src/gui/text/qtextdocument.cpp

Go to the documentation of this file.

/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qtextdocument.h"
#include <qtextformat.h>
#include "qtextdocumentlayout_p.h"
#include "qtextdocumentfragment.h"
#include "qtextdocumentfragment_p.h"
#include "qtexttable.h"
#include "qtextlist.h"
#include <qdebug.h>
#include <qregexp.h>
#include <qvarlengtharray.h>
#include <qtextcodec.h>
#include "qtexthtmlparser_p.h"
#include "qpainter.h"
#include "qprinter.h"
#include "qtextedit.h"
#include "qtextcontrol_p.h"

#include "qtextdocument_p.h"

#include <limits.h>

bool Qt::mightBeRichText(const QString& text)
{
    if (text.isEmpty())
        return false;
    int start = 0;

    while (start < text.length() && text.at(start).isSpace())
        ++start;

    // skip a leading <?xml ... ?> as for example with xhtml
    if (text.mid(start, 5) == QLatin1String("<?xml")) {
        while (start < text.length()) {
            if (text.at(start) == QLatin1Char('?')
                && start + 2 < text.length()
                && text.at(start + 1) == QLatin1Char('>')) {
                start += 2;
                break;
            }
            ++start;
        }

        while (start < text.length() && text.at(start).isSpace())
            ++start;
    }

    if (text.mid(start, 5).toLower() == QLatin1String("<!doc"))
        return true;
    int open = start;
    while (open < text.length() && text.at(open) != QLatin1Char('<')
            && text.at(open) != QLatin1Char('\n')) {
        if (text.at(open) == QLatin1Char('&') &&  text.mid(open+1,3) == QLatin1String("lt;"))
            return true; // support desperate attempt of user to see <...>
        ++open;
    }
    if (open < text.length() && text.at(open) == QLatin1Char('<')) {
        const int close = text.indexOf(QLatin1Char('>'), open);
        if (close > -1) {
            QString tag;
            for (int i = open+1; i < close; ++i) {
                if (text[i].isDigit() || text[i].isLetter())
                    tag += text[i];
                else if (!tag.isEmpty() && text[i].isSpace())
                    break;
                else if (!text[i].isSpace() && (!tag.isEmpty() || text[i] != QLatin1Char('!')))
                    return false; // that's not a tag
            }
            return QTextHtmlParser::lookupElement(tag.toLower()) != -1;
        }
    }
    return false;
}

QString Qt::escape(const QString& plain)
{
    QString rich;
    rich.reserve(int(plain.length() * 1.1));
    for (int i = 0; i < plain.length(); ++i) {
        if (plain.at(i) == QLatin1Char('<'))
            rich += QLatin1String("&lt;");
        else if (plain.at(i) == QLatin1Char('>'))
            rich += QLatin1String("&gt;");
        else if (plain.at(i) == QLatin1Char('&'))
            rich += QLatin1String("&amp;");
        else
            rich += plain.at(i);
    }
    return rich;
}

QString Qt::convertFromPlainText(const QString &plain, Qt::WhiteSpaceMode mode)
{
    int col = 0;
    QString rich;
    rich += QLatin1String("<p>");
    for (int i = 0; i < plain.length(); ++i) {
        if (plain[i] == QLatin1Char('\n')){
            int c = 1;
            while (i+1 < plain.length() && plain[i+1] == QLatin1Char('\n')) {
                i++;
                c++;
            }
            if (c == 1)
                rich += QLatin1String("<br>\n");
            else {
                rich += QLatin1String("</p>\n");
                while (--c > 1)
                    rich += QLatin1String("<br>\n");
                rich += QLatin1String("<p>");
            }
            col = 0;
        } else {
            if (mode == Qt::WhiteSpacePre && plain[i] == QLatin1Char('\t')){
                rich += QChar(0x00a0U);
                ++col;
                while (col % 8) {
                    rich += QChar(0x00a0U);
                    ++col;
                }
            }
            else if (mode == Qt::WhiteSpacePre && plain[i].isSpace())
                rich += QChar(0x00a0U);
            else if (plain[i] == QLatin1Char('<'))
                rich += QLatin1String("&lt;");
            else if (plain[i] == QLatin1Char('>'))
                rich += QLatin1String("&gt;");
            else if (plain[i] == QLatin1Char('&'))
                rich += QLatin1String("&amp;");
            else
                rich += plain[i];
            ++col;
        }
    }
    if (col != 0)
        rich += QLatin1String("</p>");
    return rich;
}

