textbreakiteratoricu.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2006 Lars Knoll <[e-mail]>
 * Copyright (C) 2007 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"
#include "TextBreakIterator.h"

#include "PlatformString.h"
#include "TextBreakIteratorInternalICU.h"

#include <unicode/ubrk.h>
#include <wtf/Assertions.h>

namespace WebCore {

static TextBreakIterator* setUpIterator(bool& createdIterator, TextBreakIterator*& iterator,
    UBreakIteratorType type, const UChar* string, int length)
{
    if (!string)
        return 0;

    if (!createdIterator) {
        UErrorCode openStatus = U_ZERO_ERROR;
        iterator = static_cast<TextBreakIterator*>(ubrk_open(type, currentTextBreakLocaleID(), 0, 0, &openStatus));
        createdIterator = true;
        ASSERT_WITH_MESSAGE(U_SUCCESS(openStatus), "ICU could not open a break iterator: %s (%d)", u_errorName(openStatus), openStatus);
    }
    if (!iterator)
        return 0;

    UErrorCode setTextStatus = U_ZERO_ERROR;
    ubrk_setText(iterator, string, length, &setTextStatus);
    if (U_FAILURE(setTextStatus))
        return 0;

    return iterator;
}

TextBreakIterator* characterBreakIterator(const UChar* string, int length)
{
    static bool createdCharacterBreakIterator = false;
    static TextBreakIterator* staticCharacterBreakIterator;
    return setUpIterator(createdCharacterBreakIterator,
        staticCharacterBreakIterator, UBRK_CHARACTER, string, length);
}

TextBreakIterator* wordBreakIterator(const UChar* string, int length)
{
    static bool createdWordBreakIterator = false;
    static TextBreakIterator* staticWordBreakIterator;
    return setUpIterator(createdWordBreakIterator,
        staticWordBreakIterator, UBRK_WORD, string, length);
}

TextBreakIterator* lineBreakIterator(const UChar* string, int length)
{
    static bool createdLineBreakIterator = false;
    static TextBreakIterator* staticLineBreakIterator;
    return setUpIterator(createdLineBreakIterator,
        staticLineBreakIterator, UBRK_LINE, string, length);
}

TextBreakIterator* sentenceBreakIterator(const UChar* string, int length)
{
    static bool createdSentenceBreakIterator = false;
    static TextBreakIterator* staticSentenceBreakIterator;
    return setUpIterator(createdSentenceBreakIterator,
        staticSentenceBreakIterator, UBRK_SENTENCE, string, length);
}

int textBreakFirst(TextBreakIterator* bi)
{
    return ubrk_first(bi);
}

int textBreakNext(TextBreakIterator* bi)
{
    return ubrk_next(bi);
}

int textBreakPreceding(TextBreakIterator* bi, int pos)
{
    return ubrk_preceding(bi, pos);
}

int textBreakFollowing(TextBreakIterator* bi, int pos)
{
    return ubrk_following(bi, pos);
}

int textBreakCurrent(TextBreakIterator* bi)
{
    return ubrk_current(bi);
}

bool isTextBreak(TextBreakIterator* bi, int pos)
{
    return ubrk_isBoundary(bi, pos);
}

static TextBreakIterator* setUpIteratorWithRules(bool& createdIterator, TextBreakIterator*& iterator,
    const char* breakRules, const UChar* string, int length)
{
    if (!string)
        return 0;

    if (!createdIterator) {
        UParseError parseStatus;
        UErrorCode openStatus = U_ZERO_ERROR;
        String rules(breakRules);
        iterator = static_cast<TextBreakIterator*>(ubrk_openRules(rules.characters(), rules.length(), 0, 0, &parseStatus, &openStatus));
        createdIterator = true;
        ASSERT_WITH_MESSAGE(U_SUCCESS(openStatus), "ICU could not open a break iterator: %s (%d)", u_errorName(openStatus), openStatus);
    }
    if (!iterator)
        return 0;

    UErrorCode setTextStatus = U_ZERO_ERROR;
    ubrk_setText(iterator, string, length, &setTextStatus);
    if (U_FAILURE(setTextStatus))
        return 0;

    return iterator;
}

TextBreakIterator* cursorMovementIterator(const UChar* string, int length)
{
    // This rule set is based on character-break iterator rules of ICU 3.8
    // <http://source.icu-project.org/repos/icu/icu/tags/release-3-8/source/data/brkitr/char.txt>.
    static const char* kRules =
        "$CR      = [\\p{Grapheme_Cluster_Break = CR}];"
        "$LF      = [\\p{Grapheme_Cluster_Break = LF}];"
        "$Control = [\\p{Grapheme_Cluster_Break = Control}];"
        "$VoiceMarks = [\\uff9e\\uff9f];"
        "$Extend  = [\\p{Grapheme_Cluster_Break = Extend} $VoiceMarks];"
        "$L       = [\\p{Grapheme_Cluster_Break = L}];"
        "$V       = [\\p{Grapheme_Cluster_Break = V}];"
        "$T       = [\\p{Grapheme_Cluster_Break = T}];"
        "$LV      = [\\p{Grapheme_Cluster_Break = LV}];"
        "$LVT     = [\\p{Grapheme_Cluster_Break = LVT}];"
        "$HangulSyllable = $L+ | ($L* ($LV? $V+ | $LV | $LVT) $T*) | $T+;"
        "!!forward;"
        "$CR $LF;"
        "([^$Control $CR $LF] | $HangulSyllable) $Extend*;"
        "!!reverse;"
        "$BackHangulSyllable = $L+ | ($T* ($V+$LV? | $LV | $LVT) $L*) | $T+;"
        "$BackOneCluster = ($LF $CR) | ($Extend* ([^$Control $CR $LF] | $BackHangulSyllable));"
        "$BackOneCluster;"
        "!!safe_reverse;"
        "$V+ $L;"
        "!!safe_forward;"
        "$V+ $T;";
    static bool createdInputCursorIterator = false;
    static TextBreakIterator* staticInputCursorIterator;
    return setUpIteratorWithRules(createdInputCursorIterator, staticInputCursorIterator, kRules, string, length);
}

}