(svn r25653) -Add: Caret movement by words for CJK languages.
This commit is contained in:
michi_cc
167
src/string.cpp
167
src/string.cpp
@@ -661,50 +661,132 @@ int strnatcmp(const char *s1, const char *s2, bool ignore_garbage_at_front)
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class IcuStringIterator : public StringIterator
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{
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icu::BreakIterator *char_itr; ///< ICU iterator for characters.
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icu::BreakIterator *word_itr; ///< ICU iterator for words.
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const char *string; ///< Iteration string in UTF-8.
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SmallVector<UChar, 32> utf16_str; ///< UTF-16 copy of the string.
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SmallVector<size_t, 32> utf16_to_utf8; ///< Mapping from UTF-16 code point position to index in the UTF-8 source string.
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public:
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IcuStringIterator() : char_itr(NULL)
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IcuStringIterator() : char_itr(NULL), word_itr(NULL)
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{
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UErrorCode status = U_ZERO_ERROR;
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this->char_itr = icu::BreakIterator::createCharacterInstance(icu::Locale(_current_language != NULL ? _current_language->isocode : "en"), status);
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this->word_itr = icu::BreakIterator::createWordInstance(icu::Locale(_current_language != NULL ? _current_language->isocode : "en"), status);
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*this->utf16_str.Append() = '\0';
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*this->utf16_to_utf8.Append() = 0;
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}
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virtual ~IcuStringIterator()
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{
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delete this->char_itr;
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delete this->word_itr;
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}
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virtual void SetString(const char *s)
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{
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this->string = s;
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/* Unfortunately current ICU versions only provide rudimentary support
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* for word break iterators (especially for CJK languages) in combination
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* with UTF-8 input. As a work around we have to convert the input to
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* UTF-16 and create a mapping back to UTF-8 character indices. */
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this->utf16_str.Clear();
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this->utf16_to_utf8.Clear();
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while (*s != '\0') {
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size_t idx = s - this->string;
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WChar c = Utf8Consume(&s);
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if (c < 0x10000) {
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*this->utf16_str.Append() = (UChar)c;
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} else {
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/* Make a surrogate pair. */
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*this->utf16_str.Append() = (UChar)(0xD800 + ((c - 0x10000) >> 10));
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*this->utf16_str.Append() = (UChar)(0xDC00 + ((c - 0x10000) & 0x3FF));
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*this->utf16_to_utf8.Append() = idx;
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}
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*this->utf16_to_utf8.Append() = idx;
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}
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*this->utf16_str.Append() = '\0';
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*this->utf16_to_utf8.Append() = s - this->string;
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UText text = UTEXT_INITIALIZER;
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UErrorCode status = U_ZERO_ERROR;
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utext_openUTF8(&text, s, -1, &status);
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utext_openUChars(&text, this->utf16_str.Begin(), this->utf16_str.Length() - 1, &status);
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this->char_itr->setText(&text, status);
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this->word_itr->setText(&text, status);
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this->char_itr->first();
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this->word_itr->first();
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}
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virtual size_t SetCurPosition(size_t pos)
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{
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/* Convert incoming position to an UTF-16 string index. */
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uint utf16_pos = 0;
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for (uint i = 0; i < this->utf16_to_utf8.Length(); i++) {
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if (this->utf16_to_utf8[i] == pos) {
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utf16_pos = i;
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break;
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}
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}
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/* isBoundary has the documented side-effect of setting the current
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* position to the first valid boundary equal to or greater than
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* the passed value. */
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this->char_itr->isBoundary((int32_t)pos);
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return this->char_itr->current();
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this->char_itr->isBoundary(utf16_pos);
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return this->utf16_to_utf8[this->char_itr->current()];
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}
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virtual size_t Next()
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virtual size_t Next(IterType what)
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{
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int32_t pos = this->char_itr->next();
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return pos == icu::BreakIterator::DONE ? END : pos;
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int32_t pos;
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switch (what) {
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case ITER_CHARACTER:
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pos = this->char_itr->next();
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break;
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case ITER_WORD:
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pos = this->word_itr->following(this->char_itr->current());
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/* The ICU word iterator considers both the start and the end of a word a valid
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* break point, but we only want word starts. Move to the next location in
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* case the new position points to whitespace. */
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while (pos != icu::BreakIterator::DONE && IsWhitespace(Utf16DecodeChar((const uint16 *)&this->utf16_str[pos]))) pos = this->word_itr->next();
