NoteFontSize: Simplify the code

lib/screens/note_viewer.dart

@@ -135,7 +135,7 @@ class NoteViewer extends StatelessWidget {
     theme = theme.copyWith(
       textTheme: theme.textTheme.copyWith(
         body1: theme.textTheme.body1
-            .copyWith(fontSize: Settings.instance.getNoteViewerFontSize()),
+            .copyWith(fontSize: Settings.instance.noteFontSize.toDouble()),
       ),
     );
 

lib/screens/settings_screen.dart

@@ -37,6 +37,8 @@ class SettingsListState extends State<SettingsList> {
 
   @override
   Widget build(BuildContext context) {
+    var settings = Settings.instance;
+
     var saveGitAuthor = (String gitAuthor) {
       Settings.instance.gitAuthor = gitAuthor;
       Settings.instance.save();
@@ -130,18 +132,18 @@ class SettingsListState extends State<SettingsList> {
       ),
       ListTile(
         title: Text("Font Size"),
-        subtitle: Text(
-          Settings.noteViewerFontSizeToString(
-              Settings.instance.noteViewerFontSize),
-        ),
+        subtitle: Text(settings.noteFontSize.toPublicString()),
         onTap: () async {
-          String result = await showDialog<String>(
-              context: context, builder: (context) => FontSizeSettingsDialog());
+          var fontSize = await showDialog<NoteFontSize>(
+            context: context,
+            builder: (context) => FontSizeSettingsDialog(),
+          );
 
-          var fontSize = Settings.noteViewerFontSizeFromString(result);
-          Settings.instance.noteViewerFontSize = fontSize;
-          Settings.instance.save();
-          setState(() {});
+          if (fontSize != null) {
+            Settings.instance.noteFontSize = fontSize;
+            Settings.instance.save();
+            setState(() {});
+          }
         },
       ),
       SettingsHeader("Git Author Settings"),
@@ -269,54 +271,11 @@ class FontSizeSettingsDialog extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    var style = Theme.of(context).textTheme.body1;
-    var sizes = <Widget>[
-      ListTile(
-        title: Text("Extra Small",
-            style: style.copyWith(
-                fontSize: Settings.noteViewerFontSizeToDouble(
-                    NoteViewerFontSize.ExtraSmall))),
-        onTap: () {
-          Navigator.of(context).pop("Extra Small");
-        },
-      ),
-      ListTile(
-        title: Text("Small",
-            style: style.copyWith(
-                fontSize: Settings.noteViewerFontSizeToDouble(
-                    NoteViewerFontSize.Small))),
-        onTap: () {
-          Navigator.of(context).pop("Small");
-        },
-      ),
-      ListTile(
-        title: Text("Normal",
-            style: style.copyWith(
-                fontSize: Settings.noteViewerFontSizeToDouble(
-                    NoteViewerFontSize.Normal))),
-        onTap: () {
-          Navigator.of(context).pop("Normal");
-        },
-      ),
-      ListTile(
-        title: Text("Large",
-            style: style.copyWith(
-                fontSize: Settings.noteViewerFontSizeToDouble(
-                    NoteViewerFontSize.Large))),
-        onTap: () {
-          Navigator.of(context).pop("Large");
-        },
-      ),
-      ListTile(
-        title: Text("Extra Large",
-            style: style.copyWith(
-                fontSize: Settings.noteViewerFontSizeToDouble(
-                    NoteViewerFontSize.ExtraLarge))),
-        onTap: () {
-          Navigator.of(context).pop("Extra Large");
-        },
-      ),
-    ];
+    var sizes = <Widget>[];
+    for (var fontSize in NoteFontSize.options) {
+      var tile = _constructTile(context, fontSize);
+      sizes.add(tile);
+    }
 
     return AlertDialog(
       title: Text(title),
@@ -327,4 +286,16 @@ class FontSizeSettingsDialog extends StatelessWidget {
       ),
     );
   }
+
+  ListTile _constructTile(BuildContext context, NoteFontSize fontSize) {
+    var style = Theme.of(context).textTheme.body1;
+    style = style.copyWith(fontSize: fontSize.toDouble());
+
+    return ListTile(
+      title: Text(fontSize.toPublicString(), style: style),
+      onTap: () {
+        Navigator.of(context).pop(fontSize);
+      },
+    );
+  }
 }

lib/settings.dart

@@ -1,6 +1,5 @@
 import 'package:shared_preferences/shared_preferences.dart';
 
-enum NoteViewerFontSize { Normal, Small, ExtraSmall, Large, ExtraLarge }
 enum NoteFileNameFormat {
   Iso8601,
   Iso8601WithTimeZone,
@@ -22,7 +21,7 @@ class Settings {
   NoteFileNameFormat noteFileNameFormat =
       NoteFileNameFormat.Iso8601WithTimeZone;
 
