diff --git a/lib/main.dart b/lib/main.dart
index 1e3b8c2..f2386ec 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/cupertino.dart';
+import 'package:git_touch/models/code.dart';
 import 'package:git_touch/models/settings.dart';
 import 'package:git_touch/models/theme.dart';
 import 'package:git_touch/screens/issues.dart';
@@ -34,6 +35,7 @@ class _HomeState extends State<Home> {
       // FIXME:
       Provider.of<ThemeModel>(context).init();
       Provider.of<SettingsModel>(context).init();
+      Provider.of<CodeModel>(context).init();
     });
   }
 
@@ -134,7 +136,7 @@ class _HomeState extends State<Home> {
     }
 
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return CupertinoApp(
           home: CupertinoTheme(
             data: CupertinoThemeData(
@@ -181,6 +183,7 @@ class App extends StatelessWidget {
         ChangeNotifierProvider(builder: (context) => NotificationModel()),
         ChangeNotifierProvider(builder: (context) => ThemeModel()),
         ChangeNotifierProvider(builder: (context) => SettingsModel()),
+        ChangeNotifierProvider(builder: (context) => CodeModel()),
       ],
       child: Home(),
     );
diff --git a/lib/models/code.dart b/lib/models/code.dart
new file mode 100644
index 0000000..558a59d
--- /dev/null
+++ b/lib/models/code.dart
@@ -0,0 +1,71 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter_highlight/theme_map.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class CodeModel with ChangeNotifier {
+  static const _kTheme = 'code-theme';
+  static const _kFontSize = 'code-font-size';
+  static const _kFontFamily = 'code-font-family';
+
+  static var themes = themeMap.keys.toList();
+  static const fontSizes = [12, 13, 14, 15, 16, 17, 18, 19, 20];
+  static const fontFamilies = ['System'];
+
+  String _theme = 'github';
+  int _fontSize = 14;
+  String _fontFamily = 'System';
+
+  String get theme => _theme;
+  int get fontSize => _fontSize;
+  String get fontFamily => _fontFamily;
+
+  init() async {
+    var prefs = await SharedPreferences.getInstance();
+    var vh = prefs.getString(_kTheme);
+    var vs = prefs.getInt(_kFontSize);
+    var vf = prefs.getString(_kFontFamily);
+
+    print('read code: $vh, $vs, $vf');
+    if (themeMap.keys.contains(vh)) {
+      _theme = vh;
+    }
+    if (fontSizes.contains(vs)) {
+      _fontSize = vs;
+    }
+    if (fontFamilies.contains(vf)) {
+      _fontFamily = vf;
+    }
+
+    notifyListeners();
+  }
+
+  setTheme(String v) async {
+    var prefs = await SharedPreferences.getInstance();
+
+    await prefs.setString(_kTheme, v);
+    print('write code theme: $v');
+
+    _theme = v;
+    notifyListeners();
+  }
+
+  setFontSize(int v) async {
+    var prefs = await SharedPreferences.getInstance();
+
+    await prefs.setInt(_kFontSize, v);
+    print('write code font size: $v');
+
+    _fontSize = v;
+    notifyListeners();
+  }
+
+  setFontFamily(String v) async {
+    var prefs = await SharedPreferences.getInstance();
+
+    await prefs.setString(_kFontFamily, v);
+    print('write code font family: $v');
+
+    _fontFamily = v;
+    notifyListeners();
+  }
+}
diff --git a/lib/models/theme.dart b/lib/models/theme.dart
index 8338750..fc869db 100644
--- a/lib/models/theme.dart
+++ b/lib/models/theme.dart
@@ -10,10 +10,10 @@ class DialogOption<T> {
   DialogOption({this.value, this.widget});
 }
 
