Don't draw labels of features for which the value is not contained in the unique value renderer

git-svn-id: http://svn.osgeo.org/qgis/trunk@6505 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/core/qgsvectorlayer.cpp

@@ -261,7 +261,7 @@ void QgsVectorLayer::drawLabels(QPainter * p, QgsRect & viewExtent, QgsMapToPixe
 {
   QgsDebugMsg("Starting draw of labels");
 
-  if ( /*1 == 1 */ mRenderer && mLabelOn)
+  if (mRenderer && mLabelOn)
   {
     QgsAttributeList attributes = mRenderer->classificationAttributes();
 
@@ -286,19 +286,24 @@ void QgsVectorLayer::drawLabels(QPainter * p, QgsRect & viewExtent, QgsMapToPixe
         // don't render labels of deleted features
         if (!mDeletedFeatureIds.contains(fet.featureId()))
         {
-          bool sel = mSelectedFeatureIds.contains(fet.featureId());
-          mLabel->renderLabel ( p, viewExtent, ct, 
+	  if(mRenderer->willRenderFeature(&fet))
+	    {
+	      bool sel = mSelectedFeatureIds.contains(fet.featureId());
+	      mLabel->renderLabel ( p, viewExtent, ct, 
               theMapToPixelTransform, fet, sel, 0, scale);
+	    }
         }
         featureCount++;
       }
 
       // render labels of not-commited features
       for (QgsFeatureList::iterator it = mAddedFeatures.begin(); it != mAddedFeatures.end(); ++it)
       {
-        bool sel = mSelectedFeatureIds.contains((*it).featureId());
-        mLabel->renderLabel ( p, viewExtent, ct,
-            theMapToPixelTransform, *it, sel, 0, scale);
+	if(mRenderer->willRenderFeature(&(*it)))
+	  {
+	    bool sel = mSelectedFeatureIds.contains((*it).featureId());
+	    mLabel->renderLabel ( p, viewExtent, ct, theMapToPixelTransform, *it, sel, 0, scale);
+	  }
       }
     }
     catch (QgsCsException &e)

src/core/renderer/qgsrenderer.h

@@ -44,10 +44,13 @@ class CORE_EXPORT QgsRenderer
     QgsRenderer();
     /** Virtual destructor because we have virtual methods... */
     virtual ~QgsRenderer();
+    /** Determines if a feature will be rendered or not 
+	@param f a pointer to the feature to determine if rendering will happen*/
+    virtual bool willRenderFeature(QgsFeature *f) {return true;}
     /**A vector layer passes features to a renderer object to change the brush and pen of the qpainter
      @param p the painter storing brush and pen
      @param f a pointer to the feature to be rendered
-     @param pic pointer to a marker from SVG (is only used by marker renderers)
+     @param pic pointer to an image (used for point symbols)
      @param scalefactor pointer to the scale factor for the marker image*/
     virtual void renderFeature(QPainter* p, QgsFeature& f,QImage* pic, double* scalefactor, bool selected, double widthScale = 1.)=0;
     /**Reads the renderer configuration from an XML file

src/core/renderer/qgsuniquevaluerenderer.cpp

@@ -93,62 +93,78 @@ int QgsUniqueValueRenderer::classificationField()
 {
     return mClassificationField;
 }
+
+bool QgsUniqueValueRenderer::willRenderFeature(QgsFeature *f)
+{
+  return (symbolForFeature(f) != 0);
+}
 
 void QgsUniqueValueRenderer::renderFeature(QPainter* p, QgsFeature& f,QImage* img, 
 	double* scalefactor, bool selected, double widthScale)
 {
-    const QgsAttributeMap& attrs = f.attributeMap();
-    QString value = attrs[mClassificationField].fieldValue();
+  QgsSymbol* symbol = symbolForFeature(&f);
+  if(!symbol) //no matching symbol
+    {
+      if ( img && mVectorType == QGis::Point )
+	{
+	  img->fill(0);
+	}
+      else if ( mVectorType != QGis::Point )
+	{
+	  p->setPen(Qt::NoPen);
+	  p->setBrush(Qt::NoBrush);
+	}
+      return;
+    }
 
