diff --git a/messageviewer/src/messagepartthemes/default/defaultrenderer.cpp b/messageviewer/src/messagepartthemes/default/defaultrenderer.cpp
--- a/messageviewer/src/messagepartthemes/default/defaultrenderer.cpp
+++ b/messageviewer/src/messagepartthemes/default/defaultrenderer.cpp
@@ -866,7 +866,7 @@
         return false;
 
     const auto plugin = registry.at(0);
-    return plugin->render(this, msgPart, htmlWriter);
+    return plugin->render(msgPart, htmlWriter, this);
 }
 
 QString DefaultRendererPrivate::renderFactory(const MessagePart::Ptr &msgPart, HtmlWriter *_htmlWriter)
diff --git a/messageviewer/src/messagepartthemes/default/defaultrenderer_p.h b/messageviewer/src/messagepartthemes/default/defaultrenderer_p.h
--- a/messageviewer/src/messagepartthemes/default/defaultrenderer_p.h
+++ b/messageviewer/src/messagepartthemes/default/defaultrenderer_p.h
@@ -20,6 +20,7 @@
 #define __MESSAGEVIEWER_DEFAULTRENDERER_P_H__
 
 #include "defaultrenderer.h"
+#include "messagepartrendererbase.h"
 
 #include <MimeTreeParser/MessagePart>
 
@@ -35,14 +36,14 @@
 }
 
 namespace MimeTreeParser {
-class DefaultRendererPrivate
+class DefaultRendererPrivate : public MessageViewer::RenderContext
 {
 public:
     DefaultRendererPrivate(const MessagePart::Ptr &msgPart, CSSHelperBase *cssHelper, HtmlWriter *writer, const MessagePartRendererFactory *rendererFactory);
     ~DefaultRendererPrivate();
 
     QString alignText();
-    CSSHelperBase *cssHelper() const;
+    CSSHelperBase *cssHelper() const override;
 
     Interface::ObjectTreeSource *source() const;
 
@@ -58,7 +59,7 @@
     void render(const EncryptedMessagePart::Ptr &mp, HtmlWriter *htmlWriter);
     void render(const AlternativeMessagePart::Ptr &mp, HtmlWriter *htmlWriter);
     void render(const CertMessagePart::Ptr &mp, HtmlWriter *htmlWriter);
-    bool renderWithFactory(const QString &className, const MessagePart::Ptr &msgPart, HtmlWriter *writer);
+    bool renderWithFactory(const QString &className, const MessagePart::Ptr &msgPart, HtmlWriter *writer) override;
     QString renderFactory(const MessagePart::Ptr &msgPart, HtmlWriter *htmlWriter);
 
     QString mHtml;
diff --git a/messageviewer/src/messagepartthemes/default/messagepartrenderbase.cpp b/messageviewer/src/messagepartthemes/default/messagepartrenderbase.cpp
--- a/messageviewer/src/messagepartthemes/default/messagepartrenderbase.cpp
+++ b/messageviewer/src/messagepartthemes/default/messagepartrenderbase.cpp
@@ -29,10 +29,21 @@
 
 #include "messagepartrendererbase.h"
 
+#include <QApplication>
+
+using namespace MessageViewer;
+
+RenderContext::~RenderContext() = default;
+
 MessagePartRendererBase::MessagePartRendererBase()
 {
 }
 
 MessagePartRendererBase::~MessagePartRendererBase()
 {
 }
+
+QString MessagePartRendererBase::alignText() const
+{
+    return QApplication::isRightToLeft() ? QStringLiteral("rtl") : QStringLiteral("ltr");
+}
diff --git a/messageviewer/src/messagepartthemes/default/messagepartrendererbase.h b/messageviewer/src/messagepartthemes/default/messagepartrendererbase.h
--- a/messageviewer/src/messagepartthemes/default/messagepartrendererbase.h
+++ b/messageviewer/src/messagepartthemes/default/messagepartrendererbase.h
@@ -38,18 +38,33 @@
 #include <QSharedPointer>
 
 namespace MimeTreeParser {
-class DefaultRendererPrivate;
 class HtmlWriter;
 class MessagePart;
 typedef QSharedPointer<MessagePart> MessagePartPtr;
 }
 
