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Diffstat (limited to 'java/src/org/kelar/inputmethod/latin/utils/ScriptUtils.java')
| -rw-r--r-- | java/src/org/kelar/inputmethod/latin/utils/ScriptUtils.java | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/java/src/org/kelar/inputmethod/latin/utils/ScriptUtils.java b/java/src/org/kelar/inputmethod/latin/utils/ScriptUtils.java new file mode 100644 index 000000000..981bc6649 --- /dev/null +++ b/java/src/org/kelar/inputmethod/latin/utils/ScriptUtils.java @@ -0,0 +1,195 @@ +/* + * Copyright (C) 2012 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.kelar.inputmethod.latin.utils; + +import java.util.Locale; +import java.util.TreeMap; + +/** + * A class to help with handling different writing scripts. + */ +public class ScriptUtils { + + // Used for hardware keyboards + public static final int SCRIPT_UNKNOWN = -1; + + public static final int SCRIPT_ARABIC = 0; + public static final int SCRIPT_ARMENIAN = 1; + public static final int SCRIPT_BENGALI = 2; + public static final int SCRIPT_CYRILLIC = 3; + public static final int SCRIPT_DEVANAGARI = 4; + public static final int SCRIPT_GEORGIAN = 5; + public static final int SCRIPT_GREEK = 6; + public static final int SCRIPT_HEBREW = 7; + public static final int SCRIPT_KANNADA = 8; + public static final int SCRIPT_KHMER = 9; + public static final int SCRIPT_LAO = 10; + public static final int SCRIPT_LATIN = 11; + public static final int SCRIPT_MALAYALAM = 12; + public static final int SCRIPT_MYANMAR = 13; + public static final int SCRIPT_SINHALA = 14; + public static final int SCRIPT_TAMIL = 15; + public static final int SCRIPT_TELUGU = 16; + public static final int SCRIPT_THAI = 17; + + private static final TreeMap<String, Integer> mLanguageCodeToScriptCode; + + static { + mLanguageCodeToScriptCode = new TreeMap<>(); + mLanguageCodeToScriptCode.put("", SCRIPT_LATIN); // default + mLanguageCodeToScriptCode.put("ar", SCRIPT_ARABIC); + mLanguageCodeToScriptCode.put("hy", SCRIPT_ARMENIAN); + mLanguageCodeToScriptCode.put("bn", SCRIPT_BENGALI); + mLanguageCodeToScriptCode.put("bg", SCRIPT_CYRILLIC); + mLanguageCodeToScriptCode.put("sr", SCRIPT_CYRILLIC); + mLanguageCodeToScriptCode.put("ru", SCRIPT_CYRILLIC); + mLanguageCodeToScriptCode.put("ka", SCRIPT_GEORGIAN); + mLanguageCodeToScriptCode.put("el", SCRIPT_GREEK); + mLanguageCodeToScriptCode.put("iw", SCRIPT_HEBREW); + mLanguageCodeToScriptCode.put("km", SCRIPT_KHMER); + mLanguageCodeToScriptCode.put("lo", SCRIPT_LAO); + mLanguageCodeToScriptCode.put("ml", SCRIPT_MALAYALAM); + mLanguageCodeToScriptCode.put("my", SCRIPT_MYANMAR); + mLanguageCodeToScriptCode.put("si", SCRIPT_SINHALA); + mLanguageCodeToScriptCode.put("ta", SCRIPT_TAMIL); + mLanguageCodeToScriptCode.put("te", SCRIPT_TELUGU); + mLanguageCodeToScriptCode.put("th", SCRIPT_THAI); + } + + /* + * Returns whether the code point is a letter that makes sense for the specified + * locale for this spell checker. + * The dictionaries supported by Latin IME are described in res/xml/spellchecker.xml + * and is limited to EFIGS languages and Russian. + * Hence at the moment this explicitly tests for Cyrillic characters or Latin characters + * as appropriate, and explicitly excludes CJK, Arabic and Hebrew characters. + */ + public static boolean isLetterPartOfScript(final int codePoint, final int scriptId) { + switch (scriptId) { + case SCRIPT_ARABIC: + // Arabic letters can be in any of the following blocks: + // Arabic U+0600..U+06FF + // Arabic Supplement, Thaana U+0750..U+077F, U+0780..U+07BF + // Arabic Extended-A U+08A0..U+08FF + // Arabic Presentation Forms-A U+FB50..U+FDFF + // Arabic Presentation Forms-B U+FE70..U+FEFF + return (codePoint >= 0x600 && codePoint <= 0x6FF) + || (codePoint >= 0x750 && codePoint <= 0x7BF) + || (codePoint >= 0x8A0 && codePoint <= 0x8FF) + || (codePoint >= 0xFB50 && codePoint <= 0xFDFF) + || (codePoint >= 0xFE70 && codePoint <= 0xFEFF); + case SCRIPT_ARMENIAN: + // Armenian letters are in the Armenian unicode block, U+0530..U+058F and + // Alphabetic Presentation Forms block, U+FB00..U+FB4F, but only in the Armenian part + // of that block, which is U+FB13..U+FB17. + return (codePoint >= 0x530 && codePoint <= 0x58F + || codePoint >= 0xFB13 && codePoint <= 0xFB17); + case SCRIPT_BENGALI: + // Bengali unicode block is U+0980..U+09FF + return (codePoint >= 0x980 && codePoint <= 0x9FF); + case SCRIPT_CYRILLIC: + // All Cyrillic characters are in the 400~52F block. There are some in the upper + // Unicode range, but they are archaic characters that are not used in modern + // Russian and are not used by our dictionary. + return codePoint >= 0x400 && codePoint <= 0x52F && Character.isLetter(codePoint); + case SCRIPT_DEVANAGARI: + // Devanagari unicode block is +0900..U+097F + return (codePoint >= 0x900 && codePoint <= 0x97F); + case SCRIPT_GEORGIAN: + // Georgian letters are in the Georgian unicode block, U+10A0..U+10FF, + // or Georgian supplement block, U+2D00..U+2D2F + return (codePoint >= 0x10A0 && codePoint <= 0x10FF + || codePoint >= 0x2D00 && codePoint <= 0x2D2F); + case SCRIPT_GREEK: + // Greek letters are either in the 370~3FF range (Greek & Coptic), or in the + // 1F00~1FFF range (Greek extended). Our dictionary contains both sort of characters. + // Our dictionary also contains a few words with 0xF2; it would be best to check + // if that's correct, but a web search does return results for these words so + // they are probably okay. + return (codePoint >= 0x370 && codePoint <= 0x3FF) + || (codePoint >= 0x1F00 && codePoint <= 0x1FFF) + || codePoint == 0xF2; + case SCRIPT_HEBREW: + // Hebrew letters are in the Hebrew unicode block, which spans from U+0590 to U+05FF, + // or in the Alphabetic Presentation Forms block, U+FB00..U+FB4F, but only in the + // Hebrew part of that block, which is U+FB1D..U+FB4F. + return (codePoint >= 0x590 && codePoint <= 0x5FF + || codePoint >= 0xFB1D && codePoint <= 0xFB4F); + case SCRIPT_KANNADA: + // Kannada unicode block is U+0C80..U+0CFF + return (codePoint >= 0xC80 && codePoint <= 0xCFF); + case SCRIPT_KHMER: + // Khmer letters are in unicode block U+1780..U+17FF, and the Khmer symbols block + // is U+19E0..U+19FF + return (codePoint >= 0x1780 && codePoint <= 0x17FF + || codePoint >= 0x19E0 && codePoint <= 0x19FF); + case SCRIPT_LAO: + // The Lao block is U+0E80..U+0EFF + return (codePoint >= 0xE80 && codePoint <= 0xEFF); + case SCRIPT_LATIN: + // Our supported latin script dictionaries (EFIGS) at the moment only include + // characters in the C0, C1, Latin Extended A and B, IPA extensions unicode + // blocks. As it happens, those are back-to-back in the code range 0x40 to 0x2AF, + // so the below is a very efficient way to test for it. As for the 0-0x3F, it's + // excluded from isLetter anyway. + return codePoint <= 0x2AF && Character.isLetter(codePoint); + case SCRIPT_MALAYALAM: + // Malayalam unicode block is U+0D00..U+0D7F + return (codePoint >= 0xD00 && codePoint <= 0xD7F); + case SCRIPT_MYANMAR: + // Myanmar has three unicode blocks : + // Myanmar U+1000..U+109F + // Myanmar extended-A U+AA60..U+AA7F + // Myanmar extended-B U+A9E0..U+A9FF + return (codePoint >= 0x1000 && codePoint <= 0x109F + || codePoint >= 0xAA60 && codePoint <= 0xAA7F + || codePoint >= 0xA9E0 && codePoint <= 0xA9FF); + case SCRIPT_SINHALA: + // Sinhala unicode block is U+0D80..U+0DFF + return (codePoint >= 0xD80 && codePoint <= 0xDFF); + case SCRIPT_TAMIL: + // Tamil unicode block is U+0B80..U+0BFF + return (codePoint >= 0xB80 && codePoint <= 0xBFF); + case SCRIPT_TELUGU: + // Telugu unicode block is U+0C00..U+0C7F + return (codePoint >= 0xC00 && codePoint <= 0xC7F); + case SCRIPT_THAI: + // Thai unicode block is U+0E00..U+0E7F + return (codePoint >= 0xE00 && codePoint <= 0xE7F); + case SCRIPT_UNKNOWN: + return true; + default: + // Should never come here + throw new RuntimeException("Impossible value of script: " + scriptId); + } + } + + /** + * @param locale spell checker locale + * @return internal Latin IME script code that maps to a language code + * {@see http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes} + */ + public static int getScriptFromSpellCheckerLocale(final Locale locale) { + String language = locale.getLanguage(); + Integer script = mLanguageCodeToScriptCode.get(language); + if (script == null) { + // Default to Latin. + script = mLanguageCodeToScriptCode.get(""); + } + return script; + } +} |