michael@0: /* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko;
michael@0: 
michael@0: import android.content.BroadcastReceiver;
michael@0: import android.content.Context;
michael@0: import android.content.Intent;
michael@0: import android.content.IntentFilter;
michael@0: import android.content.SharedPreferences;
michael@0: import android.content.res.Configuration;
michael@0: import android.content.res.Resources;
michael@0: import android.util.Log;
michael@0: 
michael@0: import java.util.Locale;
michael@0: import java.util.concurrent.atomic.AtomicBoolean;
michael@0: import java.util.concurrent.atomic.AtomicReference;
michael@0: 
michael@0: /**
michael@0:  * This class manages persistence, application, and otherwise handling of
michael@0:  * user-specified locales.
michael@0:  *
michael@0:  * Of note:
michael@0:  *
michael@0:  * * It's a singleton, because its scope extends to that of the application,
michael@0:  *   and definitionally all changes to the locale of the app must go through
michael@0:  *   this.
michael@0:  * * It's lazy.
michael@0:  * * It has ties into the Gecko event system, because it has to tell Gecko when
michael@0:  *   to switch locale.
michael@0:  * * It relies on using the SharedPreferences file owned by the browser (in
michael@0:  *   Fennec's case, "GeckoApp") for performance.
michael@0:  */
michael@0: public class BrowserLocaleManager implements LocaleManager {
michael@0:     private static final String LOG_TAG = "GeckoLocales";
michael@0: 
michael@0:     private static final String EVENT_LOCALE_CHANGED = "Locale:Changed";
michael@0:     private static final String PREF_LOCALE = "locale";
michael@0: 
michael@0:     // This is volatile because we don't impose restrictions
michael@0:     // over which thread calls our methods.
michael@0:     private volatile Locale currentLocale = null;
michael@0: 
michael@0:     private AtomicBoolean inited = new AtomicBoolean(false);
michael@0:     private boolean systemLocaleDidChange = false;
michael@0:     private BroadcastReceiver receiver;
michael@0: 
michael@0:     private static AtomicReference<LocaleManager> instance = new AtomicReference<LocaleManager>();
michael@0: 
michael@0:     public static LocaleManager getInstance() {
michael@0:         LocaleManager localeManager = instance.get();
michael@0:         if (localeManager != null) {
michael@0:             return localeManager;
michael@0:         }
michael@0: 
michael@0:         localeManager = new BrowserLocaleManager();
michael@0:         if (instance.compareAndSet(null, localeManager)) {
michael@0:             return localeManager;
michael@0:         } else {
michael@0:             return instance.get();
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Gecko uses locale codes like "es-ES", whereas a Java {@link Locale}
michael@0:      * stringifies as "es_ES".
michael@0:      *
michael@0:      * This method approximates the Java 7 method <code>Locale#toLanguageTag()</code>.
michael@0:      *
michael@0:      * @return a locale string suitable for passing to Gecko.
michael@0:      */
michael@0:     public static String getLanguageTag(final Locale locale) {
michael@0:         // If this were Java 7:
michael@0:         // return locale.toLanguageTag();
michael@0: 
michael@0:         String language = locale.getLanguage();  // Can, but should never be, an empty string.
michael@0:         // Modernize certain language codes.
michael@0:         if (language.equals("iw")) {
michael@0:             language = "he";
michael@0:         } else if (language.equals("in")) {
michael@0:             language = "id";
michael@0:         } else if (language.equals("ji")) {
michael@0:             language = "yi";
michael@0:         }
michael@0: 
michael@0:         String country = locale.getCountry();    // Can be an empty string.
michael@0:         if (country.equals("")) {
michael@0:             return language;
michael@0:         }
michael@0:         return language + "-" + country;
michael@0:     }
michael@0: 
michael@0:     private static Locale parseLocaleCode(final String localeCode) {
michael@0:         int index;
michael@0:         if ((index = localeCode.indexOf('-')) != -1 ||
michael@0:             (index = localeCode.indexOf('_')) != -1) {
michael@0:             final String langCode = localeCode.substring(0, index);
michael@0:             final String countryCode = localeCode.substring(index + 1);
michael@0:             return new Locale(langCode, countryCode);
michael@0:         } else {
michael@0:             return new Locale(localeCode);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Ensure that you call this early in your application startup,
michael@0:      * and with a context that's sufficiently long-lived (typically
michael@0:      * the application context).
michael@0:      *
michael@0:      * Calling multiple times is harmless.
michael@0:      */
michael@0:     @Override
michael@0:     public void initialize(final Context context) {
michael@0:         if (!inited.compareAndSet(false, true)) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         receiver = new BroadcastReceiver() {
michael@0:             @Override
michael@0:             public void onReceive(Context context, Intent intent) {
michael@0:                 systemLocaleDidChange = true;
michael@0:             }
michael@0:         };
michael@0:         context.registerReceiver(receiver, new IntentFilter(Intent.ACTION_LOCALE_CHANGED));
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public boolean systemLocaleDidChange() {
michael@0:         return systemLocaleDidChange;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Every time the system gives us a new configuration, it
michael@0:      * carries the external locale. Fix it.
michael@0:      */
michael@0:     @Override
michael@0:     public void correctLocale(Context context, Resources res, Configuration config) {
michael@0:         final Locale current = getCurrentLocale(context);
michael@0:         if (current == null) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         // I know it's tempting to short-circuit here if the config seems to be
michael@0:         // up-to-date, but the rest is necessary.
