refactor to a more general convertFromRenderer function

Author: leyan

python/core/symbology-ng/qgscategorizedsymbolrendererv2.sip

@@ -55,7 +55,7 @@ class QgsCategorizedSymbolRendererV2 : QgsFeatureRendererV2
 
     virtual QString dump() const;
 
-    virtual QgsFeatureRendererV2* clone() /Factory/;
+    virtual QgsFeatureRendererV2* clone() const /Factory/;
 
     virtual void toSld( QDomDocument& doc, QDomElement &element ) const;
 
@@ -147,9 +147,10 @@ class QgsCategorizedSymbolRendererV2 : QgsFeatureRendererV2
     // @note added in 2.5
     virtual void checkLegendSymbolItem( QString key, bool state = true );
 
-    //! convert the renderer to a rule based renderer with equivalent rules
+    //! creates a QgsCategorizedSymbolRendererV2 from an existing renderer.
     //! @note added in 2.5
-    virtual QgsRuleBasedRendererV2* convertToRuleBasedRenderer() /Factory/;
+    //! @returns a new renderer if the conversion was possible, otherwise 0.
+    static QgsCategorizedSymbolRendererV2* convertFromRenderer( const QgsFeatureRendererV2 *renderer ) /Factory/;
 
   protected:
     void rebuildHash();

python/core/symbology-ng/qgsgraduatedsymbolrendererv2.sip

@@ -59,7 +59,7 @@ class QgsGraduatedSymbolRendererV2 : QgsFeatureRendererV2
 
     virtual QString dump() const;
 
-    virtual QgsFeatureRendererV2* clone() /Factory/;
+    virtual QgsFeatureRendererV2* clone() const /Factory/;
 
     virtual void toSld( QDomDocument& doc, QDomElement &element ) const;
 
@@ -173,11 +173,10 @@ class QgsGraduatedSymbolRendererV2 : QgsFeatureRendererV2
     // @note added in 2.5
     virtual void checkLegendSymbolItem( QString key, bool state = true );
 
-    //! convert the renderer to a rule based renderer with equivalent rules
+    //! creates a QgsGraduatedSymbolRendererV2 from an existing renderer.
     //! @note added in 2.5
-    virtual QgsRuleBasedRendererV2* convertToRuleBasedRenderer() /Factory/;
-
-
+    //! @returns a new renderer if the conversion was possible, otherwise 0.
+    static QgsGraduatedSymbolRendererV2* convertFromRenderer( const QgsFeatureRendererV2 *renderer ) /Factory/;
 
   protected:
     QgsSymbolV2* symbolForValue( double value );

python/core/symbology-ng/qgsinvertedpolygonrenderer.sip

@@ -12,7 +12,7 @@ class QgsInvertedPolygonRenderer : QgsFeatureRendererV2
     virtual ~QgsInvertedPolygonRenderer();
 
     /** Used to clone this feature renderer.*/
-    virtual QgsFeatureRendererV2* clone() /Factory/;
+    virtual QgsFeatureRendererV2* clone() const /Factory/;
 
     virtual void startRender( QgsRenderContext& context, const QgsFields& fields );
 
@@ -81,4 +81,10 @@ class QgsInvertedPolygonRenderer : QgsFeatureRendererV2
         This will involve some CPU-demanding computations and is thus disabled by default.
     */
     void setPreprocessingEnabled( bool enabled );
+
+    /** creates a QgsInvertedPolygonRenderer by a conversion from an existing renderer.
+        @note added in 2.5
+        @returns a new renderer if the conversion was possible, otherwise 0.
+        */
+    static QgsInvertedPolygonRenderer* convertFromRenderer( const QgsFeatureRendererV2* renderer ) /Factory/;
 };

python/core/symbology-ng/qgspointdisplacementrenderer.sip

@@ -7,7 +7,7 @@ class QgsPointDisplacementRenderer : QgsFeatureRendererV2
     QgsPointDisplacementRenderer( const QString& labelAttributeName = "" );
     ~QgsPointDisplacementRenderer();
 
-    QgsFeatureRendererV2* clone() /Factory/;
+    QgsFeatureRendererV2* clone() const /Factory/;
 
     virtual void toSld( QDomDocument& doc, QDomElement &element ) const;
 
