TextCheckingHelper.cpp   [plain text]

/*
 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
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#include "config.h"
#include "TextCheckingHelper.h"

#include "Document.h"
#include "DocumentMarkerController.h"
#include "Range.h"
#include "TextCheckerClient.h"
#include "TextIterator.h"
#include "VisiblePosition.h"
#include "visible_units.h"

namespace WebCore {

static PassRefPtr<Range> expandToParagraphBoundary(PassRefPtr<Range> range)
{
    ExceptionCode ec = 0;
    RefPtr<Range> paragraphRange = range->cloneRange(ec);
    setStart(paragraphRange.get(), startOfParagraph(range->startPosition()));
    setEnd(paragraphRange.get(), endOfParagraph(range->endPosition()));
    return paragraphRange;
}

TextCheckingParagraph::TextCheckingParagraph(PassRefPtr<Range> checkingRange)
    : m_checkingRange(checkingRange)
    , m_checkingStart(-1)
    , m_checkingEnd(-1)
    , m_checkingLength(-1)
{
}

TextCheckingParagraph::~TextCheckingParagraph()
{
}

void TextCheckingParagraph::expandRangeToNextEnd()
{
    ASSERT(m_checkingRange);
    setEnd(paragraphRange().get(), endOfParagraph(startOfNextParagraph(paragraphRange()->startPosition())));
    invalidateParagraphRangeValues();
}

void TextCheckingParagraph::invalidateParagraphRangeValues()
{
    m_checkingStart = m_checkingEnd = -1;
    m_offsetAsRange = 0;
    m_text = String();
}

int TextCheckingParagraph::rangeLength() const
{
    ASSERT(m_checkingRange);
    return TextIterator::rangeLength(paragraphRange().get());
}

PassRefPtr<Range> TextCheckingParagraph::paragraphRange() const
{
    ASSERT(m_checkingRange);
    if (!m_paragraphRange)
        m_paragraphRange = expandToParagraphBoundary(checkingRange());
    return m_paragraphRange;
}

PassRefPtr<Range> TextCheckingParagraph::subrange(int characterOffset, int characterCount) const
{
    ASSERT(m_checkingRange);
    return TextIterator::subrange(paragraphRange().get(), characterOffset, characterCount);
}

int TextCheckingParagraph::offsetTo(const Position& position, ExceptionCode& ec) const
{
    ASSERT(m_checkingRange);
    RefPtr<Range> range = offsetAsRange();
    range->setEnd(position.containerNode(), position.computeOffsetInContainerNode(), ec);
    if (ec)
        return 0;
    return TextIterator::rangeLength(range.get());
}

bool TextCheckingParagraph::isEmpty() const
{
    // Both predicates should have same result, but we check both just for sure.
    // We need to investigate to remove this redundancy.
    return isRangeEmpty() || isTextEmpty();
}

PassRefPtr<Range> TextCheckingParagraph::offsetAsRange() const
{
    ASSERT(m_checkingRange);
    if (!m_offsetAsRange) {
        ExceptionCode ec = 0;
        m_offsetAsRange = Range::create(paragraphRange()->startContainer(ec)->document(), paragraphRange()->startPosition(), checkingRange()->startPosition());
    }

    return m_offsetAsRange;
}

const String& TextCheckingParagraph::text() const
{
    ASSERT(m_checkingRange);
    if (m_text.isEmpty())
        m_text = plainText(paragraphRange().get());
    return m_text; 
}

int TextCheckingParagraph::checkingStart() const
{
    ASSERT(m_checkingRange);
    if (m_checkingStart == -1)
        m_checkingStart = TextIterator::rangeLength(offsetAsRange().get());
    return m_checkingStart;
}

int TextCheckingParagraph::checkingEnd() const
{
    ASSERT(m_checkingRange);
    if (m_checkingEnd == -1)
        m_checkingEnd = checkingStart() + TextIterator::rangeLength(checkingRange().get());
    return m_checkingEnd;
}

int TextCheckingParagraph::checkingLength() const
{
    ASSERT(m_checkingRange);
    if (-1 == m_checkingLength)
        m_checkingLength = TextIterator::rangeLength(checkingRange().get());
    return m_checkingLength;
}

TextCheckingHelper::TextCheckingHelper(EditorClient* client, PassRefPtr<Range> range)
    : m_client(client)
    , m_range(range)
{
    ASSERT_ARG(m_client, m_client);
    ASSERT_ARG(m_range, m_range);
}

