Check in the pristine copy of ICU 4.6...

icu46/source/i18n/titletrn.cpp

+/*
+**********************************************************************
+*   Copyright (C) 2001-2007, 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 "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), NULL)
+{
+    // 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.
+ */
+Transliterator* TitlecaseTransliterator::clone(void) 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(fCsp, 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 UChar *s;
+    int32_t textPos, delta, result, locCache=0;
+
+    for(textPos=offsets.start; textPos<offsets.limit;) {
+        csc.cpStart=textPos;
+        c=text.char32At(textPos);
+        csc.cpLimit=textPos+=U16_LENGTH(c);
+
+        type=ucase_getTypeOrIgnorable(fCsp, c);
+        if(type>=0) { // not case-ignorable
+            if(doTitle) {
+                result=ucase_toFullTitle(fCsp, c, utrans_rep_caseContextIterator, &csc, &s, "", &locCache);
+            } else {
+                result=ucase_toFullLower(fCsp, c, utrans_rep_caseContextIterator, &csc, &s, "", &locCache);
+            }
+            doTitle = (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 */