Add asImage method for QgsSymbol

Author: NathanW2

python/core/symbology-ng/qgssymbolv2.sip

@@ -85,6 +85,8 @@ class QgsSymbolV2
     //! @note customContext parameter added in 2.6
     void drawPreviewIcon( QPainter* painter, QSize size, QgsRenderContext* customContext = 0 );
 
+    QImage asImage( QSize size, QgsRenderContext* customContext = 0 );
+
     QImage bigSymbolPreviewImage();
 
     QString dump() const;

src/core/symbology-ng/qgssymbolv2.cpp

@@ -308,6 +308,19 @@ void QgsSymbolV2::drawPreviewIcon( QPainter* painter, QSize size, QgsRenderConte
   }
 }
 
+QImage QgsSymbolV2::asImage( QSize size, QgsRenderContext* customContext )
+{
+  QImage image( size , QImage::Format_ARGB32_Premultiplied );
+  image.fill( 0 );
+
+  QPainter p( &image );
+  p.setRenderHint( QPainter::Antialiasing );
+
+  drawPreviewIcon( &p, size, customContext );
+
+  return image;
+}
+
 
 QImage QgsSymbolV2::bigSymbolPreviewImage()
 {

src/core/symbology-ng/qgssymbolv2.h

@@ -110,6 +110,8 @@ class CORE_EXPORT QgsSymbolV2
     //! @note customContext parameter added in 2.6
     void drawPreviewIcon( QPainter* painter, QSize size, QgsRenderContext* customContext = 0 );
 
+    QImage asImage( QSize size, QgsRenderContext* customContext = 0 );
+
     QImage bigSymbolPreviewImage();
 
     QString dump() const;