ListGroupPreference: Make items abstract

Allow items to be of any class instead of strings.

Item serialization and deserialization methods are in a separate class
because they are also used in a static context.

1 files changed, 7 insertions, 2 deletions

diff --git a/srcs/juloo.keyboard2/LayoutsPreference.java b/srcs/juloo.keyboard2/LayoutsPreference.java
index 4ce8dfa..a891ed8 100644
--- a/srcs/juloo.keyboard2/LayoutsPreference.java
+++ b/srcs/juloo.keyboard2/LayoutsPreference.java
@@ -13,10 +13,12 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
-public class LayoutsPreference extends ListGroupPreference
+public class LayoutsPreference extends ListGroupPreference<String>
 {
   static final String KEY = "layouts";
   static final List<String> DEFAULT = Collections.singletonList("system");
+  static final ListGroupPreference.Serializer<String> SERIALIZER =
+    new ListGroupPreference.StringSerializer();
 
   /** Layout names as stored in the preferences. */
   List<String> _layout_names;
@@ -34,7 +36,7 @@ public class LayoutsPreference extends ListGroupPreference
 
   public static List<String> load_from_preferences(SharedPreferences prefs)
   {
-    return load_from_preferences(KEY, prefs, DEFAULT);
+    return load_from_preferences(KEY, prefs, DEFAULT, SERIALIZER);
   }
 
   @Override
@@ -67,6 +69,9 @@ public class LayoutsPreference extends ListGroupPreference
     return (_values.size() > 1);
   }
 
+  @Override
+  Serializer<String> get_serializer() { return SERIALIZER; }
+
   void select(final SelectionCallback callback)
   {
     ArrayAdapter layouts = new ArrayAdapter(getContext(), android.R.layout.simple_list_item_1, _layout_display_names);