Merge pull request #46657 from nirvn/label_alg

[feature][processing] A brand new Extract labels algorithm
qgis · Jan 6, 2022 · 3c001de · 3c001de
2 parents 34458c4 + e2bb0bb
commit 3c001de
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Showing 9 changed files with 616 additions and 1 deletion.
diff --git a/src/analysis/CMakeLists.txt b/src/analysis/CMakeLists.txt
@@ -90,6 +90,7 @@ set(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmextractbyexpression.cpp
   processing/qgsalgorithmextractbyextent.cpp
   processing/qgsalgorithmextractbylocation.cpp
+  processing/qgsalgorithmextractlabels.cpp
   processing/qgsalgorithmextractlayoutmapextent.cpp
   processing/qgsalgorithmextractzmvalues.cpp
   processing/qgsalgorithmextractvertices.cpp

diff --git a/src/analysis/processing/qgsalgorithmextractlabels.cpp b/src/analysis/processing/qgsalgorithmextractlabels.cpp
diff --git a/src/analysis/processing/qgsalgorithmextractlabels.h b/src/analysis/processing/qgsalgorithmextractlabels.h
@@ -0,0 +1,62 @@
+/***************************************************************************
+  qgsalgorithmextractlabels.h - QgsExtractLabelsAlgorithm
+ ---------------------
+ begin                : 30.12.2021
+ copyright            : (C) 2021 by Mathieu Pellerin
+ email                : nirvn dot asia at gmail dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSALGORITHMEXTRACTLABELS_H
+#define QGSALGORITHMEXTRACTLABELS_H
+
+#define SIP_NO_FILE
+
+#include "qgis_sip.h"
+#include "qgsprocessingalgorithm.h"
+#include "qgslabelingenginesettings.h"
+
+///@cond PRIVATE
+
+class QgsExtractLabelsAlgorithm : public QgsProcessingAlgorithm
+{
+  public:
+    QgsExtractLabelsAlgorithm() = default;
+
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    Flags flags() const override;
+    QString group() const override;
+    QString groupId() const override;
+    QString shortHelpString() const override;
+    QString shortDescription() const override;
+    QgsExtractLabelsAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+
+    bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+
+  private:
+
+    QList<QgsMapLayer *> mMapLayers;
+    QMap<QString, QString> mMapLayerNames;
+    QMap<QString, QString> mMapThemeStyleOverrides;
+    QgsLabelingEngineSettings mLabelSettings;
+    QgsCoordinateReferenceSystem mCrs;
+
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMEXTRACTLABELS_H
diff --git a/src/analysis/processing/qgsnativealgorithms.cpp b/src/analysis/processing/qgsnativealgorithms.cpp
@@ -73,6 +73,7 @@
 #include "qgsalgorithmextractbyexpression.h"
 #include "qgsalgorithmextractbyextent.h"
 #include "qgsalgorithmextractbylocation.h"
+#include "qgsalgorithmextractlabels.h"
 #include "qgsalgorithmextractlayoutmapextent.h"
 #include "qgsalgorithmextractvertices.h"
 #include "qgsalgorithmextractspecificvertices.h"
@@ -321,6 +322,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsExtractByExpressionAlgorithm() );
   addAlgorithm( new QgsExtractByExtentAlgorithm() );
   addAlgorithm( new QgsExtractByLocationAlgorithm() );
+  addAlgorithm( new QgsExtractLabelsAlgorithm() );
   addAlgorithm( new QgsExtractMValuesAlgorithm() );
   addAlgorithm( new QgsExtractVerticesAlgorithm() );
   addAlgorithm( new QgsExtractSpecificVerticesAlgorithm() );

diff --git a/src/core/labeling/qgslabelsink.cpp b/src/core/labeling/qgslabelsink.cpp
@@ -32,6 +32,12 @@ void QgsLabelSinkProvider::drawLabel( QgsRenderContext &context, pal::LabelPosit
   mLabelSink->drawLabel( layerId(), context, label, mSettings );
 }
 
