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      1 /*
      2  * Copyright (C) 2010 Google Inc.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
      5  * use this file except in compliance with the License. You may obtain a copy of
      6  * the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
     12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
     13  * License for the specific language governing permissions and limitations under
     14  * the License.
     15  */
     16 
     17 package com.android.inputmethod.latin;
     18 
     19 import java.util.Locale;
     20 
     21 import android.content.SharedPreferences;
     22 import android.content.SharedPreferences.Editor;
     23 import android.preference.PreferenceManager;
     24 import android.text.TextUtils;
     25 
     26 /**
     27  * Keeps track of list of selected input languages and the current
     28  * input language that the user has selected.
     29  */
     30 public class LanguageSwitcher {
     31 
     32     private Locale[] mLocales;
     33     private LatinIME mIme;
     34     private String[] mSelectedLanguageArray;
     35     private String   mSelectedLanguages;
     36     private int      mCurrentIndex = 0;
     37     private String   mDefaultInputLanguage;
     38     private Locale   mDefaultInputLocale;
     39     private Locale   mSystemLocale;
     40 
     41     public LanguageSwitcher(LatinIME ime) {
     42         mIme = ime;
     43         mLocales = new Locale[0];
     44     }
     45 
     46     public Locale[]  getLocales() {
     47         return mLocales;
     48     }
     49 
     50     public int getLocaleCount() {
     51         return mLocales.length;
     52     }
     53 
     54     /**
     55      * Loads the currently selected input languages from shared preferences.
     56      * @param sp
     57      * @return whether there was any change
     58      */
     59     public boolean loadLocales(SharedPreferences sp) {
     60         String selectedLanguages = sp.getString(LatinIME.PREF_SELECTED_LANGUAGES, null);
     61         String currentLanguage   = sp.getString(LatinIME.PREF_INPUT_LANGUAGE, null);
     62         if (selectedLanguages == null || selectedLanguages.length() < 1) {
     63             loadDefaults();
     64             if (mLocales.length == 0) {
     65                 return false;
     66             }
     67             mLocales = new Locale[0];
     68             return true;
     69         }
     70         if (selectedLanguages.equals(mSelectedLanguages)) {
     71             return false;
     72         }
     73         mSelectedLanguageArray = selectedLanguages.split(",");
     74         mSelectedLanguages = selectedLanguages; // Cache it for comparison later
     75         constructLocales();
     76         mCurrentIndex = 0;
     77         if (currentLanguage != null) {
     78             // Find the index
     79             mCurrentIndex = 0;
     80             for (int i = 0; i < mLocales.length; i++) {
     81                 if (mSelectedLanguageArray[i].equals(currentLanguage)) {
     82                     mCurrentIndex = i;
     83                     break;
     84                 }
     85             }
     86             // If we didn't find the index, use the first one
     87         }
     88         return true;
     89     }
     90 
     91     private void loadDefaults() {
     92         mDefaultInputLocale = mIme.getResources().getConfiguration().locale;
     93         String country = mDefaultInputLocale.getCountry();
     94         mDefaultInputLanguage = mDefaultInputLocale.getLanguage() +
     95                 (TextUtils.isEmpty(country) ? "" : "_" + country);
     96     }
     97 
     98     private void constructLocales() {
     99         mLocales = new Locale[mSelectedLanguageArray.length];
    100         for (int i = 0; i < mLocales.length; i++) {
    101             final String lang = mSelectedLanguageArray[i];
    102             mLocales[i] = new Locale(lang.substring(0, 2),
    103                     lang.length() > 4 ? lang.substring(3, 5) : "");
    104         }
    105     }
    106 
    107     /**
    108      * Returns the currently selected input language code, or the display language code if
    109      * no specific locale was selected for input.
    110      */
    111     public String getInputLanguage() {
    112         if (getLocaleCount() == 0) return mDefaultInputLanguage;
    113 
    114         return mSelectedLanguageArray[mCurrentIndex];
    115     }
    116 
    117     /**
    118      * Returns the list of enabled language codes.
    119      */
    120     public String[] getEnabledLanguages() {
    121         return mSelectedLanguageArray;
    122     }
    123 
    124     /**
    125      * Returns the currently selected input locale, or the display locale if no specific
    126      * locale was selected for input.
    127      * @return
    128      */
    129     public Locale getInputLocale() {
    130         if (getLocaleCount() == 0) return mDefaultInputLocale;
    131 
    132         return mLocales[mCurrentIndex];
    133     }
    134 
    135     /**
    136      * Returns the next input locale in the list. Wraps around to the beginning of the
    137      * list if we're at the end of the list.
    138      * @return
    139      */
    140     public Locale getNextInputLocale() {
    141         if (getLocaleCount() == 0) return mDefaultInputLocale;
    142 
    143         return mLocales[(mCurrentIndex + 1) % mLocales.length];
    144     }
    145 
    146     /**
    147      * Sets the system locale (display UI) used for comparing with the input language.
    148      * @param locale the locale of the system
    149      */
    150     public void setSystemLocale(Locale locale) {
    151         mSystemLocale = locale;
    152     }
    153 
    154     /**
    155      * Returns the system locale.
    156      * @return the system locale
    157      */
    158     public Locale getSystemLocale() {
    159         return mSystemLocale;
    160     }
    161 
    162     /**
    163      * Returns the previous input locale in the list. Wraps around to the end of the
    164      * list if we're at the beginning of the list.
    165      * @return
    166      */
    167     public Locale getPrevInputLocale() {
    168         if (getLocaleCount() == 0) return mDefaultInputLocale;
    169 
    170         return mLocales[(mCurrentIndex - 1 + mLocales.length) % mLocales.length];
    171     }
    172 
    173     public void reset() {
    174         mCurrentIndex = 0;
    175     }
    176 
    177     public void next() {
    178         mCurrentIndex++;
    179         if (mCurrentIndex >= mLocales.length) mCurrentIndex = 0; // Wrap around
    180     }
    181 
    182     public void prev() {
    183         mCurrentIndex--;
    184         if (mCurrentIndex < 0) mCurrentIndex = mLocales.length - 1; // Wrap around
    185     }
    186 
    187     public void persist() {
    188         SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(mIme);
    189         Editor editor = sp.edit();
    190         editor.putString(LatinIME.PREF_INPUT_LANGUAGE, getInputLanguage());
    191         editor.commit();
    192     }
    193 
    194     static String toTitleCase(String s) {
    195         if (s.length() == 0) {
    196             return s;
    197         }
    198 
    199         return Character.toUpperCase(s.charAt(0)) + s.substring(1);
    200     }
    201 }
    202