#ifndef QT_NO_TEXTCODEC

QTextCodec *Qt::codecForHtml(const QByteArray &ba)
{
    return QTextCodec::codecForHtml(ba);
}
#endif

QTextDocument::QTextDocument(QObject *parent)
    : QObject(*new QTextDocumentPrivate, parent)
{
    Q_D(QTextDocument);
    d->init();
}

QTextDocument::QTextDocument(const QString &text, QObject *parent)
    : QObject(*new QTextDocumentPrivate, parent)
{
    Q_D(QTextDocument);
    d->init();
    QTextCursor(this).insertText(text);
}

QTextDocument::QTextDocument(QTextDocumentPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
    Q_D(QTextDocument);
    d->init();
}

QTextDocument::~QTextDocument()
{
}


QTextDocument *QTextDocument::clone(QObject *parent) const
{
    Q_D(const QTextDocument);
    QTextDocument *doc = new QTextDocument(parent);
    QTextCursor(doc).insertFragment(QTextDocumentFragment(this));
    doc->d_func()->title = d->title;
    doc->d_func()->pageSize = d->pageSize;
    doc->d_func()->useDesignMetrics = d->useDesignMetrics;
    doc->d_func()->setDefaultFont(d->defaultFont());
    doc->d_func()->resources = d->resources;
    doc->d_func()->defaultStyleSheet = d->defaultStyleSheet;
    doc->d_func()->parsedDefaultStyleSheet = d->parsedDefaultStyleSheet;
    return doc;
}

bool QTextDocument::isEmpty() const
{
    Q_D(const QTextDocument);
    /* because if we're empty we still have one single paragraph as
     * one single fragment */
    return d->length() <= 1;
}

void QTextDocument::clear()
{
    Q_D(QTextDocument);
    d->clear();
    d->resources.clear();
}

void QTextDocument::undo(QTextCursor *cursor)
{
    Q_D(QTextDocument);
    const int pos = d->undoRedo(true);
    if (cursor && pos >= 0) {
        *cursor = QTextCursor(this);
        cursor->setPosition(pos);
    }
}

void QTextDocument::redo(QTextCursor *cursor)
{
    Q_D(QTextDocument);
    const int pos = d->undoRedo(false);
    if (cursor && pos >= 0) {
        *cursor = QTextCursor(this);
        cursor->setPosition(pos);
    }
}

void QTextDocument::undo()
{
    Q_D(QTextDocument);
    d->undoRedo(true);
}

void QTextDocument::redo()
{
    Q_D(QTextDocument);
    d->undoRedo(false);
}

void QTextDocument::appendUndoItem(QAbstractUndoItem *item)
{
    Q_D(QTextDocument);
    d->appendUndoItem(item);
}

void QTextDocument::setUndoRedoEnabled(bool enable)
{
    Q_D(QTextDocument);
    d->enableUndoRedo(enable);
}

bool QTextDocument::isUndoRedoEnabled() const
{
    Q_D(const QTextDocument);
    return d->isUndoRedoEnabled();
}

int QTextDocument::maximumBlockCount() const
{
    Q_D(const QTextDocument);
    return d->maximumBlockCount;
}

void QTextDocument::setMaximumBlockCount(int maximum)
{
    Q_D(QTextDocument);
    d->maximumBlockCount = maximum;
    d->ensureMaximumBlockCount();
}

void QTextDocument::markContentsDirty(int from, int length)
{
    Q_D(QTextDocument);
    if (!d->inContentsChange)
        d->beginEditBlock();
    d->documentChange(from, length);
    if (!d->inContentsChange)
        d->endEditBlock();
}

void QTextDocument::setUseDesignMetrics(bool b)
{
    Q_D(QTextDocument);
    d->useDesignMetrics = b;
    if (d->lout)
        d->lout->documentChanged(0, 0, d->length());
}

bool QTextDocument::useDesignMetrics() const
{
    Q_D(const QTextDocument);
    return d->useDesignMetrics;
}