@@ -69,6 +69,11 @@ class QgsPointDisplacementRenderer : QgsFeatureRendererV2
     void setTolerance( double t );
     double tolerance() const;
 
+    //! creates a QgsPointDisplacementRenderer from an existing renderer.
+    //! @note added in 2.5
+    //! @returns a new renderer if the conversion was possible, otherwise 0.
+    static QgsPointDisplacementRenderer* convertFromRenderer(const QgsFeatureRendererV2 *renderer ) /Factory/;
+
   private:
     QgsPointDisplacementRenderer( const QgsPointDisplacementRenderer & );
     QgsPointDisplacementRenderer & operator=( const QgsPointDisplacementRenderer & );

python/core/symbology-ng/qgsrendererv2.sip

@@ -71,7 +71,7 @@ class QgsFeatureRendererV2
 
     virtual ~QgsFeatureRendererV2();
 
-    virtual QgsFeatureRendererV2* clone() = 0 /Factory/;
+    virtual QgsFeatureRendererV2* clone() const = 0 /Factory/;
 
     virtual bool renderFeature( QgsFeature& feature, QgsRenderContext& context, int layer = -1, bool selected = false, bool drawVertexMarker = false );
 
@@ -175,10 +175,6 @@ class QgsFeatureRendererV2
     //! @note added in 1.9
     virtual QgsSymbolV2List symbolsForFeature( QgsFeature& feat );
 
-    //! convert the renderer to a rule based renderer with equivalent rules, if possible
-    //! @note added in 2.5
-    virtual QgsRuleBasedRendererV2* convertToRuleBasedRenderer() /Factory/;
-
   protected:
     QgsFeatureRendererV2( QString type );
 

python/core/symbology-ng/qgsrulebasedrendererv2.sip

@@ -164,7 +164,7 @@ class QgsRuleBasedRendererV2 : QgsFeatureRendererV2
 
     virtual QList<QString> usedAttributes();
 
-    virtual QgsFeatureRendererV2* clone() /Factory/;
+    virtual QgsFeatureRendererV2* clone() const /Factory/;
 
     virtual void toSld( QDomDocument& doc, QDomElement &element ) const;
 
@@ -231,9 +231,13 @@ class QgsRuleBasedRendererV2 : QgsFeatureRendererV2
     //! take a rule and create a list of new rules with intervals of scales given by the passed scale denominators
     static void refineRuleScales( QgsRuleBasedRendererV2::Rule* initialRule, QList<int> scales );
 
-    //! convert the renderer to a rule based renderer with equivalent rules, if possible
+    //! creates a QgsRuleBasedRendererV2 from an existing renderer.
     //! @note added in 2.5
-    virtual QgsRuleBasedRendererV2* convertToRuleBasedRenderer() /Factory/;
+    //! @returns a new renderer if the conversion was possible, otherwise 0.
+    static QgsRuleBasedRendererV2* convertFromRenderer( const QgsFeatureRendererV2 *renderer ) /Factory/;
+
+    //! helper function to convert the size scale and rotation fields present in some other renderers to data defined symbology
+    static void convertToDataDefinedSymbology( QgsSymbolV2* symbol, QString sizeScaleField, QString rotationField );
 
   private:
     QgsRuleBasedRendererV2( const QgsRuleBasedRendererV2 & );

python/core/symbology-ng/qgssinglesymbolrendererv2.sip

@@ -37,7 +37,7 @@ class QgsSingleSymbolRendererV2 : QgsFeatureRendererV2
 
     virtual QString dump() const;
 
-    virtual QgsFeatureRendererV2* clone() /Factory/;
+    virtual QgsFeatureRendererV2* clone() const /Factory/;
 
     virtual void toSld( QDomDocument& doc, QDomElement &element ) const;
     static QgsFeatureRendererV2* createFromSld( QDomElement& element, QGis::GeometryType geomType );
@@ -66,9 +66,10 @@ class QgsSingleSymbolRendererV2 : QgsFeatureRendererV2
     //! @note added in 2.6
     virtual QgsLegendSymbolListV2 legendSymbolItemsV2() const;
 
