Allow multiple custom layouts

This merges the "Layouts" option with the "Custom layout" option.
A custom layout becomes an item in the "Layouts" list among the other
layouts. It's possible to add several custom layouts.

Selecting the "Custom layout" item in the list opens a second dialog for
entering the layout description.

Layouts are serialized as JSON object and are decoded solely in the
LayoutsPreference class.

21 files changed, 194 insertions, 107 deletions

diff --git a/gen_layouts.py b/gen_layouts.py
index 44c3563..c2e6e8d 100644
--- a/gen_layouts.py
+++ b/gen_layouts.py
@@ -54,9 +54,9 @@ def generate_arrays(out, layouts):
             item.text = s
             elem.append(item)
         return elem
-    none_item = [ ("system", "@string/pref_layout_e_system") ]
+    system_item = [ ("system", "@string/pref_layout_e_system") ]
     custom_item = [ ("custom", "@string/pref_layout_e_custom") ]
-    values_items, entries_items = zip(*(none_item + layouts + custom_item)) # unzip
+    values_items, entries_items = zip(*(system_item + layouts + custom_item)) # unzip
     ids_items = map(lambda s: "@xml/%s" % s if s not in ["system", "custom"] else "-1", values_items)
     root = XML.Element("resources")
     root.append(XML.Comment(text="DO NOT EDIT. This file is generated, see gen_layouts.py."))
diff --git a/res/values-cs/strings.xml b/res/values-cs/strings.xml
index 5371835..f4df544 100644
--- a/res/values-cs/strings.xml
+++ b/res/values-cs/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Vlastní rozvržení</string>
   <string name="pref_layouts_add">Přidat alternativní rozložení</string>
   <string name="pref_layouts_item">Rozložení %1$d: %2$s</string>
+  <string name="pref_custom_layout_title">Vlastní rozvržení</string>
   <string name="pref_show_numpad_title">Zobrazit NumPad</string>
   <string name="pref_show_numpad_never">Nikdy</string>
   <string name="pref_show_numpad_landscape">Pouze v režimu na šířku</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Velmi dlouhá</string>
   <string name="pref_key_horizontal_space">Horizontální mezery mezi klávesami</string>
   <string name="pref_key_vertical_space">Vertikální mezery mezi klávesami</string>
-  <string name="pref_category_advanced">Pokročilé</string>
-  <string name="pref_custom_layout_title">Vlastní rozvržení</string>
-  <string name="pref_custom_layout_summary">Více informací naleznete ve zdrojovém kódu. Tato možnost není určena pro běžné užití.</string>
   <string name="pref_vibration_e_disabled">Deaktivovány</string>
   <string name="pref_vibration_e_system">Dle systému</string>
   <string name="pref_vibration_e_strong">Silné</string>
@@ -101,4 +99,5 @@
   <string name="key_descr_º">Indikátor řadové číslovky</string>
   <string name="key_descr_superscript">Horní index</string>
   <string name="key_descr_subscript">Dolní index</string>
+  <string name="pref_category_advanced">Pokročilé</string>
 </resources>
diff --git a/res/values-de/strings.xml b/res/values-de/strings.xml
index 1a20fef..cebedd4 100644
--- a/res/values-de/strings.xml
+++ b/res/values-de/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Eigenes Layout</string>
   <string name="pref_layouts_add">Alternatives Layout hinzufügen</string>
   <string name="pref_layouts_item">Layout %1$d: %2$s</string>
+  <string name="pref_custom_layout_title">Eigenes Layout</string>
   <string name="pref_show_numpad_title">Ziffernblock anzeigen</string>
   <string name="pref_show_numpad_never">Nie</string>
   <string name="pref_show_numpad_landscape">Nur im Querformat</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Sehr weit</string>
   <string name="pref_key_horizontal_space">Horizontaler Abstand zwischen den Tasten</string>
   <string name="pref_key_vertical_space">Vertikaler Abstand zwischen den Tasten</string>
-  <string name="pref_category_advanced">Erweitert</string>
-  <string name="pref_custom_layout_title">Eigenes Layout</string>
-  <string name="pref_custom_layout_summary">Bitte Sourcecode ansehen. Diese Option ist nicht zur Verwendung vorgesehen.</string>
   <string name="pref_vibration_e_disabled">Deaktiviert</string>
   <string name="pref_vibration_e_system">System</string>
   <string name="pref_vibration_e_strong">Stark</string>
@@ -101,4 +99,5 @@
   <string name="key_descr_º">Ordinalzeichen</string>
   <string name="key_descr_superscript">Hochgestellt</string>
   <string name="key_descr_subscript">Tiefgestellt</string>
+  <string name="pref_category_advanced">Erweitert</string>
 </resources>
diff --git a/res/values-es/strings.xml b/res/values-es/strings.xml
index ddc7358..9b26c53 100644
--- a/res/values-es/strings.xml
+++ b/res/values-es/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Formato personalizado</string>
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <string name="pref_custom_layout_title">Formato personalizado</string>
   <string name="pref_show_numpad_title">Mostrar pad numérico</string>
   <string name="pref_show_numpad_never">Nunca</string>
   <string name="pref_show_numpad_landscape">Solo en modo paisaje</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Muy lejana</string>
   <string name="pref_key_horizontal_space">Espaciado horizontal entre las teclas</string>
   <string name="pref_key_vertical_space">Espaciado vertical entre las teclas</string>
-  <string name="pref_category_advanced">Avanzado</string>
-  <string name="pref_custom_layout_title">Formato personalizado</string>
