Allow using a custom layout

Add an option for specifying an XML layout description as a string.

The option is a bit rough at the moment:

- No documentation, users have to be aware of the keyboard's code to use
  this option.
- No error are shown, the layout will fallback to qwerty on error.

res/values/arrays.xml

@@ -26,6 +26,7 @@
     <item>jcuken_ua</item>
     <item>bangla</item>
     <item>hindi</item>
+    <item>custom</item>
   </string-array>
   <string-array name="pref_layout_entries">
     <item>None</item>
@@ -53,6 +54,7 @@
     <item>ЙЦУКЕН (Українська)</item>
     <item>বাংলা</item>
     <item>हिन्दी</item>
+    <item>@string/pref_layout_e_custom</item>
   </string-array>
   <string-array name="pref_accents_entries">
     <item>@string/pref_accents_e_all_installed</item>

res/values/strings.xml

@@ -7,6 +7,7 @@
   <string name="pref_label_brightness">Adjust label brightness</string>
   <string name="pref_layout_title">Change keyboard layout</string>
   <string name="pref_layout_e_system">System settings</string>
+  <string name="pref_layout_e_custom">Custom layout</string>
   <string name="pref_accents_title">Accents</string>
   <string name="pref_accents_e_all_installed">Show accents for all installed languages</string>
   <string name="pref_accents_e_selected">Only show accents for the selected language</string>
@@ -51,6 +52,9 @@
   <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="key_action_next">Next</string>
   <string name="key_action_done">Done</string>
   <string name="key_action_go">Go</string>

res/xml/settings.xml

@@ -54,4 +54,7 @@
     <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>

srcs/juloo.keyboard2/Config.java

@@ -26,6 +26,7 @@ final class Config
   // From preferences
   public KeyboardData layout; // Or 'null' for the system defaults
   public KeyboardData second_layout; // Or 'null' for none
+  public KeyboardData custom_layout; // Might be 'null'
   public boolean show_numpad = false;
   public float swipe_dist_px;
   public boolean vibrateEnabled;
@@ -66,6 +67,7 @@ final class Config
     // default values
     layout = null;
     second_layout = null;
+    custom_layout = null;
     vibrateEnabled = true;
     longPressTimeout = 600;
     longPressInterval = 65;
@@ -117,6 +119,7 @@ final class Config
     }
     layout = layout_of_string(res, _prefs.getString("layout", "none"));
     second_layout = layout_of_string(res, _prefs.getString("second_layout", "none"));
+    custom_layout = KeyboardData.load_string(_prefs.getString("custom_layout", ""));
     // The baseline for the swipe distance correspond to approximately the
     // width of a key in portrait mode, as most layouts have 10 columns.
     // Multipled by the DPI ratio because most swipes are made in the diagonals.
@@ -252,6 +255,7 @@ final class Config
     switch (name)
     {
       case "system": case "none": return null;
+      case "custom": if (custom_layout != null) return custom_layout; break;
       case "azerty": id = R.xml.azerty; break;
       case "bangla": id = R.xml.bangla; break;
       case "bgph1": id = R.xml.local_bgph1; break;

srcs/juloo.keyboard2/KeyboardData.java

@@ -1,6 +1,9 @@
 package juloo.keyboard2;
 
 import android.content.res.Resources;
+import android.content.res.XmlResourceParser;
+import android.util.Xml;
+import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -126,6 +129,7 @@ class KeyboardData
     return _pin_entry;
   }
 
+  /** Load a layout from a resource ID. Returns [null] on error. */
   public static KeyboardData load(Resources res, int id)
   {
     KeyboardData l = _layoutCache.get(id);
@@ -133,7 +137,9 @@ class KeyboardData
     {
       try
       {
-        l = parse_keyboard(res.getXml(id));
+        XmlResourceParser parser = res.getXml(id);
+        l = parse_keyboard(parser);
+        parser.close();
         _layoutCache.put(id, l);
       }
       catch (Exception e)
@@ -144,6 +150,21 @@ class KeyboardData
     return l;
   }
 
+  /** Load a layout from a string. Returns [null] on error. */
+  public static KeyboardData load_string(String src)
+  {
+    try
+    {
+      XmlPullParser parser = Xml.newPullParser();
+      parser.setInput(new StringReader(src));
+      return parse_keyboard(parser);
+    }
+    catch (Exception e)
+    {
+      return null;
+    }
+  }
+
   private static KeyboardData parse_keyboard(XmlPullParser parser) throws Exception
   {
     if (!expect_tag(parser, "keyboard"))