Add methods for retrieving extra parameters from symbol render

python/core/symbology-ng/qgsrendererv2.sip

@@ -263,6 +263,15 @@ class QgsFeatureRendererV2
      */
     void setForceRasterRender( bool forceRaster );
 
+    /** Returns the result of the feature rendering operation. This should only be
+     * called immediately after a rendering operation (eg calling renderFeature).
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 renderFeature
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderFeature return a QgsRenderResult
+    const QgsRenderResult& renderResult() const;
+
   protected:
     QgsFeatureRendererV2( QString type );
 
@@ -291,6 +300,16 @@ class QgsFeatureRendererV2
      */
     void copyPaintEffect( QgsFeatureRendererV2 *destRenderer ) const;
 
+    /** Sets the result of the symbol rendering operation. Subclasses should call
+     * this method after rendering a feature and update the render result to reflect
+     * to actual result of the feature render.
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the renderFeature method
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    void setRenderResult( const QgsRenderResult& result );
+
   private:
     QgsFeatureRendererV2( const QgsFeatureRendererV2 & );
     QgsFeatureRendererV2 & operator=( const QgsFeatureRendererV2 & );

python/core/symbology-ng/qgssymbollayerv2.sip

@@ -260,6 +260,15 @@ class QgsSymbolLayerV2
      */
     void setPaintEffect( QgsPaintEffect* effect /Transfer/);
 
+    /** Returns the result of the symbol rendering operation. This should only be
+     * called immediately after a rendering operation (eg calling renderPoint).
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the render methods
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    const QgsRenderResult& renderResult() const;
+
   protected:
     QgsSymbolLayerV2( QgsSymbolV2::SymbolType type, bool locked = false );
 
@@ -306,6 +315,16 @@ class QgsSymbolLayerV2
      */
     void copyPaintEffect( QgsSymbolLayerV2* destLayer ) const;
 
+    /** Sets the result of the symbol rendering operation. Subclasses should call
+     * this method after rendering a symbol and update the render result to reflect
+     * to actual result of the symbol render.
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the render methods
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    void setRenderResult( const QgsRenderResult& result );
+
 };
 
 //////////////////////

python/core/symbology-ng/qgssymbolv2.sip

@@ -1,6 +1,39 @@
 
 typedef QList<QgsSymbolLayerV2*> QgsSymbolLayerV2List;
 
+/** \ingroup core
+ * \class QgsRenderResult
+ * \brief A simple container for the results of a rendering operation
+ * \note Added in version 2.12
+ */
+
+class QgsRenderResult
+{
+%TypeHeaderCode
+#include <qgssymbolv2.h>
+%End
+  public:
+
+    /** Constructor for QgsRenderResult
+     * @param symbolRendered initial value for symbolRendered member
+     */
+    QgsRenderResult( bool symbolRendered );
+
+    /** Bounds of rendered symbol shape.
+     * @note only implemented for marker symbol types
+     */
+    QRectF symbolBounds;
+
+    //! True if a symbol was rendered during the render operation
+    bool symbolRendered;
+
+    /** Unites the render result with another QgsRenderResult object
+     * @param other other render result
+     */
+    void unite( const QgsRenderResult& other );
+};
+
+
 class QgsSymbolV2
 {
 %TypeHeaderCode
@@ -163,6 +196,15 @@ class QgsSymbolV2
     void setLayer( const QgsVectorLayer* layer );
     const QgsVectorLayer* layer() const;
 
+     /** Returns the result of the symbol rendering operation. This should only be
+     * called immediately after a rendering operation (eg calling renderPoint).
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the render methods
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    const QgsRenderResult& renderResult() const;
+
   protected:
     QgsSymbolV2( SymbolType type, QgsSymbolLayerV2List layers /Transfer/ ); // can't be instantiated
 

src/core/symbology-ng/qgsmarkersymbollayerv2.cpp

@@ -541,15 +541,18 @@ void QgsSimpleMarkerSymbolLayerV2::renderPoint( const QPointF& point, QgsSymbolV
     }
   }
 
