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.

1 files changed, 6 insertions, 0 deletions

diff --git a/srcs/juloo.keyboard2/LayoutsPreference.java b/srcs/juloo.keyboard2/LayoutsPreference.java
index d6669ba..f15bad9 100644
--- a/srcs/juloo.keyboard2/LayoutsPreference.java
+++ b/srcs/juloo.keyboard2/LayoutsPreference.java
@@ -75,6 +75,12 @@ public class LayoutsPreference extends ListGroupPreference<LayoutsPreference.Lay
     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);