-class ThemeMap {
+class AppThemeMap {
   static const material = 0;
   static const cupertino = 1;
-  static const values = [ThemeMap.material, ThemeMap.cupertino];
+  static const values = [AppThemeMap.material, AppThemeMap.cupertino];
 }
 
 class ThemeModel with ChangeNotifier {
@@ -28,12 +28,12 @@ class ThemeModel with ChangeNotifier {
 
     int v = prefs.getInt(storageKey);
     print('read theme: $v');
-    if (ThemeMap.values.contains(v)) {
+    if (AppThemeMap.values.contains(v)) {
       _theme = v;
     } else if (Platform.isIOS) {
-      _theme = ThemeMap.cupertino;
+      _theme = AppThemeMap.cupertino;
     } else {
-      _theme = ThemeMap.material;
+      _theme = AppThemeMap.material;
     }
 
     notifyListeners();
@@ -55,7 +55,7 @@ class ThemeModel with ChangeNotifier {
     bool fullscreenDialog = false,
   }) {
     switch (theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         Navigator.of(context).push(CupertinoPageRoute(
           builder: builder,
           fullscreenDialog: fullscreenDialog,
@@ -71,7 +71,7 @@ class ThemeModel with ChangeNotifier {
 
   Future<bool> showConfirm(BuildContext context, String text) {
     switch (theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return showCupertinoDialog(
           context: context,
           builder: (context) {
@@ -130,7 +130,7 @@ class ThemeModel with ChangeNotifier {
     var cancelWidget = Text('Cancel');
 