-  <string name="pref_custom_layout_summary">Revisar el código fuente. Esta opción no está pensada para ser usada.</string>
   <string name="pref_vibration_e_disabled">Deshabilitada</string>
   <string name="pref_vibration_e_system">Sistema</string>
   <string name="pref_vibration_e_strong">Fuerte</string>
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <string name="pref_category_advanced">Avanzado</string>
 </resources>
diff --git a/res/values-fa/strings.xml b/res/values-fa/strings.xml
index 87ed44b..32cd8e0 100644
--- a/res/values-fa/strings.xml
+++ b/res/values-fa/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">طرح صفارشی</string>
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <string name="pref_custom_layout_title">طرح شخصی</string>
   <string name="pref_show_numpad_title">نمایش پد شماره‌ها</string>
   <string name="pref_show_numpad_never">هرگز</string>
   <string name="pref_show_numpad_landscape">فقط در حالت افقی</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">بسیار دور</string>
   <string name="pref_key_horizontal_space">فاصله افقی بین کلیدها</string>
   <string name="pref_key_vertical_space">فاصله عمودی بین کلیدها</string>
-  <string name="pref_category_advanced">پیشرفته</string>
-  <string name="pref_custom_layout_title">طرح شخصی</string>
-  <string name="pref_custom_layout_summary">کد منبع را ببینید. این گزینه قرار نیست استفاده شود.</string>
   <!-- <string name="pref_vibration_e_disabled">Disabled</string> -->
   <!-- <string name="pref_vibration_e_system">System</string> -->
   <!-- <string name="pref_vibration_e_strong">Strong</string> -->
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <string name="pref_category_advanced">پیشرفته</string>
 </resources>
diff --git a/res/values-fr/strings.xml b/res/values-fr/strings.xml
index ee1d60c..b5407bb 100644
--- a/res/values-fr/strings.xml
+++ b/res/values-fr/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Disposition personnalisée</string>
   <string name="pref_layouts_add">Ajouter un clavier alternatif</string>
   <string name="pref_layouts_item">Disposition %1$d: %2$s</string>
+  <string name="pref_custom_layout_title">Disposition personnalisée</string>
   <string name="pref_show_numpad_title">Afficher le pavé numérique</string>
   <string name="pref_show_numpad_never">Jamais</string>
   <string name="pref_show_numpad_landscape">Seulement en mode paysage</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Très longue</string>
   <string name="pref_key_horizontal_space">Espacement horizontal entre les touches</string>
   <string name="pref_key_vertical_space">Espacement vertical entre les touches</string>
-  <string name="pref_category_advanced">Avancé</string>
-  <string name="pref_custom_layout_title">Disposition personnalisée</string>
-  <string name="pref_custom_layout_summary">Cette option n\'est pas faite pour être utilisée.</string>
   <string name="pref_vibration_e_disabled">Désactivé</string>
   <string name="pref_vibration_e_system">Système</string>
   <string name="pref_vibration_e_strong">Fort</string>
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <string name="pref_category_advanced">Avancé</string>
 </resources>
diff --git a/res/values-it/strings.xml b/res/values-it/strings.xml
index 9483cec..d8424ad 100644
--- a/res/values-it/strings.xml
+++ b/res/values-it/strings.xml
@@ -14,6 +14,7 @@
   <!-- <string name="pref_layout_e_custom">Custom layout</string> -->
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <!-- <string name="pref_custom_layout_title">Custom layout</string> -->
   <!-- <string name="pref_show_numpad_title">Show NumPad</string> -->
   <!-- <string name="pref_show_numpad_never">Never</string> -->
   <!-- <string name="pref_show_numpad_landscape">Only in landscape mode</string> -->
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Molto distante</string>
   <string name="pref_key_horizontal_space">Spazio orizzontale tra i tasti</string>
   <string name="pref_key_vertical_space">Spazio verticale tra i tasti</string>
-  <!-- <string name="pref_category_advanced">Advanced</string> -->
-  <!-- <string name="pref_custom_layout_title">Custom layout</string> -->
-  <!-- <string name="pref_custom_layout_summary">See the source code. This option is not meant to be used.</string> -->
   <!-- <string name="pref_vibration_e_disabled">Disabled</string> -->
   <!-- <string name="pref_vibration_e_system">System</string> -->
   <!-- <string name="pref_vibration_e_strong">Strong</string> -->
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <!-- <string name="pref_category_advanced">Advanced</string> -->
 </resources>
diff --git a/res/values-ko/strings.xml b/res/values-ko/strings.xml
index eebbe33..1ee49df 100644
--- a/res/values-ko/strings.xml
+++ b/res/values-ko/strings.xml
@@ -14,6 +14,7 @@
   <!-- <string name="pref_layout_e_custom">Custom layout</string> -->
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <!-- <string name="pref_custom_layout_title">Custom layout</string> -->
   <!-- <string name="pref_show_numpad_title">Show NumPad</string> -->
   <!-- <string name="pref_show_numpad_never">Never</string> -->
   <!-- <string name="pref_show_numpad_landscape">Only in landscape mode</string> -->
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">매우 넓음</string>
   <string name="pref_key_horizontal_space">키보드 양 옆 간격</string>
   <string name="pref_key_vertical_space">키보드 세로 간격</string>
-  <!-- <string name="pref_category_advanced">Advanced</string> -->
