( QgsExpressionContextUtils::layerScope( ml ) );
     job.context()->setPainter( painter );
     job.context()->setLabelingEngine( labelingEngine2 );
+    job.context()->setLabelSink( labelSink() );
     job.context()->setCoordinateTransform( ct );
     job.context()->setExtent( r1 );
     if ( !haveExtentInLayerCrs )

diff --git a/src/core/maprenderer/qgsmaprendererjob.h b/src/core/maprenderer/qgsmaprendererjob.h
@@ -26,7 +26,7 @@
 #include <QElapsedTimer>
 
 #include "qgsrendercontext.h"
-
+#include "qgslabelsink.h"
 #include "qgsmapsettings.h"
 #include "qgsmaskidprovider.h"
 #include "qgssettingsentry.h"
@@ -352,6 +352,22 @@ class CORE_EXPORT QgsMapRendererJob : public QObject SIP_ABSTRACT
      */
     void setCache( QgsMapRendererCache *cache );
 
+    /**
+     * Returns the label sink associated to this rendering job.
+     * \note not available in Python bindings
+     * \since QGIS 3.24
+     */
+    QgsLabelSink *labelSink() const { return mLabelSink; } SIP_SKIP
+
+    /**
+     * Assigns the label sink which will take over responsability for handling labels
+     * during the rendering job.
+     * \note the ownership is not transferred
+     * \note not available in Python bindings
+     * \since QGIS 3.24
+     */
+    void setLabelSink( QgsLabelSink *sink ) { mLabelSink = sink; } SIP_SKIP
+
     /**
      * Returns the total time it took to finish the job (in milliseconds).
      * \see perLayerRenderingTime()
@@ -559,6 +575,8 @@ class CORE_EXPORT QgsMapRendererJob : public QObject SIP_ABSTRACT
      */
     virtual void startPrivate() = 0;
 
+    QgsLabelSink *mLabelSink = nullptr;
+
 };
 
 

diff --git a/src/core/maprenderer/qgsmaprenderersequentialjob.cpp b/src/core/maprenderer/qgsmaprenderersequentialjob.cpp
@@ -66,6 +66,7 @@ void QgsMapRendererSequentialJob::startPrivate()
   mPainter = new QPainter( &mImage );
 
   mInternalJob = new QgsMapRendererCustomPainterJob( mSettings, mPainter );
+  mInternalJob->setLabelSink( labelSink() );
   mInternalJob->setCache( mCache );
 
   connect( mInternalJob, &QgsMapRendererJob::finished, this, &QgsMapRendererSequentialJob::internalFinished );

diff --git a/src/core/qgsrendercontext.h b/src/core/qgsrendercontext.h
@@ -27,6 +27,7 @@
 #include "qgscoordinatetransform.h"
 #include "qgsexpressioncontext.h"
 #include "qgsfeaturefilterprovider.h"
+#include "qgslabelsink.h"
 #include "qgsmaptopixel.h"
 #include "qgsmapunitscale.h"
 #include "qgsrectangle.h"
@@ -365,6 +366,12 @@ class CORE_EXPORT QgsRenderContext : public QgsTemporalRangeObject
      */
     QgsLabelingEngine *labelingEngine() const { return mLabelingEngine; } SIP_SKIP
 
+    /**
+     * Returns the associated label sink, or NULLPTR if not set.
+     * \since QGIS 3.24
+     */
+    QgsLabelSink *labelSink() const { return mLabelSink; } SIP_SKIP
+
     /**
      * Returns the color to use when rendering selected features.
      *
@@ -531,11 +538,18 @@ class CORE_EXPORT QgsRenderContext : public QgsTemporalRangeObject
     void setForceVectorOutput( bool force );
 
     /**
-     * Assign new labeling engine
+     * Assigns the labeling engine
      * \note not available in Python bindings
      */
     void setLabelingEngine( QgsLabelingEngine *engine ) { mLabelingEngine = engine; } SIP_SKIP
 
+    /**
+     * Assigns the label sink which will take over responsability for handling labels.
+     * \note the ownership is not transferred
+     * \since QGIS 3.24
+     */
+    void setLabelSink( QgsLabelSink *sink ) { mLabelSink = sink; } SIP_SKIP
+
     /**
      * Sets the \a color to use when rendering selected features.
      *
@@ -1024,9 +1038,12 @@ class CORE_EXPORT QgsRenderContext : public QgsTemporalRangeObject
 
     double mSymbologyReferenceScale = -1;
 
-    //! Newer labeling engine implementation (can be NULLPTR)
+    //! Labeling engine implementation (can be NULLPTR)
     QgsLabelingEngine *mLabelingEngine = nullptr;
 
+    //! Label sink (can be NULLPTR)
+    QgsLabelSink *mLabelSink = nullptr;
+
     //! Color used for features that are marked as selected
     QColor mSelectionColor;
 

