Applied patch from ticket #565 Do not render features or their labels…

… if their classification value doesn't match a symbol's lower/upper range

git-svn-id: http://svn.osgeo.org/qgis/branches/Release-0_8_0@6502 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/core/qgsrenderer.cpp

@@ -72,3 +72,8 @@ bool QgsRenderer::containsPixmap() const
     }
 }
 
+bool QgsRenderer::willRenderFeature(QgsFeature *f) 
+{
+  // Normally render the feature, unless told otherwise
+  return true;
+}

src/core/qgsrenderer.h

@@ -48,6 +48,9 @@ class 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); 
     /**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

src/gui/qgsgraduatedsymbolrenderer.cpp

@@ -83,22 +83,20 @@ void QgsGraduatedSymbolRenderer::removeSymbols()
     mSymbols.clear();
 }
 
-void QgsGraduatedSymbolRenderer::renderFeature(QPainter * p, QgsFeature * f, QPixmap* pic, 
-	double* scalefactor, bool selected, double widthScale)
+bool QgsGraduatedSymbolRenderer::willRenderFeature(QgsFeature *f)
 {
-  //first find out the value for the classification attribute
-  std::vector < QgsFeatureAttribute > vec = f->attributeMap();
-  double value = vec[0].fieldValue().toDouble();
-
-  std::list < QgsSymbol* >::iterator it;
-  //find the first render item which contains the feature
-  for (it = mSymbols.begin(); it != mSymbols.end(); ++it)
-  {
-    if (value >= (*it)->lowerValue().toDouble() && value <= (*it)->upperValue().toDouble())
+  std::list < QgsSymbol* >::iterator it = firstSymbolForFeature(f);
+  if (it == mSymbols.end())      //only draw features which are covered by a render item 
     {
-      break;
+      return false;
     }
-  }
+  return true;
+}
+
+void QgsGraduatedSymbolRenderer::renderFeature(QPainter * p, QgsFeature * f, QPixmap* pic, 
+	double* scalefactor, bool selected, double widthScale)
+{
+  std::list < QgsSymbol* >::iterator it = firstSymbolForFeature(f);
 
   if (it == mSymbols.end())      //only draw features which are covered by a render item
   {
@@ -142,6 +140,24 @@ void QgsGraduatedSymbolRenderer::renderFeature(QPainter * p, QgsFeature * f, QPi
   }
 }
 
+std::list < QgsSymbol* >::iterator QgsGraduatedSymbolRenderer::firstSymbolForFeature(QgsFeature *f) 
+{
+  //first find out the value for the classification attribute
+  std::vector < QgsFeatureAttribute > vec = f->attributeMap();
+  double value = vec[0].fieldValue().toDouble();
+
+  std::list < QgsSymbol* >::iterator it;
+  //find the first render item which contains the feature
+  for (it = mSymbols.begin(); it != mSymbols.end(); ++it)
+  {
+    if (value >= (*it)->lowerValue().toDouble() && value <= (*it)->upperValue().toDouble())
+    {
+      break;
+    }
+  }
+  return it;
+}
+
 void QgsGraduatedSymbolRenderer::readXML(const QDomNode& rnode, QgsVectorLayer& vl)
 {
     mVectorType = vl.vectorType();

src/gui/qgsgraduatedsymbolrenderer.h

@@ -45,6 +45,9 @@ class QgsGraduatedSymbolRenderer: public QgsRenderer
     int classificationField() const;
     /**Removes all symbols*/
     void removeSymbols();
+    /**Determines if an OGRFeature is in range of any symbol's upper and lower bounds 
+     @param f a pointer to the feature to check*/ 
+    bool willRenderFeature(QgsFeature *f); 
     /**Renders an OGRFeature
      \param p a painter (usually the one from the current map canvas)
      \param f a pointer to a feature to render
@@ -75,6 +78,10 @@ class QgsGraduatedSymbolRenderer: public QgsRenderer
     int mClassificationField;
     /**List holding the symbols for the individual classes*/
     std::list<QgsSymbol*> mSymbols;
+
+ private:
+    /**Helper function for finding symbol having feature value in range*/ 
+    std::list < QgsSymbol* >::iterator firstSymbolForFeature(QgsFeature *f); 
 
 };
 

src/gui/qgsvectorlayer.cpp

@@ -360,9 +360,11 @@ void QgsVectorLayer::drawLabels(QPainter * p, QgsRect * viewExtent, QgsMapToPixe
           if(mDeletedFeatureIds.find(fet->featureId())==mDeletedFeatureIds.end())
           {
             bool sel=mSelectedFeatureIds.find(fet->featureId()) != mSelectedFeatureIds.end();
-            mLabel->renderLabel ( p, viewExtent, *mCoordinateTransform, 
-                projectionsEnabledFlag,
-                theMapToPixelTransform, fet, sel, 0, scale);
+	    if (m_renderer && m_renderer->willRenderFeature(fet)) 
+            { 
+	      mLabel->renderLabel ( p, viewExtent, *mCoordinateTransform, projectionsEnabledFlag, \
+theMapToPixelTransform, fet, sel, 0, scale);
+	    }
           }
         }
         delete fet;
@@ -374,8 +376,11 @@ void QgsVectorLayer::drawLabels(QPainter * p, QgsRect * viewExtent, QgsMapToPixe
       for(std::vector<QgsFeature*>::iterator it=mAddedFeatures.begin();it!=mAddedFeatures.end();++it)
       {
         bool sel=mSelectedFeatureIds.find((*it)->featureId()) != mSelectedFeatureIds.end();
-        mLabel->renderLabel ( p, viewExtent, *mCoordinateTransform, projectionsEnabledFlag,
+	if (m_renderer && m_renderer->willRenderFeature(fet)) 
+	  {
+	    mLabel->renderLabel ( p, viewExtent, *mCoordinateTransform, projectionsEnabledFlag,
             theMapToPixelTransform, *it, sel, 0, scale);
+	  }
       }
     }
     catch (QgsCsException &e)
@@ -880,24 +885,31 @@ void QgsVectorLayer::draw(QPainter * p,
           sel = FALSE;
         }
 
-	m_renderer->renderFeature(p, fet, &marker, &markerScaleFactor, sel, widthScale );
-	double scale = markerScaleFactor * symbolScale;
-        drawFeature(p,
+	if (m_renderer->willRenderFeature(fet))
+	  { 
+	    m_renderer->renderFeature(p, fet, &marker, &markerScaleFactor, sel, widthScale );
+	    double scale = markerScaleFactor * symbolScale;
+	    drawFeature(p,
                     fet,
                     theMapToPixelTransform,
                     &marker,
                     scale,
                     projectionsEnabledFlag,
                     drawingToEditingCanvas);
-	++featureCount;
-	delete fet;
+	    ++featureCount;
+	    delete fet;
+	  }
       }	
 
       //also draw the not yet commited features
       if(mEditable)
 	{
 	  for(std::vector<QgsFeature*>::iterator it = mAddedFeatures.begin(); it != mAddedFeatures.end(); ++it)
 	    {
+	      if (!m_renderer->willRenderFeature(*it)) 
+              { 
+                continue; 
+              }  
 	      bool sel=mSelectedFeatureIds.find((*it)->featureId()) != mSelectedFeatureIds.end();
 	      m_renderer->renderFeature(p, *it, &marker, &markerScaleFactor, sel, widthScale);
 	      double scale = markerScaleFactor * symbolScale;