-    //! convert the renderer to a rule based renderer with equivalent rules
+    //! creates a QgsSingleSymbolRendererV2 from an existing renderer.
     //! @note added in 2.5
-    virtual QgsRuleBasedRendererV2* convertToRuleBasedRenderer() /Factory/;
+    //! @returns a new renderer if the conversion was possible, otherwise 0.
+    static QgsSingleSymbolRendererV2* convertFromRenderer( const QgsFeatureRendererV2 *renderer ) /Factory/;
 
   private:
     QgsSingleSymbolRendererV2( const QgsSingleSymbolRendererV2 & );

src/core/symbology-ng/qgscategorizedsymbolrendererv2.cpp

@@ -19,7 +19,8 @@
 #include "qgssymbolv2.h"
 #include "qgssymbollayerv2utils.h"
 #include "qgsvectorcolorrampv2.h"
-#include "qgsrulebasedrendererv2.h"
+#include "qgspointdisplacementrenderer.h"
+#include "qgsinvertedpolygonrenderer.h"
 
 #include "qgsfeature.h"
 #include "qgsvectorlayer.h"
@@ -463,7 +464,7 @@ QString QgsCategorizedSymbolRendererV2::dump() const
   return s;
 }
 
-QgsFeatureRendererV2* QgsCategorizedSymbolRendererV2::clone()
+QgsFeatureRendererV2* QgsCategorizedSymbolRendererV2::clone() const
 {
   QgsCategorizedSymbolRendererV2* r = new QgsCategorizedSymbolRendererV2( mAttrName, mCategories );
   if ( mSourceSymbol.data() )
@@ -760,93 +761,21 @@ void QgsCategorizedSymbolRendererV2::checkLegendSymbolItem( QString key, bool st
 
 QgsMarkerSymbolV2 QgsCategorizedSymbolRendererV2::sSkipRender;
 
-QgsRuleBasedRendererV2* QgsCategorizedSymbolRendererV2::convertToRuleBasedRenderer()
+QgsCategorizedSymbolRendererV2* QgsCategorizedSymbolRendererV2::convertFromRenderer( const QgsFeatureRendererV2 *renderer )
 {
-  QgsRuleBasedRendererV2::Rule* rootrule = new QgsRuleBasedRendererV2::Rule( NULL );
-
-  QString expression;
-  QString sizeExpression;
-  QString value;
-  for ( int i = 0; i < mCategories.size();++i )
+  if ( renderer->type() == "categorizedSymbol" )
   {
-    QgsRuleBasedRendererV2::Rule* rule = new QgsRuleBasedRendererV2::Rule( NULL );
-
-    rule->setLabel( mCategories[i].label() );
-
-    //We first define the rule corresponding to the category
-    //If the value is a number, we can use it directly, otherwise we need to quote it in the rule
-    if ( QVariant( mCategories[i].value() ).convert( QVariant::Double ) )
-    {
-      value = mCategories[i].value().toString();
-    }
-    else
-    {
-      value = "'" + mCategories[i].value().toString() + "'";
-    }
-
-    //An empty category is equivalent to the ELSE keyword
-    if ( value == "''" )
-      expression = "ELSE";
-    else
-      expression = classAttribute() + " = " + value;
-    rule->setFilterExpression( expression );
-
-    //Then we construct an equivalent symbol.
-    //Ideally we could simply copy the symbol, but the categorized renderer allows a separate interface to specify
-    //data dependent area and rotation, so we need to convert these to obtain the same rendering
-
-    QgsSymbolV2* origSymbol = mCategories[i].symbol()->clone();
-
-    switch ( origSymbol->type() )
-    {
-      case QgsSymbolV2::Marker:
-        for ( int j = 0; j < origSymbol->symbolLayerCount();++j )
-        {
-          QgsMarkerSymbolLayerV2* msl = static_cast<QgsMarkerSymbolLayerV2*>( origSymbol->symbolLayer( j ) );
-          if ( mSizeScale.data() )
-          {
-            sizeExpression = QString( "%1*(%2)" ).arg( msl->size() ).arg( sizeScaleField() );
-            msl->setDataDefinedProperty( "size", sizeExpression );
-          }
-          if ( mRotation.data() )
-          {
-            msl->setDataDefinedProperty( "angle", rotationField() );
-          }
-        }
-        break;
-      case QgsSymbolV2::Line:
-        if ( mSizeScale.data() )
-        {
-          for ( int j = 0; j < origSymbol->symbolLayerCount();++j )
-          {
-            if ( origSymbol->symbolLayer( j )->layerType() == "SimpleLine" )
-            {
-              QgsLineSymbolLayerV2* lsl = static_cast<QgsLineSymbolLayerV2*>( origSymbol->symbolLayer( j ) );
-              sizeExpression = QString( "%1*(%2)" ).arg( lsl->width() ).arg( sizeScaleField() );
-              lsl->setDataDefinedProperty( "width", sizeExpression );
-            }
-            if ( origSymbol->symbolLayer( j )->layerType() == "MarkerLine" )
-            {
-              QgsSymbolV2* marker = origSymbol->symbolLayer( j )->subSymbol();
-              for ( int k = 0; k < marker->symbolLayerCount();++k )
-              {
-                QgsMarkerSymbolLayerV2* msl = static_cast<QgsMarkerSymbolLayerV2*>( marker->symbolLayer( k ) );
-                sizeExpression = QString( "%1*(%2)" ).arg( msl->size() ).arg( sizeScaleField() );
-                msl->setDataDefinedProperty( "size", sizeExpression );
-              }
-            }
-          }
-        }
-        break;
-      default:
-        break;
-    }
-
-    rule->setSymbol( origSymbol );
-
-    rootrule->appendChild( rule );
+    return dynamic_cast<QgsCategorizedSymbolRendererV2*>( renderer->clone() );
   }
-
-  return new QgsRuleBasedRendererV2( rootrule );
-
+  if ( renderer->type() == "pointDisplacement" )
+  {
+    const QgsPointDisplacementRenderer* pointDisplacementRenderer = dynamic_cast<const QgsPointDisplacementRenderer*>( renderer );
+    return convertFromRenderer( pointDisplacementRenderer->embeddedRenderer() );
+  }
+  if ( renderer->type() == "invertedPolygonRenderer" )
+  {
+    const QgsInvertedPolygonRenderer* invertedPolygonRenderer = dynamic_cast<const QgsInvertedPolygonRenderer*>( renderer );
+    return convertFromRenderer( invertedPolygonRenderer->embeddedRenderer() );
+  }
+  return 0;
 }

