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#include "LayoutUtils.h" 184e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 1914e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonakanamespace minikin { 2014e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonaka 21acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka/* 22acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka * Determine whether the code unit is a word space for the purposes of justification. 239b0b003dc15c6741ddf164d1aa39965110b79b80Roozbeh Pournader * TODO: Support NBSP and other stretchable whitespace (b/34013491 and b/68204709). 24acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka */ 25acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonakabool isWordSpace(uint16_t code_unit) { 269b0b003dc15c6741ddf164d1aa39965110b79b80Roozbeh Pournader return code_unit == ' '; 27acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka} 28acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka 294e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 304e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * For the purpose of layout, a word break is a boundary with no 314e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * kerning or complex script processing. This is necessarily a 324e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * heuristic, but should be accurate most of the time. 334e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 34acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonakastatic bool isWordBreakAfter(uint16_t c) { 35510047d8fd99c960d131c701bdee217d1970987fRoozbeh Pournader if (c == ' ' || (0x2000 <= c && c <= 0x200A) || c == 0x3000) { 364e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // spaces 374e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return true; 384e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 394e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // Note: kana is not included, as sophisticated fonts may kern kana 404e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return false; 414e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 424e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 43acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonakastatic bool isWordBreakBefore(uint16_t c) { 444e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // CJK ideographs (and yijing hexagram symbols) 45510047d8fd99c960d131c701bdee217d1970987fRoozbeh Pournader return isWordBreakAfter(c) || (0x3400 <= c && c <= 0x9FFF); 464e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 474e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 484e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 494e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Return offset of previous word break. It is either < offset or == 0. 504e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 511d461589869ee5b7102f96271b0ef0a776ab513cSeigo Nonakasize_t getPrevWordBreakForCache(const uint16_t* chars, size_t offset, size_t len) { 524e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset == 0) return 0; 534e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset > len) offset = len; 544e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[offset - 1])) { 554e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return offset - 1; 564e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 574e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka for (size_t i = offset - 1; i > 0; i--) { 584e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[i]) || isWordBreakAfter(chars[i - 1])) { 594e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return i; 604e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 614e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 624e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return 0; 634e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 644e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 654e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 664e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Return offset of next word break. It is either > offset or == len. 674e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 681d461589869ee5b7102f96271b0ef0a776ab513cSeigo Nonakasize_t getNextWordBreakForCache(const uint16_t* chars, size_t offset, size_t len) { 694e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset >= len) return len; 704e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakAfter(chars[offset])) { 714e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return offset + 1; 724e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 734e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka for (size_t i = offset + 1; i < len; i++) { 744e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // No need to check isWordBreakAfter(chars[i - 1]) since it is checked 754e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // in previous iteration. Note that isWordBreakBefore returns true 764e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // whenever isWordBreakAfter returns true. 774e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[i])) { 784e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return i; 794e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 804e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 814e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return len; 824e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 8314e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonaka 8414e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonaka} // namespace minikin 85