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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 **********************************************************************
5 *   Copyright (C) 2001-2011, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 **********************************************************************
8 *   Date        Name        Description
9 *   05/24/01    aliu        Creation.
10 **********************************************************************
11 */
12 
13 #include "unicode/utypes.h"
14 
15 #if !UCONFIG_NO_TRANSLITERATION
16 
17 #include "unicode/uchar.h"
18 #include "unicode/uniset.h"
19 #include "unicode/ustring.h"
20 #include "unicode/utf16.h"
21 #include "titletrn.h"
22 #include "umutex.h"
23 #include "ucase.h"
24 #include "cpputils.h"
25 
26 U_NAMESPACE_BEGIN
27 
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TitlecaseTransliterator)28 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TitlecaseTransliterator)
29 
30 TitlecaseTransliterator::TitlecaseTransliterator() :
31     CaseMapTransliterator(UNICODE_STRING("Any-Title", 9), NULL)
32 {
33     // Need to look back 2 characters in the case of "can't"
34     setMaximumContextLength(2);
35 }
36 
37 /**
38  * Destructor.
39  */
~TitlecaseTransliterator()40 TitlecaseTransliterator::~TitlecaseTransliterator() {
41 }
42 
43 /**
44  * Copy constructor.
45  */
TitlecaseTransliterator(const TitlecaseTransliterator & o)46 TitlecaseTransliterator::TitlecaseTransliterator(const TitlecaseTransliterator& o) :
47     CaseMapTransliterator(o)
48 {
49 }
50 
51 /**
52  * Assignment operator.
53  */
54 /*TitlecaseTransliterator& TitlecaseTransliterator::operator=(
55                              const TitlecaseTransliterator& o) {
56     CaseMapTransliterator::operator=(o);
57     return *this;
58 }*/
59 
60 /**
61  * Transliterator API.
62  */
clone(void) const63 Transliterator* TitlecaseTransliterator::clone(void) const {
64     return new TitlecaseTransliterator(*this);
65 }
66 
67 /**
68  * Implements {@link Transliterator#handleTransliterate}.
69  */
handleTransliterate(Replaceable & text,UTransPosition & offsets,UBool isIncremental) const70 void TitlecaseTransliterator::handleTransliterate(
71                                   Replaceable& text, UTransPosition& offsets,
72                                   UBool isIncremental) const
73 {
74     // TODO reimplement, see ustrcase.c
75     // using a real word break iterator
76     //   instead of just looking for a transition between cased and uncased characters
77     // call CaseMapTransliterator::handleTransliterate() for lowercasing? (set fMap)
78     // needs to take isIncremental into account because case mappings are context-sensitive
79     //   also detect when lowercasing function did not finish because of context
80 
81     if (offsets.start >= offsets.limit) {
82         return;
83     }
84 
85     // case type: >0 cased (UCASE_LOWER etc.)  ==0 uncased  <0 case-ignorable
86     int32_t type;
87 
88     // Our mode; we are either converting letter toTitle or
89     // toLower.
90     UBool doTitle = TRUE;
91 
92     // Determine if there is a preceding context of cased case-ignorable*,
93     // in which case we want to start in toLower mode.  If the
94     // prior context is anything else (including empty) then start
95     // in toTitle mode.
96     UChar32 c;
97     int32_t start;
98     for (start = offsets.start - 1; start >= offsets.contextStart; start -= U16_LENGTH(c)) {
99         c = text.char32At(start);
100         type=ucase_getTypeOrIgnorable(c);
101         if(type>0) { // cased
102             doTitle=FALSE;
103             break;
104         } else if(type==0) { // uncased but not ignorable
105             break;
106         }
107         // else (type<0) case-ignorable: continue
108     }
109 
110     // Convert things after a cased character toLower; things
111     // after an uncased, non-case-ignorable character toTitle.  Case-ignorable
112     // characters are copied directly and do not change the mode.
113     UCaseContext csc;
114     uprv_memset(&csc, 0, sizeof(csc));
115     csc.p = &text;
116     csc.start = offsets.contextStart;
117     csc.limit = offsets.contextLimit;
118 
119     UnicodeString tmp;
120     const UChar *s;
121     int32_t textPos, delta, result;
122 
123     for(textPos=offsets.start; textPos<offsets.limit;) {
124         csc.cpStart=textPos;
125         c=text.char32At(textPos);
126         csc.cpLimit=textPos+=U16_LENGTH(c);
127 
128         type=ucase_getTypeOrIgnorable(c);
129         if(type>=0) { // not case-ignorable
130             if(doTitle) {
131                 result=ucase_toFullTitle(c, utrans_rep_caseContextIterator, &csc, &s, UCASE_LOC_ROOT);
132             } else {
133                 result=ucase_toFullLower(c, utrans_rep_caseContextIterator, &csc, &s, UCASE_LOC_ROOT);
134             }
135             doTitle = (UBool)(type==0); // doTitle=isUncased
136 
137             if(csc.b1 && isIncremental) {
138                 // fMap() tried to look beyond the context limit
139                 // wait for more input
140                 offsets.start=csc.cpStart;
141                 return;
142             }
143 
144             if(result>=0) {
145                 // replace the current code point with its full case mapping result
146                 // see UCASE_MAX_STRING_LENGTH
147                 if(result<=UCASE_MAX_STRING_LENGTH) {
148                     // string s[result]
149                     tmp.setTo(FALSE, s, result);
150                     delta=result-U16_LENGTH(c);
151                 } else {
152                     // single code point
153                     tmp.setTo(result);
154                     delta=tmp.length()-U16_LENGTH(c);
155                 }
156                 text.handleReplaceBetween(csc.cpStart, textPos, tmp);
157                 if(delta!=0) {
158                     textPos+=delta;
159                     csc.limit=offsets.contextLimit+=delta;
160                     offsets.limit+=delta;
161                 }
162             }
163         }
164     }
165     offsets.start=textPos;
166 }
167 
168 U_NAMESPACE_END
169 
170 #endif /* #if !UCONFIG_NO_TRANSLITERATION */
171