qsyntaxhighlighter.cpp

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#include "qsyntaxhighlighter.h"

#ifndef QT_NO_SYNTAXHIGHLIGHTER
#include <private/qobject_p.h>
#include <qtextdocument.h>
#include <private/qtextdocument_p.h>
#include <qtextlayout.h>
#include <qpointer.h>
#include <qtextobject.h>
#include <qtextcursor.h>
#include <qdebug.h>
#include <qtextedit.h>
#include <qtimer.h>

QT_BEGIN_NAMESPACE

class QSyntaxHighlighterPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QSyntaxHighlighter)
public:
    inline QSyntaxHighlighterPrivate()
        : rehighlightPending(false), inReformatBlocks(false)
    {}

    QPointer<QTextDocument> doc;

    void _q_reformatBlocks(int from, int charsRemoved, int charsAdded);
    void reformatBlocks(int from, int charsRemoved, int charsAdded);
    void reformatBlock(const QTextBlock &block);

    inline void rehighlight(QTextCursor &cursor, QTextCursor::MoveOperation operation) {
        inReformatBlocks = true;
        cursor.beginEditBlock();
        int from = cursor.position();
        cursor.movePosition(operation);
        reformatBlocks(from, 0, cursor.position() - from);
        cursor.endEditBlock();
        inReformatBlocks = false;
    }

    inline void _q_delayedRehighlight() {
        if (!rehighlightPending)
            return;
        rehighlightPending = false;
        q_func()->rehighlight();
    }

    void applyFormatChanges();
    QVector<QTextCharFormat> formatChanges;
    QTextBlock currentBlock;
    bool rehighlightPending;
    bool inReformatBlocks;
};

void QSyntaxHighlighterPrivate::applyFormatChanges()
{
    bool formatsChanged = false;

    QTextLayout *layout = currentBlock.layout();

    QList<QTextLayout::FormatRange> ranges = layout->additionalFormats();

    const int preeditAreaStart = layout->preeditAreaPosition();
    const int preeditAreaLength = layout->preeditAreaText().length();

    if (preeditAreaLength != 0) {
        QList<QTextLayout::FormatRange>::Iterator it = ranges.begin();
        while (it != ranges.end()) {
            if (it->start >= preeditAreaStart
                && it->start + it->length <= preeditAreaStart + preeditAreaLength) {
                ++it;
            } else {
                it = ranges.erase(it);
                formatsChanged = true;
            }
        }
    } else if (!ranges.isEmpty()) {
        ranges.clear();
        formatsChanged = true;
    }

    QTextCharFormat emptyFormat;

    QTextLayout::FormatRange r;
    r.start = -1;

    int i = 0;
    while (i < formatChanges.count()) {

        while (i < formatChanges.count() && formatChanges.at(i) == emptyFormat)
            ++i;

        if (i >= formatChanges.count())
            break;

        r.start = i;
        r.format = formatChanges.at(i);

        while (i < formatChanges.count() && formatChanges.at(i) == r.format)
            ++i;

        if (i >= formatChanges.count())
            break;

        r.length = i - r.start;

        if (preeditAreaLength != 0) {
            if (r.start >= preeditAreaStart)
                r.start += preeditAreaLength;
            else if (r.start + r.length >= preeditAreaStart)
                r.length += preeditAreaLength;
        }

        ranges << r;
        formatsChanged = true;
        r.start = -1;
    }

    if (r.start != -1) {
        r.length = formatChanges.count() - r.start;

        if (preeditAreaLength != 0) {
            if (r.start >= preeditAreaStart)
                r.start += preeditAreaLength;
            else if (r.start + r.length >= preeditAreaStart)
                r.length += preeditAreaLength;
        }

        ranges << r;
        formatsChanged = true;
    }

    if (formatsChanged) {
        layout->setAdditionalFormats(ranges);
        doc->markContentsDirty(currentBlock.position(), currentBlock.length());
    }
}

void QSyntaxHighlighterPrivate::_q_reformatBlocks(int from, int charsRemoved, int charsAdded)
{
    if (!inReformatBlocks)
        reformatBlocks(from, charsRemoved, charsAdded);
}

void QSyntaxHighlighterPrivate::reformatBlocks(int from, int charsRemoved, int charsAdded)
{
    rehighlightPending = false;

    QTextBlock block = doc->findBlock(from);
    if (!block.isValid())
        return;

    int endPosition;
    QTextBlock lastBlock = doc->findBlock(from + charsAdded + (charsRemoved > 0 ? 1 : 0));
    if (lastBlock.isValid())
        endPosition = lastBlock.position() + lastBlock.length();
    else
        endPosition = doc->docHandle()->length();

    bool forceHighlightOfNextBlock = false;

    while (block.isValid() && (block.position() < endPosition || forceHighlightOfNextBlock)) {
        const int stateBeforeHighlight = block.userState();

        reformatBlock(block);

        forceHighlightOfNextBlock = (block.userState() != stateBeforeHighlight);

        block = block.next();
    }

    formatChanges.clear();
}

void QSyntaxHighlighterPrivate::reformatBlock(const QTextBlock &block)
{
    Q_Q(QSyntaxHighlighter);