michael@0: 
michael@0:         config.locale = current;
michael@0: 
michael@0:         // The following two lines are heavily commented in case someone
michael@0:         // decides to chase down performance improvements and decides to
michael@0:         // question what's going on here.
michael@0:         // Both lines should be cheap, *but*...
michael@0: 
michael@0:         // This is unnecessary for basic string choice, but it almost
michael@0:         // certainly comes into play when rendering numbers, deciding on RTL,
michael@0:         // etc. Take it out if you can prove that's not the case.
michael@0:         Locale.setDefault(current);
michael@0: 
michael@0:         // This seems to be a no-op, but every piece of documentation under the
michael@0:         // sun suggests that it's necessary, and it certainly makes sense.
michael@0:         res.updateConfiguration(config, res.getDisplayMetrics());
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public String getAndApplyPersistedLocale(Context context) {
michael@0:         initialize(context);
michael@0: 
michael@0:         final long t1 = android.os.SystemClock.uptimeMillis();
michael@0:         final String localeCode = getPersistedLocale(context);
michael@0:         if (localeCode == null) {
michael@0:             return null;
michael@0:         }
michael@0: 
michael@0:         // Note that we don't tell Gecko about this. We notify Gecko when the
michael@0:         // locale is set, not when we update Java.
michael@0:         final String resultant = updateLocale(context, localeCode);
michael@0: 
michael@0:         if (resultant == null) {
michael@0:             // Update the configuration anyway.
michael@0:             updateConfiguration(context, currentLocale);
michael@0:         }
michael@0: 
michael@0:         final long t2 = android.os.SystemClock.uptimeMillis();
michael@0:         Log.i(LOG_TAG, "Locale read and update took: " + (t2 - t1) + "ms.");
michael@0:         return resultant;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns the set locale if it changed.
michael@0:      *
michael@0:      * Always persists and notifies Gecko.
michael@0:      */
michael@0:     @Override
michael@0:     public String setSelectedLocale(Context context, String localeCode) {
michael@0:         final String resultant = updateLocale(context, localeCode);
michael@0: 
michael@0:         // We always persist and notify Gecko, even if nothing seemed to
michael@0:         // change. This might happen if you're picking a locale that's the same
michael@0:         // as the current OS locale. The OS locale might change next time we
michael@0:         // launch, and we need the Gecko pref and persisted locale to have been
michael@0:         // set by the time that happens.
michael@0:         persistLocale(context, localeCode);
michael@0: 
michael@0:         // Tell Gecko.
michael@0:         GeckoEvent ev = GeckoEvent.createBroadcastEvent(EVENT_LOCALE_CHANGED, BrowserLocaleManager.getLanguageTag(getCurrentLocale(context)));
michael@0:         GeckoAppShell.sendEventToGecko(ev);
michael@0: 
michael@0:         return resultant;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * This is public to allow for an activity to force the
michael@0:      * current locale to be applied if necessary (e.g., when
michael@0:      * a new activity launches).
michael@0:      */
michael@0:     @Override
michael@0:     public void updateConfiguration(Context context, Locale locale) {
michael@0:         Resources res = context.getResources();
michael@0:         Configuration config = res.getConfiguration();
michael@0:         config.locale = locale;
michael@0:         res.updateConfiguration(config, res.getDisplayMetrics());
michael@0:     }
michael@0: 
michael@0:     private SharedPreferences getSharedPreferences(Context context) {
michael@0:         return GeckoSharedPrefs.forApp(context);
michael@0:     }
michael@0: 
michael@0:     private String getPersistedLocale(Context context) {
michael@0:         final SharedPreferences settings = getSharedPreferences(context);
michael@0:         final String locale = settings.getString(PREF_LOCALE, "");
michael@0: 
michael@0:         if ("".equals(locale)) {
michael@0:             return null;
michael@0:         }
michael@0:         return locale;
michael@0:     }
michael@0: 
michael@0:     private void persistLocale(Context context, String localeCode) {
michael@0:         final SharedPreferences settings = getSharedPreferences(context);
michael@0:         settings.edit().putString(PREF_LOCALE, localeCode).commit();
michael@0:     }
michael@0: 
michael@0:     private Locale getCurrentLocale(Context context) {
michael@0:         if (currentLocale != null) {
michael@0:             return currentLocale;
michael@0:         }
michael@0: 
michael@0:         final String current = getPersistedLocale(context);
michael@0:         if (current == null) {
michael@0:             return null;
michael@0:         }
michael@0:         return currentLocale = parseLocaleCode(current);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Updates the Java locale and the Android configuration.
michael@0:      *
michael@0:      * Returns the persisted locale if it differed.
michael@0:      *
michael@0:      * Does not notify Gecko.
michael@0:      */
michael@0:     private String updateLocale(Context context, String localeCode) {
michael@0:         // Fast path.
michael@0:         final Locale defaultLocale = Locale.getDefault();
michael@0:         if (defaultLocale.toString().equals(localeCode)) {
michael@0:             return null;
michael@0:         }
michael@0: 
michael@0:         final Locale locale = parseLocaleCode(localeCode);
michael@0: 
michael@0:         // Fast path.
michael@0:         if (defaultLocale.equals(locale)) {
michael@0:             return null;
michael@0:         }
michael@0: 
michael@0:         Locale.setDefault(locale);
michael@0:         currentLocale = locale;
michael@0: 
michael@0:         // Update resources.
michael@0:         updateConfiguration(context, locale);
michael@0: 
michael@0:         return locale.toString();
michael@0:     }
michael@0: }