void QTextDocument::drawContents(QPainter *p, const QRectF &rect)
{
    p->save();
    QAbstractTextDocumentLayout::PaintContext ctx;
    if (rect.isValid()) {
        p->setClipRect(rect);
        ctx.clip = rect;
    }
    documentLayout()->draw(p, ctx);
    p->restore();
}

void QTextDocument::setTextWidth(qreal width)
{
    Q_D(QTextDocument);
    QSizeF sz = d->pageSize;
    sz.setWidth(width);
    sz.setHeight(-1);
    setPageSize(sz);
}

qreal QTextDocument::textWidth() const
{
    Q_D(const QTextDocument);
    return d->pageSize.width();
}

qreal QTextDocument::idealWidth() const
{
#ifndef QT_NO_PROPERTIES
    QAbstractTextDocumentLayout *lout = documentLayout();
    if (lout->metaObject()->indexOfProperty("idealWidth") == -1)
        return textWidth();
    return lout->property("idealWidth").toDouble();
#else
    return textWidth();
#endif
}

void QTextDocument::adjustSize()
{
    // Pull this private function in from qglobal.cpp
    Q_CORE_EXPORT unsigned int qt_int_sqrt(unsigned int n);

    QFont f = defaultFont();
    QFontMetrics fm(f);
    int mw =  fm.width(QLatin1Char('x')) * 80;
    int w = mw;
    setPageSize(QSizeF(w, -1));
    QSizeF size = documentLayout()->documentSize();
    if (size.width() != 0) {
        w = qt_int_sqrt((uint)(5 * size.height() * size.width() / 3));
        setPageSize(QSizeF(qMin(w, mw), -1));

        size = documentLayout()->documentSize();
        if (w*3 < 5*size.height()) {
            w = qt_int_sqrt((uint)(2 * size.height() * size.width()));
            setPageSize(QSizeF(qMin(w, mw), -1));
        }
    }
}

QSizeF QTextDocument::size() const
{
    return documentLayout()->documentSize();
}

int QTextDocument::blockCount() const
{
    Q_D(const QTextDocument);
    return d->blockMap().numNodes();
}

void QTextDocument::setDefaultStyleSheet(const QString &sheet)
{
    Q_D(QTextDocument);
    d->defaultStyleSheet = sheet;
    QCss::Parser parser(sheet);
    d->parsedDefaultStyleSheet = QCss::StyleSheet();
    parser.parse(&d->parsedDefaultStyleSheet);
}

QString QTextDocument::defaultStyleSheet() const
{
    Q_D(const QTextDocument);
    return d->defaultStyleSheet;
}

bool QTextDocument::isUndoAvailable() const
{
    Q_D(const QTextDocument);
    return d->isUndoAvailable();
}

bool QTextDocument::isRedoAvailable() const
{
    Q_D(const QTextDocument);
    return d->isRedoAvailable();
}

void QTextDocument::setDocumentLayout(QAbstractTextDocumentLayout *layout)
{
    Q_D(QTextDocument);
    d->setLayout(layout);
}

QAbstractTextDocumentLayout *QTextDocument::documentLayout() const
{
    Q_D(const QTextDocument);
    if (!d->lout) {
        QTextDocument *that = const_cast<QTextDocument *>(this);
        that->d_func()->setLayout(new QTextDocumentLayout(that));
    }
    return d->lout;
}


QString QTextDocument::metaInformation(MetaInformation info) const
{
    if (info != DocumentTitle)
        return QString();
    Q_D(const QTextDocument);
    return d->title;
}

void QTextDocument::setMetaInformation(MetaInformation info, const QString &string)
{
    if (info != DocumentTitle)
        return;
    Q_D(QTextDocument);
    d->title = string;
}

QString QTextDocument::toPlainText() const
{
    Q_D(const QTextDocument);
    QString txt = d->plainText();
    txt.replace(QTextBeginningOfFrame, QLatin1Char('\n'));
    txt.replace(QTextEndOfFrame, QLatin1Char('\n'));
    txt.replace(QChar::ParagraphSeparator, QLatin1Char('\n'));
    txt.replace(QChar::LineSeparator, QLatin1Char('\n'));
    txt.replace(QChar::Nbsp, QLatin1Char(' '));
    return txt;
}

void QTextDocument::setPlainText(const QString &text)
{
    Q_D(QTextDocument);
    setUndoRedoEnabled(false);
    d->clear();
    QTextCursor(this).insertText(text);
    setUndoRedoEnabled(true);
}

void QTextDocument::setHtml(const QString &html)
{
    Q_D(QTextDocument);
    setUndoRedoEnabled(false);
    d->clear();
    QTextHtmlImporter(this, html).import();
    setUndoRedoEnabled(true);
}

