1/*
2**********************************************************************
3*   Copyright (C) 2001-2007, 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 "titletrn.h"
19#include "umutex.h"
20#include "ucase.h"
21#include "cpputils.h"
22
23U_NAMESPACE_BEGIN
24
25UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TitlecaseTransliterator)
26
27TitlecaseTransliterator::TitlecaseTransliterator() :
28    CaseMapTransliterator(UNICODE_STRING("Any-Title", 9), NULL)
29{
30    // Need to look back 2 characters in the case of "can't"
31    setMaximumContextLength(2);
32}
33
34/**
35 * Destructor.
36 */
37TitlecaseTransliterator::~TitlecaseTransliterator() {
38}
39
40/**
41 * Copy constructor.
42 */
43TitlecaseTransliterator::TitlecaseTransliterator(const TitlecaseTransliterator& o) :
44    CaseMapTransliterator(o)
45{
46}
47
48/**
49 * Assignment operator.
50 */
51/*TitlecaseTransliterator& TitlecaseTransliterator::operator=(
52                             const TitlecaseTransliterator& o) {
53    CaseMapTransliterator::operator=(o);
54    return *this;
55}*/
56
57/**
58 * Transliterator API.
59 */
60Transliterator* TitlecaseTransliterator::clone(void) const {
61    return new TitlecaseTransliterator(*this);
62}
63
64/**
65 * Implements {@link Transliterator#handleTransliterate}.
66 */
67void TitlecaseTransliterator::handleTransliterate(
68                                  Replaceable& text, UTransPosition& offsets,
69                                  UBool isIncremental) const
70{
71    // TODO reimplement, see ustrcase.c
72    // using a real word break iterator
73    //   instead of just looking for a transition between cased and uncased characters
74    // call CaseMapTransliterator::handleTransliterate() for lowercasing? (set fMap)
75    // needs to take isIncremental into account because case mappings are context-sensitive
76    //   also detect when lowercasing function did not finish because of context
77
78    if (offsets.start >= offsets.limit) {
79        return;
80    }
81
82    // case type: >0 cased (UCASE_LOWER etc.)  ==0 uncased  <0 case-ignorable
83    int32_t type;
84
85    // Our mode; we are either converting letter toTitle or
86    // toLower.
87    UBool doTitle = TRUE;
88
89    // Determine if there is a preceding context of cased case-ignorable*,
90    // in which case we want to start in toLower mode.  If the
91    // prior context is anything else (including empty) then start
92    // in toTitle mode.
93    UChar32 c;
94    int32_t start;
95    for (start = offsets.start - 1; start >= offsets.contextStart; start -= U16_LENGTH(c)) {
96        c = text.char32At(start);
97        type=ucase_getTypeOrIgnorable(fCsp, c);
98        if(type>0) { // cased
99            doTitle=FALSE;
100            break;
101        } else if(type==0) { // uncased but not ignorable
102            break;
103        }
104        // else (type<0) case-ignorable: continue
105    }
106
107    // Convert things after a cased character toLower; things
108    // after an uncased, non-case-ignorable character toTitle.  Case-ignorable
109    // characters are copied directly and do not change the mode.
110    UCaseContext csc;
111    uprv_memset(&csc, 0, sizeof(csc));
112    csc.p = &text;
113    csc.start = offsets.contextStart;
114    csc.limit = offsets.contextLimit;
115
116    UnicodeString tmp;
117    const UChar *s;
118    int32_t textPos, delta, result, locCache=0;
119
120    for(textPos=offsets.start; textPos<offsets.limit;) {
121        csc.cpStart=textPos;
122        c=text.char32At(textPos);
123        csc.cpLimit=textPos+=U16_LENGTH(c);
124
125        type=ucase_getTypeOrIgnorable(fCsp, c);
126        if(type>=0) { // not case-ignorable
127            if(doTitle) {
128                result=ucase_toFullTitle(fCsp, c, utrans_rep_caseContextIterator, &csc, &s, "", &locCache);
129            } else {
130                result=ucase_toFullLower(fCsp, c, utrans_rep_caseContextIterator, &csc, &s, "", &locCache);
131            }
132            doTitle = (UBool)(type==0); // doTitle=isUncased
133
134            if(csc.b1 && isIncremental) {
135                // fMap() tried to look beyond the context limit
136                // wait for more input
137                offsets.start=csc.cpStart;
138                return;
139            }
140
141            if(result>=0) {
142                // replace the current code point with its full case mapping result
143                // see UCASE_MAX_STRING_LENGTH
144                if(result<=UCASE_MAX_STRING_LENGTH) {
145                    // string s[result]
146                    tmp.setTo(FALSE, s, result);
147                    delta=result-U16_LENGTH(c);
148                } else {
149                    // single code point
150                    tmp.setTo(result);
151                    delta=tmp.length()-U16_LENGTH(c);
152                }
153                text.handleReplaceBetween(csc.cpStart, textPos, tmp);
154                if(delta!=0) {
155                    textPos+=delta;
156                    csc.limit=offsets.contextLimit+=delta;
157                    offsets.limit+=delta;
158                }
159            }
160        }
161    }
162    offsets.start=textPos;
163}
164
165U_NAMESPACE_END
166
167#endif /* #if !UCONFIG_NO_TRANSLITERATION */
168