Support early abortion of vector layer feature counter

Refs #43572
qgis · Jun 18, 2021 · b16465b · b16465b
1 parent e7433f4
commit b16465b
Show file tree

Hide file tree

Showing 3 changed files with 29 additions and 7 deletions.
diff --git a/python/core/auto_generated/vector/qgsvectorlayerfeaturecounter.sip.in b/python/core/auto_generated/vector/qgsvectorlayerfeaturecounter.sip.in
@@ -32,14 +32,17 @@ Create a new feature counter for ``layer``.
 :param context: Specific :py:class:`QgsExpressionContext` to use during the rendering step.
 :param storeSymbolFids: If ``True`` will store the feature ids (fids), otherwise will only count the number of features per symbol. Default ``False``.
 %End
-
+    ~QgsVectorLayerFeatureCounter();
 
     virtual bool run();
 
 %Docstring
 Calculates the feature count and Ids per symbol
 %End
 
+    virtual void cancel();
+
+
 
     long long featureCount( const QString &legendKey ) const;
 %Docstring

diff --git a/src/core/vector/qgsvectorlayerfeaturecounter.cpp b/src/core/vector/qgsvectorlayerfeaturecounter.cpp
@@ -16,6 +16,7 @@
 #include "qgsvectorlayerfeaturecounter.h"
 #include "qgsvectorlayer.h"
 #include "qgsfeatureid.h"
+#include "qgsfeedback.h"
 
 QgsVectorLayerFeatureCounter::QgsVectorLayerFeatureCounter( QgsVectorLayer *layer, const QgsExpressionContext &context, bool storeSymbolFids )
   : QgsTask( tr( "Counting features in %1" ).arg( layer->name() ), QgsTask::CanCancel )
@@ -31,6 +32,8 @@ QgsVectorLayerFeatureCounter::QgsVectorLayerFeatureCounter( QgsVectorLayer *laye
   }
 }
 
+QgsVectorLayerFeatureCounter::~QgsVectorLayerFeatureCounter() = default;
+
 bool QgsVectorLayerFeatureCounter::run()
 {
   mSymbolFeatureCountMap.clear();
@@ -48,6 +51,8 @@ bool QgsVectorLayerFeatureCounter::run()
   // If there are no features to be counted, we can spare us the trouble
   if ( mFeatureCount > 0 )
   {
+    mFeedback = std::make_unique< QgsFeedback >();
+
     int featuresCounted = 0;
 
     // Renderer (rule based) may depend on context scale, with scale is ignored if 0
@@ -59,10 +64,11 @@ bool QgsVectorLayerFeatureCounter::run()
     if ( !mRenderer->filterNeedsGeometry() )
       request.setFlags( QgsFeatureRequest::NoGeometry );
     request.setSubsetOfAttributes( mRenderer->usedAttributes( renderContext ), mSource->fields() );
-    QgsFeatureIterator fit = mSource->getFeatures( request );
 
-    // TODO: replace QgsInterruptionChecker with QgsFeedback
-    // fit.setInterruptionChecker( mFeedback );
+    request.setFeedback( mFeedback.get() );
+    mExpressionContext.setFeedback( mFeedback.get() );
+
+    QgsFeatureIterator fit = mSource->getFeatures( request );
 
     mRenderer->startRender( renderContext, mSource->fields() );
 
@@ -91,17 +97,27 @@ bool QgsVectorLayerFeatureCounter::run()
       if ( isCanceled() )
       {
         mRenderer->stopRender( renderContext );
+        mFeedback.reset();
         return false;
       }
     }
     mRenderer->stopRender( renderContext );
+    mExpressionContext.setFeedback( nullptr );
+    mFeedback.reset();
   }
   setProgress( 100 );
   emit symbolsCounted();
   return true;
 }
 
-QHash<QString, long long> QgsVectorLayerFeatureCounter::symbolFeatureCountMap() const
+void QgsVectorLayerFeatureCounter::cancel()
+{
+  if ( mFeedback )
+    mFeedback->cancel();
+  QgsTask::cancel();
+}
+
+QHash<QString, long> QgsVectorLayerFeatureCounter::symbolFeatureCountMap() const
 {
   return mSymbolFeatureCountMap;
 }

diff --git a/src/core/vector/qgsvectorlayerfeaturecounter.h b/src/core/vector/qgsvectorlayerfeaturecounter.h
@@ -43,13 +43,15 @@ class CORE_EXPORT QgsVectorLayerFeatureCounter : public QgsTask
      * \param storeSymbolFids If TRUE will store the feature ids (fids), otherwise will only count the number of features per symbol. Default FALSE.
      */
     QgsVectorLayerFeatureCounter( QgsVectorLayer *layer, const QgsExpressionContext &context = QgsExpressionContext(), bool storeSymbolFids = false );
-
+    ~QgsVectorLayerFeatureCounter() override;
 
     /**
      * Calculates the feature count and Ids per symbol
      */
     bool run() override;
 
+    void cancel() override;
+
     /**
      * Returns the count for each symbol. Only valid after the symbolsCounted()
      * signal has been emitted.
@@ -95,8 +97,9 @@ class CORE_EXPORT QgsVectorLayerFeatureCounter : public QgsTask
     QgsExpressionContext mExpressionContext;
     QHash<QString, long long> mSymbolFeatureCountMap;
     QHash<QString, QgsFeatureIds> mSymbolFeatureIdMap;
+    std::unique_ptr< QgsFeedback > mFeedback;
     bool mWithFids = false;
-    int mFeatureCount;
+    long mFeatureCount = 0;
 
 };