+  QgsRenderResult result( true );
   if ( mUsingCache )
   {
     //QgsDebugMsg( QString("XXX using cache") );
     // we will use cached image
     QImage &img = context.selected() ? mSelCache : mCache;
     double s = img.width() / context.renderContext().rasterScaleFactor();
-    p->drawImage( QRectF( point.x() - s / 2.0 + off.x(),
+    QRectF imgRect( point.x() - s / 2.0 + off.x(),
                     point.y() - s / 2.0 + off.y(),
-                          s, s ), img );
+                    s, s );
+    p->drawImage( imgRect, img );
+    result.symbolBounds = imgRect;
   }
   else
   {
@@ -606,11 +609,25 @@ void QgsSimpleMarkerSymbolLayerV2::renderPoint( const QPointF& point, QgsSymbolV
     p->setBrush( context.selected() ? mSelBrush : mBrush );
     p->setPen( context.selected() ? mSelPen : mPen );
 
+    QRectF boundingRect;
     if ( !mPolygon.isEmpty() )
-      p->drawPolygon( transform.map( mPolygon ) );
+    {
-    else
+      QPolygonF transformed = transform.map( mPolygon );
-      p->drawPath( transform.map( mPath ) );
+      boundingRect = transformed.boundingRect();
+      p->drawPolygon( transformed );
+
     }
+    else
+    {
+      QPainterPath transformed = transform.map( mPath );
+      boundingRect = transformed.boundingRect();
+      p->drawPath( transformed );
+    }
+    //adjust bounding rect for pen width
+    result.symbolBounds = boundingRect.adjusted( -mPen.widthF() / 2.0, -mPen.widthF() / 2.0,
+                          mPen.widthF() / 2.0, mPen.widthF() / 2.0 );
+  }
+  setRenderResult( result );
 }
 
 

src/core/symbology-ng/qgsrendererv2.cpp

@@ -218,6 +218,7 @@ QgsFeatureRendererV2::QgsFeatureRendererV2( QString type )
     , mCurrentVertexMarkerSize( 3 )
     , mPaintEffect( 0 )
     , mForceRaster( false )
+    , mRenderResult( QgsRenderResult( true ) )
 {
   mPaintEffect = QgsPaintEffectRegistry::defaultStack();
   mPaintEffect->setEnabled( false );
@@ -270,9 +271,13 @@ bool QgsFeatureRendererV2::renderFeature( QgsFeature& feature, QgsRenderContext&
 {
   QgsSymbolV2* symbol = symbolForFeature( feature, context );
   if ( symbol == NULL )
+  {
+    setRenderResult( QgsRenderResult( false ) );
     return false;
+  }
 
   renderFeatureWithSymbol( feature, symbol, context, layer, selected, drawVertexMarker );
+  setRenderResult( symbol->renderResult() );
   return true;
 }
 
@@ -810,3 +815,8 @@ void QgsFeatureRendererV2::convertSymbolRotation( QgsSymbolV2 * symbol, const QS
     s->setDataDefinedAngle( dd );
   }
 }
+
+void QgsFeatureRendererV2::setRenderResult( const QgsRenderResult& result )
+{
+  mRenderResult = result;
+}

src/core/symbology-ng/qgsrendererv2.h

@@ -311,6 +311,15 @@ class CORE_EXPORT QgsFeatureRendererV2
      */
     void setForceRasterRender( bool forceRaster ) { mForceRaster = forceRaster; }
 
+    /** Returns the result of the feature rendering operation. This should only be
+     * called immediately after a rendering operation (eg calling renderFeature).
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 renderFeature
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderFeature return a QgsRenderResult
+    const QgsRenderResult& renderResult() const { return mRenderResult; }
+
   protected:
     QgsFeatureRendererV2( QString type );
 
@@ -361,8 +370,20 @@ class CORE_EXPORT QgsFeatureRendererV2
      */
     static void convertSymbolRotation( QgsSymbolV2 * symbol, const QString & field );
 
+    /** Sets the result of the symbol rendering operation. Subclasses should call
+     * this method after rendering a feature and update the render result to reflect
+     * to actual result of the feature render.
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the renderFeature method
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    void setRenderResult( const QgsRenderResult& result );
+
   private:
     Q_DISABLE_COPY( QgsFeatureRendererV2 )
+
+    QgsRenderResult mRenderResult;
 };
 
 // for some reason SIP compilation fails if these lines are not included:

src/core/symbology-ng/qgsrulebasedrendererv2.cpp

@@ -815,6 +815,8 @@ bool QgsRuleBasedRendererV2::renderFeature( QgsFeature& feature,
 {
   Q_UNUSED( layer );
 