-  <!-- <string name="pref_custom_layout_title">Custom layout</string> -->
-  <!-- <string name="pref_custom_layout_summary">See the source code. This option is not meant to be used.</string> -->
   <!-- <string name="pref_vibration_e_disabled">Disabled</string> -->
   <!-- <string name="pref_vibration_e_system">System</string> -->
   <!-- <string name="pref_vibration_e_strong">Strong</string> -->
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <!-- <string name="pref_category_advanced">Advanced</string> -->
 </resources>
diff --git a/res/values-lv/strings.xml b/res/values-lv/strings.xml
index 9c339ef..829cd3c 100644
--- a/res/values-lv/strings.xml
+++ b/res/values-lv/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Pielāgots izkārtojums</string>
   <string name="pref_layouts_add">Pievienot aizstājējizkārtojumu</string>
   <string name="pref_layouts_item">Izkārtojums %1$d: %2$s</string>
+  <string name="pref_custom_layout_title">Pielāgots izkārtojums</string>
   <string name="pref_show_numpad_title">Rādīt ciparnīcu</string>
   <string name="pref_show_numpad_never">Nekad</string>
   <string name="pref_show_numpad_landscape">Tikai guleniskajā skatā</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Ļoti tāls</string>
   <string name="pref_key_horizontal_space">Līmeniskais attālums starp taustiņiem</string>
   <string name="pref_key_vertical_space">Stateniskais attālums starp taustiņiem</string>
-  <string name="pref_category_advanced">Papildu</string>
-  <string name="pref_custom_layout_title">Pielāgots izkārtojums</string>
-  <string name="pref_custom_layout_summary">Skatīt pirmkodu. Šī iespēja nav paredzēta izmantošanai.</string>
   <string name="pref_vibration_e_disabled">Atspējota</string>
   <string name="pref_vibration_e_system">Sistēmas</string>
   <string name="pref_vibration_e_strong">Spēcīga</string>
@@ -103,4 +101,5 @@
   <string name="key_descr_º">Kārtas rādītājs</string>
   <string name="key_descr_superscript">Augšraksts</string>
   <string name="key_descr_subscript">Apakšraksts</string>
+  <string name="pref_category_advanced">Papildu</string>
 </resources>
diff --git a/res/values-pl/strings.xml b/res/values-pl/strings.xml
index 3e517dc..867d3c5 100644
--- a/res/values-pl/strings.xml
+++ b/res/values-pl/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Własny układ</string>
   <string name="pref_layouts_add">Dodaj dodatkowy układ</string>
   <string name="pref_layouts_item">Układ %1$d: %2$s</string>
+  <string name="pref_custom_layout_title">Własny układ</string>
   <string name="pref_show_numpad_title">Pokaż klawiaturę numeryczną</string>
   <string name="pref_show_numpad_never">Nigdy</string>
   <string name="pref_show_numpad_landscape">Tylko w orientacji poziomej</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Bardzo duża</string>
   <string name="pref_key_horizontal_space">Odległość pomiędzy klawiszami w poziomie</string>
   <string name="pref_key_vertical_space">Odległość pomiędzy klawiszami w pionie</string>
-  <string name="pref_category_advanced">Zaawansowane</string>
-  <string name="pref_custom_layout_title">Własny układ</string>
-  <string name="pref_custom_layout_summary">Zobacz kod źródłowy. Ta opcja nie jest przeznaczona do użycia.</string>
   <string name="pref_vibration_e_disabled">Wyłączone</string>
   <string name="pref_vibration_e_system">Systemowe</string>
   <string name="pref_vibration_e_strong">Silne</string>
@@ -101,4 +99,5 @@
   <string name="key_descr_º">Wskaźnik porządkowy (męski)</string>
   <string name="key_descr_superscript">Indeks górny</string>
   <string name="key_descr_subscript">Indeks dolny</string>
+  <string name="pref_category_advanced">Zaawansowane</string>
 </resources>
diff --git a/res/values-pt/strings.xml b/res/values-pt/strings.xml
index ea80b76..f7ac20f 100644
--- a/res/values-pt/strings.xml
+++ b/res/values-pt/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Layout personalizado</string>
   <string name="pref_layouts_add">Adicione um layout alternativo</string>
   <string name="pref_layouts_item">Layout %1$d: %2$s</string>
+  <string name="pref_custom_layout_title">Layout personalizado</string>
   <string name="pref_show_numpad_title">Mostrar Teclado Numérico</string>
   <string name="pref_show_numpad_never">Nunca</string>
   <string name="pref_show_numpad_landscape">Somente no modo paisagem</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Muito longo</string>
   <string name="pref_key_horizontal_space">Distância horizontal entre teclas</string>
   <string name="pref_key_vertical_space">Distância vertical entre teclas</string>
-  <string name="pref_category_advanced">Avançado</string>
-  <string name="pref_custom_layout_title">Layout personalizado</string>
-  <string name="pref_custom_layout_summary">Veja o código-fonte. Esta opção não deve ser usada.</string>
   <string name="pref_vibration_e_disabled">Desabilitado</string>
   <string name="pref_vibration_e_system">Sistema</string>
   <string name="pref_vibration_e_strong">Intenso</string>
@@ -101,4 +99,5 @@
   <string name="key_descr_º">Indicador Ordinal</string>
   <string name="key_descr_superscript">Sobrescrito</string>
   <string name="key_descr_subscript">Subscrito</string>
+  <string name="pref_category_advanced">Avançado</string>
 </resources>
diff --git a/res/values-ro/strings.xml b/res/values-ro/strings.xml
index 383f207..0b3beec 100644
--- a/res/values-ro/strings.xml
+++ b/res/values-ro/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Aranjament personalizat</string>