+namespace MessageViewer {
+
+class CSSHelperBase;
+
+class RenderContext
+{
+public:
+    virtual ~RenderContext();
+
+    virtual CSSHelperBase* cssHelper() const = 0;
+    virtual bool renderWithFactory(const QString &className, const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *writer) = 0;
+};
+
 class MessagePartRendererBase
 {
 public:
     MessagePartRendererBase();
     virtual ~MessagePartRendererBase();
-    virtual bool render(MimeTreeParser::DefaultRendererPrivate *, const MimeTreeParser::MessagePartPtr &, MimeTreeParser::HtmlWriter *htmlWriter)
+    virtual bool render(const MimeTreeParser::MessagePartPtr &, MimeTreeParser::HtmlWriter *htmlWriter, RenderContext *context)
     const = 0;
+
+    QString alignText() const;
 };
+}
 #endif
diff --git a/messageviewer/src/messagepartthemes/default/messagepartrendererfactory.h b/messageviewer/src/messagepartthemes/default/messagepartrendererfactory.h
--- a/messageviewer/src/messagepartthemes/default/messagepartrendererfactory.h
+++ b/messageviewer/src/messagepartthemes/default/messagepartrendererfactory.h
@@ -39,9 +39,9 @@
 #include <vector>
 
 class QString;
-class MessagePartRendererBase;
 
 namespace MessageViewer {
+class MessagePartRendererBase;
 class MessagePartRendererFactoryPrivate;
 
 class MESSAGEVIEWER_EXPORT MessagePartRendererFactory
diff --git a/messageviewer/src/messagepartthemes/default/messagepartrendererfactory_p.h b/messageviewer/src/messagepartthemes/default/messagepartrendererfactory_p.h
--- a/messageviewer/src/messagepartthemes/default/messagepartrendererfactory_p.h
+++ b/messageviewer/src/messagepartthemes/default/messagepartrendererfactory_p.h
@@ -32,10 +32,10 @@
 
 #include <QMap>
 
-class MessagePartRendererBase;
 
 namespace MessageViewer {
 
+class MessagePartRendererBase;
 typedef QMap<QString, std::vector<MessagePartRendererBase *> > TypeRegistry;
 
 class MessagePartRendererFactoryPrivate
diff --git a/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.h b/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.h
--- a/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.h
+++ b/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.h
@@ -22,14 +22,16 @@
 
 #include "../messagepartrendererbase.h"
 
-#include <QSharedPointer>
+namespace MessageViewer {
 
 class AttachmentMessagePartRenderer : public MessagePartRendererBase
 {
 public:
     AttachmentMessagePartRenderer();
     virtual ~AttachmentMessagePartRenderer();
-    bool render(MimeTreeParser::DefaultRendererPrivate *drp, const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *htmlWriter) const override;
+    bool render(const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *htmlWriter, RenderContext *context) const override;
 };
 
+}
+
 #endif
diff --git a/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.cpp b/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.cpp
--- a/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.cpp
+++ b/messageviewer/src/messagepartthemes/default/plugins/attachmentmessagepartrenderer.cpp
@@ -33,15 +33,17 @@
 #include <KLocalizedString>
 #include <QUrl>
 
+using namespace MessageViewer;
+
 AttachmentMessagePartRenderer::AttachmentMessagePartRenderer()
 {
 }
 
 AttachmentMessagePartRenderer::~AttachmentMessagePartRenderer()
 {
 }
 
-bool AttachmentMessagePartRenderer::render(MimeTreeParser::DefaultRendererPrivate* drp, const MimeTreeParser::MessagePartPtr& msgPart, MimeTreeParser::HtmlWriter* htmlWriter) const
+bool AttachmentMessagePartRenderer::render(const MimeTreeParser::MessagePartPtr& msgPart, MimeTreeParser::HtmlWriter* htmlWriter, RenderContext *context) const
 {
     auto mp = msgPart.dynamicCast<AttachmentMessagePart>();
     if (!mp) {
@@ -58,7 +60,7 @@
     const auto tmpAsIcon = mp->asIcon();
 
     if (tmpAsIcon == MimeTreeParser::NoIcon) {
-        return drp->renderWithFactory(QStringLiteral("MimeTreeParser::TextMessagePart"), mp, htmlWriter);
+        return context->renderWithFactory(QStringLiteral("MimeTreeParser::TextMessagePart"), mp, htmlWriter);
     }
 
     Grantlee::Template t = MessageViewer::MessagePartRendererManager::self()->loadByName(QStringLiteral(
@@ -75,7 +77,7 @@
                                                               asUnicodeString(), true));
     block.setProperty("link", nodeHelper->asHREF(node, QStringLiteral("body")));
     block.setProperty("showLink", mp->showLink());
-    block.setProperty("dir", drp->alignText());
+    block.setProperty("dir", alignText());
     block.setProperty("iconSize",
                       MessageViewer::MessagePartRendererManager::self()->iconCurrentSize());
     block.setProperty("inline", (tmpAsIcon == MimeTreeParser::IconInline));
diff --git a/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.h b/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.h
--- a/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.h
+++ b/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.h
@@ -24,12 +24,16 @@
 