-    std::map<QString,QgsSymbol*>::iterator it=mSymbols.find(value);
-    if(it!=mSymbols.end())
+  // Point 
+  if ( img && mVectorType == QGis::Point ) 
     {
-	QgsSymbol* symbol = it->second;
-
-	// Point 
-	if ( img && mVectorType == QGis::Point ) {
-	    *img = symbol->getPointSymbolAsImage(  widthScale,
-		                                       selected, mSelectionColor );
-	    
-	    if ( scalefactor ) *scalefactor = 1;
-	} 
-
-        // Line, polygon
- 	else if ( mVectorType != QGis::Point )
+      *img = symbol->getPointSymbolAsImage(  widthScale, selected, mSelectionColor );
+      if ( scalefactor ) 
 	{
-	    if( !selected ) 
-	    {
-		QPen pen=symbol->pen();
-		pen.setWidthF ( widthScale * pen.width() );
-		p->setPen(pen);
-		p->setBrush(symbol->brush());
-	    }
-	    else
-	    {
-		QPen pen=symbol->pen();
-		pen.setWidthF ( widthScale * pen.width() );
-		pen.setColor(mSelectionColor);
-		QBrush brush=symbol->brush();
+	  *scalefactor = 1;
+	}
+    } 
+  
+  // Line, polygon
+  else if ( mVectorType != QGis::Point )
+    {
+      if( !selected ) 
+	{
+	  QPen pen=symbol->pen();
+	  pen.setWidthF ( widthScale * pen.width() );
+	  p->setPen(pen);
+	  p->setBrush(symbol->brush());
+	}
+      else
+	{
+	  QPen pen=symbol->pen();
+	  pen.setWidthF ( widthScale * pen.width() );
+	  pen.setColor(mSelectionColor);
+	  QBrush brush=symbol->brush();
 		brush.setColor(mSelectionColor);
 		p->setPen(pen);
 		p->setBrush(brush);
-	    }
 	}
     }
-    else
+}
+
+QgsSymbol* QgsUniqueValueRenderer::symbolForFeature(const QgsFeature* f)
+{
+  //first find out the value
+  const QgsAttributeMap& attrs = f->attributeMap();
+  QString value = attrs[mClassificationField].fieldValue();
+  
+  std::map<QString,QgsSymbol*>::iterator it=mSymbols.find(value);
+  if(it == mSymbols.end())
     {
-      //no matching symbol found. In this case, set Qt::NoPen, Qt::NoBrush or transparent image
-	if ( img && mVectorType == QGis::Point )
-	  {
-	    img->fill(0);
-	  }
-	else if ( mVectorType != QGis::Point )
-	  {
-	    p->setPen(Qt::NoPen);
-	    p->setBrush(Qt::NoBrush);
-	  }
+      return 0;
+    }
+  else
+    {
+      return it->second;
     }
-    
 }
 
 void QgsUniqueValueRenderer::readXML(const QDomNode& rnode, QgsVectorLayer& vl)

src/core/renderer/qgsuniquevaluerenderer.h

@@ -28,6 +28,9 @@ class CORE_EXPORT QgsUniqueValueRenderer: public QgsRenderer
     QgsUniqueValueRenderer(const QgsUniqueValueRenderer& other);
     QgsUniqueValueRenderer& operator=(const QgsUniqueValueRenderer& other);
     virtual ~QgsUniqueValueRenderer();
+    /** Determines if a feature will be rendered or not 
+	@param f a pointer to the feature to determine if rendering will happen*/
+    bool willRenderFeature(QgsFeature *f);
     void renderFeature(QPainter* p, QgsFeature& f,QImage* img, double* scalefactor, bool selected, double widthScale = 1.);
     /**Reads the renderer configuration from an XML file
      @param rnode the DOM node to read 
@@ -58,6 +61,8 @@ class CORE_EXPORT QgsUniqueValueRenderer: public QgsRenderer
     int mClassificationField;
     /**Symbols for the unique values*/
     std::map<QString, QgsSymbol*> mSymbols;
+    /**Returns the symbol for a feature or 0 if there isn't any*/
+    QgsSymbol* symbolForFeature(const QgsFeature* f);
 };
 
 inline bool QgsUniqueValueRenderer::needsAttributes() const