Swap some members to unique_ptrs to make ownership clearer

src/core/symbology-ng/qgssymbol.cpp

@@ -83,7 +83,6 @@ QgsSymbol::QgsSymbol( SymbolType type, const QgsSymbolLayerList &layers )
   , mRenderHints( 0 )
   , mClipFeaturesToExtent( true )
   , mLayer( nullptr )
-  , mSymbolRenderContext( nullptr )
 {
 
   // check they're all correct symbol layers
@@ -188,7 +187,6 @@ void QgsSymbol::_getPolygon( QPolygonF &pts, QList<QPolygonF> &holes, QgsRenderC
 
 QgsSymbol::~QgsSymbol()
 {
-  delete mSymbolRenderContext;
   // delete all symbol layers (we own them, so it's okay)
   qDeleteAll( mLayers );
 }
@@ -377,14 +375,12 @@ bool QgsSymbol::changeSymbolLayer( int index, QgsSymbolLayer *layer )
 
 void QgsSymbol::startRender( QgsRenderContext &context, const QgsFields &fields )
 {
-  delete mSymbolRenderContext;
-  mSymbolRenderContext = new QgsSymbolRenderContext( context, outputUnit(), mAlpha, false, mRenderHints, nullptr, fields, mapUnitScale() );
+  mSymbolRenderContext.reset( new QgsSymbolRenderContext( context, outputUnit(), mAlpha, false, mRenderHints, nullptr, fields, mapUnitScale() ) );
 
   QgsSymbolRenderContext symbolContext( context, outputUnit(), mAlpha, false, mRenderHints, nullptr, fields, mapUnitScale() );
 
-  QgsExpressionContextScope *scope = QgsExpressionContextUtils::updateSymbolScope( this, new QgsExpressionContextScope() );
-
-  mSymbolRenderContext->setExpressionContextScope( scope );
+  std::unique_ptr< QgsExpressionContextScope > scope( QgsExpressionContextUtils::updateSymbolScope( this, new QgsExpressionContextScope() ) );
+  mSymbolRenderContext->setExpressionContextScope( scope.release() );
 
   Q_FOREACH ( QgsSymbolLayer *layer, mLayers )
   {
@@ -410,8 +406,7 @@ void QgsSymbol::stopRender( QgsRenderContext &context )
     }
   }
 
-  delete mSymbolRenderContext;
-  mSymbolRenderContext = nullptr;
+  mSymbolRenderContext.reset( nullptr );
 
   mLayer = nullptr;
 }
@@ -985,7 +980,7 @@ void QgsSymbol::renderFeature( const QgsFeature &feature, QgsRenderContext &cont
 
 QgsSymbolRenderContext *QgsSymbol::symbolRenderContext()
 {
-  return mSymbolRenderContext;
+  return mSymbolRenderContext.get();
 }
 
 void QgsSymbol::renderVertexMarker( QPointF pt, QgsRenderContext &context, int currentVertexMarkerType, int currentVertexMarkerSize )
@@ -998,7 +993,6 @@ void QgsSymbol::renderVertexMarker( QPointF pt, QgsRenderContext &context, int c
 
 QgsSymbolRenderContext::QgsSymbolRenderContext( QgsRenderContext &c, QgsUnitTypes::RenderUnit u, qreal alpha, bool selected, QgsSymbol::RenderHints renderHints, const QgsFeature *f, const QgsFields &fields, const QgsMapUnitScale &mapUnitScale )
   : mRenderContext( c )
-  , mExpressionContextScope( nullptr )
   , mOutputUnit( u )
   , mMapUnitScale( mapUnitScale )
   , mAlpha( alpha )
@@ -1011,11 +1005,6 @@ QgsSymbolRenderContext::QgsSymbolRenderContext( QgsRenderContext &c, QgsUnitType
 {
 }
 
-QgsSymbolRenderContext::~QgsSymbolRenderContext()
-{
-  delete mExpressionContextScope;
-}
-
 void QgsSymbolRenderContext::setOriginalValueVariable( const QVariant &value )
 {
   mRenderContext.expressionContext().setOriginalValueVariable( value );
@@ -1043,12 +1032,12 @@ QgsSymbolRenderContext &QgsSymbolRenderContext::operator=( const QgsSymbolRender
 
 QgsExpressionContextScope *QgsSymbolRenderContext::expressionContextScope()
 {
-  return mExpressionContextScope;
+  return mExpressionContextScope.get();
 }
 
 void QgsSymbolRenderContext::setExpressionContextScope( QgsExpressionContextScope *contextScope )
 {
-  mExpressionContextScope = contextScope;
+  mExpressionContextScope.reset( contextScope );
 }
 
 ///////////////////

src/core/symbology-ng/qgssymbol.h

@@ -363,7 +363,7 @@ class CORE_EXPORT QgsSymbol
 
   private:
     //! Initialized in startRender, destroyed in stopRender
-    QgsSymbolRenderContext *mSymbolRenderContext = nullptr;
+    std::unique_ptr< QgsSymbolRenderContext > mSymbolRenderContext;
 
     Q_DISABLE_COPY( QgsSymbol )
 
@@ -391,7 +391,6 @@ class CORE_EXPORT QgsSymbolRenderContext
      * \param mapUnitScale
      */
     QgsSymbolRenderContext( QgsRenderContext &c, QgsUnitTypes::RenderUnit u, qreal alpha = 1.0, bool selected = false, QgsSymbol::RenderHints renderHints = 0, const QgsFeature *f = nullptr, const QgsFields &fields = QgsFields(), const QgsMapUnitScale &mapUnitScale = QgsMapUnitScale() );
-    ~QgsSymbolRenderContext();
 
     QgsRenderContext &renderContext() { return mRenderContext; }
     const QgsRenderContext &renderContext() const { return mRenderContext; }
@@ -497,11 +496,11 @@ class CORE_EXPORT QgsSymbolRenderContext
      *
      * \param contextScope An expression scope for details about this symbol
      */
-    void setExpressionContextScope( QgsExpressionContextScope *contextScope );
+    void setExpressionContextScope( QgsExpressionContextScope *contextScope SIP_TRANSFER );
 
   private:
     QgsRenderContext &mRenderContext;
-    QgsExpressionContextScope *mExpressionContextScope = nullptr;
+    std::unique_ptr< QgsExpressionContextScope > mExpressionContextScope;
     QgsUnitTypes::RenderUnit mOutputUnit;
     QgsMapUnitScale mMapUnitScale;
     qreal mAlpha;