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <string name="pref_custom_layout_title">Aranjament personalizat</string>
   <string name="pref_show_numpad_title">Arată NumPad</string>
   <string name="pref_show_numpad_never">Niciodată</string>
   <string name="pref_show_numpad_landscape">Doar în mod panoramă</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Foarte depărtată</string>
   <string name="pref_key_horizontal_space">Distanța orizontală dintre taste</string>
   <string name="pref_key_vertical_space">Distanța verticală dintre taste</string>
-  <string name="pref_category_advanced">Setări avansate</string>
-  <string name="pref_custom_layout_title">Aranjament personalizat</string>
-  <string name="pref_custom_layout_summary">Deschide codul sursă. Această opțiune nu e destinată spre folosință.</string>
   <!-- <string name="pref_vibration_e_disabled">Disabled</string> -->
   <!-- <string name="pref_vibration_e_system">System</string> -->
   <!-- <string name="pref_vibration_e_strong">Strong</string> -->
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <string name="pref_category_advanced">Setări avansate</string>
 </resources>
diff --git a/res/values-ru/strings.xml b/res/values-ru/strings.xml
index fe97626..e79648d 100644
--- a/res/values-ru/strings.xml
+++ b/res/values-ru/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Пользовательская раскладка</string>
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <string name="pref_custom_layout_title">Пользовательская раскладка</string>
   <string name="pref_show_numpad_title">Показывать NumPad</string>
   <string name="pref_show_numpad_never">Никогда</string>
   <string name="pref_show_numpad_landscape">Только в ландшафтном режиме</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Очень далеко</string>
   <string name="pref_key_horizontal_space">Горизонтальное расстояние между клавишами</string>
   <string name="pref_key_vertical_space">Расстояние по вертикали между клавишами</string>
-  <string name="pref_category_advanced">Расширенные настройки</string>
-  <string name="pref_custom_layout_title">Пользовательская раскладка</string>
-  <string name="pref_custom_layout_summary">Откройте исходный код. Эта параметр не предназначен для использования.</string>
   <!-- <string name="pref_vibration_e_disabled">Disabled</string> -->
   <!-- <string name="pref_vibration_e_system">System</string> -->
   <!-- <string name="pref_vibration_e_strong">Strong</string> -->
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <string name="pref_category_advanced">Расширенные настройки</string>
 </resources>
diff --git a/res/values-tr/strings.xml b/res/values-tr/strings.xml
index b277718..4022f2c 100644
--- a/res/values-tr/strings.xml
+++ b/res/values-tr/strings.xml
@@ -14,6 +14,7 @@
   <!-- <string name="pref_layout_e_custom">Custom layout</string> -->
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <!-- <string name="pref_custom_layout_title">Custom layout</string> -->
   <!-- <string name="pref_show_numpad_title">Show NumPad</string> -->
   <!-- <string name="pref_show_numpad_never">Never</string> -->
   <!-- <string name="pref_show_numpad_landscape">Only in landscape mode</string> -->
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Çok uzun</string>
   <string name="pref_key_horizontal_space">Tuşlar arasındaki yatay boşluk</string>
   <string name="pref_key_vertical_space">Tuşlar arasındaki dikey boşluk</string>
-  <!-- <string name="pref_category_advanced">Advanced</string> -->
-  <!-- <string name="pref_custom_layout_title">Custom layout</string> -->
-  <!-- <string name="pref_custom_layout_summary">See the source code. This option is not meant to be used.</string> -->
   <!-- <string name="pref_vibration_e_disabled">Disabled</string> -->
   <!-- <string name="pref_vibration_e_system">System</string> -->
   <!-- <string name="pref_vibration_e_strong">Strong</string> -->
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <!-- <string name="pref_category_advanced">Advanced</string> -->
 </resources>
diff --git a/res/values-vi/strings.xml b/res/values-vi/strings.xml
index 31c8ec6..1037d9b 100644
--- a/res/values-vi/strings.xml
+++ b/res/values-vi/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Tùy chỉnh bố cục</string>
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <string name="pref_custom_layout_title">Tùy chỉnh bố cục</string>
   <string name="pref_show_numpad_title">Hiện NumPad</string>
   <string name="pref_show_numpad_never">Không bao giờ</string>
   <string name="pref_show_numpad_landscape">Chỉ trong chế độ phong cảnh</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Rất xa</string>
   <string name="pref_key_horizontal_space">Khoảng cách giữa các phím theo chiều ngang</string>
   <string name="pref_key_vertical_space">Khoảng cách giữa các phím theo chiều dọc</string>
-  <string name="pref_category_advanced">Nâng cao</string>
-  <string name="pref_custom_layout_title">Tùy chỉnh bố cục</string>
-  <string name="pref_custom_layout_summary">Hãy xem mã nguồn. Lựa chọn này không có mục đích sử dụng.</string>
   <!-- <string name="pref_vibration_e_disabled">Disabled</string> -->
   <!-- <string name="pref_vibration_e_system">System</string> -->
   <!-- <string name="pref_vibration_e_strong">Strong</string> -->
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <string name="pref_category_advanced">Nâng cao</string>
 </resources>
