diff --git a/plugins/messageviewer/bodypartformatter/autotests/diffdata/diff-akonadiconsole-16.12-master-ref.diff b/plugins/messageviewer/bodypartformatter/autotests/diffdata/diff-akonadiconsole-16.12-master-ref.diff
--- a/plugins/messageviewer/bodypartformatter/autotests/diffdata/diff-akonadiconsole-16.12-master-ref.diff
+++ b/plugins/messageviewer/bodypartformatter/autotests/diffdata/diff-akonadiconsole-16.12-master-ref.diff
@@ -1,4 +1,4 @@
-<br><div align="center"><pre style="text-align: left; border: solid black 1px; padding: 0.5em; margin: 0em;"><span style="font-weight:bold;">diff --git a/CMakeLists.txt b/CMakeLists.txt</span>
+<pre><span style="font-weight:bold;">diff --git a/CMakeLists.txt b/CMakeLists.txt</span>
 index b4ef75c..258dcc1 100644
 <span style="color:#0057ae;">--- a/CMakeLists.txt</span>
 <span style="color:#0057ae;">+++ b/CMakeLists.txt</span>
@@ -1096,5 +1096,4 @@
      virtual ~TagPropertiesDialog();
  
      Akonadi::Tag tag() const;
-
-</pre></div>
\ No newline at end of file
+</pre>
diff --git a/plugins/messageviewer/bodypartformatter/autotests/diffdata/kcontact1-ref.diff b/plugins/messageviewer/bodypartformatter/autotests/diffdata/kcontact1-ref.diff
--- a/plugins/messageviewer/bodypartformatter/autotests/diffdata/kcontact1-ref.diff
+++ b/plugins/messageviewer/bodypartformatter/autotests/diffdata/kcontact1-ref.diff
@@ -1,4 +1,4 @@
-<br><div align="center"><pre style="text-align: left; border: solid black 1px; padding: 0.5em; margin: 0em;">commit 93f6aaf446133e05826a4d8e50e2da8ffac7c28f
+<pre>commit 93f6aaf446133e05826a4d8e50e2da8ffac7c28f
 Author: David Faure &lt;faure@kde.org&gt;
 Date:   Mon Apr 17 20:41:55 2017 +0200
 
@@ -475,5 +475,4 @@
  
                  currentVCard.addLine(vCardLine);
              }
-
-</pre></div>
\ No newline at end of file
+</pre>
diff --git a/plugins/messageviewer/bodypartformatter/autotests/diffdata/test1-ref.diff b/plugins/messageviewer/bodypartformatter/autotests/diffdata/test1-ref.diff
--- a/plugins/messageviewer/bodypartformatter/autotests/diffdata/test1-ref.diff
+++ b/plugins/messageviewer/bodypartformatter/autotests/diffdata/test1-ref.diff
@@ -1,4 +1,4 @@
-<br><div align="center"><pre style="text-align: left; border: solid black 1px; padding: 0.5em; margin: 0em;"><span style="font-weight:bold;">diff --git a/plugins/messageviewer/bodypartformatter/ms-tnef/application_ms-tnef.cpp b/plugins/messageviewer/bodypartformatter/ms-tnef/application_ms-tnef.cpp</span>
+<pre><span style="font-weight:bold;">diff --git a/plugins/messageviewer/bodypartformatter/ms-tnef/application_ms-tnef.cpp b/plugins/messageviewer/bodypartformatter/ms-tnef/application_ms-tnef.cpp</span>
 index b69f56c0..2cc4ab92 100644
 <span style="color:#0057ae;">--- a/plugins/messageviewer/bodypartformatter/ms-tnef/application_ms-tnef.cpp</span>
 <span style="color:#0057ae;">+++ b/plugins/messageviewer/bodypartformatter/ms-tnef/application_ms-tnef.cpp</span>
@@ -11,5 +11,4 @@
  
              const QString iconName = QUrl::fromLocalFile(MessageViewer::Util::iconPathForMimetype(att-&gt;mimeTag(),
                                                                                                    KIconLoader::Desktop, attFileName)).url();
-
-</pre></div>
\ No newline at end of file
+</pre>
diff --git a/plugins/messageviewer/bodypartformatter/autotests/diffhighlightertest.cpp b/plugins/messageviewer/bodypartformatter/autotests/diffhighlightertest.cpp
--- a/plugins/messageviewer/bodypartformatter/autotests/diffhighlightertest.cpp
+++ b/plugins/messageviewer/bodypartformatter/autotests/diffhighlightertest.cpp
@@ -21,11 +21,17 @@
 #include "../xdiff/diffhighlighter.h"
 
