Misc cleanups following c9f0d83

python/core/qgsfeaturefilterprovider.sip

@@ -1,7 +1,9 @@
-/**
- * Interface used by class that will filter the features of a layer.
- * The only method `filterFeatures` fill the `QgsFeatureRequest` to get only the
- * wanted features.
+/** \ingroup core
+ * \class QgsFeatureFilterProvider
+ * Abstract interface for use by classes that filter the features of a layer.
+ * A QgsFeatureFilterProvider provides a method for modifying a QgsFeatureRequest in place to apply
+ * additional filters to the request.
+ * \note added in QGIS 2.14
  **/
 class QgsFeatureFilterProvider
 {
@@ -10,15 +12,16 @@ class QgsFeatureFilterProvider
 %End
 
   public:
-    /** Add some filter to the feature request to don't have the unauthorized (unauthorised) features
+
+    /** Add additional filters to the feature request to further restrict the features returned by the request.
+     * Derived classes must implement this method.
      * @param layer the layer to filter
      * @param featureRequest the feature request to update
-     * @note not available in Python bindings
      */
     virtual void filterFeatures( const QgsVectorLayer* layer, QgsFeatureRequest& featureRequest ) const = 0;
 
     /** Create a clone of the feature filter provider
      * @return a new clone
      */
-    virtual QgsFeatureFilterProvider* clone() const = 0;
+    virtual QgsFeatureFilterProvider* clone() const = 0 /Factory/;
 };

python/core/qgsfeaturerequest.sip

@@ -50,10 +50,26 @@ class QgsFeatureRequest
     QgsFeatureRequest& setFilterFids( const QgsFeatureIds& fids );
     const QgsFeatureIds& filterFids() const;
 
-    //! Set filter expression. {@see QgsExpression}
+    /** Set the filter expression. {@see QgsExpression}
+     * @param expression expression string
+     * @see filterExpression
+     * @see setExpressionContext
+     */
     QgsFeatureRequest& setFilterExpression( const QString& expression );
+
+    /** Returns the filter expression if set.
+     * @see setFilterExpression
+     * @see expressionContext
+     */
     QgsExpression* filterExpression() const;
 
+    /** Modifies the existing filter expression to add an additional expression filter. The
+     * filter expressions are combined using AND, so only features matching both
+     * the existing expression and the additional expression will be returned.
+     * @note added in QGIS 2.14
+     */
+    QgsFeatureRequest& combineFilterExpression( const QString& expression );
+
     /** Returns the expression context used to evaluate filter expressions.
      * @note added in QGIS 2.12
      * @see setExpressionContext

python/core/qgsmaprenderer.sip

@@ -288,10 +288,12 @@ class QgsMapRenderer : QObject
      */
     bool splitLayersExtent( QgsMapLayer* layer, QgsRectangle& extent /In,Out/, QgsRectangle& r2 /Out/ );
 
-    /** Set a feature filter provider to filter the features
+    /** Set a feature filter provider to filter the features shown in the map.
      * @param ffp the feature filter provider
+     * @note added in QGIS 2.14
      */
     void setFeatureFilterProvider( const QgsFeatureFilterProvider* ffp );
+
   signals:
 
     //! @deprecated in 2.4 - not emitted anymore

python/core/qgsrendercontext.sip

@@ -140,4 +140,18 @@ class QgsRenderContext
     /** Sets pointer to original (unsegmentized) geometry
         @geometry the geometry*/
     void setGeometry( const QgsAbstractGeometryV2* geometry );
+
+    /** Set a filter feature provider used for additional filtering of rendered features.
+     * @param ffp the filter feature provider
+     * @note added in QGIS 2.14
+     * @see featureFilterProvider()
+     */
+    void setFeatureFilterProvider( const QgsFeatureFilterProvider* ffp );
+
+    /** Get the filter feature provider used for additional filtering of rendered features.
+     * @return the filter feature provider
+     * @note added in QGIS 2.14
+     * @see setFeatureFilterProvider()
+     */
+    const QgsFeatureFilterProvider* featureFilterProvider() const;
 };

src/core/qgsfeaturefilterprovider.h

@@ -26,21 +26,25 @@ class QgsFeatureRequest;
 
