14e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/* 24e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Copyright (C) 2015 The Android Open Source Project 34e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * 44e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Licensed under the Apache License, Version 2.0 (the "License"); 54e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * you may not use this file except in compliance with the License. 64e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * You may obtain a copy of the License at 74e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * 84e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * http://www.apache.org/licenses/LICENSE-2.0 94e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * 104e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Unless required by applicable law or agreed to in writing, software 114e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * distributed under the License is distributed on an "AS IS" BASIS, 124e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 134e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * See the License for the specific language governing permissions and 144e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * limitations under the License. 154e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 164e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 174e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka#define LOG_TAG "Minikin" 184e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 194e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka#include "LayoutUtils.h" 204e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 214e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 224e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * For the purpose of layout, a word break is a boundary with no 234e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * kerning or complex script processing. This is necessarily a 244e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * heuristic, but should be accurate most of the time. 254e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 264e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonakastatic bool isWordBreakAfter(int c) { 274e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (c == ' ' || (c >= 0x2000 && c <= 0x200a) || c == 0x3000) { 284e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // spaces 294e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return true; 304e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 314e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // Note: kana is not included, as sophisticated fonts may kern kana 324e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return false; 334e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 344e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 354e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonakastatic bool isWordBreakBefore(int c) { 364e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // CJK ideographs (and yijing hexagram symbols) 374e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return isWordBreakAfter(c) || (c >= 0x3400 && c <= 0x9fff); 384e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 394e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 404e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 414e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Return offset of previous word break. It is either < offset or == 0. 424e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 434e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonakasize_t getPrevWordBreakForCache( 444e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka const uint16_t* chars, size_t offset, size_t len) { 454e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset == 0) return 0; 464e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset > len) offset = len; 474e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[offset - 1])) { 484e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return offset - 1; 494e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 504e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka for (size_t i = offset - 1; i > 0; i--) { 514e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[i]) || isWordBreakAfter(chars[i - 1])) { 524e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return i; 534e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 544e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 554e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return 0; 564e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 574e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 584e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 594e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Return offset of next word break. It is either > offset or == len. 604e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 614e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonakasize_t getNextWordBreakForCache( 624e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka const uint16_t* chars, size_t offset, size_t len) { 634e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset >= len) return len; 644e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakAfter(chars[offset])) { 654e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return offset + 1; 664e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 674e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka for (size_t i = offset + 1; i < len; i++) { 684e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // No need to check isWordBreakAfter(chars[i - 1]) since it is checked 694e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // in previous iteration. Note that isWordBreakBefore returns true 704e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // whenever isWordBreakAfter returns true. 714e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[i])) { 724e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return i; 734e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 744e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 754e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return len; 764e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 77