QTextCursor QTextDocument::find(const QString &subString, int from, FindFlags options) const
{
    QRegExp expr(subString);
    expr.setPatternSyntax(QRegExp::FixedString);
    expr.setCaseSensitivity((options & QTextDocument::FindCaseSensitively) ? Qt::CaseSensitive : Qt::CaseInsensitive);

    return find(expr, from, options);
}

QTextCursor QTextDocument::find(const QString &subString, const QTextCursor &from, FindFlags options) const
{
    const int pos = (from.isNull() ? 0 : from.selectionEnd());
    QRegExp expr(subString);
    expr.setPatternSyntax(QRegExp::FixedString);
    expr.setCaseSensitivity((options & QTextDocument::FindCaseSensitively) ? Qt::CaseSensitive : Qt::CaseInsensitive);

    return find(expr, pos, options);
}


static bool findInBlock(const QTextBlock &block, const QString &text, const QRegExp &expression, int offset,
                        QTextDocument::FindFlags options, QTextCursor &cursor)
{
    const QRegExp expr(expression);

    int idx = -1;
    while (offset >=0 && offset <= text.length()) {
        idx = (options & QTextDocument::FindBackward) ?
               expr.lastIndexIn(text, offset) : expr.indexIn(text, offset);
        if (idx == -1)
            return false;

        if (options & QTextDocument::FindWholeWords) {
            const int start = idx;
            const int end = start + expr.matchedLength();
            if ((start != 0 && text.at(start - 1).isLetterOrNumber())
                || (end != text.length() && text.at(end).isLetterOrNumber())) {
                //if this is not a whole word, continue the search in the string
                offset = (options & QTextDocument::FindBackward) ? idx-1 : end+1;
                continue;
            }
        }
        //we have a hit, return the cursor for that.
        break;
    }
    if (idx == -1)
        return false;
    cursor = QTextCursor(block.docHandle(), block.position() + idx);
    cursor.setPosition(cursor.position() + expr.matchedLength(), QTextCursor::KeepAnchor);
    return true;
}

QTextCursor QTextDocument::find(const QRegExp & expr, int from, FindFlags options) const
{
    Q_D(const QTextDocument);

    if (expr.isEmpty())
        return QTextCursor();

    int pos = from;
    //the cursor is positioned between characters, so for a backward search
    //do not include the character given in the position.
    if (options & FindBackward) {
        --pos ;
        if(pos < 0)
            return QTextCursor();
    }

    QTextCursor cursor;
    QTextBlock block = d->blocksFind(pos);

    if (!(options & FindBackward)) {
       int blockOffset = qMax(0, pos - block.position());
        while (block.isValid()) {
            const QString blockText = block.text();
            if (findInBlock(block, blockText, expr, blockOffset, options, cursor))
                return cursor;
            blockOffset = 0;
            block = block.next();
        }
    } else {
        int blockOffset = pos - block.position();
        while (block.isValid()) {
            const QString blockText = block.text();
            if (findInBlock(block, blockText, expr, blockOffset, options, cursor))
                return cursor;
            block = block.previous();
            blockOffset = block.length() - 1;
        }
    }

    return QTextCursor();
}

QTextCursor QTextDocument::find(const QRegExp &expr, const QTextCursor &from, FindFlags options) const
{
    const int pos = (from.isNull() ? 0 : from.selectionEnd());
    return find(expr, pos, options);
}


QTextObject *QTextDocument::createObject(const QTextFormat &f)
{
    QTextObject *obj = 0;
    if (f.isListFormat())
        obj = new QTextList(this);
    else if (f.isTableFormat())
        obj = new QTextTable(this);
    else if (f.isFrameFormat())
        obj = new QTextFrame(this);

    return obj;
}

QTextFrame *QTextDocument::frameAt(int pos) const
{
    Q_D(const QTextDocument);
    return d->frameAt(pos);
}

QTextFrame *QTextDocument::rootFrame() const
{
    Q_D(const QTextDocument);
    return d->rootFrame();
}