 #include <QSharedPointer>
 
+namespace MessageViewer {
+
 class MessagePartRenderer : public MessagePartRendererBase
 {
 public:
     MessagePartRenderer();
     virtual ~MessagePartRenderer();
-    bool render(MimeTreeParser::DefaultRendererPrivate *drp, const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *htmlWriter) const override;
+    bool render(const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *htmlWriter, RenderContext *context) const override;
 };
 
+}
+
 #endif
diff --git a/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.cpp b/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.cpp
--- a/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.cpp
+++ b/messageviewer/src/messagepartthemes/default/plugins/messagepartrenderer.cpp
@@ -26,22 +26,24 @@
 
 #include <MimeTreeParser/HtmlWriter>
 
+using namespace MessageViewer;
+
 MessagePartRenderer::MessagePartRenderer()
 {
 }
 
 MessagePartRenderer::~MessagePartRenderer()
 {
 }
 
-bool MessagePartRenderer::render(MimeTreeParser::DefaultRendererPrivate *drp, const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *htmlWriter) const
+bool MessagePartRenderer::render(const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *htmlWriter, RenderContext *context) const
 {
     MimeTreeParser::AttachmentMarkBlock block(nullptr, msgPart->attachmentContent());
     if (msgPart->isAttachment()) {
         htmlWriter->write(block.enter());
     }
 
-    htmlWriter->write(quotedHTML(msgPart->text(), msgPart->source(), drp->cssHelper()));
+    htmlWriter->write(quotedHTML(msgPart->text(), msgPart->source(), context->cssHelper()));
     htmlWriter->write(block.exit());
     return true;
 }
diff --git a/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.h b/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.h
--- a/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.h
+++ b/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.h
@@ -22,14 +22,16 @@
 
 #include "../messagepartrendererbase.h"
 
-#include <QSharedPointer>
+namespace MessageViewer {
 
 class TextMessagePartRenderer : public MessagePartRendererBase
 {
 public:
     TextMessagePartRenderer();
     virtual ~TextMessagePartRenderer();
-    bool render(MimeTreeParser::DefaultRendererPrivate* drp, const MimeTreeParser::MessagePartPtr& msgPart, MimeTreeParser::HtmlWriter *htmlWriter) const override;
+    bool render(const MimeTreeParser::MessagePartPtr& msgPart, MimeTreeParser::HtmlWriter *htmlWriter, RenderContext *context) const override;
 };
 
+}
+
 #endif
diff --git a/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.cpp b/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.cpp
--- a/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.cpp
+++ b/messageviewer/src/messagepartthemes/default/plugins/textmessagepartrenderer.cpp
@@ -31,7 +31,7 @@
 #include <grantlee/context.h>
 #include <grantlee/template.h>
 
-#include <QApplication>
+using namespace MessageViewer;
 
 TextMessagePartRenderer::TextMessagePartRenderer()
 {
@@ -41,13 +41,9 @@
 {
 }
 
-static QString alignText()
-{
-    return QApplication::isRightToLeft() ? QStringLiteral("rtl") : QStringLiteral("ltr");
-}
-
-bool TextMessagePartRenderer::render(MimeTreeParser::DefaultRendererPrivate* drp, const MimeTreeParser::MessagePartPtr& msgPart, MimeTreeParser::HtmlWriter* htmlWriter) const
+bool TextMessagePartRenderer::render(const MimeTreeParser::MessagePartPtr& msgPart, MimeTreeParser::HtmlWriter* htmlWriter, RenderContext *context) const
 {
+    Q_UNUSED(context);
     auto mp = msgPart.dynamicCast<TextMessagePart>();
     if (!mp)
         return false;
diff --git a/mimetreeparser/src/viewer/messagepart.h b/mimetreeparser/src/viewer/messagepart.h
--- a/mimetreeparser/src/viewer/messagepart.h
+++ b/mimetreeparser/src/viewer/messagepart.h
@@ -37,8 +37,10 @@
 #include <memory>
 
 class QTextCodec;
+namespace MessageViewer {
 class TextMessagePartRenderer;
 class AttachmentMessagePartRenderer;
+}
 
 namespace GpgME {
 class ImportResult;
@@ -207,8 +209,8 @@
     bool mDecryptMessage;
     bool mIsHidden;
 
-    friend class ::TextMessagePartRenderer;
-    friend class ::AttachmentMessagePartRenderer;
+    friend class MessageViewer::TextMessagePartRenderer;
+    friend class MessageViewer::AttachmentMessagePartRenderer;
     friend class ObjectTreeParser;
 };