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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/intl/UnicodeProperties.h"
#include "mozilla/intl/WordBreaker.h"
#include "mozilla/StaticPrefs_layout.h"
#include "nsComplexBreaker.h"
#include "nsTArray.h"
#include "nsUnicodeProperties.h"
using mozilla::intl::Script;
using mozilla::intl::UnicodeProperties;
using mozilla::intl::WordBreaker;
using mozilla::intl::WordRange;
using mozilla::unicode::GetGenCategory;
#define IS_ASCII(c) (0 == (0xFF80 & (c)))
#define ASCII_IS_ALPHA(c) \
((('a' <= (c)) && ((c) <= 'z')) || (('A' <= (c)) && ((c) <= 'Z')))
#define ASCII_IS_DIGIT(c) (('0' <= (c)) && ((c) <= '9'))
#define ASCII_IS_SPACE(c) \
((' ' == (c)) || ('\t' == (c)) || ('\r' == (c)) || ('\n' == (c)))
#define IS_ALPHABETICAL_SCRIPT(c) ((c) < 0x2E80)
// we change the beginning of IS_HAN from 0x4e00 to 0x3400 to relfect
// Unicode 3.0
#define IS_HAN(c) \
((0x3400 <= (c)) && ((c) <= 0x9fff)) || ((0xf900 <= (c)) && ((c) <= 0xfaff))
#define IS_KATAKANA(c) ((0x30A0 <= (c)) && ((c) <= 0x30FF))
#define IS_HIRAGANA(c) ((0x3040 <= (c)) && ((c) <= 0x309F))
#define IS_HALFWIDTHKATAKANA(c) ((0xFF60 <= (c)) && ((c) <= 0xFF9F))
// Return true if aChar belongs to a SEAsian script that is written without
// word spaces, so we need to use the "complex breaker" to find possible word
// boundaries. (https://en.wikipedia.org/wiki/Scriptio_continua)
// (How well this works depends on the level of platform support for finding
// possible line breaks - or possible word boundaries - in the particular
// script. Thai, at least, works pretty well on the major desktop OSes. If
// the script is not supported by the platform, we just won't find any useful
// boundaries.)
static bool IsScriptioContinua(char16_t aChar) {
Script sc = UnicodeProperties::GetScriptCode(aChar);
return sc == Script::THAI || sc == Script::MYANMAR || sc == Script::KHMER ||
sc == Script::JAVANESE || sc == Script::BALINESE ||
sc == Script::SUNDANESE || sc == Script::LAO;
}
/* static */
WordBreaker::WordBreakClass WordBreaker::GetClass(char16_t c) {
// begin of the hack
if (IS_ALPHABETICAL_SCRIPT(c)) {
if (IS_ASCII(c)) {
if (ASCII_IS_SPACE(c)) {
return kWbClassSpace;
}
if (ASCII_IS_ALPHA(c) || ASCII_IS_DIGIT(c) ||
(c == '_' && !StaticPrefs::layout_word_select_stop_at_underscore())) {
return kWbClassAlphaLetter;
}
return kWbClassPunct;
}
if (c == 0x00A0 /*NBSP*/) {
return kWbClassSpace;
}
if (GetGenCategory(c) == nsUGenCategory::kPunctuation) {
return kWbClassPunct;
}
if (IsScriptioContinua(c)) {
return kWbClassScriptioContinua;
}
return kWbClassAlphaLetter;
}
if (IS_HAN(c)) {
return kWbClassHanLetter;
}
if (IS_KATAKANA(c)) {
return kWbClassKatakanaLetter;
}
if (IS_HIRAGANA(c)) {
return kWbClassHiraganaLetter;
}
if (IS_HALFWIDTHKATAKANA(c)) {
return kWbClassHWKatakanaLetter;
}
if (GetGenCategory(c) == nsUGenCategory::kPunctuation) {
return kWbClassPunct;
}
if (IsScriptioContinua(c)) {
return kWbClassScriptioContinua;
}
return kWbClassAlphaLetter;
}
WordRange WordBreaker::FindWord(const char16_t* aText, uint32_t aLen,
uint32_t aPos) {
MOZ_ASSERT(aText);
if (aPos >= aLen) {
return {aLen, aLen};
}
WordBreakClass c = GetClass(aText[aPos]);
WordRange range{0, aLen};
// Scan forward
for (uint32_t i = aPos + 1; i <= aLen; i++) {
if (c != GetClass(aText[i])) {
range.mEnd = i;
break;
}
}
// Scan backward
for (uint32_t i = aPos; i > 0; i--) {
if (c != GetClass(aText[i - 1])) {
range.mBegin = i;
break;
}
}
if (kWbClassScriptioContinua == c) {
// we pass the whole text segment to the complex word breaker to find a
// shorter answer
AutoTArray<uint8_t, 256> breakBefore;
breakBefore.SetLength(range.mEnd - range.mBegin);
ComplexBreaker::GetBreaks(aText + range.mBegin, range.mEnd - range.mBegin,
breakBefore.Elements());
// Scan forward
for (uint32_t i = aPos + 1; i < range.mEnd; i++) {
if (breakBefore[i - range.mBegin]) {
range.mEnd = i;
break;
}
}
// Scan backward
for (uint32_t i = aPos; i > range.mBegin; i--) {
if (breakBefore[i - range.mBegin]) {
range.mBegin = i;
break;
}
}
}
return range;
}
int32_t WordBreaker::Next(const char16_t* aText, uint32_t aLen, uint32_t aPos) {
MOZ_ASSERT(aText);
if (aPos >= aLen) {
return NS_WORDBREAKER_NEED_MORE_TEXT;
}
const WordBreakClass posClass = GetClass(aText[aPos]);
uint32_t nextBreakPos;
for (nextBreakPos = aPos + 1; nextBreakPos < aLen; ++nextBreakPos) {
if (posClass != GetClass(aText[nextBreakPos])) {
break;
}
}
if (kWbClassScriptioContinua == posClass) {
// We pass the whole text segment to the complex word breaker to find a
// shorter answer.
const char16_t* segStart = aText + aPos;
const uint32_t segLen = nextBreakPos - aPos + 1;
AutoTArray<uint8_t, 256> breakBefore;
breakBefore.SetLength(segLen);
ComplexBreaker::GetBreaks(segStart, segLen, breakBefore.Elements());
for (uint32_t i = aPos + 1; i < nextBreakPos; ++i) {
if (breakBefore[i - aPos]) {
nextBreakPos = i;
break;
}
}
}
MOZ_ASSERT(nextBreakPos != aPos);
return nextBreakPos;
}
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