 
 /** \ingroup core
- * Interface used by class that will filter the features of a layer.
- * The only method `filterFeatures` fill the `QgsFeatureRequest` to get only the
- * wanted features.
+ * \class QgsFeatureFilterProvider
+ * Abstract interface for use by classes that filter the features of a layer.
+ * A QgsFeatureFilterProvider provides a method for modifying a QgsFeatureRequest in place to apply
+ * additional filters to the request.
+ * \note added in QGIS 2.14
  **/
+
 class CORE_EXPORT QgsFeatureFilterProvider
 {
   public:
 
     /** Constructor */
-    QgsFeatureFilterProvider() {};
+    QgsFeatureFilterProvider() {}
 
     /** Destructor */
-    virtual ~QgsFeatureFilterProvider() {};
+    virtual ~QgsFeatureFilterProvider() {}
 
-    /** Add some filter to the feature request to don't have the unauthorized (unauthorised) features
+    /** Add additional filters to the feature request to further restrict the features returned by the request.
+     * Derived classes must implement this method.
      * @param layer the layer to filter
      * @param featureRequest the feature request to update
      */

src/core/qgsfeaturerequest.cpp

@@ -117,6 +117,19 @@ QgsFeatureRequest& QgsFeatureRequest::setFilterExpression( const QString& expres
   return *this;
 }
 
+QgsFeatureRequest&QgsFeatureRequest::combineFilterExpression( const QString& expression )
+{
+  if ( mFilterExpression )
+  {
+    setFilterExpression( QString( "(%1) AND (%2)" ).arg( mFilterExpression->expression(), expression ) );
+  }
+  else
+  {
+    setFilterExpression( expression );
+  }
+  return *this;
+}
+
 QgsFeatureRequest &QgsFeatureRequest::setExpressionContext( const QgsExpressionContext &context )
 {
   mExpressionContext = context;

src/core/qgsfeaturerequest.h

@@ -144,6 +144,13 @@ class CORE_EXPORT QgsFeatureRequest
      */
     QgsExpression* filterExpression() const { return mFilterExpression; }
 
+    /** Modifies the existing filter expression to add an additional expression filter. The
+     * filter expressions are combined using AND, so only features matching both
+     * the existing expression and the additional expression will be returned.
+     * @note added in QGIS 2.14
+     */
+    QgsFeatureRequest& combineFilterExpression( const QString& expression );
+
     /** Returns the expression context used to evaluate filter expressions.
      * @note added in QGIS 2.12
      * @see setExpressionContext

src/core/qgsmaprenderer.h

@@ -335,8 +335,9 @@ class CORE_EXPORT QgsMapRenderer : public QObject
      */
     bool splitLayersExtent( QgsMapLayer* layer, QgsRectangle& extent, QgsRectangle& r2 );
 
-    /** Set a feature filter provider to filter the features
+    /** Set a feature filter provider to filter the features shown in the map.
      * @param ffp the feature filter provider
+     * @note added in QGIS 2.14
      */
     void setFeatureFilterProvider( const QgsFeatureFilterProvider* ffp )
     {

src/core/qgsrendercontext.cpp

@@ -21,6 +21,7 @@
 #include "qgsmapsettings.h"
 #include "qgsexpression.h"
 #include "qgsvectorlayer.h"
+#include "qgsfeaturefilterprovider.h"
 
 QgsRenderContext::QgsRenderContext()
     : mFlags( DrawEditingInfo | UseAdvancedEffects | DrawSelection | UseRenderingOptimization )
@@ -40,11 +41,8 @@ QgsRenderContext::QgsRenderContext()
 
