tor-browser

titletrn.cpp (5458B)

---

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
**********************************************************************
*   Copyright (C) 2001-2011, International Business Machines
*   Corporation and others.  All Rights Reserved.
**********************************************************************
*   Date        Name        Description
*   05/24/01    aliu        Creation.
**********************************************************************
*/

#include "unicode/utypes.h"

#if !UCONFIG_NO_TRANSLITERATION

#include "unicode/uchar.h"
#include "unicode/uniset.h"
#include "unicode/ustring.h"
#include "unicode/utf16.h"
#include "titletrn.h"
#include "umutex.h"
#include "ucase.h"
#include "cpputils.h"

U_NAMESPACE_BEGIN

UOBJECT_DEFINE_RTTI_IMPLEMENTATION(TitlecaseTransliterator)

TitlecaseTransliterator::TitlecaseTransliterator() :
   CaseMapTransliterator(UNICODE_STRING("Any-Title", 9), nullptr)
{
   // Need to look back 2 characters in the case of "can't"
   setMaximumContextLength(2);
}

/**
* Destructor.
*/
TitlecaseTransliterator::~TitlecaseTransliterator() {
}

/**
* Copy constructor.
*/
TitlecaseTransliterator::TitlecaseTransliterator(const TitlecaseTransliterator& o) :
   CaseMapTransliterator(o)
{
}

/**
* Assignment operator.
*/
/*TitlecaseTransliterator& TitlecaseTransliterator::operator=(
                            const TitlecaseTransliterator& o) {
   CaseMapTransliterator::operator=(o);
   return *this;
}*/

/**
* Transliterator API.
*/
TitlecaseTransliterator* TitlecaseTransliterator::clone() const {
   return new TitlecaseTransliterator(*this);
}

/**
* Implements {@link Transliterator#handleTransliterate}.
*/
void TitlecaseTransliterator::handleTransliterate(
                                 Replaceable& text, UTransPosition& offsets,
                                 UBool isIncremental) const
{
   // TODO reimplement, see ustrcase.c
   // using a real word break iterator
   //   instead of just looking for a transition between cased and uncased characters
   // call CaseMapTransliterator::handleTransliterate() for lowercasing? (set fMap)
   // needs to take isIncremental into account because case mappings are context-sensitive
   //   also detect when lowercasing function did not finish because of context

   if (offsets.start >= offsets.limit) {
       return;
   }

   // case type: >0 cased (UCASE_LOWER etc.)  ==0 uncased  <0 case-ignorable
   int32_t type;

   // Our mode; we are either converting letter toTitle or
   // toLower.
   UBool doTitle = true;
   
   // Determine if there is a preceding context of cased case-ignorable*,
   // in which case we want to start in toLower mode.  If the
   // prior context is anything else (including empty) then start
   // in toTitle mode.
   UChar32 c;
   int32_t start;
   for (start = offsets.start - 1; start >= offsets.contextStart; start -= U16_LENGTH(c)) {
       c = text.char32At(start);
       type=ucase_getTypeOrIgnorable(c);
       if(type>0) { // cased
           doTitle=false;
           break;
       } else if(type==0) { // uncased but not ignorable
           break;
       }
       // else (type<0) case-ignorable: continue
   }
   
   // Convert things after a cased character toLower; things
   // after an uncased, non-case-ignorable character toTitle.  Case-ignorable
   // characters are copied directly and do not change the mode.
   UCaseContext csc;
   uprv_memset(&csc, 0, sizeof(csc));
   csc.p = &text;
   csc.start = offsets.contextStart;
   csc.limit = offsets.contextLimit;

   UnicodeString tmp;
   const char16_t *s;
   int32_t textPos, delta, result;

   for(textPos=offsets.start; textPos<offsets.limit;) {
       csc.cpStart=textPos;
       c=text.char32At(textPos);
       csc.cpLimit=textPos+=U16_LENGTH(c);

       type=ucase_getTypeOrIgnorable(c);
       if(type>=0) { // not case-ignorable
           if(doTitle) {
               result=ucase_toFullTitle(c, utrans_rep_caseContextIterator, &csc, &s, UCASE_LOC_ROOT);
           } else {
               result=ucase_toFullLower(c, utrans_rep_caseContextIterator, &csc, &s, UCASE_LOC_ROOT);
           }
           doTitle = static_cast<UBool>(type == 0); // doTitle=isUncased

           if(csc.b1 && isIncremental) {
               // fMap() tried to look beyond the context limit
               // wait for more input
               offsets.start=csc.cpStart;
               return;
           }

           if(result>=0) {
               // replace the current code point with its full case mapping result
               // see UCASE_MAX_STRING_LENGTH
               if(result<=UCASE_MAX_STRING_LENGTH) {
                   // string s[result]
                   tmp.setTo(false, s, result);
                   delta=result-U16_LENGTH(c);
               } else {
                   // single code point
                   tmp.setTo(result);
                   delta=tmp.length()-U16_LENGTH(c);
               }
               text.handleReplaceBetween(csc.cpStart, textPos, tmp);
               if(delta!=0) {
                   textPos+=delta;
                   csc.limit=offsets.contextLimit+=delta;
                   offsets.limit+=delta;
               }
           }
       }
   }
   offsets.start=textPos;
}

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_TRANSLITERATION */