     switch (theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return showCupertinoDialog<T>(
           context: context,
           builder: (BuildContext context) {
@@ -181,4 +181,38 @@ class ThemeModel with ChangeNotifier {
         );
     }
   }
+
+  Future<T> showPicker<T>(
+    BuildContext context, {
+    @required int initialItem,
+    @required List<Widget> children,
+    @required Function(int) onSelectedItemChanged,
+  }) {
+    switch (theme) {
+      case AppThemeMap.cupertino:
+        return showCupertinoModalPopup<T>(
+          context: context,
+          builder: (context) {
+            return Container(
+              height: 300,
+              child: CupertinoPicker(
+                backgroundColor: CupertinoColors.white,
+                children: children,
+                itemExtent: 40,
+                scrollController:
+                    FixedExtentScrollController(initialItem: initialItem),
+                onSelectedItemChanged: onSelectedItemChanged,
+              ),
+            );
+          },
+        );
+      default:
+        return showModalBottomSheet<T>(
+          context: context,
+          builder: (context) {
+            return null; // TODO:
+          },
+        );
+    }
+  }
 }
diff --git a/lib/scaffolds/list.dart b/lib/scaffolds/list.dart
index eb65a52..e3e8a08 100644
--- a/lib/scaffolds/list.dart
+++ b/lib/scaffolds/list.dart
@@ -184,7 +184,7 @@ class _ListScaffoldState<T, K> extends State<ListScaffold<T, K>> {
   @override
   Widget build(BuildContext context) {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         List<Widget> slivers = [
           CupertinoSliverRefreshControl(onRefresh: _refresh)
         ];
diff --git a/lib/scaffolds/long_list.dart b/lib/scaffolds/long_list.dart
index d90d3d7..df98502 100644
--- a/lib/scaffolds/long_list.dart
+++ b/lib/scaffolds/long_list.dart
@@ -181,7 +181,7 @@ class _LongListScaffoldState<T, K> extends State<LongListScaffold<T, K>> {
   @override
   Widget build(BuildContext context) {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         List<Widget> slivers = [
           CupertinoSliverRefreshControl(onRefresh: _refresh)
         ];
diff --git a/lib/scaffolds/refresh.dart b/lib/scaffolds/refresh.dart
index 6b175bc..2bf2022 100644
--- a/lib/scaffolds/refresh.dart
+++ b/lib/scaffolds/refresh.dart
@@ -80,7 +80,7 @@ class _RefreshScaffoldState<T> extends State<RefreshScaffold<T>> {
   @override
   Widget build(BuildContext context) {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return CupertinoPageScaffold(
           navigationBar: CupertinoNavigationBar(
             middle: widget.title,
diff --git a/lib/scaffolds/refresh_stateless.dart b/lib/scaffolds/refresh_stateless.dart
index 7840116..7e214e8 100644
--- a/lib/scaffolds/refresh_stateless.dart
+++ b/lib/scaffolds/refresh_stateless.dart
@@ -41,7 +41,7 @@ class RefreshStatelessScaffold extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return CupertinoPageScaffold(
           navigationBar:
               CupertinoNavigationBar(middle: title, trailing: trailing),
diff --git a/lib/scaffolds/simple.dart b/lib/scaffolds/simple.dart
index 3f1ef5d..0c7861b 100644
--- a/lib/scaffolds/simple.dart
+++ b/lib/scaffolds/simple.dart
@@ -22,7 +22,7 @@ class SimpleScaffold extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return CupertinoPageScaffold(
           navigationBar:
               CupertinoNavigationBar(middle: title, trailing: trailing),
@@ -32,11 +32,7 @@ class SimpleScaffold extends StatelessWidget {
         );
       default:
         return Scaffold(
-          appBar: AppBar(
-            title: title,
-            actions: actions,
-            bottom: bottom,
-          ),
+          appBar: AppBar(title: title, actions: actions, bottom: bottom),
           body: SingleChildScrollView(child: bodyBuilder()),
         );
     }
diff --git a/lib/screens/code_settings.dart b/lib/screens/code_settings.dart
new file mode 100644
index 0000000..7f8e07b
--- /dev/null
+++ b/lib/screens/code_settings.dart
@@ -0,0 +1,105 @@
+import 'dart:async';
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_highlight/flutter_highlight.dart';
+import 'package:flutter_highlight/theme_map.dart';
+import 'package:git_touch/models/code.dart';
+import 'package:git_touch/models/theme.dart';
+import 'package:git_touch/scaffolds/simple.dart';
+import 'package:git_touch/utils/utils.dart';
+import 'package:git_touch/widgets/app_bar_title.dart';
+import 'package:git_touch/widgets/table_view.dart';
+import 'package:provider/provider.dart';
+
+class CodeSettingsScreen extends StatelessWidget {
+  final String code;
+  final String language;
+
+  CodeSettingsScreen(this.code, this.language);
+
+  static Timer _themeDebounce;
+
+  @override
+  Widget build(BuildContext context) {
+    var codeProvider = Provider.of<CodeModel>(context);
+
+    return SimpleScaffold(
+      title: AppBarTitle('Code theme'),
+      bodyBuilder: () {
+        return Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: <Widget>[
+            TableView(
+              items: [
+                TableViewItem(
+                    text: Text('Syntax Highlighting'),
+                    rightWidget: Text(codeProvider.theme),
+                    onTap: () {
+                      Provider.of<ThemeModel>(context).showPicker(
+                        context,
+                        children: CodeModel.themes.map((k) => Text(k)).toList(),
+                        initialItem:
+                            CodeModel.themes.indexOf(codeProvider.theme),
+                        onSelectedItemChanged: (int value) {
+                          if (_themeDebounce?.isActive ?? false)
+                            _themeDebounce.cancel();
+                          _themeDebounce =
+                              Timer(const Duration(milliseconds: 500), () {
+                            Provider.of<CodeModel>(context)
+                                .setTheme(CodeModel.themes[value]);
+                          });
+                        },
+                      );
+                    }),
+                TableViewItem(
+                  text: Text('Font Size'),
+                  rightWidget: Text(codeProvider.fontSize.toString()),
+                  onTap: () {
+                    Provider.of<ThemeModel>(context).showPicker(
+                      context,
+                      children: CodeModel.fontSizes
+                          .map((k) => Text(k.toString()))
+                          .toList(),
+                      initialItem:
+                          CodeModel.fontSizes.indexOf(codeProvider.fontSize),
+                      onSelectedItemChanged: (int value) {
+                        if (_themeDebounce?.isActive ?? false)
+                          _themeDebounce.cancel();
+                        _themeDebounce =
+                            Timer(const Duration(milliseconds: 500), () {
+                          Provider.of<CodeModel>(context)
+                              .setFontSize(CodeModel.fontSizes[value]);
+                        });
+                      },
+                    );
+                  },
+                ),
+                TableViewItem(
+                  text: Text('Font Family'),
+                  rightWidget: Text(codeProvider.fontFamily.toString()),
+                  onTap: () {
+                    // TODO:
+                  },
+                ),
+              ],
+            ),
+            SingleChildScrollView(
+              scrollDirection: Axis.horizontal,
+              child: HighlightView(
+                code,
+                language: language,
+                theme: themeMap[codeProvider.theme],
+                textStyle: TextStyle(
+                  fontSize: codeProvider.fontSize.toDouble(),
+                  fontFamily: monospaceFont,
+                ),
+                padding: const EdgeInsets.all(10),
+              ),
+            )
+          ],
+        );
+      },
+    );
+  }
+}
diff --git a/lib/screens/notifications.dart b/lib/screens/notifications.dart
index 8120135..80fdf78 100644
--- a/lib/screens/notifications.dart
+++ b/lib/screens/notifications.dart
@@ -184,7 +184,7 @@ $key: pullRequest(number: ${item.number}) {
 