 #include <QProcess>
+#include <QStandardPaths>
 #include <QTest>
 
 DiffHighlighterTest::DiffHighlighterTest(QObject *parent)
     : QObject(parent)
 {
+    QStandardPaths::setTestModeEnabled(true);
+    // trick the highlighter into using the light color theme
+    auto pal = QGuiApplication::palette();
+    pal.setColor(QPalette::Base, Qt::white);
+    QGuiApplication::setPalette(pal);
 }
 
 QString readDiffFile(const QString &diffFile)
diff --git a/plugins/messageviewer/bodypartformatter/xdiff/CMakeLists.txt b/plugins/messageviewer/bodypartformatter/xdiff/CMakeLists.txt
--- a/plugins/messageviewer/bodypartformatter/xdiff/CMakeLists.txt
+++ b/plugins/messageviewer/bodypartformatter/xdiff/CMakeLists.txt
@@ -4,6 +4,11 @@
 
 add_library(messageviewer_bodypartformatter_text_xdiff MODULE ${messageviewer_bodypartformatter_text_xdiff_PART_SRCS})
 
-target_link_libraries(messageviewer_bodypartformatter_text_xdiff  Qt5::Core KF5::I18n KF5::CoreAddons KF5::IconThemes KF5::WidgetsAddons KF5::MessageViewer KF5::SyntaxHighlighting)
+target_link_libraries(messageviewer_bodypartformatter_text_xdiff
+    Qt5::Core
+    KF5::MessageViewer
+    KF5::SyntaxHighlighting
+    Grantlee5::Templates
+)
 
 install(TARGETS messageviewer_bodypartformatter_text_xdiff  DESTINATION ${KDE_INSTALL_PLUGINDIR}/messageviewer/bodypartformatter)
diff --git a/plugins/messageviewer/bodypartformatter/xdiff/diffhighlighter.cpp b/plugins/messageviewer/bodypartformatter/xdiff/diffhighlighter.cpp
--- a/plugins/messageviewer/bodypartformatter/xdiff/diffhighlighter.cpp
+++ b/plugins/messageviewer/bodypartformatter/xdiff/diffhighlighter.cpp
@@ -21,16 +21,18 @@
 #include <KSyntaxHighlighting/Format>
 #include <KSyntaxHighlighting/Theme>
 #include <KSyntaxHighlighting/State>
+
+#include <QGuiApplication>
 #include <QPalette>
 
 DiffHighlighter::DiffHighlighter()
 {
     mDef = mRepo.definitionForName(QStringLiteral("Diff"));
     setDefinition(mDef);
 
-    setTheme(/*(palette().color(QPalette::Base).lightness() < 128)
-                 ? mRepo.defaultTheme(KSyntaxHighlighting::Repository::DarkTheme)*/
-        /*:*/ mRepo.defaultTheme(KSyntaxHighlighting::Repository::LightTheme));
+    setTheme(QGuiApplication::palette().color(QPalette::Base).lightness() < 128
+        ? mRepo.defaultTheme(KSyntaxHighlighting::Repository::DarkTheme)
+        : mRepo.defaultTheme(KSyntaxHighlighting::Repository::LightTheme));
 }
 
 DiffHighlighter::~DiffHighlighter()
@@ -40,16 +42,7 @@
 void DiffHighlighter::highlightDiff(const QString &str)
 {
     mOutputDiff.clear();
-
-    static const QLatin1String tableStyle(
-        "style=\""
-        "text-align: left; "
-        "border: solid black 1px; "
-        "padding: 0.5em; "
-        "margin: 0em;\"");
-
-    mOutputDiff = QStringLiteral("<br><div align=\"center\">");
-    mOutputDiff += QStringLiteral("<pre ") + tableStyle + QLatin1Char('>');
+    mOutputDiff = QStringLiteral("<pre>");
 
     KSyntaxHighlighting::State state;
 
@@ -61,8 +54,7 @@
         state = highlightLine(mCurrentLine, state);
         mOutputDiff += QLatin1Char('\n');
     }
-    mOutputDiff += QLatin1Char('\n');
-    mOutputDiff += QLatin1String("</pre></div>");
+    mOutputDiff += QLatin1String("</pre>\n");
 }
 
 void DiffHighlighter::applyFormat(int offset, int length, const KSyntaxHighlighting::Format &format)
diff --git a/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.cpp b/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.cpp
--- a/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.cpp
+++ b/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.cpp
@@ -31,58 +31,60 @@
 
 #include "diffhighlighter.h"
 
-#include <MessageViewer/BodyPartURLHandler>
-#include <MimeTreeParser/BodyPartFormatter>
-#include <MimeTreeParser/BodyPart>
+#include <MessageViewer/MessagePartRendererBase>
+#include <MessageViewer/MessagePartRendererManager>
+#include <MessageViewer/MessagePartRenderPlugin>
+
+#include <MimeTreeParser/MessagePart>
 #include <MimeTreeParser/HtmlWriter>
 
-#include <kstringhandler.h>
+#include <grantlee/template.h>
 
 namespace {
-// TODO: Show filename header to make it possible to save the patch.
 // FIXME: The box should only be as wide as necessary.
 
-class Formatter : public MimeTreeParser::Interface::BodyPartFormatter
+class Formatter : public MessageViewer::MessagePartRendererBase
 {
 public:
-    Result format(MimeTreeParser::Interface::BodyPart *bodyPart, MimeTreeParser::HtmlWriter *writer) const override
+    bool render(const MimeTreeParser::MessagePartPtr &msgPart, MimeTreeParser::HtmlWriter *htmlWriter, MessageViewer::RenderContext *context) const override
     {
-        if (!writer) {
-            return Ok;
-        }
-
-        if (bodyPart->defaultDisplay() == MimeTreeParser::Interface::BodyPart::AsIcon) {
-            return AsIcon;
-        }
-
-        const QString diff = bodyPart->asText();
-        if (diff.isEmpty()) {
-            return AsIcon;
-        }
-
-        DiffHighlighter highLighter;
-        highLighter.highlightDiff(diff);
-        const QString html = highLighter.outputDiff();
-        writer->write(html);
-
-        return Ok;
+        Q_UNUSED(context);
+        auto mp = msgPart.dynamicCast<MimeTreeParser::AttachmentMessagePart>();
+        if (!mp || mp->isHidden() || mp->text().isEmpty() || mp->asIcon() != MimeTreeParser::NoIcon)
+            return false;
+
+        const bool diffMimeType = msgPart->content()->contentType()->mimeType() == "text/x-patch"
+                               || msgPart->content()->contentType()->mimeType() == "text/x-diff";
+        const bool diffFileName = msgPart->content()->contentType()->name().endsWith(QLatin1String(".diff"))
+                               || msgPart->content()->contentType()->name().endsWith(QLatin1String(".patch"));
+        if (!diffMimeType && !diffFileName)
+            return false;
+
+        auto c = MessageViewer::MessagePartRendererManager::self()->createContext();
+        c.insert(QStringLiteral("block"), msgPart.data());
+        c.insert(QStringLiteral("content"), QVariant::fromValue<MessageViewer::GrantleeCallback>([msgPart](Grantlee::OutputStream *stream) {
+            DiffHighlighter highLighter;
+            highLighter.highlightDiff(msgPart->text());
+            *stream << highLighter.outputDiff();
+        }));
+
+        auto t = MessageViewer::MessagePartRendererManager::self()->loadByName(QStringLiteral(":/textmessagepart.html"));
+        Grantlee::OutputStream s(htmlWriter->stream());
+        t->render(&s, &c);
+        return true;
     }
-
-    // unhide the overload with three arguments
-    using MimeTreeParser::Interface::BodyPartFormatter::format;
 };
 
-class Plugin : public QObject, public MimeTreeParser::Interface::BodyPartFormatterPlugin
+class Plugin : public QObject, public MessageViewer::MessagePartRenderPlugin
 {
     Q_OBJECT
-    Q_INTERFACES(MimeTreeParser::Interface::BodyPartFormatterPlugin)
+    Q_INTERFACES(MessageViewer::MessagePartRenderPlugin)
     Q_PLUGIN_METADATA(IID "com.kde.messageviewer.bodypartformatter" FILE "text_xdiff.json")
 public:
-    const MimeTreeParser::Interface::BodyPartFormatter *bodyPartFormatter(int idx) const override
+    MessageViewer::MessagePartRendererBase* renderer(int index) override
     {
-        if (idx == 0) {
+        if (index == 0)
             return new Formatter();
-        }
         return nullptr;
     }
 };
diff --git a/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.json b/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.json
--- a/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.json
+++ b/plugins/messageviewer/bodypartformatter/xdiff/text_xdiff.json
@@ -1,5 +1,3 @@
-{ "formatter":
-    [
-        { "mimetype": "text/x-patch" }
-    ]
+{
+    "renderer": [ { "type": "MimeTreeParser::AttachmentMessagePart" } ]
 }