-  NoteViewerFontSize noteViewerFontSize = NoteViewerFontSize.Normal;
+  NoteFontSize noteFontSize;
 
   bool collectUsageStatistics = true;
   bool collectCrashReports = true;
@@ -31,11 +30,10 @@ class Settings {
     gitAuthor = pref.getString("gitAuthor") ?? gitAuthor;
     gitAuthorEmail = pref.getString("gitAuthorEmail") ?? gitAuthorEmail;
 
-    String str;
-    str = pref.getString("noteViewerFontSize") ?? noteViewerFontSize.toString();
-    noteViewerFontSize =
-        NoteViewerFontSize.values.firstWhere((e) => e.toString() == str);
+    noteFontSize =
+        NoteFontSize.fromInternalString(pref.getString("noteFontSize"));
 
+    String str;
     str = pref.getString("noteFileNameFormat") ?? noteFileNameFormat.toString();
     noteFileNameFormat =
         NoteFileNameFormat.values.firstWhere((e) => e.toString() == str);
@@ -50,7 +48,7 @@ class Settings {
     var pref = await SharedPreferences.getInstance();
     pref.setString("gitAuthor", gitAuthor);
     pref.setString("gitAuthorEmail", gitAuthorEmail);
-    pref.setString("noteViewerFontSize", noteViewerFontSize.toString());
+    pref.setString("noteFontSize", noteFontSize.toInternalString());
     pref.setString("noteFileNameFormat", noteFileNameFormat.toString());
     pref.setBool("collectUsageStatistics", collectUsageStatistics);
     pref.setBool("collectCrashReports", collectCrashReports);
@@ -60,61 +58,62 @@ class Settings {
       f();
     }
   }
+}
 
-  double getNoteViewerFontSize() {
-    return noteViewerFontSizeToDouble(noteViewerFontSize);
+class NoteFontSize {
+  static const ExtraSmall = NoteFontSize("ExtraSmall", "Small", 12.0);
+  static const Small = NoteFontSize("Small", "Small", 16.0);
+  static const Normal = NoteFontSize("Normal", "Normal", 18.0);
+  static const Large = NoteFontSize("Large", "Large", 22.0);
+  static const ExtraLarge = NoteFontSize("ExtraLarge", "Extra Large", 26.0);
+
+  static const options = <NoteFontSize>[
+    ExtraSmall,
+    Small,
+    Normal,
+    Large,
+    ExtraLarge,
+  ];
+
+  static NoteFontSize fromInternalString(String str) {
+    for (var opt in options) {
+      if (opt.toInternalString() == str) {
+        return opt;
+      }
+    }
+    return Normal;
   }
 
-  static double noteViewerFontSizeToDouble(NoteViewerFontSize size) {
-    switch (size) {
-      case NoteViewerFontSize.Normal:
-        return 18.0;
-      case NoteViewerFontSize.Small:
-        return 15.0;
-      case NoteViewerFontSize.ExtraSmall:
-        return 12.0;
-      case NoteViewerFontSize.Large:
-        return 22.0;
-      case NoteViewerFontSize.ExtraLarge:
-        return 26.0;
+  static NoteFontSize fromPublicString(String str) {
+    for (var opt in options) {
+      if (opt.toPublicString() == str) {
+        return opt;
+      }
     }
-
-    assert(false, "noteViewerFontSizeToDouble: We should never be here");
-    return 50000.0;
+    return Normal;
   }
 
-  static String noteViewerFontSizeToString(NoteViewerFontSize size) {
-    switch (size) {
-      case NoteViewerFontSize.Normal:
-        return "Normal";
-      case NoteViewerFontSize.Small:
-        return "Small";
-      case NoteViewerFontSize.ExtraSmall:
-        return "Extra Small";
-      case NoteViewerFontSize.Large:
-        return "Large";
-      case NoteViewerFontSize.ExtraLarge:
-        return "Extra Large";
-    }
+  final String _str;
+  final String _publicStr;
+  final double _value;
 
-    assert(false, "noteViewerFontSizeToString: We should never be here");
+  const NoteFontSize(this._str, this._publicStr, this._value);
+
+  String toInternalString() {
+    return _str;
+  }
+
+  String toPublicString() {
+    return _publicStr;
+  }
+
+  double toDouble() {
+    return _value;
+  }
+
+  @override
+  String toString() {
+    assert(false, "NoteFontSize toString should never be called");
     return "";
   }
-
-  static NoteViewerFontSize noteViewerFontSizeFromString(String val) {
-    switch (val) {
-      case "Extra Small":
-        return NoteViewerFontSize.ExtraSmall;
-      case "Small":
-        return NoteViewerFontSize.Small;
-      case "Normal":
-        return NoteViewerFontSize.Normal;
-      case "Large":
-        return NoteViewerFontSize.Large;
-      case "Extra Large":
-        return NoteViewerFontSize.ExtraLarge;
-      default:
-        return NoteViewerFontSize.Normal;
-    }
-  }
 }