QTextObject *QTextDocument::object(int objectIndex) const
{
    Q_D(const QTextDocument);
    return d->objectForIndex(objectIndex);
}

QTextObject *QTextDocument::objectForFormat(const QTextFormat &f) const
{
    Q_D(const QTextDocument);
    return d->objectForFormat(f);
}


QTextBlock QTextDocument::findBlock(int pos) const
{
    Q_D(const QTextDocument);
    return QTextBlock(docHandle(), d->blockMap().findNode(pos));
}

QTextBlock QTextDocument::begin() const
{
    Q_D(const QTextDocument);
    return QTextBlock(docHandle(), d->blockMap().begin().n);
}

QTextBlock QTextDocument::end() const
{
    return QTextBlock(docHandle(), 0);
}

void QTextDocument::setPageSize(const QSizeF &size)
{
    Q_D(QTextDocument);
    d->pageSize = size;
    if (d->lout)
        d->lout->documentChanged(0, 0, d->length());
}

QSizeF QTextDocument::pageSize() const
{
    Q_D(const QTextDocument);
    return d->pageSize;
}

int QTextDocument::pageCount() const
{
    return documentLayout()->pageCount();
}

void QTextDocument::setDefaultFont(const QFont &font)
{
    Q_D(QTextDocument);
    d->setDefaultFont(font);
    if (d->lout)
        d->lout->documentChanged(0, 0, d->length());
}

QFont QTextDocument::defaultFont() const
{
    Q_D(const QTextDocument);
    return d->defaultFont();
}

bool QTextDocument::isModified() const
{
    return docHandle()->isModified();
}

void QTextDocument::setModified(bool m)
{
    docHandle()->setModified(m);
}

#ifndef QT_NO_PRINTER
static void printPage(int index, QPainter *painter, const QTextDocument *doc, const QRectF &body, const QPointF &pageNumberPos)
{
    painter->save();
    painter->translate(body.left(), body.top() - (index - 1) * body.height());
    QRectF view(0, (index - 1) * body.height(), body.width(), body.height());

    QAbstractTextDocumentLayout *layout = doc->documentLayout();
    QAbstractTextDocumentLayout::PaintContext ctx;

    painter->setClipRect(view);
    ctx.clip = view;

    // don't use the system palette text as default text color, on HP/UX
    // for example that's white, and white text on white paper doesn't
    // look that nice
    ctx.palette.setColor(QPalette::Text, Qt::black);

    layout->draw(painter, ctx);

    if (!pageNumberPos.isNull()) {
        painter->setClipping(false);
        painter->setFont(QFont(doc->defaultFont()));
        const QString pageString = QString::number(index);

        painter->drawText(qRound(pageNumberPos.x() - painter->fontMetrics().width(pageString)),
                          qRound(pageNumberPos.y() + view.top()),
                          pageString);
    }

    painter->restore();
}

void QTextDocument::print(QPrinter *printer) const
{
    Q_D(const QTextDocument);
    QPainter p(printer);

    // Check that there is a valid device to print to.
    if (!p.isActive())
        return;

    const QTextDocument *doc = this;
    QTextDocument *clonedDoc = 0;
    (void)doc->documentLayout(); // make sure that there is a layout

    QRectF body = QRectF(QPointF(0, 0), d->pageSize);
    QPointF pageNumberPos;

    if (d->pageSize.isValid()
        && d->pageSize.height() != INT_MAX) {
        extern int qt_defaultDpi();

        qreal sourceDpiX = qt_defaultDpi();
        qreal sourceDpiY = sourceDpiX;

        QPaintDevice *dev = doc->documentLayout()->paintDevice();
        if (dev) {
            sourceDpiX = dev->logicalDpiX();
            sourceDpiY = dev->logicalDpiY();
        }

        const qreal dpiScaleX = qreal(printer->logicalDpiX()) / sourceDpiX;
        const qreal dpiScaleY = qreal(printer->logicalDpiY()) / sourceDpiY;

        // scale to dpi
        p.scale(dpiScaleX, dpiScaleY);

        QSizeF scaledPageSize = d->pageSize;
        scaledPageSize.rwidth() *= dpiScaleX;
        scaledPageSize.rheight() *= dpiScaleY;

        const QSizeF printerPageSize(printer->width(), printer->height());

