Migrate layouts preferences

The new `layouts` preference replaces three previous preferences:

    layout
    second_layout
    custom_layout

Add a preference migration function, which first migration is to
migrate layouts into the new preference.

The migration must also be called from the SettingsActivity as it might
use a different preference store due to the boot-aware preference copy.

srcs/juloo.keyboard2/Config.java

@@ -348,6 +348,7 @@ char inverse_numpad_char(char c)
   public static void initGlobalConfig(SharedPreferences prefs, Resources res,
       IKeyEventHandler handler)
   {
+    migrate(prefs);
     _globalConfig = new Config(prefs, res, handler);
   }
 
@@ -360,4 +361,45 @@ public static interface IKeyEventHandler
   {
     public void key_up(KeyValue value, Pointers.Modifiers flags);
   }
+
+  /** Config migrations. */
+
+  private static int CONFIG_VERSION = 1;
+
+  public static void migrate(SharedPreferences prefs)
+  {
+    int saved_version = prefs.getInt("version", 0);
+    Logs.debug_config_migration(saved_version, CONFIG_VERSION);
+    if (saved_version == CONFIG_VERSION)
+      return;
+    SharedPreferences.Editor e = prefs.edit();
+    e.putInt("version", CONFIG_VERSION);
+    // Migrations might run on an empty [prefs] for new installs, in this case
+    // they set the default values of complex options.
+    switch (saved_version) // Fallback switch
+    {
+      case 0:
+        // Primary, secondary and custom layout options are merged into the new
+        // Layouts option. This also sets the default value.
+        List<LayoutsPreference.Layout> l = new ArrayList<LayoutsPreference.Layout>();
+        l.add(migrate_layout(prefs.getString("layout", "system")));
+        String snd_layout = prefs.getString("second_layout", "none");
+        if (snd_layout != null && !snd_layout.equals("none"))
+          l.add(migrate_layout(snd_layout));
+        String custom_layout = prefs.getString("custom_layout", "");
+        if (custom_layout != null && !custom_layout.equals(""))
+          l.add(new LayoutsPreference.CustomLayout(custom_layout));
+        LayoutsPreference.save_to_preferences(e, l);
+      case 1:
+      default: break;
+    }
+    e.commit();
+  }
+
+  private static LayoutsPreference.Layout migrate_layout(String name)
+  {
+    if (name == null || name.equals("system"))
+      return new LayoutsPreference.SystemLayout();
+    return new LayoutsPreference.NamedLayout(name);
+  }
 }

srcs/juloo.keyboard2/Keyboard2.java

@@ -93,9 +93,9 @@ public void onCreate()
     super.onCreate();
     KeyboardData.init(getResources());
     SharedPreferences prefs = DirectBootAwarePreferences.get_shared_preferences(this);
-    prefs.registerOnSharedPreferenceChangeListener(this);
     _keyeventhandler = new KeyEventHandler(getMainLooper(), this.new Receiver());
     Config.initGlobalConfig(prefs, getResources(), _keyeventhandler);
+    prefs.registerOnSharedPreferenceChangeListener(this);
     _config = Config.globalConfig();
     _keyboardView = (Keyboard2View)inflate_view(R.layout.keyboard);
     _keyboardView.reset();

srcs/juloo.keyboard2/LayoutsPreference.java

@@ -75,6 +75,12 @@ else if (l instanceof CustomLayout)
     return layouts;
   }
 
+  /** Does not call [prefs.commit()]. */
+  public static void save_to_preferences(SharedPreferences.Editor prefs, List<Layout> items)
+  {
+    save_to_preferences(KEY, prefs, items, SERIALIZER);
+  }
+
   public static KeyboardData layout_of_string(Resources res, String name)
   {
     int id = layout_id_of_name(res, name);

srcs/juloo.keyboard2/ListGroupPreference.java

@@ -78,6 +78,12 @@ static <E> List<E> load_from_preferences(String key,
     return (s != null) ? load_from_string(s, serializer) : def;
   }
 
+  /** Save items into the preferences. Does not call [prefs.commit()]. */
+  static <E> void save_to_preferences(String key, SharedPreferences.Editor prefs, List<E> items, Serializer<E> serializer)
+  {
+    prefs.putString(key, save_to_string(items, serializer));
+  }
+
   /** Decode a list of string previously encoded with [save_to_string]. Returns
       [null] on error. */
   static <E> List<E> load_from_string(String inp, Serializer<E> serializer)
@@ -92,6 +98,7 @@ static <E> List<E> load_from_string(String inp, Serializer<E> serializer)
     }
     catch (JSONException e)
     {
+      Logs.exn("load_from_string", e);
       return null;
     }
   }
@@ -107,7 +114,10 @@ static <E> String save_to_string(List<E> items, Serializer<E> serializer)
       {
         serialized_items.add(serializer.save_item(it));
       }
-      catch (JSONException e) {}
+      catch (JSONException e)
+      {
+        Logs.exn("save_to_string", e);
+      }
     }
     return (new JSONArray(serialized_items)).toString();
   }

srcs/juloo.keyboard2/Logs.java

@@ -27,9 +27,25 @@ public static void debug_startup_input_view(EditorInfo info, Config conf)
     _debug_logs.println("actionLabel: "+conf.actionLabel);
   }
 
+  public static void debug_config_migration(int from_version, int to_version)
+  {
+    debug("Migrating config version from " + from_version + " to " + to_version);
+  }
+
   public static void debug(String s)
   {
     if (_debug_logs != null)
       _debug_logs.println(s);
   }
+
+  public static void exn(String msg, Exception e)
+  {
+    Log.e(TAG, msg, e);
+  }
+
+  public static void trace()
+  {
+    if (_debug_logs != null)
+      _debug_logs.println(Log.getStackTraceString(new Exception()));
+  }
 }

srcs/juloo.keyboard2/SettingsActivity.java

@@ -16,7 +16,12 @@ public void onCreate(Bundle savedInstanceState)
     super.onCreate(savedInstanceState);
     // The preferences can't be read when in direct-boot mode. Avoid crashing
     // and don't allow changing the settings.
-    try { getPreferenceManager().getSharedPreferences(); }
+    // Run the config migration on this prefs as it might be different from the
+    // one used by the keyboard, which have been migrated.
+    try
+    {
+      Config.migrate(getPreferenceManager().getSharedPreferences());
+    }
     catch (Exception _e) { fallbackEncrypted(); return; }
     addPreferencesFromResource(R.xml.settings);
   }