Bug 1019981 - Part 1: remove Language section from preferences if locale switching is disabled. r=nalexander

configure.in

@@ -3938,6 +3938,7 @@ MOZ_ANDROID_HISTORY=
 MOZ_WEBSMS_BACKEND=
 MOZ_ANDROID_BEAM=
 MOZ_ANDROID_SYNTHAPKS=
+MOZ_LOCALE_SWITCHER=
 ACCESSIBILITY=1
 MOZ_TIME_MANAGER=
 MOZ_PAY=
@@ -4947,6 +4948,13 @@ if test -n "$MOZ_WEBSMS_BACKEND"; then
     AC_DEFINE(MOZ_WEBSMS_BACKEND)
 fi
 
+dnl ========================================================
+dnl = Enable runtime locale switching on Android
+dnl ========================================================
+if test -n "$MOZ_LOCALE_SWITCHER"; then
+    AC_DEFINE(MOZ_LOCALE_SWITCHER)
+fi
+
 dnl ========================================================
 dnl = Enable NFC permission on Android
 dnl ========================================================
@@ -8567,6 +8575,7 @@ AC_SUBST(MOZ_ANDROID_HISTORY)
 AC_SUBST(MOZ_WEBSMS_BACKEND)
 AC_SUBST(MOZ_ANDROID_BEAM)
 AC_SUBST(MOZ_ANDROID_SYNTHAPKS)
+AC_SUBST(MOZ_LOCALE_SWITCHER)
 AC_SUBST(MOZ_DISABLE_GECKOVIEW)
 AC_SUBST(ENABLE_STRIP)
 AC_SUBST(PKG_SKIP_STRIP)

mobile/android/base/AppConstants.java.in

@@ -121,6 +121,13 @@ public class AppConstants {
     false;
 #endif
 
+    public static final boolean MOZ_LOCALE_SWITCHER =
+#ifdef MOZ_LOCALE_SWITCHER
+    true;
+#else
+    false;
+#endif
+
     public static final boolean MOZ_UPDATER =
 #ifdef MOZ_UPDATER
     true;

mobile/android/base/BrowserLocaleManager.java

@@ -75,6 +75,10 @@ public class BrowserLocaleManager implements LocaleManager {
         }
     }
 
+    public boolean isEnabled() {
+        return AppConstants.MOZ_LOCALE_SWITCHER;
+    }
+
     /**
      * Gecko uses locale codes like "es-ES", whereas a Java {@link Locale}
      * stringifies as "es_ES".

mobile/android/base/LocaleManager.java

@@ -18,6 +18,11 @@ import android.content.res.Resources;
  */
 public interface LocaleManager {
     void initialize(Context context);
+
+    /**
+     * @return true if locale switching is enabled.
+     */
+    boolean isEnabled();
     Locale getCurrentLocale(Context context);
     String getAndApplyPersistedLocale(Context context);
     void correctLocale(Context context, Resources resources, Configuration newConfig);

mobile/android/base/preferences/GeckoPreferences.java

@@ -131,6 +131,7 @@ OnSharedPreferenceChangeListener
      * Track the last locale so we know whether to redisplay.
      */
     private Locale lastLocale = Locale.getDefault();
+    private boolean localeSwitchingIsEnabled;
 
     private void updateActionBarTitle(int title) {
         if (Build.VERSION.SDK_INT >= 14) {
@@ -268,6 +269,9 @@ OnSharedPreferenceChangeListener
         // Apply the current user-selected locale, if necessary.
         checkLocale();
 
+        // Track this so we can decide whether to show locale options.
+        localeSwitchingIsEnabled = BrowserLocaleManager.getInstance().isEnabled();
+
         // For Android v11+ where we use Fragments (v11+ only due to bug 866352),
         // check that PreferenceActivity.EXTRA_SHOW_FRAGMENT has been set
         // (or set it) before super.onCreate() is called so Android can display
@@ -397,6 +401,18 @@ OnSharedPreferenceChangeListener
     public void onBuildHeaders(List<Header> target) {
         if (onIsMultiPane()) {
             loadHeadersFromResource(R.xml.preference_headers, target);
+
+            // If locale switching is disabled, remove the section
+            // entirely. This logic will need to be extended when
+            // content language selection (Bug 881510) is implemented.
+            if (!localeSwitchingIsEnabled) {
+                for (Header header : target) {
+                    if (header.id == R.id.pref_header_language) {
+                        target.remove(header);
+                        break;
+                    }
+                }
+            }
         }
     }
 
@@ -564,9 +580,20 @@ OnSharedPreferenceChangeListener
     private void setupPreferences(PreferenceGroup preferences, ArrayList<String> prefs) {
         for (int i = 0; i < preferences.getPreferenceCount(); i++) {
             Preference pref = preferences.getPreference(i);
+
+            // Eliminate locale switching if necessary.
+            // This logic will need to be extended when
+            // content language selection (Bug 881510) is implemented.
+            if (!localeSwitchingIsEnabled &&
+                "preferences_locale".equals(pref.getExtras().getString("resource", null))) {
+                preferences.removePreference(pref);
+                i--;
+                continue;
+            }
+
             String key = pref.getKey();
             if (pref instanceof PreferenceGroup) {
-                // If no datareporting is enabled, remove UI.
+                // If datareporting is disabled, remove UI.
                 if (PREFS_DATA_REPORTING_PREFERENCES.equals(key)) {
                     if (!AppConstants.MOZ_DATA_REPORTING) {
                         preferences.removePreference(pref);

mobile/android/base/resources/xml-v11/preference_headers.xml

@@ -28,7 +28,8 @@
     </header>
 
     <header android:fragment="org.mozilla.gecko.preferences.GeckoPreferenceFragment"
-            android:title="@string/pref_header_language">
+            android:title="@string/pref_header_language"
+            android:id="@+id/pref_header_language">
         <extra android:name="resource"
                android:value="preferences_locale" />
     </header>

mobile/android/confvars.sh

@@ -64,6 +64,9 @@ MOZ_SERVICES_FXACCOUNTS=1
 # Enable Wifi-AP/cell tower data reporting
 MOZ_DATA_REPORTING=1
 
+# Enable runtime locale switching.
+MOZ_LOCALE_SWITCHER=1
+
 # Enable the "synthetic APKs" implementation of Open Web Apps.
 MOZ_ANDROID_SYNTHAPKS=1