+  setRenderResult( QgsRenderResult( false ) );
+
   int flags = ( selected ? FeatIsSelected : 0 ) | ( drawVertexMarker ? FeatDrawMarkers : 0 );
   mCurrentFeatures.append( FeatureToRender( feature, flags ) );
 
@@ -873,6 +875,10 @@ void QgsRuleBasedRendererV2::stopRender( QgsRenderContext& context )
         {
           int flags = job->ftr.flags;
           renderFeatureWithSymbol( job->ftr.feat, job->symbol, context, i, flags & FeatIsSelected, flags & FeatDrawMarkers );
+
+          QgsRenderResult newRenderResult = job->symbol->renderResult();
+          newRenderResult.unite( renderResult() );
+          setRenderResult( newRenderResult );
         }
       }
     }

src/core/symbology-ng/qgssymbollayerv2.cpp

@@ -334,6 +334,7 @@ QgsSymbolLayerV2::QgsSymbolLayerV2( QgsSymbolV2::SymbolType type, bool locked )
     , mLocked( locked )
     , mRenderingPass( 0 )
     , mPaintEffect( 0 )
+    , mRenderResult( QgsRenderResult( true ) )
 {
   mPaintEffect = QgsPaintEffectRegistry::defaultStack();
   mPaintEffect->setEnabled( false );
@@ -482,6 +483,11 @@ void QgsSymbolLayerV2::copyPaintEffect( QgsSymbolLayerV2 *destLayer ) const
   destLayer->setPaintEffect( mPaintEffect->clone() );
 }
 
+void QgsSymbolLayerV2::setRenderResult( const QgsRenderResult& result )
+{
+  mRenderResult = result;
+}
+
 QgsMarkerSymbolLayerV2::QgsMarkerSymbolLayerV2( bool locked )
     : QgsSymbolLayerV2( QgsSymbolV2::Marker, locked )
     , mAngle( 0 )

src/core/symbology-ng/qgssymbollayerv2.h

@@ -247,6 +247,15 @@ class CORE_EXPORT QgsSymbolLayerV2
      */
     void setPaintEffect( QgsPaintEffect* effect );
 
+    /** Returns the result of the symbol rendering operation. This should only be
+     * called immediately after a rendering operation (eg calling renderPoint).
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the render methods
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    const QgsRenderResult& renderResult() const { return mRenderResult; }
+
   protected:
     QgsSymbolLayerV2( QgsSymbolV2::SymbolType type, bool locked = false );
 
@@ -307,6 +316,16 @@ class CORE_EXPORT QgsSymbolLayerV2
      */
     void copyPaintEffect( QgsSymbolLayerV2* destLayer ) const;
 
+    /** Sets the result of the symbol rendering operation. Subclasses should call
+     * this method after rendering a symbol and update the render result to reflect
+     * to actual result of the symbol render.
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the render methods
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    void setRenderResult( const QgsRenderResult& result );
+
     static const QString EXPR_SIZE;
     static const QString EXPR_ANGLE;
     static const QString EXPR_NAME;
@@ -365,6 +384,10 @@ class CORE_EXPORT QgsSymbolLayerV2
     static const QString EXPR_OFFSET_ALONG_LINE;
     static const QString EXPR_HORIZONTAL_ANCHOR_POINT;
     static const QString EXPR_VERTICAL_ANCHOR_POINT;
+
+  private:
+
+    QgsRenderResult mRenderResult;
 };
 
 //////////////////////

src/core/symbology-ng/qgssymbolv2.cpp

@@ -81,6 +81,7 @@ QgsSymbolV2::QgsSymbolV2( SymbolType type, QgsSymbolLayerV2List layers )
     , mRenderHints( 0 )
     , mClipFeaturesToExtent( true )
     , mLayer( 0 )
+    , mRenderResult( QgsRenderResult( true ) )
 {
 
   // check they're all correct symbol layers
@@ -831,6 +832,8 @@ void QgsMarkerSymbolV2::renderPointUsingLayer( QgsMarkerSymbolLayerV2* layer, co
   {
     layer->renderPoint( point, context );
   }
+
+  mRenderResult = layer->renderResult();
 }
 
 void QgsMarkerSymbolV2::renderPoint( const QPointF& point, const QgsFeature* f, QgsRenderContext& context, int layer, bool selected )
@@ -846,10 +849,13 @@ void QgsMarkerSymbolV2::renderPoint( const QPointF& point, const QgsFeature* f,
     return;
   }
 