+void QgsLabelSinkProvider::drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const
+{
+  Q_ASSERT( mLabelSink );
+  mLabelSink->drawUnplacedLabel( layerId(), context, label, mSettings );
+}
+
 QgsRuleBasedLabelSinkProvider::QgsRuleBasedLabelSinkProvider( const QgsRuleBasedLabeling &rules, QgsVectorLayer *layer, QgsLabelSink *sink )
   : QgsRuleBasedLabelProvider( rules, layer, false )
   , mLabelSink( sink )
@@ -55,3 +61,9 @@ void QgsRuleBasedLabelSinkProvider::drawLabel( QgsRenderContext &context, pal::L
   Q_ASSERT( mLabelSink );
   mLabelSink->drawLabel( layerId(), context, label, mSettings );
 }
+
+void QgsRuleBasedLabelSinkProvider::drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const
+{
+  Q_ASSERT( mLabelSink );
+  mLabelSink->drawUnplacedLabel( layerId(), context, label, mSettings );
+}
diff --git a/src/core/labeling/qgslabelsink.h b/src/core/labeling/qgslabelsink.h
@@ -45,6 +45,23 @@ class QgsLabelSink
      * to another desired location.
      */
     virtual void drawLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings ) = 0;
+
+    /**
+     * The drawLabel method is called for each unplaced label.
+     * \param layerId The layer ID associated to the label
+     * \param context The render context object
+     * \param label The label object
+     * \param settings The layer labeling settings
+     * \since QGIS 3.24
+     */
+    virtual void drawUnplacedLabel( const QString &layerId, QgsRenderContext &context, pal::LabelPosition *label, const QgsPalLayerSettings &settings )
+    {
+      Q_UNUSED( layerId );
+      Q_UNUSED( context )
+      Q_UNUSED( label );
+      Q_UNUSED( settings );
+      return;
+    }
 };
 
 /**
@@ -61,6 +78,7 @@ class QgsLabelSinkProvider : public QgsVectorLayerLabelProvider
     explicit QgsLabelSinkProvider( QgsVectorLayer *layer, const QString &providerId, QgsLabelSink *sink, const QgsPalLayerSettings *settings );
 
     void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
+    void drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
 
   private:
     QgsLabelSink *mLabelSink = nullptr;
@@ -86,6 +104,7 @@ class QgsRuleBasedLabelSinkProvider : public QgsRuleBasedLabelProvider
     Q_DECL_DEPRECATED void reinit( QgsVectorLayer *layer );
 
     void drawLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
+    void drawUnplacedLabel( QgsRenderContext &context, pal::LabelPosition *label ) const override;
 
     //! Creates a  QgsRuleBasedLabelSinkProvider
     QgsVectorLayerLabelProvider *createProvider( QgsVectorLayer *layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings *settings ) override;

diff --git a/src/core/labeling/qgstextlabelfeature.h b/src/core/labeling/qgstextlabelfeature.h
@@ -30,7 +30,7 @@ class QgsTextCharacterFormat;
  *
  * \note not part of public API
  */
-class QgsTextLabelFeature : public QgsLabelFeature
+class CORE_EXPORT QgsTextLabelFeature : public QgsLabelFeature
 {
   public:
     //! Construct text label feature

diff --git a/src/core/maprenderer/qgsmaprenderercustompainterjob.cpp b/src/core/maprenderer/qgsmaprenderercustompainterjob.cpp
@@ -331,6 +331,7 @@ void QgsMapRendererCustomPainterJob::doRender()
     emit layerRendered( job.layerId );
   }
 
+  emit renderingLayersFinished();
   QgsDebugMsgLevel( QStringLiteral( "Done rendering map layers" ), 5 );
 
   if ( mSettings.testFlag( Qgis::MapSettingsFlag::DrawLabeling ) && !mLabelJob.context.renderingStopped() )

diff --git a/tests/src/analysis/testqgsprocessingalgs.cpp b/tests/src/analysis/testqgsprocessingalgs.cpp
@@ -64,6 +64,7 @@
 #include "qgsannotationlayer.h"
 #include "qgsannotationmarkeritem.h"
 #include "qgscolorrampimpl.h"
+#include "qgstextformat.h"
 
 class TestQgsProcessingAlgs: public QObject
 {
@@ -198,6 +199,8 @@ class TestQgsProcessingAlgs: public QObject
     void uploadGpsData();
     void transferMainAnnotationLayer();
 