diff --git a/res/values-zh-rCN/strings.xml b/res/values-zh-rCN/strings.xml
index 7f6129b..80277b0 100644
--- a/res/values-zh-rCN/strings.xml
+++ b/res/values-zh-rCN/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">自定义布局</string>
   <!-- <string name="pref_layouts_add">Add an alternate layout</string> -->
   <!-- <string name="pref_layouts_item">Layout %1$d: %2$s</string> -->
+  <string name="pref_custom_layout_title">自定义布局</string>
   <string name="pref_show_numpad_title">显示数字小键盘</string>
   <string name="pref_show_numpad_never">从不</string>
   <string name="pref_show_numpad_landscape">只在横屏显示</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">非常长</string>
   <string name="pref_key_horizontal_space">按键的左右边距</string>
   <string name="pref_key_vertical_space">按键的上下边距</string>
-  <string name="pref_category_advanced">高级设置</string>
-  <string name="pref_custom_layout_title">自定义布局</string>
-  <string name="pref_custom_layout_summary">请查看源代码。这个选项不应该在正常情况下使用。</string>
   <string name="pref_vibration_e_disabled">禁用</string>
   <string name="pref_vibration_e_system">使用系统振动强度</string>
   <string name="pref_vibration_e_strong">强</string>
@@ -101,4 +99,5 @@
   <!-- <string name="key_descr_º">Ordinal Indicator</string> -->
   <!-- <string name="key_descr_superscript">Superscript</string> -->
   <!-- <string name="key_descr_subscript">Subscript</string> -->
+  <string name="pref_category_advanced">高级设置</string>
 </resources>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 72e651a..c8620f7 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -14,6 +14,7 @@
   <string name="pref_layout_e_custom">Custom layout</string>
   <string name="pref_layouts_add">Add an alternate layout</string>
   <string name="pref_layouts_item">Layout %1$d: %2$s</string>
+  <string name="pref_custom_layout_title">Custom layout</string>
   <string name="pref_show_numpad_title">Show NumPad</string>
   <string name="pref_show_numpad_never">Never</string>
   <string name="pref_show_numpad_landscape">Only in landscape mode</string>
@@ -65,9 +66,6 @@
   <string name="pref_swipe_dist_e_very_far">Very far</string>
   <string name="pref_key_horizontal_space">Horizontal spacing between the keys</string>
   <string name="pref_key_vertical_space">Vertical spacing between the keys</string>
-  <string name="pref_category_advanced">Advanced</string>
-  <string name="pref_custom_layout_title">Custom layout</string>
-  <string name="pref_custom_layout_summary">See the source code. This option is not meant to be used.</string>
   <string name="pref_vibration_e_disabled">Disabled</string>
   <string name="pref_vibration_e_system">System</string>
   <string name="pref_vibration_e_strong">Strong</string>
@@ -101,4 +99,6 @@
   <string name="key_descr_º">Ordinal Indicator</string>
   <string name="key_descr_superscript">Superscript</string>
   <string name="key_descr_subscript">Subscript</string>
+  <!-- Unused -->
+  <string name="pref_category_advanced">Advanced</string>
 </resources>
diff --git a/res/xml/settings.xml b/res/xml/settings.xml
index c670dfb..f6467d6 100644
--- a/res/xml/settings.xml
+++ b/res/xml/settings.xml
@@ -46,7 +46,4 @@
     <juloo.common.IntSlideBarPreference android:key="key_vertical_space" android:title="@string/pref_key_vertical_space" android:summary="%sdp" android:defaultValue="2" min="0" max="8"/>
     <juloo.common.IntSlideBarPreference android:key="key_horizontal_space" android:title="@string/pref_key_horizontal_space" android:summary="%sdp" android:defaultValue="2" min="0" max="8"/>
   </PreferenceCategory>
-  <PreferenceCategory android:title="@string/pref_category_advanced">
-    <EditTextPreference android:key="custom_layout" android:title="@string/pref_custom_layout_title" android:summary="@string/pref_custom_layout_summary" android:inputType="text|textMultiLine|textLongMessage"/>
-  </PreferenceCategory>
 </PreferenceScreen>
diff --git a/srcs/juloo.keyboard2/Config.java b/srcs/juloo.keyboard2/Config.java
index 24565ab..4684194 100644
--- a/srcs/juloo.keyboard2/Config.java
+++ b/srcs/juloo.keyboard2/Config.java
@@ -3,7 +3,6 @@ package juloo.keyboard2;
 import android.content.SharedPreferences;
 import android.content.res.Configuration;
 import android.content.res.Resources;
-import android.content.res.TypedArray;
 import android.os.Build;
 import android.util.DisplayMetrics;
 import android.util.TypedValue;
@@ -28,7 +27,6 @@ final class Config
   // From preferences
   /** [null] represent the [system] layout. */
   public List<KeyboardData> layouts;
-  public KeyboardData custom_layout; // Might be 'null'
   public boolean show_numpad = false;
   // From the 'numpad_layout' option, also apply to the numeric pane.
   public boolean inverse_numpad = false;
@@ -114,11 +112,7 @@ final class Config
     {
       keyboardHeightPercent = _prefs.getInt("keyboard_height", 35);
     }
-    List<String> layout_names = LayoutsPreference.load_from_preferences(_prefs);
-    layouts = new ArrayList<KeyboardData>();
-    for (String l : layout_names)
-      layouts.add(layout_of_string(res, l));
-    custom_layout = KeyboardData.load_string(_prefs.getString("custom_layout", ""));
+    layouts = LayoutsPreference.load_from_preferences(res, _prefs);
     inverse_numpad = _prefs.getString("numpad_layout", "default").equals("low_first");
     number_row = _prefs.getBoolean("number_row", false);
     // The baseline for the swipe distance correspond to approximately the
@@ -335,36 +329,6 @@ final class Config
     }
   }
 
