1/* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of 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, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package com.android.inputmethod.latin.utils; 18 19import java.util.Locale; 20import java.util.TreeMap; 21 22/** 23 * A class to help with handling different writing scripts. 24 */ 25public class ScriptUtils { 26 27 // Used for hardware keyboards 28 public static final int SCRIPT_UNKNOWN = -1; 29 30 public static final int SCRIPT_ARABIC = 0; 31 public static final int SCRIPT_ARMENIAN = 1; 32 public static final int SCRIPT_BENGALI = 2; 33 public static final int SCRIPT_CYRILLIC = 3; 34 public static final int SCRIPT_DEVANAGARI = 4; 35 public static final int SCRIPT_GEORGIAN = 5; 36 public static final int SCRIPT_GREEK = 6; 37 public static final int SCRIPT_HEBREW = 7; 38 public static final int SCRIPT_KANNADA = 8; 39 public static final int SCRIPT_KHMER = 9; 40 public static final int SCRIPT_LAO = 10; 41 public static final int SCRIPT_LATIN = 11; 42 public static final int SCRIPT_MALAYALAM = 12; 43 public static final int SCRIPT_MYANMAR = 13; 44 public static final int SCRIPT_SINHALA = 14; 45 public static final int SCRIPT_TAMIL = 15; 46 public static final int SCRIPT_TELUGU = 16; 47 public static final int SCRIPT_THAI = 17; 48 49 private static final TreeMap<String, Integer> mLanguageCodeToScriptCode; 50 51 static { 52 mLanguageCodeToScriptCode = new TreeMap<>(); 53 mLanguageCodeToScriptCode.put("", SCRIPT_LATIN); // default 54 mLanguageCodeToScriptCode.put("ar", SCRIPT_ARABIC); 55 mLanguageCodeToScriptCode.put("hy", SCRIPT_ARMENIAN); 56 mLanguageCodeToScriptCode.put("bn", SCRIPT_BENGALI); 57 mLanguageCodeToScriptCode.put("bg", SCRIPT_CYRILLIC); 58 mLanguageCodeToScriptCode.put("sr", SCRIPT_CYRILLIC); 59 mLanguageCodeToScriptCode.put("ru", SCRIPT_CYRILLIC); 60 mLanguageCodeToScriptCode.put("ka", SCRIPT_GEORGIAN); 61 mLanguageCodeToScriptCode.put("el", SCRIPT_GREEK); 62 mLanguageCodeToScriptCode.put("iw", SCRIPT_HEBREW); 63 mLanguageCodeToScriptCode.put("km", SCRIPT_KHMER); 64 mLanguageCodeToScriptCode.put("lo", SCRIPT_LAO); 65 mLanguageCodeToScriptCode.put("ml", SCRIPT_MALAYALAM); 66 mLanguageCodeToScriptCode.put("my", SCRIPT_MYANMAR); 67 mLanguageCodeToScriptCode.put("si", SCRIPT_SINHALA); 68 mLanguageCodeToScriptCode.put("ta", SCRIPT_TAMIL); 69 mLanguageCodeToScriptCode.put("te", SCRIPT_TELUGU); 70 mLanguageCodeToScriptCode.put("th", SCRIPT_THAI); 71 } 72 73 /* 74 * Returns whether the code point is a letter that makes sense for the specified 75 * locale for this spell checker. 76 * The dictionaries supported by Latin IME are described in res/xml/spellchecker.xml 77 * and is limited to EFIGS languages and Russian. 78 * Hence at the moment this explicitly tests for Cyrillic characters or Latin characters 79 * as appropriate, and explicitly excludes CJK, Arabic and Hebrew characters. 80 */ 81 public static boolean isLetterPartOfScript(final int codePoint, final int scriptId) { 82 switch (scriptId) { 83 case SCRIPT_ARABIC: 84 // Arabic letters can be in any of the following blocks: 85 // Arabic U+0600..U+06FF 86 // Arabic Supplement, Thaana U+0750..U+077F, U+0780..U+07BF 87 // Arabic Extended-A U+08A0..U+08FF 88 // Arabic Presentation Forms-A U+FB50..U+FDFF 89 // Arabic Presentation Forms-B U+FE70..U+FEFF 90 return (codePoint >= 0x600 && codePoint <= 0x6FF) 91 || (codePoint >= 0x750 && codePoint <= 0x7BF) 92 || (codePoint >= 0x8A0 && codePoint <= 0x8FF) 93 || (codePoint >= 0xFB50 && codePoint <= 0xFDFF) 94 || (codePoint >= 0xFE70 && codePoint <= 0xFEFF); 95 case SCRIPT_ARMENIAN: 96 // Armenian letters are in the Armenian unicode block, U+0530..U+058F and 97 // Alphabetic Presentation Forms block, U+FB00..U+FB4F, but only in the Armenian part 98 // of that block, which is U+FB13..U+FB17. 99 return (codePoint >= 0x530 && codePoint <= 0x58F 100 || codePoint >= 0xFB13 && codePoint <= 0xFB17); 101 case SCRIPT_BENGALI: 102 // Bengali unicode block is U+0980..U+09FF 103 return (codePoint >= 0x980 && codePoint <= 0x9FF); 104 case SCRIPT_CYRILLIC: 105 // All Cyrillic characters are in the 400~52F block. There are some in the upper 106 // Unicode range, but they are archaic characters that are not used in modern 107 // Russian and are not used by our dictionary. 