QgsVectorLayer, countSymbolFeatures return QgsVectorLayerFeatureCounter

qgis · Sep 19, 2017 · f88af6d · f88af6d
1 parent 08cacd4
commit f88af6d
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Showing 3 changed files with 22 additions and 20 deletions.
diff --git a/python/core/qgsvectorlayer.sip b/python/core/qgsvectorlayer.sip
@@ -854,20 +854,21 @@ Return the provider type for this layer
 .. versionadded:: 2.10
 %End
 
-    bool countSymbolFeatures();
+    QgsVectorLayerFeatureCounter *countSymbolFeatures();
 %Docstring
  Count features for symbols.
- The method will return immediately. You will need to connect to the
- symbolFeatureCountMapChanged() signal to be notified when the freshly updated
- feature counts are ready.
+ The method will return the feature counter task. You will need to
+ connect to the symbolFeatureCountMapChanged() signal to be
+ notified when the freshly updated feature counts are ready.
 
 .. note::
 
-   If you need to wait for the results, create and start your own QgsVectorLayerFeatureCounter
-       task and call waitForFinished().
+   If the count features for symbols has been already done a
+       None is returned. If you need to wait for the results,
+       you can call waitForFinished() on the feature counter.
 
 .. versionadded:: 3.0
- :rtype: bool
+ :rtype: QgsVectorLayerFeatureCounter
 %End
 
     virtual bool setSubsetString( const QString &subset );

diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -726,27 +726,27 @@ class QgsVectorLayerInterruptionCheckerDuringCountSymbolFeatures: public QgsInte
     QProgressDialog *mDialog = nullptr;
 };
 
-bool QgsVectorLayer::countSymbolFeatures()
+QgsVectorLayerFeatureCounter *QgsVectorLayer::countSymbolFeatures()
 {
-  if ( mSymbolFeatureCounted )
-    return true;
+  if ( mSymbolFeatureCounted || mFeatureCounter )
+    return mFeatureCounter;
 
   mSymbolFeatureCountMap.clear();
 
   if ( !mValid )
   {
     QgsDebugMsg( "invoked with invalid layer" );
-    return false;
+    return mFeatureCounter;
   }
   if ( !mDataProvider )
   {
     QgsDebugMsg( "invoked with null mDataProvider" );
-    return false;
+    return mFeatureCounter;
   }
   if ( !mRenderer )
   {
     QgsDebugMsg( "invoked with null mRenderer" );
-    return false;
+    return mFeatureCounter;
   }
 
   if ( !mFeatureCounter )
@@ -758,7 +758,7 @@ bool QgsVectorLayer::countSymbolFeatures()
     QgsApplication::taskManager()->addTask( mFeatureCounter );
   }
 
-  return true;
+  return mFeatureCounter;
 }
 
 void QgsVectorLayer::updateExtents( bool force )

diff --git a/src/core/qgsvectorlayer.h b/src/core/qgsvectorlayer.h
@@ -836,16 +836,17 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
 
     /**
      * Count features for symbols.
-     * The method will return immediately. You will need to connect to the
-     * symbolFeatureCountMapChanged() signal to be notified when the freshly updated
-     * feature counts are ready.
+     * The method will return the feature counter task. You will need to
+     * connect to the symbolFeatureCountMapChanged() signal to be
+     * notified when the freshly updated feature counts are ready.
      *
-     * \note If you need to wait for the results, create and start your own QgsVectorLayerFeatureCounter
-     *       task and call waitForFinished().
+     * \note If the count features for symbols has been already done a
+     *       nullptr is returned. If you need to wait for the results,
+     *       you can call waitForFinished() on the feature counter.
      *
      * \since This is asynchronous since QGIS 3.0
      */
-    bool countSymbolFeatures();
+    QgsVectorLayerFeatureCounter *countSymbolFeatures();
 
     /**
      * Set the string (typically sql) used to define a subset of the layer