-  /** Obtained from XML. */
-  static List<String> layout_ids_str = null;
-  static TypedArray layout_ids_res = null;
-
-  /** Might return [null] if the selected layout is "system", "custom" or if
-      the name is not recognized. */
-  public KeyboardData layout_of_string(Resources res, String name)
-  {
-    if (layout_ids_str == null)
-    {
-      layout_ids_str = Arrays.asList(res.getStringArray(R.array.pref_layout_values));
-      layout_ids_res = res.obtainTypedArray(R.array.layout_ids);
-    }
-    int i = layout_ids_str.indexOf(name);
-    if (i >= 0)
-    {
-      int id = layout_ids_res.getResourceId(i, 0);
-      if (id > 0)
-        return KeyboardData.load(res, id);
-      // Fallthrough
-    }
-    switch (name)
-    {
-      case "custom": return custom_layout;
-      case "system":
-      case "none":
-      default: return null;
-    }
-  }
-
   char inverse_numpad_char(char c)
   {
     switch (c)
diff --git a/srcs/juloo.keyboard2/Keyboard2.java b/srcs/juloo.keyboard2/Keyboard2.java
index 5f7442b..92507ed 100644
--- a/srcs/juloo.keyboard2/Keyboard2.java
+++ b/srcs/juloo.keyboard2/Keyboard2.java
@@ -155,7 +155,7 @@ public class Keyboard2 extends InputMethodService
       {
         String s = subtype.getExtraValueOf("default_layout");
         if (s != null)
-          default_layout = _config.layout_of_string(getResources(), s);
+          default_layout = LayoutsPreference.layout_of_string(getResources(), s);
         refreshAccentsOption(imm, subtype);
       }
     }
diff --git a/srcs/juloo.keyboard2/LayoutsPreference.java b/srcs/juloo.keyboard2/LayoutsPreference.java
index ba28630..a65b350 100644
--- a/srcs/juloo.keyboard2/LayoutsPreference.java
+++ b/srcs/juloo.keyboard2/LayoutsPreference.java
@@ -5,6 +5,7 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.SharedPreferences;
 import android.content.res.Resources;
+import android.content.res.TypedArray;
 import android.util.AttributeSet;
 import android.widget.ArrayAdapter;
 import android.widget.EditText;
@@ -12,16 +13,17 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import org.json.JSONException;
+import org.json.JSONObject;
 
