1 /* 2 * Copyright (C) 2014 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 #ifndef MINIKIN_GRAPHEME_BREAK_H 18 #define MINIKIN_GRAPHEME_BREAK_H 19 20 #include <stddef.h> 21 #include <unicode/utf16.h> 22 23 namespace minikin { 24 25 class GraphemeBreak { 26 public: 27 // These values must be kept in sync with CURSOR_AFTER etc in Paint.java 28 enum MoveOpt { 29 AFTER = 0, 30 AT_OR_AFTER = 1, 31 BEFORE = 2, 32 AT_OR_BEFORE = 3, 33 AT = 4 34 }; 35 36 // Determine whether the given offset is a grapheme break. 37 // This implementation generally follows Unicode's UTR #29 extended 38 // grapheme break, with various tweaks. 39 static bool isGraphemeBreak(const float* advances, 40 const uint16_t* buf, 41 size_t start, 42 size_t count, 43 size_t offset); 44 45 // Matches Android's Java API. Note, return (size_t)-1 for AT to 46 // signal non-break because unsigned return type. 47 static size_t getTextRunCursor(const float* advances, 48 const uint16_t* buf, 49 size_t start, 50 size_t count, 51 size_t offset, 52 MoveOpt opt); 53 }; 54 55 } // namespace minikin 56 57 #endif // MINIKIN_GRAPHEME_BREAK_H 58