1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/i18n/break_iterator.h"
6
7 #include "base/logging.h"
8 #include "third_party/icu/source/common/unicode/ubrk.h"
9 #include "third_party/icu/source/common/unicode/uchar.h"
10 #include "third_party/icu/source/common/unicode/ustring.h"
11
12 namespace base {
13 namespace i18n {
14
15 const size_t npos = -1;
16
BreakIterator(const string16 & str,BreakType break_type)17 BreakIterator::BreakIterator(const string16& str, BreakType break_type)
18 : iter_(NULL),
19 string_(str),
20 break_type_(break_type),
21 prev_(npos),
22 pos_(0) {
23 }
24
~BreakIterator()25 BreakIterator::~BreakIterator() {
26 if (iter_)
27 ubrk_close(static_cast<UBreakIterator*>(iter_));
28 }
29
Init()30 bool BreakIterator::Init() {
31 UErrorCode status = U_ZERO_ERROR;
32 UBreakIteratorType break_type;
33 switch (break_type_) {
34 case BREAK_CHARACTER:
35 break_type = UBRK_CHARACTER;
36 break;
37 case BREAK_WORD:
38 break_type = UBRK_WORD;
39 break;
40 case BREAK_LINE:
41 case BREAK_NEWLINE:
42 break_type = UBRK_LINE;
43 break;
44 default:
45 NOTREACHED() << "invalid break_type_";
46 return false;
47 }
48 iter_ = ubrk_open(break_type, NULL,
49 string_.data(), static_cast<int32_t>(string_.size()),
50 &status);
51 if (U_FAILURE(status)) {
52 NOTREACHED() << "ubrk_open failed";
53 return false;
54 }
55 // Move the iterator to the beginning of the string.
56 ubrk_first(static_cast<UBreakIterator*>(iter_));
57 return true;
58 }
59
Advance()60 bool BreakIterator::Advance() {
61 int32_t pos;
62 int32_t status;
63 prev_ = pos_;
64 switch (break_type_) {
65 case BREAK_CHARACTER:
66 case BREAK_WORD:
67 case BREAK_LINE:
68 pos = ubrk_next(static_cast<UBreakIterator*>(iter_));
69 if (pos == UBRK_DONE) {
70 pos_ = npos;
71 return false;
72 }
73 pos_ = static_cast<size_t>(pos);
74 return true;
75 case BREAK_NEWLINE:
76 do {
77 pos = ubrk_next(static_cast<UBreakIterator*>(iter_));
78 if (pos == UBRK_DONE)
79 break;
80 pos_ = static_cast<size_t>(pos);
81 status = ubrk_getRuleStatus(static_cast<UBreakIterator*>(iter_));
82 } while (status >= UBRK_LINE_SOFT && status < UBRK_LINE_SOFT_LIMIT);
83 if (pos == UBRK_DONE && prev_ == pos_) {
84 pos_ = npos;
85 return false;
86 }
87 return true;
88 default:
89 NOTREACHED() << "invalid break_type_";
90 return false;
91 }
92 }
93
IsWord() const94 bool BreakIterator::IsWord() const {
95 int32_t status = ubrk_getRuleStatus(static_cast<UBreakIterator*>(iter_));
96 return (break_type_ == BREAK_WORD && status != UBRK_WORD_NONE);
97 }
98
IsEndOfWord(size_t position) const99 bool BreakIterator::IsEndOfWord(size_t position) const {
100 if (break_type_ != BREAK_WORD)
101 return false;
102
103 UBreakIterator* iter = static_cast<UBreakIterator*>(iter_);
104 UBool boundary = ubrk_isBoundary(iter, static_cast<int32_t>(position));
105 int32_t status = ubrk_getRuleStatus(iter);
106 return (!!boundary && status != UBRK_WORD_NONE);
107 }
108
IsStartOfWord(size_t position) const109 bool BreakIterator::IsStartOfWord(size_t position) const {
110 if (break_type_ != BREAK_WORD)
111 return false;
112
113 UBreakIterator* iter = static_cast<UBreakIterator*>(iter_);
114 UBool boundary = ubrk_isBoundary(iter, static_cast<int32_t>(position));
115 ubrk_next(iter);
116 int32_t next_status = ubrk_getRuleStatus(iter);
117 return (!!boundary && next_status != UBRK_WORD_NONE);
118 }
119
GetString() const120 string16 BreakIterator::GetString() const {
121 DCHECK(prev_ != npos && pos_ != npos);
122 return string_.substr(prev_, pos_ - prev_);
123 }
124
125 } // namespace i18n
126 } // namespace base
127