+    void extractLabels();
+
   private:
 
     bool imageCheck( const QString &testName, const QString &renderedImage );
@@ -7173,6 +7176,62 @@ void TestQgsProcessingAlgs::exportMeshTimeSeries()
   outputFile.close();
 }
 
+void TestQgsProcessingAlgs::extractLabels()
+{
+  QgsProject project;
+  QgsVectorLayer *pointsLayer = new QgsVectorLayer( mPointLayerPath,
+      QStringLiteral( "points" ), QStringLiteral( "ogr" ) );
+  QVERIFY( mPointsLayer->isValid() );
+  project.addMapLayer( pointsLayer );
+
+  QgsTextFormat format = QgsTextFormat::fromQFont( QgsFontUtils::getStandardTestFont() );
+  format.setSize( 10 );
+  QgsPalLayerSettings settings;
+  settings.fieldName = QStringLiteral( "Class" );
+  settings.setFormat( format );
+  pointsLayer->setLabeling( new QgsVectorLayerSimpleLabeling( settings ) );
+
+  std::unique_ptr< QgsProcessingAlgorithm > alg( QgsApplication::processingRegistry()->createAlgorithmById( QStringLiteral( "native:extractlabels" ) ) );
+  QVERIFY( alg != nullptr );
+
+  QgsReferencedRectangle extent( QgsRectangle( -120, 20, -80, 50 ), QgsCoordinateReferenceSystem( QStringLiteral( "EPSG:4326" ) ) );
+
+  QVariantMap parameters;
+  parameters.insert( QStringLiteral( "EXTENT" ), extent );
+  parameters.insert( QStringLiteral( "SCALE" ), 9000000.00 );
+  parameters.insert( QStringLiteral( "DPI" ), 96.00 );
+  parameters.insert( QStringLiteral( "OUTPUT" ), QgsProcessing::TEMPORARY_OUTPUT );
+
+  bool ok = false;
+  std::unique_ptr< QgsProcessingContext > context = std::make_unique< QgsProcessingContext >();
+  context->setProject( &project );
+  QgsProcessingFeedback feedback;
+
+  QVariantMap results;
+  results = alg->run( parameters, *context, &feedback, &ok );
+  QVERIFY( ok );
+
+  QgsVectorLayer *resultLayer = qobject_cast< QgsVectorLayer * >( context->getMapLayer( results.value( QStringLiteral( "OUTPUT" ) ).toString() ) );
+  QVERIFY( resultLayer );
+  QCOMPARE( resultLayer->wkbType(), QgsWkbTypes::Point );
+  QCOMPARE( resultLayer->featureCount(), 17 );
+
+  QgsFeature feature = resultLayer->getFeature( 1 );
+  QVariantMap attributes = feature.attributeMap();
+  QCOMPARE( attributes[QStringLiteral( "Layer" )], QStringLiteral( "points" ) );
+  QCOMPARE( attributes[QStringLiteral( "FeatureID" )], 1 );
+  QCOMPARE( attributes[QStringLiteral( "LabelText" )], QStringLiteral( "Biplane" ) );
+  QCOMPARE( attributes[QStringLiteral( "LabelRotation" )], 0.0 );
+  QCOMPARE( attributes[QStringLiteral( "Family" )], QStringLiteral( "QGIS Vera Sans" ) );
+  QCOMPARE( attributes[QStringLiteral( "Size" )], 9.75 );
+  QCOMPARE( attributes[QStringLiteral( "Italic" )], false );
+  QCOMPARE( attributes[QStringLiteral( "Bold" )], false );
+  QCOMPARE( attributes[QStringLiteral( "FontStyle" )], QStringLiteral( "Roman" ) );
+  QCOMPARE( attributes[QStringLiteral( "FontLetterSpacing" )], 0.0 );
+  QCOMPARE( attributes[QStringLiteral( "FontWordSpacing" )], 0.0 );
+  QCOMPARE( attributes[QStringLiteral( "MultiLineAlignment" )], QStringLiteral( "left" ) );
+  QCOMPARE( attributes[QStringLiteral( "MultiLineHeight" )], 1.0 );
+}
 
 bool TestQgsProcessingAlgs::imageCheck( const QString &testName, const QString &renderedImage )
 {