TextCheckingHelper::~TextCheckingHelper()
{
}


int TextCheckingHelper::findFirstGrammarDetail(const Vector<GrammarDetail>& grammarDetails, int badGrammarPhraseLocation, int /*badGrammarPhraseLength*/, int startOffset, int endOffset, bool markAll)
{
#if USE(GRAMMAR_CHECKING)
    // Found some bad grammar. Find the earliest detail range that starts in our search range (if any).
    // Optionally add a DocumentMarker for each detail in the range.
    int earliestDetailLocationSoFar = -1;
    int earliestDetailIndex = -1;
    for (unsigned i = 0; i < grammarDetails.size(); i++) {
        const GrammarDetail* detail = &grammarDetails[i];
        ASSERT(detail->length > 0 && detail->location >= 0);
        
        int detailStartOffsetInParagraph = badGrammarPhraseLocation + detail->location;
        
        // Skip this detail if it starts before the original search range
        if (detailStartOffsetInParagraph < startOffset)
            continue;
        
        // Skip this detail if it starts after the original search range
        if (detailStartOffsetInParagraph >= endOffset)
            continue;
        
        if (markAll) {
            RefPtr<Range> badGrammarRange = TextIterator::subrange(m_range.get(), badGrammarPhraseLocation - startOffset + detail->location, detail->length);
            ExceptionCode ec = 0;
            badGrammarRange->startContainer(ec)->document()->markers()->addMarker(badGrammarRange.get(), DocumentMarker::Grammar, detail->userDescription);
            ASSERT(!ec);
        }
        
        // Remember this detail only if it's earlier than our current candidate (the details aren't in a guaranteed order)
        if (earliestDetailIndex < 0 || earliestDetailLocationSoFar > detail->location) {
            earliestDetailIndex = i;
            earliestDetailLocationSoFar = detail->location;
        }
    }
    
    return earliestDetailIndex;
#else
    ASSERT_NOT_REACHED();
    UNUSED_PARAM(grammarDetails);
    UNUSED_PARAM(badGrammarPhraseLocation);
    UNUSED_PARAM(startOffset);
    UNUSED_PARAM(endOffset);
    UNUSED_PARAM(markAll);
    return 0;
#endif
}

String TextCheckingHelper::findFirstBadGrammar(GrammarDetail& outGrammarDetail, int& outGrammarPhraseOffset, bool markAll)
{
    ASSERT(WTF_USE_GRAMMAR_CHECKING);
    // Initialize out parameters; these will be updated if we find something to return.
    outGrammarDetail.location = -1;
    outGrammarDetail.length = 0;
    outGrammarDetail.guesses.clear();
    outGrammarDetail.userDescription = "";
    outGrammarPhraseOffset = 0;
    
    String firstBadGrammarPhrase;

    // Expand the search range to encompass entire paragraphs, since grammar checking needs that much context.
    // Determine the character offset from the start of the paragraph to the start of the original search range,
    // since we will want to ignore results in this area.
    TextCheckingParagraph paragraph(m_range);
    
    // Start checking from beginning of paragraph, but skip past results that occur before the start of the original search range.
    int startOffset = 0;
    while (startOffset < paragraph.checkingEnd()) {
        Vector<GrammarDetail> grammarDetails;
        int badGrammarPhraseLocation = -1;
        int badGrammarPhraseLength = 0;
        m_client->textChecker()->checkGrammarOfString(paragraph.textCharacters() + startOffset, paragraph.textLength() - startOffset, grammarDetails, &badGrammarPhraseLocation, &badGrammarPhraseLength);
        
        if (!badGrammarPhraseLength) {
            ASSERT(badGrammarPhraseLocation == -1);
            return String();
        }

        ASSERT(badGrammarPhraseLocation >= 0);
        badGrammarPhraseLocation += startOffset;

        
        // Found some bad grammar. Find the earliest detail range that starts in our search range (if any).
        int badGrammarIndex = findFirstGrammarDetail(grammarDetails, badGrammarPhraseLocation, badGrammarPhraseLength, paragraph.checkingStart(), paragraph.checkingEnd(), markAll);
        if (badGrammarIndex >= 0) {
            ASSERT(static_cast<unsigned>(badGrammarIndex) < grammarDetails.size());
            outGrammarDetail = grammarDetails[badGrammarIndex];
        }

        // If we found a detail in range, then we have found the first bad phrase (unless we found one earlier but
        // kept going so we could mark all instances).
        if (badGrammarIndex >= 0 && firstBadGrammarPhrase.isEmpty()) {
            outGrammarPhraseOffset = badGrammarPhraseLocation - paragraph.checkingStart();
            firstBadGrammarPhrase = paragraph.textSubstring(badGrammarPhraseLocation, badGrammarPhraseLength);
            
            // Found one. We're done now, unless we're marking each instance.
            if (!markAll)
                break;
        }

        // These results were all between the start of the paragraph and the start of the search range; look
        // beyond this phrase.
        startOffset = badGrammarPhraseLocation + badGrammarPhraseLength;
    }
    
    return firstBadGrammarPhrase;
}


bool TextCheckingHelper::isUngrammatical(Vector<String>& guessesVector) const
{
    ASSERT(WTF_USE_GRAMMAR_CHECKING);
    if (!m_client)
        return false;