108 return codePoint >= 0x400 && codePoint <= 0x52F && Character.isLetter(codePoint); 109 case SCRIPT_DEVANAGARI: 110 // Devanagari unicode block is +0900..U+097F 111 return (codePoint >= 0x900 && codePoint <= 0x97F); 112 case SCRIPT_GEORGIAN: 113 // Georgian letters are in the Georgian unicode block, U+10A0..U+10FF, 114 // or Georgian supplement block, U+2D00..U+2D2F 115 return (codePoint >= 0x10A0 && codePoint <= 0x10FF 116 || codePoint >= 0x2D00 && codePoint <= 0x2D2F); 117 case SCRIPT_GREEK: 118 // Greek letters are either in the 370~3FF range (Greek & Coptic), or in the 119 // 1F00~1FFF range (Greek extended). Our dictionary contains both sort of characters. 120 // Our dictionary also contains a few words with 0xF2; it would be best to check 121 // if that's correct, but a web search does return results for these words so 122 // they are probably okay. 123 return (codePoint >= 0x370 && codePoint <= 0x3FF) 124 || (codePoint >= 0x1F00 && codePoint <= 0x1FFF) 125 || codePoint == 0xF2; 126 case SCRIPT_HEBREW: 127 // Hebrew letters are in the Hebrew unicode block, which spans from U+0590 to U+05FF, 128 // or in the Alphabetic Presentation Forms block, U+FB00..U+FB4F, but only in the 129 // Hebrew part of that block, which is U+FB1D..U+FB4F. 130 return (codePoint >= 0x590 && codePoint <= 0x5FF 131 || codePoint >= 0xFB1D && codePoint <= 0xFB4F); 132 case SCRIPT_KANNADA: 133 // Kannada unicode block is U+0C80..U+0CFF 134 return (codePoint >= 0xC80 && codePoint <= 0xCFF); 135 case SCRIPT_KHMER: 136 // Khmer letters are in unicode block U+1780..U+17FF, and the Khmer symbols block 137 // is U+19E0..U+19FF 138 return (codePoint >= 0x1780 && codePoint <= 0x17FF 139 || codePoint >= 0x19E0 && codePoint <= 0x19FF); 140 case SCRIPT_LAO: 141 // The Lao block is U+0E80..U+0EFF 142 return (codePoint >= 0xE80 && codePoint <= 0xEFF); 143 case SCRIPT_LATIN: 144 // Our supported latin script dictionaries (EFIGS) at the moment only include 145 // characters in the C0, C1, Latin Extended A and B, IPA extensions unicode 146 // blocks. As it happens, those are back-to-back in the code range 0x40 to 0x2AF, 147 // so the below is a very efficient way to test for it. As for the 0-0x3F, it's 148 // excluded from isLetter anyway. 149 return codePoint <= 0x2AF && Character.isLetter(codePoint); 150 case SCRIPT_MALAYALAM: 151 // Malayalam unicode block is U+0D00..U+0D7F 152 return (codePoint >= 0xD00 && codePoint <= 0xD7F); 153 case SCRIPT_MYANMAR: 154 // Myanmar has three unicode blocks : 155 // Myanmar U+1000..U+109F 156 // Myanmar extended-A U+AA60..U+AA7F 157 // Myanmar extended-B U+A9E0..U+A9FF 158 return (codePoint >= 0x1000 && codePoint <= 0x109F 159 || codePoint >= 0xAA60 && codePoint <= 0xAA7F 160 || codePoint >= 0xA9E0 && codePoint <= 0xA9FF); 161 case SCRIPT_SINHALA: 162 // Sinhala unicode block is U+0D80..U+0DFF 163 return (codePoint >= 0xD80 && codePoint <= 0xDFF); 164 case SCRIPT_TAMIL: 165 // Tamil unicode block is U+0B80..U+0BFF 166 return (codePoint >= 0xB80 && codePoint <= 0xBFF); 167 case SCRIPT_TELUGU: 168 // Telugu unicode block is U+0C00..U+0C7F 169 return (codePoint >= 0xC00 && codePoint <= 0xC7F); 170 case SCRIPT_THAI: 171 // Thai unicode block is U+0E00..U+0E7F 172 return (codePoint >= 0xE00 && codePoint <= 0xE7F); 173 case SCRIPT_UNKNOWN: 174 return true; 175 default: 176 // Should never come here 177 throw new RuntimeException("Impossible value of script: " + scriptId); 178 } 179 } 180 181 /** 182 * @param locale spell checker locale 183 * @return internal Latin IME script code that maps to a language code 184 * {@see http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes} 185 */ 186 public static int getScriptFromSpellCheckerLocale(final Locale locale) { 187 String language = locale.getLanguage(); 188 Integer script = mLanguageCodeToScriptCode.get(language); 189 if (script == null) { 190 // Default to Latin. 191 script = mLanguageCodeToScriptCode.get(""); 192 } 193 return script; 194 } 195} 196