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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 
     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  */
     40 TitlecaseTransliterator::~TitlecaseTransliterator() {
     41 }
     42 
     43 /**
     44  * Copy constructor.
     45  */
     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  */
     63 Transliterator* TitlecaseTransliterator::clone(void) const {
     64     return new TitlecaseTransliterator(*this);
     65 }
     66 
     67 /**
     68  * Implements {@link Transliterator#handleTransliterate}.
     69  */
     70 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