    ExceptionCode ec;
    if (!m_range || m_range->collapsed(ec))
        return false;
    
    // Returns true only if the passed range exactly corresponds to a bad grammar detail range. This is analogous
    // to isSelectionMisspelled. It's not good enough for there to be some bad grammar somewhere in the range,
    // or overlapping the range; the ranges must exactly match.
    guessesVector.clear();
    int grammarPhraseOffset;
    
    GrammarDetail grammarDetail;
    String badGrammarPhrase = const_cast<TextCheckingHelper*>(this)->findFirstBadGrammar(grammarDetail, grammarPhraseOffset, false);    
    
    // No bad grammar in these parts at all.
    if (badGrammarPhrase.isEmpty())
        return false;
    
    // Bad grammar, but phrase (e.g. sentence) starts beyond start of range.
    if (grammarPhraseOffset > 0)
        return false;
    
    ASSERT(grammarDetail.location >= 0 && grammarDetail.length > 0);
    
    // Bad grammar, but start of detail (e.g. ungrammatical word) doesn't match start of range
    if (grammarDetail.location + grammarPhraseOffset)
        return false;
    
    // Bad grammar at start of range, but end of bad grammar is before or after end of range
    if (grammarDetail.length != TextIterator::rangeLength(m_range.get()))
        return false;
    
    // Update the spelling panel to be displaying this error (whether or not the spelling panel is on screen).
    // This is necessary to make a subsequent call to [NSSpellChecker ignoreWord:inSpellDocumentWithTag:] work
    // correctly; that call behaves differently based on whether the spelling panel is displaying a misspelling
    // or a grammar error.
    m_client->updateSpellingUIWithGrammarString(badGrammarPhrase, grammarDetail);
    
    return true;
}

Vector<String> TextCheckingHelper::guessesForMisspelledOrUngrammaticalRange(bool checkGrammar, bool& misspelled, bool& ungrammatical) const
{
#if USE(UNIFIED_TEXT_CHECKING)
    Vector<String> guesses;
    ExceptionCode ec;
    misspelled = false;
    ungrammatical = false;
    
    if (!m_client || !m_range || m_range->collapsed(ec))
        return guesses;

    // Expand the range to encompass entire paragraphs, since text checking needs that much context.
    TextCheckingParagraph paragraph(m_range);
    if (paragraph.isEmpty())
        return guesses;

    Vector<TextCheckingResult> results;
    TextCheckingTypeMask checkingTypes = checkGrammar ? (TextCheckingTypeSpelling | TextCheckingTypeGrammar) : TextCheckingTypeSpelling;
    m_client->textChecker()->checkTextOfParagraph(paragraph.textCharacters(), paragraph.textLength(), checkingTypes, results);
    
    for (unsigned i = 0; i < results.size(); i++) {
        const TextCheckingResult* result = &results[i];
        if (result->type == TextCheckingTypeSpelling && paragraph.checkingRangeMatches(result->location, result->length)) {
            String misspelledWord = paragraph.checkingSubstring();
            ASSERT(misspelledWord.length());
            m_client->textChecker()->getGuessesForWord(misspelledWord, String(), guesses);
            m_client->updateSpellingUIWithMisspelledWord(misspelledWord);
            misspelled = true;
            return guesses;
        }
    }
    
    if (!checkGrammar)
        return guesses;
        
    for (unsigned i = 0; i < results.size(); i++) {
        const TextCheckingResult* result = &results[i];
        if (result->type == TextCheckingTypeGrammar && paragraph.isCheckingRangeCoveredBy(result->location, result->length)) {
            for (unsigned j = 0; j < result->details.size(); j++) {
                const GrammarDetail* detail = &result->details[j];
                ASSERT(detail->length > 0 && detail->location >= 0);
                if (paragraph.checkingRangeMatches(result->location + detail->location, detail->length)) {
                    String badGrammarPhrase = paragraph.textSubstring(result->location, result->length);
                    ASSERT(badGrammarPhrase.length());
                    for (unsigned k = 0; k < detail->guesses.size(); k++)
                        guesses.append(detail->guesses[k]);
                    m_client->updateSpellingUIWithGrammarString(badGrammarPhrase, *detail);
                    ungrammatical = true;
                    return guesses;
                }
            }
        }
    }
    return guesses;
#else
    ASSERT_NOT_REACHED();
    UNUSED_PARAM(checkGrammar);
    UNUSED_PARAM(misspelled);
    UNUSED_PARAM(ungrammatical);
    return Vector<String>();
#endif // USE(UNIFIED_TEXT_CHECKING)
}



}