-public class LayoutsPreference extends ListGroupPreference<String>
+public class LayoutsPreference extends ListGroupPreference<LayoutsPreference.Layout>
 {
   static final String KEY = "layouts";
-  static final List<String> DEFAULT = Collections.singletonList("system");
-  static final ListGroupPreference.Serializer<String> SERIALIZER =
-    new ListGroupPreference.StringSerializer();
+  static final List<Layout> DEFAULT =
+    Collections.singletonList((Layout)new SystemLayout());
+  static final ListGroupPreference.Serializer<Layout> SERIALIZER =
+    new Serializer();
 
-  /** Layout names as stored in the preferences. */
-  List<String> _layout_names;
   /** Text displayed for each layout in the dialog list. */
   String[] _layout_display_names;
 
@@ -30,13 +32,56 @@ public class LayoutsPreference extends ListGroupPreference<String>
     super(ctx, attrs);
     setKey(KEY);
     Resources res = ctx.getResources();
-    _layout_names = Arrays.asList(res.getStringArray(R.array.pref_layout_values));
     _layout_display_names = res.getStringArray(R.array.pref_layout_entries);
   }
 
-  public static List<String> load_from_preferences(SharedPreferences prefs)
+  /** Obtained from [res/values/layouts.xml]. */
+  static List<String> _unsafe_layout_ids_str = null;
+  static TypedArray _unsafe_layout_ids_res = null;
+
+  /** Layout internal names. Contains "system" and "custom". */
+  public static List<String> get_layout_names(Resources res)
+  {
+    if (_unsafe_layout_ids_str == null)
+      _unsafe_layout_ids_str = Arrays.asList(
+          res.getStringArray(R.array.pref_layout_values));
+    return _unsafe_layout_ids_str;
+  }
+
+  /** Layout resource id for a layout name. [-1] if not found. */
+  public static int layout_id_of_name(Resources res, String name)
+  {
+    if (_unsafe_layout_ids_res == null)
+      _unsafe_layout_ids_res = res.obtainTypedArray(R.array.layout_ids);
+    int i = get_layout_names(res).indexOf(name);
+    if (i >= 0)
+      return _unsafe_layout_ids_res.getResourceId(i, 0);
+    return -1;
+  }
+
+  /** [null] for the "system" layout. */
+  public static List<KeyboardData> load_from_preferences(Resources res, SharedPreferences prefs)
+  {
+    List<KeyboardData> layouts = new ArrayList<KeyboardData>();
+    for (Layout l : load_from_preferences(KEY, prefs, DEFAULT, SERIALIZER))
+    {
+      if (l instanceof NamedLayout)
+        layouts.add(layout_of_string(res, ((NamedLayout)l).name));
+      else if (l instanceof CustomLayout)
+        layouts.add(KeyboardData.load_string(((CustomLayout)l).xml));
+      else // instanceof SystemLayout
+        layouts.add(null);
+    }
+    return layouts;
+  }
+
+  public static KeyboardData layout_of_string(Resources res, String name)
   {
-    return load_from_preferences(KEY, prefs, DEFAULT, SERIALIZER);
+    int id = layout_id_of_name(res, name);
+    if (id > 0)
+      return KeyboardData.load(res, id);
+    // Might happen when the app is downgraded, return the system layout.
+    return null;
   }
 
