Improve markdown to text conversion

Use a proper markdown parser to convert the text. This way more of the
formatting is correctly removed.

lib/utils/markdown.dart

@@ -0,0 +1,53 @@
+import 'dart:core';
+
+import 'package:markdown/markdown.dart' as md;
+
+/// Builds a plain text [String] from parsed Markdown.
+class MarkdownBuilder implements md.NodeVisitor {
+  List<String> _texts = [];
+
+  String build(List<md.Node> nodes) {
+    _texts.clear();
+
+    for (md.Node node in nodes) {
+      node.accept(this);
+    }
+
+    var stringBuffer = StringBuffer();
+    _texts.forEach((String text) {
+      var t = text.trim();
+      if (t.isNotEmpty) {
+        t = t.replaceAll('\n', ' ');
+        t = t.trim();
+        stringBuffer.write(t);
+        stringBuffer.write(' ');
+      }
+    });
+
+    var str = stringBuffer.toString();
+    return str.substring(0, str.length - 1);
+  }
+
+  @override
+  void visitText(md.Text text) {
+    _texts.add(text.text);
+  }
+
+  @override
+  bool visitElementBefore(md.Element element) {
+    return true;
+  }
+
+  @override
+  void visitElementAfter(md.Element element) {
+    return;
+  }
+}
+
+String markdownToPlainText(String markdown) {
+  final List<String> lines = markdown.replaceAll('\r\n', '\n').split('\n');
+  var doc = md.Document(encodeHtml: false);
+
+  final MarkdownBuilder builder = MarkdownBuilder();
+  return builder.build(doc.parseLines(lines));
+}

lib/widgets/journal_list.dart

@@ -4,6 +4,7 @@ import 'package:intl/intl.dart';
 import 'package:journal/note.dart';
 import 'package:journal/state_container.dart';
 import 'package:journal/utils.dart';
+import 'package:journal/utils/markdown.dart';
 import 'package:path/path.dart';
 
 typedef void NoteSelectedFunction(int noteIndex);
@@ -76,10 +77,7 @@ class JournalList extends StatelessWidget {
       title = basename(journal.filePath);
     }
 
-    var body = journal.body;
+    var body = markdownToPlainText(journal.body);
-    body = body.replaceAll("\n", " ");
-    body = body.replaceAll("#", "");
-    body = body.trim();
 
     var textTheme = Theme.of(context).textTheme;
     var children = <Widget>[];

test/markdown_text_test.dart

@@ -0,0 +1,23 @@
+import 'package:journal/utils/markdown.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('Markdown To Text', () {
+    test('Test Headers', () {
+      var input = '# Hello\nHow are you?';
+      expect(markdownToPlainText(input), 'Hello How are you?');
+    });
+
+    test('Itemized LIsts', () {
+      var input = """Itemized lists
+look like:
+
+  * this one
+  * that one
+      """;
+
+      expect(markdownToPlainText(input),
+          'Itemized lists look like: this one that one');
+    });
+  });
+}