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this->char_itr->isBoundary(pos);
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break;
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default:
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NOT_REACHED();
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}
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return pos == icu::BreakIterator::DONE ? END : this->utf16_to_utf8[pos];
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}
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virtual size_t Prev()
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virtual size_t Prev(IterType what)
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{
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int32_t pos = this->char_itr->previous();
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return pos == icu::BreakIterator::DONE ? END : pos;
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int32_t pos;
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switch (what) {
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case ITER_CHARACTER:
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pos = this->char_itr->previous();
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break;
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case ITER_WORD:
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pos = this->word_itr->preceding(this->char_itr->current());
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/* The ICU word iterator considers both the start and the end of a word a valid
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* break point, but we only want word starts. Move to the previous location in
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* case the new position points to whitespace. */
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while (pos != icu::BreakIterator::DONE && IsWhitespace(Utf16DecodeChar((const uint16 *)&this->utf16_str[pos]))) pos = this->word_itr->previous();
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this->char_itr->isBoundary(pos);
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break;
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default:
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NOT_REACHED();
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}
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return pos == icu::BreakIterator::DONE ? END : this->utf16_to_utf8[pos];
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}
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};
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@@ -742,26 +824,79 @@ public:
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return this->cur_pos = pos;
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}
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virtual size_t Next()
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virtual size_t Next(IterType what)
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{
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assert(this->string != NULL);
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/* Already at the end? */
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if (this->cur_pos >= this->len) return END;
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WChar c;
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this->cur_pos += Utf8Decode(&c, this->string + this->cur_pos);
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return this->cur_pos;
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switch (what) {
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case ITER_CHARACTER: {
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WChar c;
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this->cur_pos += Utf8Decode(&c, this->string + this->cur_pos);
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return this->cur_pos;
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}
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case ITER_WORD: {
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WChar c;
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/* Consume current word. */
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size_t offs = Utf8Decode(&c, this->string + this->cur_pos);
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while (this->cur_pos < this->len && !IsWhitespace(c)) {
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this->cur_pos += offs;
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offs = Utf8Decode(&c, this->string + this->cur_pos);
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}
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/* Consume whitespace to the next word. */
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while (this->cur_pos < this->len && IsWhitespace(c)) {
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this->cur_pos += offs;
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offs = Utf8Decode(&c, this->string + this->cur_pos);
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}
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return this->cur_pos;
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}
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default:
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NOT_REACHED();
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}
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return END;
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}
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virtual size_t Prev()
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virtual size_t Prev(IterType what)
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{
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assert(this->string != NULL);
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/* Already at the beginning? */
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if (this->cur_pos == 0) return END;
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return this->cur_pos = Utf8PrevChar(this->string + this->cur_pos) - this->string;
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switch (what) {
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case ITER_CHARACTER:
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return this->cur_pos = Utf8PrevChar(this->string + this->cur_pos) - this->string;
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case ITER_WORD: {
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const char *s = this->string + this->cur_pos;
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WChar c;
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/* Consume preceding whitespace. */
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do {
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s = Utf8PrevChar(s);
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Utf8Decode(&c, s);
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} while (s > this->string && IsWhitespace(c));
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/* Consume preceding word. */
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while (s > this->string && !IsWhitespace(c)) {
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s = Utf8PrevChar(s);
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Utf8Decode(&c, s);
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}
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/* Move caret back to the beginning of the word. */
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if (IsWhitespace(c)) Utf8Consume(&s);
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return this->cur_pos = s - this->string;
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}
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default:
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NOT_REACHED();
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}
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return END;
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}
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};
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