    Q_ASSERT_X(!currentBlock.isValid(), "QSyntaxHighlighter::reformatBlock()", "reFormatBlock() called recursively");

    currentBlock = block;

    formatChanges.fill(QTextCharFormat(), block.length() - 1);
    q->highlightBlock(block.text());
    applyFormatChanges();

    currentBlock = QTextBlock();
}

QSyntaxHighlighter::QSyntaxHighlighter(QObject *parent)
    : QObject(*new QSyntaxHighlighterPrivate, parent)
{
}

QSyntaxHighlighter::QSyntaxHighlighter(QTextDocument *parent)
    : QObject(*new QSyntaxHighlighterPrivate, parent)
{
    setDocument(parent);
}

QSyntaxHighlighter::QSyntaxHighlighter(QTextEdit *parent)
    : QObject(*new QSyntaxHighlighterPrivate, parent)
{
    setDocument(parent->document());
}

QSyntaxHighlighter::~QSyntaxHighlighter()
{
    setDocument(0);
}

void QSyntaxHighlighter::setDocument(QTextDocument *doc)
{
    Q_D(QSyntaxHighlighter);
    if (d->doc) {
        disconnect(d->doc, SIGNAL(contentsChange(int,int,int)),
                   this, SLOT(_q_reformatBlocks(int,int,int)));

        QTextCursor cursor(d->doc);
        cursor.beginEditBlock();
        for (QTextBlock blk = d->doc->begin(); blk.isValid(); blk = blk.next())
            blk.layout()->clearAdditionalFormats();
        cursor.endEditBlock();
    }
    d->doc = doc;
    if (d->doc) {
        connect(d->doc, SIGNAL(contentsChange(int,int,int)),
                this, SLOT(_q_reformatBlocks(int,int,int)));
        d->rehighlightPending = true;
        QTimer::singleShot(0, this, SLOT(_q_delayedRehighlight()));
    }
}

QTextDocument *QSyntaxHighlighter::document() const
{
    Q_D(const QSyntaxHighlighter);
    return d->doc;
}

void QSyntaxHighlighter::rehighlight()
{
    Q_D(QSyntaxHighlighter);
    if (!d->doc)
        return;

    QTextCursor cursor(d->doc);
    d->rehighlight(cursor, QTextCursor::End);
}

void QSyntaxHighlighter::rehighlightBlock(const QTextBlock &block)
{
    Q_D(QSyntaxHighlighter);
    if (!d->doc || !block.isValid() || block.document() != d->doc)
        return;

    const bool rehighlightPending = d->rehighlightPending;

    QTextCursor cursor(block);
    d->rehighlight(cursor, QTextCursor::EndOfBlock);

    if (rehighlightPending)
        d->rehighlightPending = rehighlightPending;
}

void QSyntaxHighlighter::setFormat(int start, int count, const QTextCharFormat &format)
{
    Q_D(QSyntaxHighlighter);
    if (start < 0 || start >= d->formatChanges.count())
        return;

    const int end = qMin(start + count, d->formatChanges.count());
    for (int i = start; i < end; ++i)
        d->formatChanges[i] = format;
}

void QSyntaxHighlighter::setFormat(int start, int count, const QColor &color)
{
    QTextCharFormat format;
    format.setForeground(color);
    setFormat(start, count, format);
}

void QSyntaxHighlighter::setFormat(int start, int count, const QFont &font)
{
    QTextCharFormat format;
    format.setFont(font);
    setFormat(start, count, format);
}

QTextCharFormat QSyntaxHighlighter::format(int pos) const
{
    Q_D(const QSyntaxHighlighter);
    if (pos < 0 || pos >= d->formatChanges.count())
        return QTextCharFormat();
    return d->formatChanges.at(pos);
}

int QSyntaxHighlighter::previousBlockState() const
{
    Q_D(const QSyntaxHighlighter);
    if (!d->currentBlock.isValid())
        return -1;

    const QTextBlock previous = d->currentBlock.previous();
    if (!previous.isValid())
        return -1;

    return previous.userState();
}

int QSyntaxHighlighter::currentBlockState() const
{
    Q_D(const QSyntaxHighlighter);
    if (!d->currentBlock.isValid())
        return -1;

    return d->currentBlock.userState();
}

void QSyntaxHighlighter::setCurrentBlockState(int newState)
{
    Q_D(QSyntaxHighlighter);
    if (!d->currentBlock.isValid())
        return;

    d->currentBlock.setUserState(newState);
}

void QSyntaxHighlighter::setCurrentBlockUserData(QTextBlockUserData *data)
{
    Q_D(QSyntaxHighlighter);
    if (!d->currentBlock.isValid())
        return;

    d->currentBlock.setUserData(data);
}

QTextBlockUserData *QSyntaxHighlighter::currentBlockUserData() const
{
    Q_D(const QSyntaxHighlighter);
    if (!d->currentBlock.isValid())
        return 0;

    return d->currentBlock.userData();
}

QTextBlock QSyntaxHighlighter::currentBlock() const
{
    Q_D(const QSyntaxHighlighter);
    return d->currentBlock;
}

QT_END_NAMESPACE

#include "moc_qsyntaxhighlighter.cpp"

#endif // QT_NO_SYNTAXHIGHLIGHTER