   Widget _buildTitle() {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         // var textStyle = DefaultTextStyle.of(context).style;
         return DefaultTextStyle(
           style: TextStyle(fontSize: 16),
diff --git a/lib/screens/object.dart b/lib/screens/object.dart
index e28a1af..bf47c94 100644
--- a/lib/screens/object.dart
+++ b/lib/screens/object.dart
@@ -1,6 +1,10 @@
-import 'package:flutter_highlight/themes/github.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter_highlight/theme_map.dart';
+import 'package:git_touch/models/code.dart';
+import 'package:git_touch/screens/code_settings.dart';
 import 'package:git_touch/screens/image_view.dart';
 import 'package:git_touch/widgets/app_bar_title.dart';
+import 'package:git_touch/widgets/link.dart';
 import 'package:git_touch/widgets/markdown_view.dart';
 import 'package:git_touch/widgets/table_view.dart';
 import 'package:path/path.dart' as path;
@@ -10,7 +14,6 @@ import 'package:git_touch/models/settings.dart';
 import 'package:provider/provider.dart';
 import 'package:git_touch/scaffolds/refresh.dart';
 import 'package:git_touch/utils/utils.dart';
-import 'package:git_touch/widgets/link.dart';
 import 'package:primer/primer.dart';
 import 'package:seti/seti.dart';
 
@@ -29,14 +32,16 @@ class ObjectScreen extends StatelessWidget {
     this.type = 'tree',
   });
 
-  String get expression => '$branch:' + paths.join('/');
-  String get extname {
+  String get _expression => '$branch:' + paths.join('/');
+  String get _extname {
     if (paths.isEmpty) return '';
     var dotext = path.extension(paths.last);
     if (dotext.isEmpty) return '';
     return dotext.substring(1);
   }
 
+  String get _language => _extname.isEmpty ? 'plaintext' : _extname;
+
   String get rawUrl =>
       'https://raw.githubusercontent.com/$owner/$name/$branch/' +
       paths.join('/'); // TODO:
@@ -111,8 +116,9 @@ class ObjectScreen extends StatelessWidget {
     );
   }
 
-  Widget _buildBlob(payload) {
-    switch (extname) {
+  Widget _buildBlob(BuildContext context, payload) {
+    var codeProvider = Provider.of<CodeModel>(context);
+    switch (_extname) {
       case 'md':
       case 'markdown':
         return Padding(
@@ -124,10 +130,12 @@ class ObjectScreen extends StatelessWidget {
           scrollDirection: Axis.horizontal,
           child: HighlightView(
             payload['text'],
-            language: extname.isEmpty ? 'plaintext' : extname,
-            theme: githubTheme,
+            language: _language,
+            theme: themeMap[codeProvider.theme],
             padding: EdgeInsets.all(10),
-            textStyle: TextStyle(fontFamily: monospaceFont),
+            textStyle: TextStyle(
+                fontSize: codeProvider.fontSize.toDouble(),
+                fontFamily: monospaceFont),
           ),
         );
     }
@@ -140,7 +148,7 @@ class ObjectScreen extends StatelessWidget {
       onRefresh: () async {
         var data = await Provider.of<SettingsModel>(context).query('''{
   repository(owner: "$owner", name: "$name") {
-    object(expression: "$expression") {
+    object(expression: "$_expression") {
       $_subQuery
     }
   }
@@ -161,12 +169,25 @@ class ObjectScreen extends StatelessWidget {
 
         return data['repository']['object'];
       },
+      trailingBuilder: (payload) {
+        switch (type) {
+          case 'blob':
+            return Link(
+              child: Icon(Octicons.settings, size: 20),
+              material: false,
+              screenBuilder: (_) =>
+                  CodeSettingsScreen(payload['text'], _language),
+            );
+          default:
+            return null;
+        }
+      },
       bodyBuilder: (payload) {
         switch (type) {
           case 'tree':
             return _buildTree(payload);
           case 'blob':
-            return _buildBlob(payload);
+            return _buildBlob(context, payload);
           default:
             return null;
         }
diff --git a/lib/screens/search.dart b/lib/screens/search.dart
index 345d360..16ef9f6 100644
--- a/lib/screens/search.dart
+++ b/lib/screens/search.dart
@@ -46,7 +46,7 @@ class _SearchScreenState extends State<SearchScreen> {
 