src/core/symbology-ng/qgscategorizedsymbolrendererv2.h

@@ -24,7 +24,6 @@
 
 class QgsVectorColorRampV2;
 class QgsVectorLayer;
-class QgsRuleBasedRendererV2;
 
 /* \brief categorized renderer */
 class CORE_EXPORT QgsRendererCategoryV2
@@ -86,7 +85,7 @@ class CORE_EXPORT QgsCategorizedSymbolRendererV2 : public QgsFeatureRendererV2
 
     virtual QString dump() const;
 
-    virtual QgsFeatureRendererV2* clone();
+    virtual QgsFeatureRendererV2* clone() const;
 
     virtual void toSld( QDomDocument& doc, QDomElement &element ) const;
 
@@ -166,9 +165,8 @@ class CORE_EXPORT QgsCategorizedSymbolRendererV2 : public QgsFeatureRendererV2
     //! @note added in 2.0
     QgsSymbolV2::ScaleMethod scaleMethod() const { return mScaleMethod; }
 
-
     //! items of symbology items in legend should be checkable
-    // @note added in 2.5
+    //! @note added in 2.5
     virtual bool legendSymbolItemsCheckable() const;
 
     //! item in symbology was checked
@@ -183,9 +181,10 @@ class CORE_EXPORT QgsCategorizedSymbolRendererV2 : public QgsFeatureRendererV2
     //! @note added in 2.6
     virtual QString legendClassificationAttribute() const { return classAttribute(); }
 
-    //! convert the renderer to a rule based renderer with equivalent rules
+    //! creates a QgsCategorizedSymbolRendererV2 from an existing renderer.
     //! @note added in 2.5
-    virtual QgsRuleBasedRendererV2* convertToRuleBasedRenderer();
+    //! @returns a new renderer if the conversion was possible, otherwise 0.
+    static QgsCategorizedSymbolRendererV2* convertFromRenderer( const QgsFeatureRendererV2 *renderer );
 
   protected:
     QString mAttrName;