1/*
2**********************************************************************
3*   Copyright (C) 2001-2011, International Business Machines
4*   Corporation and others.  All Rights Reserved.
5**********************************************************************
6*   Date        Name        Description
7*   05/24/01    aliu        Creation.
8**********************************************************************
9*/
10
11#include "unicode/utypes.h"
12
13#if !UCONFIG_NO_TRANSLITERATION
14
15#include "unicode/uchar.h"
16#include "unicode/uniset.h"
17#include "unicode/ustring.h"
18#include "unicode/utf16.h"
19#include "titletrn.h"
20#include "umutex.h"
21#include "ucase.h"
22#include "cpputils.h"
23
24U_NAMESPACE_BEGIN
25
26UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TitlecaseTransliterator)
27
28TitlecaseTransliterator::TitlecaseTransliterator() :
29    CaseMapTransliterator(UNICODE_STRING("Any-Title", 9), NULL)
30{
31    // Need to look back 2 characters in the case of "can't"
32    setMaximumContextLength(2);
33}
34
35/**
36 * Destructor.
37 */
38TitlecaseTransliterator::~TitlecaseTransliterator() {
39}
40
41/**
42 * Copy constructor.
43 */
44TitlecaseTransliterator::TitlecaseTransliterator(const TitlecaseTransliterator& o) :
45    CaseMapTransliterator(o)
46{
47}
48
49/**
50 * Assignment operator.
51 */
52/*TitlecaseTransliterator& TitlecaseTransliterator::operator=(
53                             const TitlecaseTransliterator& o) {
54    CaseMapTransliterator::operator=(o);
55    return *this;
56}*/
57
58/**
59 * Transliterator API.
60 */
61Transliterator* TitlecaseTransliterator::clone(void) const {
62    return new TitlecaseTransliterator(*this);
63}
64
65/**
66 * Implements {@link Transliterator#handleTransliterate}.
67 */
68void TitlecaseTransliterator::handleTransliterate(
69                                  Replaceable& text, UTransPosition& offsets,
70                                  UBool isIncremental) const
71{
72    // TODO reimplement, see ustrcase.c
73    // using a real word break iterator
74    //   instead of just looking for a transition between cased and uncased characters
75    // call CaseMapTransliterator::handleTransliterate() for lowercasing? (set fMap)
76    // needs to take isIncremental into account because case mappings are context-sensitive
77    //   also detect when lowercasing function did not finish because of context
78
79    if (offsets.start >= offsets.limit) {
80        return;
81    }
82
83    // case type: >0 cased (UCASE_LOWER etc.)  ==0 uncased  <0 case-ignorable
84    int32_t type;
85
86    // Our mode; we are either converting letter toTitle or
87    // toLower.
88    UBool doTitle = TRUE;
89
90    // Determine if there is a preceding context of cased case-ignorable*,
91    // in which case we want to start in toLower mode.  If the
92    // prior context is anything else (including empty) then start
93    // in toTitle mode.
94    UChar32 c;
95    int32_t start;
96    for (start = offsets.start - 1; start >= offsets.contextStart; start -= U16_LENGTH(c)) {
97        c = text.char32At(start);
98        type=ucase_getTypeOrIgnorable(fCsp, c);
99        if(type>0) { // cased
100            doTitle=FALSE;
101            break;
102        } else if(type==0) { // uncased but not ignorable
103            break;
104        }
105        // else (type<0) case-ignorable: continue
106    }
107
108    // Convert things after a cased character toLower; things
109    // after an uncased, non-case-ignorable character toTitle.  Case-ignorable
110    // characters are copied directly and do not change the mode.
111    UCaseContext csc;
112    uprv_memset(&csc, 0, sizeof(csc));
113    csc.p = &text;
114    csc.start = offsets.contextStart;
115    csc.limit = offsets.contextLimit;
116
117    UnicodeString tmp;
118    const UChar *s;
119    int32_t textPos, delta, result, locCache=0;
120
121    for(textPos=offsets.start; textPos<offsets.limit;) {
122        csc.cpStart=textPos;
123        c=text.char32At(textPos);
124        csc.cpLimit=textPos+=U16_LENGTH(c);
125
126        type=ucase_getTypeOrIgnorable(fCsp, c);
127        if(type>=0) { // not case-ignorable
128            if(doTitle) {
129                result=ucase_toFullTitle(fCsp, c, utrans_rep_caseContextIterator, &csc, &s, "", &locCache);
130            } else {
131                result=ucase_toFullLower(fCsp, c, utrans_rep_caseContextIterator, &csc, &s, "", &locCache);
132            }
133            doTitle = (UBool)(type==0); // doTitle=isUncased
134
135            if(csc.b1 && isIncremental) {
136                // fMap() tried to look beyond the context limit
137                // wait for more input
138                offsets.start=csc.cpStart;
139                return;
140            }
141
142            if(result>=0) {
143                // replace the current code point with its full case mapping result
144                // see UCASE_MAX_STRING_LENGTH
145                if(result<=UCASE_MAX_STRING_LENGTH) {
146                    // string s[result]
147                    tmp.setTo(FALSE, s, result);
148                    delta=result-U16_LENGTH(c);
149                } else {
150                    // single code point
151                    tmp.setTo(result);
152                    delta=tmp.length()-U16_LENGTH(c);
153                }
154                text.handleReplaceBetween(csc.cpStart, textPos, tmp);
155                if(delta!=0) {
156                    textPos+=delta;
157                    csc.limit=offsets.contextLimit+=delta;
158                    offsets.limit+=delta;
159                }
160            }
161        }
162    }
163    offsets.start=textPos;
164}
165
166U_NAMESPACE_END
167
168#endif /* #if !UCONFIG_NO_TRANSLITERATION */
169