FontLanguage.cpp revision 198b46f1fea3f47ef8eb6317799c0d77aaec52f6
1/* 2 * Copyright (C) 2015 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 17#define LOG_TAG "Minikin" 18 19#include "FontLanguage.h" 20 21#include <hb.h> 22#include <unicode/uloc.h> 23 24namespace android { 25 26#define SCRIPT_TAG(c1, c2, c3, c4) \ 27 (((uint32_t)(c1)) << 24 | ((uint32_t)(c2)) << 16 | ((uint32_t)(c3)) << 8 | \ 28 ((uint32_t)(c4))) 29 30// Parse BCP 47 language identifier into internal structure 31FontLanguage::FontLanguage(const char* buf, size_t length) : FontLanguage() { 32 size_t i; 33 for (i = 0; i < length; i++) { 34 char c = buf[i]; 35 if (c == '-' || c == '_') break; 36 } 37 if (i == 2 || i == 3) { // only accept two or three letter language code. 38 mLanguage = buf[0] | (buf[1] << 8) | ((i == 3) ? (buf[2] << 16) : 0); 39 } else { 40 // We don't understand anything other than two-letter or three-letter 41 // language codes, so we skip parsing the rest of the string. 42 mLanguage = 0ul; 43 return; 44 } 45 46 size_t next; 47 for (i++; i < length; i = next + 1) { 48 for (next = i; next < length; next++) { 49 char c = buf[next]; 50 if (c == '-' || c == '_') break; 51 } 52 if (next - i == 4 && 'A' <= buf[i] && buf[i] <= 'Z') { 53 mScript = SCRIPT_TAG(buf[i], buf[i + 1], buf[i + 2], buf[i + 3]); 54 } 55 } 56 57 mSubScriptBits = scriptToSubScriptBits(mScript); 58} 59 60//static 61uint8_t FontLanguage::scriptToSubScriptBits(uint32_t script) { 62 uint8_t subScriptBits = 0u; 63 switch (script) { 64 case SCRIPT_TAG('H', 'a', 'n', 'g'): 65 subScriptBits = kHangulFlag; 66 break; 67 case SCRIPT_TAG('H', 'a', 'n', 'i'): 68 subScriptBits = kHanFlag; 69 break; 70 case SCRIPT_TAG('H', 'a', 'n', 's'): 71 subScriptBits = kHanFlag | kSimplifiedChineseFlag; 72 break; 73 case SCRIPT_TAG('H', 'a', 'n', 't'): 74 subScriptBits = kHanFlag | kTraditionalChineseFlag; 75 break; 76 case SCRIPT_TAG('H', 'i', 'r', 'a'): 77 subScriptBits = kHiraganaFlag; 78 break; 79 case SCRIPT_TAG('H', 'r', 'k', 't'): 80 subScriptBits = kKatakanaFlag | kHiraganaFlag; 81 break; 82 case SCRIPT_TAG('J', 'p', 'a', 'n'): 83 subScriptBits = kHanFlag | kKatakanaFlag | kHiraganaFlag; 84 break; 85 case SCRIPT_TAG('K', 'a', 'n', 'a'): 86 subScriptBits = kKatakanaFlag; 87 break; 88 case SCRIPT_TAG('K', 'o', 'r', 'e'): 89 subScriptBits = kHanFlag | kHangulFlag; 90 break; 91 case SCRIPT_TAG('Q', 'a', 'a', 'e'): 92 subScriptBits = kEmojiFlag; 93 break; 94 } 95 return subScriptBits; 96} 97 98std::string FontLanguage::getString() const { 99 if (mLanguage == 0ul) { 100 return "und"; 101 } 102 char buf[16]; 103 size_t i = 0; 104 buf[i++] = mLanguage & 0xFF ; 105 buf[i++] = (mLanguage >> 8) & 0xFF; 106 char third_letter = (mLanguage >> 16) & 0xFF; 107 if (third_letter != 0) buf[i++] = third_letter; 108 if (mScript != 0) { 109 buf[i++] = '-'; 110 buf[i++] = (mScript >> 24) & 0xFFu; 111 buf[i++] = (mScript >> 16) & 0xFFu; 112 buf[i++] = (mScript >> 8) & 0xFFu; 113 buf[i++] = mScript & 0xFFu; 114 } 115 return std::string(buf, i); 116} 117 118bool FontLanguage::isEqualScript(const FontLanguage other) const { 119 return other.mScript == mScript; 120} 121 122bool FontLanguage::supportsHbScript(hb_script_t script) const { 123 static_assert(SCRIPT_TAG('J', 'p', 'a', 'n') == HB_TAG('J', 'p', 'a', 'n'), 124 "The Minikin script and HarfBuzz hb_script_t have different encodings."); 125 if (script == mScript) return true; 126 uint8_t requestedBits = scriptToSubScriptBits(script); 127 return requestedBits != 0 && (mSubScriptBits & requestedBits) == requestedBits; 128} 129 130int FontLanguage::match(const FontLanguage other) const { 131 // TODO: Use script for matching. 132 return *this == other; 133} 134 135#undef SCRIPT_TAG 136} // namespace android 137