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      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 
     24 U_NAMESPACE_BEGIN
     25 
     26 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TitlecaseTransliterator)
     27 
     28 TitlecaseTransliterator::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  */
     38 TitlecaseTransliterator::~TitlecaseTransliterator() {
     39 }
     40 
     41 /**
     42  * Copy constructor.
     43  */
     44 TitlecaseTransliterator::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  */
     61 Transliterator* TitlecaseTransliterator::clone(void) const {
     62     return new TitlecaseTransliterator(*this);
     63 }
     64 
     65 /**
     66  * Implements {@link Transliterator#handleTransliterate}.
     67  */
     68 void 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 
    166 U_NAMESPACE_END
    167 
    168 #endif /* #if !UCONFIG_NO_TRANSLITERATION */
    169