   @Override
@@ -44,15 +89,28 @@ public class LayoutsPreference extends ListGroupPreference<String>
   {
     super.onSetInitialValue(restoreValue, defaultValue);
     if (_values.size() == 0)
-      set_values(new ArrayList<String>(DEFAULT), false);
+      set_values(new ArrayList<Layout>(DEFAULT), false);
+  }
+
+  String label_of_layout(Layout l)
+  {
+    if (l instanceof NamedLayout)
+    {
+      String lname = ((NamedLayout)l).name;
+      int value_i = get_layout_names(getContext().getResources()).indexOf(lname);
+      return value_i < 0 ? lname : _layout_display_names[value_i];
+    }
+    else if (l instanceof CustomLayout)
+      return getContext().getString(R.string.pref_layout_e_custom);
+    else // instanceof SystemLayout
+      return getContext().getString(R.string.pref_layout_e_system);
   }
 
   @Override
-  String label_of_value(String value, int i)
+  String label_of_value(Layout value, int i)
   {
-    int value_i = _layout_names.indexOf(value);
-    String lname = value_i < 0 ? value : _layout_display_names[value_i];
-    return getContext().getString(R.string.pref_layouts_item, i + 1, lname);
+    return getContext().getString(R.string.pref_layouts_item, i + 1,
+        label_of_layout(value));
   }
 
   @Override
@@ -70,7 +128,7 @@ public class LayoutsPreference extends ListGroupPreference<String>
   }
 
   @Override
-  Serializer<String> get_serializer() { return SERIALIZER; }
+  ListGroupPreference.Serializer<Layout> get_serializer() { return SERIALIZER; }
 
   @Override
   void select(final SelectionCallback callback)
@@ -81,9 +139,37 @@ public class LayoutsPreference extends ListGroupPreference<String>
       .setAdapter(layouts, new DialogInterface.OnClickListener(){
         public void onClick(DialogInterface _dialog, int which)
         {
-          callback.select(_layout_names.get(which));
+          String name = get_layout_names(getContext().getResources()).get(which);
+          switch (name)
+          {
+            case "system":
+              callback.select(new SystemLayout());
+              break;
+            case "custom":
+              select_custom(callback);
+              break;
+            default:
+              callback.select(new NamedLayout(name));
+              break;
+          }
+        }
+      })
+      .show();
+  }
+
+  void select_custom(final SelectionCallback callback)
+  {
+    new AlertDialog.Builder(getContext())
+      .setView(R.layout.dialog_edit_text)
+      .setTitle(R.string.pref_custom_layout_title)
+      .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener(){
+        public void onClick(DialogInterface dialog, int _which)
+        {
+          EditText input = (EditText)((AlertDialog)dialog).findViewById(R.id.text);
+          callback.select(new CustomLayout(input.getText().toString()));
         }
       })
+      .setNegativeButton(android.R.string.cancel, null)
       .show();
   }
 
@@ -95,4 +181,59 @@ public class LayoutsPreference extends ListGroupPreference<String>
       setLayoutResource(R.layout.pref_layouts_add_btn);
     }
   }
+
+  /** A layout selected by the user. The only implementations are
+      [NamedLayout], [SystemLayout] and [CustomLayout]. */
+  interface Layout {}
+
+  static final class SystemLayout implements Layout
+  {
+    public SystemLayout() {}
+  }
+
+  /** The name of a layout defined in [res/xml]. */
+  static final class NamedLayout implements Layout
+  {
+    public final String name;
+    public NamedLayout(String n) { name = n; }
+  }
+
+  /** The XML description of a custom layout. */
+  static final class CustomLayout implements Layout
+  {
+    public final String xml;
+    public CustomLayout(String c) { xml = c; }
+  }
+
+  /** Named layouts are serialized to strings and custom layouts to JSON
+      objects with a [kind] field. */
+  static class Serializer implements ListGroupPreference.Serializer<Layout>
+  {
+    public Layout load_item(Object obj) throws JSONException
+    {
+      if (obj instanceof String)
+      {
+        String name = (String)obj;
+        if (name.equals("system"))
+          return new SystemLayout();
+        return new NamedLayout(name);
+      }
+      JSONObject obj_ = (JSONObject)obj;
+      switch (obj_.getString("kind"))
+      {
+        case "custom": return new CustomLayout(obj_.getString("xml"));
+        case "system": default: return new SystemLayout();
+      }
+    }
+
+    public Object save_item(Layout v) throws JSONException
+    {
+      if (v instanceof NamedLayout)
+        return ((NamedLayout)v).name;
+      if (v instanceof CustomLayout)
+        return new JSONObject().put("kind", "custom")
+          .put("xml", ((CustomLayout)v).xml);
+      return new JSONObject().put("kind", "system");
+    }
+  }
 }