 QgsRenderContext::~QgsRenderContext()
 {
-  if ( mFeatureFilterProvider )
-  {
-    delete mFeatureFilterProvider;
-    mFeatureFilterProvider = 0;
-  }
+  delete mFeatureFilterProvider;
+  mFeatureFilterProvider = 0;
 }
 
 void QgsRenderContext::setFlags( const QgsRenderContext::Flags& flags )
@@ -151,11 +149,9 @@ void QgsRenderContext::setUseRenderingOptimization( bool enabled )
 
 void QgsRenderContext::setFeatureFilterProvider( const QgsFeatureFilterProvider* ffp )
 {
-  if ( mFeatureFilterProvider )
-  {
-    delete mFeatureFilterProvider;
-    mFeatureFilterProvider = 0;
-  }
+  delete mFeatureFilterProvider;
+  mFeatureFilterProvider = 0;
+
   if ( ffp )
   {
     mFeatureFilterProvider = ffp->clone();

src/core/qgsrendercontext.h

@@ -25,7 +25,6 @@
 #include "qgsrectangle.h"
 #include "qgsvectorsimplifymethod.h"
 #include "qgsexpressioncontext.h"
-#include "qgsfeaturefilterprovider.h"
 
 class QPainter;
 
@@ -33,8 +32,7 @@ class QgsAbstractGeometryV2;
 class QgsLabelingEngineInterface;
 class QgsLabelingEngineV2;
 class QgsMapSettings;
-class QgsExpression;
-class QgsVectorLayer;
+class QgsFeatureFilterProvider;
 
 
 /** \ingroup core
@@ -199,17 +197,19 @@ class CORE_EXPORT QgsRenderContext
     /** Sets pointer to original (unsegmentized) geometry*/
     void setGeometry( const QgsAbstractGeometryV2* geometry ) { mGeometry = geometry; }
 
-    /** Set a filter feature provider used to filter the features
+    /** Set a filter feature provider used for additional filtering of rendered features.
      * @param ffp the filter feature provider
-     * @note not available in Python bindings
+     * @note added in QGIS 2.14
+     * @see featureFilterProvider()
      */
     void setFeatureFilterProvider( const QgsFeatureFilterProvider* ffp );
 
-    /** Get the filter feature provider used to filter the features
+    /** Get the filter feature provider used for additional filtering of rendered features.
      * @return the filter feature provider
-     * @note not available in Python bindings
+     * @note added in QGIS 2.14
+     * @see setFeatureFilterProvider()
      */
-    const QgsFeatureFilterProvider* featureFilterProvider() { return mFeatureFilterProvider; }
+    const QgsFeatureFilterProvider* featureFilterProvider() const { return mFeatureFilterProvider; }
 
   private:
 

src/core/qgsvectorlayerrenderer.cpp

@@ -32,6 +32,7 @@
 #include "qgsvectorlayerlabeling.h"
 #include "qgsvectorlayerlabelprovider.h"
 #include "qgspainteffect.h"
+#include "qgsfeaturefilterprovider.h"
 
 #include <QSettings>
 #include <QPicture>
@@ -151,25 +152,17 @@ bool QgsVectorLayerRenderer::render()
 
   QgsFeatureRequest featureRequest = QgsFeatureRequest()
                                      .setFilterRect( requestExtent )
-                                     .setSubsetOfAttributes( mAttrNames, mFields );
+                                     .setSubsetOfAttributes( mAttrNames, mFields )
+                                     .setExpressionContext( mContext.expressionContext() );
 
   const QgsFeatureFilterProvider* featureFilterProvider = mContext.featureFilterProvider();
   if ( featureFilterProvider )
   {
     featureFilterProvider->filterFeatures( mLayer, featureRequest );
   }
-  if ( !rendererFilter.isNull() )
+  if ( !rendererFilter.isEmpty() && rendererFilter != "TRUE" )
   {
-    featureRequest.setExpressionContext( mContext.expressionContext() );
-    if ( !featureRequest.filterExpression() )
-    {
-      featureRequest.setFilterExpression( rendererFilter );
-    }
-    else
-    {
-      featureRequest.setFilterExpression( QString( "(%s) AND (%s)" )
-                                          .arg( rendererFilter, featureRequest.filterExpression()->expression() ) );
-    }
+    featureRequest.combineFilterExpression( rendererFilter );
   }
 
   // enable the simplification of the geometries (Using the current map2pixel context) before send it to renderer engine.