From e6863be68e100c68b215009e513b436477907564 Mon Sep 17 00:00:00 2001
From: Martin Dobias <wonder.sk@gmail.com>
Date: Thu, 22 Jun 2017 10:58:41 +0200
Subject: [PATCH] Fix subclassing of QgsDiagramRenderer in Python

---
 python/core/qgsdiagramrenderer.sip |  9 +++++++++
 src/core/qgsdiagramrenderer.h      | 12 ++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/python/core/qgsdiagramrenderer.sip b/python/core/qgsdiagramrenderer.sip
index fce5d15a5fe..ab09f9b89ba 100644
--- a/python/core/qgsdiagramrenderer.sip
+++ b/python/core/qgsdiagramrenderer.sip
@@ -450,6 +450,15 @@ class QgsDiagramRenderer
 
 %TypeHeaderCode
 #include "qgsdiagramrenderer.h"
+%End
+
+%ConvertToSubClassCode
+    if ( sipCpp->rendererName() == QStringLiteral( "SingleCategory" ) )
+      sipType = sipType_QgsSingleCategoryDiagramRenderer;
+    else if ( sipCpp->rendererName() == QStringLiteral( "LinearlyInterpolated" ) )
+      sipType = sipType_QgsLinearlyInterpolatedDiagramRenderer;
+    else
+      sipType = NULL;
 %End
   public:
 
diff --git a/src/core/qgsdiagramrenderer.h b/src/core/qgsdiagramrenderer.h
index 43dc684de29..76369c1f51e 100644
--- a/src/core/qgsdiagramrenderer.h
+++ b/src/core/qgsdiagramrenderer.h
@@ -485,6 +485,18 @@ class CORE_EXPORT QgsDiagramInterpolationSettings
 
 class CORE_EXPORT QgsDiagramRenderer
 {
+
+#ifdef SIP_RUN
+    SIP_CONVERT_TO_SUBCLASS_CODE
+    if ( sipCpp->rendererName() == QStringLiteral( "SingleCategory" ) )
+      sipType = sipType_QgsSingleCategoryDiagramRenderer;
+    else if ( sipCpp->rendererName() == QStringLiteral( "LinearlyInterpolated" ) )
+      sipType = sipType_QgsLinearlyInterpolatedDiagramRenderer;
+    else
+      sipType = NULL;
+    SIP_END
+#endif
+
   public:
 
     QgsDiagramRenderer();