diff --git a/src/core/vector/qgsvectorlayerrenderer.cpp b/src/core/vector/qgsvectorlayerrenderer.cpp
@@ -34,6 +34,7 @@
 #include "qgspainteffect.h"
 #include "qgsfeaturefilterprovider.h"
 #include "qgsexception.h"
+#include "qgslabelsink.h"
 #include "qgslogger.h"
 #include "qgssettingsregistrycore.h"
 #include "qgsexpressioncontextutils.h"
@@ -713,14 +714,35 @@ void QgsVectorLayerRenderer::prepareLabeling( QgsVectorLayer *layer, QSet<QStrin
   {
     if ( layer->labelsEnabled() )
     {
-      mLabelProvider = layer->labeling()->provider( layer );
-      if ( mLabelProvider )
+      if ( context.labelSink() )
       {
+        if ( const QgsRuleBasedLabeling *rbl = dynamic_cast<const QgsRuleBasedLabeling *>( layer->labeling() ) )
+        {
+          mLabelProvider = new QgsRuleBasedLabelSinkProvider( *rbl, layer, context.labelSink() );
+        }
+        else
+        {
+          QgsPalLayerSettings settings = layer->labeling()->settings();
+          mLabelProvider = new QgsLabelSinkProvider( layer, QString(), context.labelSink(), &settings );
+        }
         engine2->addProvider( mLabelProvider );
         if ( !mLabelProvider->prepare( context, attributeNames ) )
         {
           engine2->removeProvider( mLabelProvider );
-          mLabelProvider = nullptr; // deleted by engine
+          mLabelProvider = nullptr;
+        }
+      }
+      else
+      {
+        mLabelProvider = layer->labeling()->provider( layer );
+        if ( mLabelProvider )
+        {
+          engine2->addProvider( mLabelProvider );
+          if ( !mLabelProvider->prepare( context, attributeNames ) )
+          {
+            engine2->removeProvider( mLabelProvider );
+            mLabelProvider = nullptr; // deleted by engine
+          }
         }
       }
     }

diff --git a/tests/src/core/testqgsmaprendererjob.cpp b/tests/src/core/testqgsmaprendererjob.cpp
@@ -1,5 +1,5 @@
 /***************************************************************************
-     testqgsvectorfilewriter.cpp
+     testqgsmaprendererjob.cpp
      --------------------------------------
     Date                 : Sun Sep 16 12:22:54 AKDT 2007
     Copyright            : (C) 2007 by Tim Sutton
@@ -12,6 +12,7 @@
  *   (at your option) any later version.                                   *
  *                                                                         *
  ***************************************************************************/
+
 #include "qgstest.h"
 #include <QObject>
 #include <QString>
@@ -45,6 +46,7 @@
 #include "qgssinglesymbolrenderer.h"
 #include "qgsrasterlayertemporalproperties.h"
 #include "qgslinesymbol.h"
+#include "qgslabelsink.h"
 
 //qgs unit test utility class
 #include "qgsmultirenderchecker.h"
@@ -91,6 +93,8 @@ class TestQgsMapRendererJob : public QObject
 
     void temporalRender();
 
+    void labelSink();
+
   private:
     bool imageCheck( const QString &type, const QImage &image, int mismatchCount = 0 );
 
@@ -487,7 +491,6 @@ void TestQgsMapRendererJob::testRenderedFeatureHandlers()
   QCOMPARE( attributes.at( 2 ), QStringLiteral( "Highway,1" ) );
   QCOMPARE( attributes.at( 3 ), QStringLiteral( "Highway,1" ) );
   QCOMPARE( attributes.at( 4 ), QStringLiteral( "Jet,95,3,1,1,2" ) );
-
 }
 
 void TestQgsMapRendererJob::stagedRenderer()
@@ -947,6 +950,62 @@ void TestQgsMapRendererJob::temporalRender()
 
 }
 
+class TestLabelSink : public QgsLabelSink
+{
+  public:
+    TestLabelSink() {};
+
+    void drawLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings ) override
+    {
+      Q_UNUSED( layerId )
+      Q_UNUSED( context )
+      Q_UNUSED( label )
+      Q_UNUSED( settings )
+      drawnCount++;
+    };
+
+    int drawnCount = 0;
+};
+
+void TestQgsMapRendererJob::labelSink()
+{
+  std::unique_ptr< QgsVectorLayer > pointsLayer = std::make_unique< QgsVectorLayer >( TEST_DATA_DIR + QStringLiteral( "/points.shp" ),
+      QStringLiteral( "points" ), QStringLiteral( "ogr" ) );
+  QVERIFY( pointsLayer->isValid() );
+
+  QgsPalLayerSettings settings;
+  settings.fieldName = QStringLiteral( "Class" );
+  QgsTextFormat format;
+  format.setFont( QgsFontUtils::getStandardTestFont( QStringLiteral( "Bold" ) ).family() );
+  format.setSize( 12 );
+  format.setNamedStyle( QStringLiteral( "Bold" ) );
+  format.setColor( QColor( 200, 0, 200 ) );
+  settings.setFormat( format );
+  settings.zIndex = 1;
+
+  pointsLayer->setLabeling( new QgsVectorLayerSimpleLabeling( settings ) );
+  pointsLayer->setLabelsEnabled( true );
+
+  QgsMapSettings mapSettings;
+  mapSettings.setDestinationCrs( pointsLayer->crs() );
+  mapSettings.setExtent( pointsLayer->extent() );
+  mapSettings.setOutputSize( QSize( 512, 512 ) );
+  mapSettings.setFlag( Qgis::MapSettingsFlag::DrawLabeling, true );
+  mapSettings.setOutputDpi( 96 );
+  mapSettings.setLayers( QList< QgsMapLayer * >() << pointsLayer.get() );
+
+
+  QgsMapRendererSequentialJob renderJob( mapSettings );
+
+  std::unique_ptr<TestLabelSink> labelSink = std::make_unique<TestLabelSink>();
+  renderJob.setLabelSink( labelSink.get() );
+  renderJob.start();
+  renderJob.waitForFinished();
+  QImage img = renderJob.renderedImage();
+  QVERIFY( imageCheck( QStringLiteral( "label_sink" ), img ) );
+  QCOMPARE( labelSink->drawnCount, 17 );
+}
+
 bool TestQgsMapRendererJob::imageCheck( const QString &testName, const QImage &image, int mismatchCount )
 {
   mReport += "<h2>" + testName + "</h2>\n";

diff --git a/...estdata/control_images/map_renderer/expected_label_sink/expected_label_sink.png b/...estdata/control_images/map_renderer/expected_label_sink/expected_label_sink.png