+  QgsRenderResult combinedResult( false );
   for ( QgsSymbolLayerV2List::iterator it = mLayers.begin(); it != mLayers.end(); ++it )
   {
     renderPointUsingLayer(( QgsMarkerSymbolLayerV2* ) * it, point, symbolContext );
+    combinedResult.unite(( *it )->renderResult() );
   }
+  mRenderResult = combinedResult;
 }
 
 QgsSymbolV2* QgsMarkerSymbolV2::clone() const
@@ -1032,6 +1038,8 @@ void QgsLineSymbolV2::renderPolylineUsingLayer( QgsLineSymbolLayerV2 *layer, con
   {
     layer->renderPolyline( points, context );
   }
+
+  mRenderResult = layer->renderResult();
 }
 
 
@@ -1112,6 +1120,8 @@ void QgsFillSymbolV2::renderPolygonUsingLayer( QgsSymbolLayerV2* layer, const QP
       (( QgsLineSymbolLayerV2* )layer )->renderPolygonOutline( points, rings, context );
     }
   }
+
+  mRenderResult = layer->renderResult();
 }
 
 QRectF QgsFillSymbolV2::polygonBounds( const QPolygonF& points, const QList<QPolygonF>* rings ) const

src/core/symbology-ng/qgssymbolv2.h

@@ -45,6 +45,48 @@ class QgsDataDefined;
 
 typedef QList<QgsSymbolLayerV2*> QgsSymbolLayerV2List;
 
+
+/** \ingroup core
+ * \class QgsRenderResult
+ * \brief A simple container for the results of a rendering operation
+ * \note Added in version 2.12
+ */
+
+class QgsRenderResult
+{
+  public:
+
+    /** Constructor for QgsRenderResult
+     * @param symbolRendered initial value for symbolRendered member
+     */
+    QgsRenderResult( bool symbolRendered )
+        : symbolRendered( symbolRendered )
+    { }
+
+    /** Bounds of rendered symbol shape.
+     * @note only implemented for marker symbol types
+     */
+    QRectF symbolBounds;
+
+    //! True if a symbol was rendered during the render operation
+    bool symbolRendered;
+
+    /** Unites the render result with another QgsRenderResult object
+     * @param other other render result
+     */
+    void unite( const QgsRenderResult& other )
+    {
+      symbolRendered = symbolRendered || other.symbolRendered;
+      if ( !symbolBounds.isValid() )
+        symbolBounds = other.symbolBounds;
+      else
+        symbolBounds = symbolBounds.united( other.symbolBounds );
+    }
+};
+
+
+//////////////////////
+
 class CORE_EXPORT QgsSymbolV2
 {
   public:
@@ -212,6 +254,15 @@ class CORE_EXPORT QgsSymbolV2
     void setLayer( const QgsVectorLayer* layer ) { mLayer = layer; }
     const QgsVectorLayer* layer() const { return mLayer; }
 
+    /** Returns the result of the symbol rendering operation. This should only be
+     * called immediately after a rendering operation (eg calling renderPoint).
+     * @note added in QGIS 2.12
+     * @note this is a temporary method until QGIS 3.0. For QGIS 3.0 the render methods
+     * will return a QgsRenderResult object
+     */
+    // TODO - QGIS 3.0. Remove and make renderPoint, etc return a QgsRenderResult
+    const QgsRenderResult& renderResult() const { return mRenderResult; }
+
   protected:
     QgsSymbolV2( SymbolType type, QgsSymbolLayerV2List layers ); // can't be instantiated
 
@@ -232,6 +283,8 @@ class CORE_EXPORT QgsSymbolV2
 
     const QgsVectorLayer* mLayer; //current vectorlayer
 
+    QgsRenderResult mRenderResult;
+
 };
 
 ///////////////////////
@@ -290,11 +343,9 @@ class CORE_EXPORT QgsSymbolV2RenderContext
 };
 
 
-
 //////////////////////
 
 
-
 class CORE_EXPORT QgsMarkerSymbolV2 : public QgsSymbolV2
 {
   public: