Refactoring

app/src/main/java/eu/faircode/email/FragmentCompose.java

@@ -160,8 +160,6 @@ import org.bouncycastle.operator.RuntimeOperatorException;
 import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
 import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
 import org.bouncycastle.util.Store;
-import org.commonmark.node.Node;
-import org.commonmark.renderer.html.HtmlRenderer;
 import org.jsoup.nodes.Document;
 import org.jsoup.nodes.Element;
 import org.jsoup.select.Elements;
@@ -6718,16 +6716,8 @@ public class FragmentCompose extends FragmentBase {
             boolean dirty = false;
             String body;
             if (markdown ^ extras.getBoolean("markdown")) {
-                // Markdown to HTML
                 String text = spanned.toString().replace('\u00a0', ' ');
-
-                Markwon markwon = Markwon.builder(context)
-                        .usePlugin(HtmlPlugin.create())
-                        .build();
-                Node document = markwon.parse(text);
-
-                HtmlRenderer renderer = HtmlRenderer.builder().build();
-                String html = renderer.render(document);
+                String html = Markdown.toHtml(text);
 
                 Document doc = JsoupEx.parse(html);
                 doc.body().attr("markdown", Boolean.toString(markdown));
@@ -7699,8 +7689,8 @@ public class FragmentCompose extends FragmentBase {
 
                 Spanned spannedBody;
                 if (markdown) {
-                    // TODO: HTML to Markdown
-                    spannedBody = new SpannableStringBuilder(doc.html());
+                    String md = Markdown.fromHtml(doc);
+                    spannedBody = new SpannableStringBuilder(md);
                 } else {
                     HtmlHelper.clearAnnotations(doc); // Legacy left-overs
 

app/src/main/java/eu/faircode/email/Markdown.java

@@ -0,0 +1,39 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2024 by Marcel Bokhorst (M66B)
+*/
+
+import org.commonmark.node.Node;
+import org.commonmark.parser.Parser;
+import org.commonmark.renderer.html.HtmlRenderer;
+import org.jsoup.nodes.Document;
+
+public class Markdown {
+    static String toHtml(String markdown) {
+        Parser p = Parser.builder().build();
+        Node d = p.parse(markdown);
+        HtmlRenderer r = HtmlRenderer.builder().build();
+        return r.render(d);
+    }
+
+    static String fromHtml(Document d) {
+        // TODO: HTML to Markdown
+        throw new IllegalArgumentException("Not implemented");
+    }
+}

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -69,8 +69,6 @@ import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
 import org.bouncycastle.asn1.edec.EdECObjectIdentifiers;
 import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
 import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
-import org.commonmark.parser.Parser;
-import org.commonmark.renderer.html.HtmlRenderer;
 import org.jsoup.nodes.Document;
 import org.jsoup.nodes.Element;
 import org.jsoup.nodes.Node;
@@ -3995,13 +3993,10 @@ public class MessageHelper {
                     }
                 } else if (h.isMarkdown()) {
                     try {
-                        Parser p = Parser.builder().build();
-                        org.commonmark.node.Node d = p.parse(result);
-                        HtmlRenderer r = HtmlRenderer.builder().build();
-                        result = r.render(d);
+                        result = Markdown.toHtml(result);
                     } catch (Throwable ex) {
                         Log.e(ex);
-                        result = HtmlHelper.formatPlainText(Log.formatThrowable(ex));
+                        result = HtmlHelper.formatPlainText(result);
                     }
                 } else if (h.isPatch()) {
                     result = "<hr>" +