   Widget _buildInput() {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return CupertinoTextField(
           // padding: EdgeInsets.all(10),
           placeholder: 'Type to search',
diff --git a/lib/screens/settings.dart b/lib/screens/settings.dart
index f26d008..e0569c0 100644
--- a/lib/screens/settings.dart
+++ b/lib/screens/settings.dart
@@ -37,11 +37,11 @@ class SettingsScreen extends StatelessWidget {
             TableView(headerText: 'THEME', items: [
               TableViewItem(
                 text: Text('Material'),
-                rightWidget:
-                    _buildRightWidget(themeProvider.theme == ThemeMap.material),
+                rightWidget: _buildRightWidget(
+                    themeProvider.theme == AppThemeMap.material),
                 onTap: () {
-                  if (themeProvider.theme != ThemeMap.material) {
-                    themeProvider.setTheme(ThemeMap.material);
+                  if (themeProvider.theme != AppThemeMap.material) {
+                    themeProvider.setTheme(AppThemeMap.material);
                   }
                 },
                 hideRightChevron: true,
@@ -49,10 +49,10 @@ class SettingsScreen extends StatelessWidget {
               TableViewItem(
                 text: Text('Cupertino'),
                 rightWidget: _buildRightWidget(
-                    themeProvider.theme == ThemeMap.cupertino),
+                    themeProvider.theme == AppThemeMap.cupertino),
                 onTap: () {
-                  if (themeProvider.theme != ThemeMap.cupertino) {
-                    themeProvider.setTheme(ThemeMap.cupertino);
+                  if (themeProvider.theme != AppThemeMap.cupertino) {
+                    themeProvider.setTheme(AppThemeMap.cupertino);
                   }
                 },
                 hideRightChevron: true,
diff --git a/lib/screens/user.dart b/lib/screens/user.dart
index 84f7944..e1d3811 100644
--- a/lib/screens/user.dart
+++ b/lib/screens/user.dart
@@ -148,7 +148,7 @@ class UserScreen extends StatelessWidget {
         var payload = data[0];
         if (isMe) {
           return Link(
-            child: Icon(Icons.settings, size: 24),
+            child: Icon(Icons.settings),
             screenBuilder: (_) => SettingsScreen(),
             material: false,
             fullscreenDialog: true,
diff --git a/lib/widgets/action.dart b/lib/widgets/action.dart
index a28ade3..0aac5be 100644
--- a/lib/widgets/action.dart
+++ b/lib/widgets/action.dart
@@ -30,7 +30,7 @@ class ActionButton extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return GestureDetector(
           child: Icon(iconData, size: 24),
           onTap: () async {
diff --git a/lib/widgets/link.dart b/lib/widgets/link.dart
index 92a5f0c..7967418 100644
--- a/lib/widgets/link.dart
+++ b/lib/widgets/link.dart
@@ -66,7 +66,8 @@ class Link extends StatelessWidget {
         color: bgColor ?? Colors.white,
         child: InkWell(
           child: child,
-          splashColor: theme == ThemeMap.cupertino ? Colors.transparent : null,
+          splashColor:
+              theme == AppThemeMap.cupertino ? Colors.transparent : null,
           onTap: () => _onTap(context, theme),
         ),
       ),
diff --git a/lib/widgets/loading.dart b/lib/widgets/loading.dart
index 2b4365d..3d829c1 100644
--- a/lib/widgets/loading.dart
+++ b/lib/widgets/loading.dart
@@ -12,7 +12,7 @@ class Loading extends StatelessWidget {
     // return Image.asset('images/loading.webp');
 
     switch (Provider.of<ThemeModel>(context).theme) {
-      case ThemeMap.cupertino:
+      case AppThemeMap.cupertino:
         return CupertinoActivityIndicator(radius: 12);
       default:
         return Center(
diff --git a/pubspec.yaml b/pubspec.yaml
index fc750d3..196898b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -16,7 +16,7 @@ dependencies:
   flutter:
     sdk: flutter
   http: ^0.12.0
-  rxdart: ^0.20.0
+  rxdart: ^0.22.2
   uri: ^0.11.3
   intl: ^0.15.7
   url_launcher: ^5.0.2