        // scale to page
        p.scale(printerPageSize.width() / scaledPageSize.width(),
                printerPageSize.height() / scaledPageSize.height());
    } else {
        doc = clone(const_cast<QTextDocument *>(this));
        clonedDoc = const_cast<QTextDocument *>(doc);

        QAbstractTextDocumentLayout *layout = doc->documentLayout();
        layout->setPaintDevice(p.device());

        const int dpiy = p.device()->logicalDpiY();

        const int margin = (int) ((2/2.54)*dpiy); // 2 cm margins
        QTextFrameFormat fmt = doc->rootFrame()->frameFormat();
        fmt.setMargin(margin);
        doc->rootFrame()->setFrameFormat(fmt);

        body = QRectF(0, 0, p.device()->width(), p.device()->height());
        pageNumberPos = QPointF(body.width() - margin,
                                body.height() - margin
                                + QFontMetrics(doc->defaultFont(), p.device()).ascent()
                                + 5 * p.device()->logicalDpiY() / 72);

        QFont font(doc->defaultFont());
        font.setPointSize(10); // we define 10pt to be a nice base size for printing
        clonedDoc->setDefaultFont(font);
        clonedDoc->setPageSize(body.size());
    }

    int docCopies;
    int pageCopies;
    if (printer->collateCopies() == true){
        docCopies = 1;
        pageCopies = printer->numCopies();
    } else {
        docCopies = printer->numCopies();
        pageCopies = 1;
    }

    int fromPage = printer->fromPage();
    int toPage = printer->toPage();
    bool ascending = true;

    if (fromPage == 0 && toPage == 0) {
        fromPage = 1;
        toPage = doc->pageCount();
    }

    if (printer->pageOrder() == QPrinter::LastPageFirst) {
        int tmp = fromPage;
        fromPage = toPage;
        toPage = tmp;
        ascending = false;
    }

    for (int i = 0; i < docCopies; ++i) {

        int page = fromPage;
        while (true) {
            for (int j = 0; j < pageCopies; ++j) {
                if (printer->printerState() == QPrinter::Aborted
                    || printer->printerState() == QPrinter::Error)
                    goto UserCanceled;
                printPage(page, &p, doc, body, pageNumberPos);
                if (j < pageCopies - 1)
                    printer->newPage();
            }

            if (page == toPage)
                break;

            if (ascending)
                ++page;
            else
                --page;

            printer->newPage();
        }

        if ( i < docCopies - 1)
            printer->newPage();
    }

UserCanceled:
    delete clonedDoc;
}
#endif

QVariant QTextDocument::resource(int type, const QUrl &name) const
{
    Q_D(const QTextDocument);
    QVariant r = d->resources.value(name);
    if (!r.isValid()) {
        r = d->cachedResources.value(name);
        if (!r.isValid())
            r = const_cast<QTextDocument *>(this)->loadResource(type, name);
    }
    return r;
}

void QTextDocument::addResource(int type, const QUrl &name, const QVariant &resource)
{
    Q_UNUSED(type);
    Q_D(QTextDocument);
    d->resources.insert(name, resource);
}

QVariant QTextDocument::loadResource(int type, const QUrl &name)
{
    Q_D(QTextDocument);
    QVariant r;
    if (QTextDocument *doc = qobject_cast<QTextDocument *>(parent()))
        r = doc->loadResource(type, name);
#ifndef QT_NO_TEXTEDIT
    else if (QTextEdit *edit = qobject_cast<QTextEdit *>(parent()))
        r = edit->loadResource(type, name);
#endif
#ifndef QT_NO_TEXTCONTROL
    else if (QTextControl *control = qobject_cast<QTextControl *>(parent()))
        r = control->loadResource(type, name);
#endif
    if (!r.isNull()) {
        if (type == ImageResource && r.type() == QVariant::ByteArray) {
            QPixmap pm;
            pm.loadFromData(r.toByteArray());
            if (!pm.isNull())
                r = pm;
        }
        d->cachedResources.insert(name, r);
    }
    return r;
}

static QTextFormat formatDifference(const QTextFormat &from, const QTextFormat &to)
{
    QTextFormat diff = to;

    const QMap<int, QVariant> props = to.properties();
    for (QMap<int, QVariant>::ConstIterator it = props.begin(), end = props.end();
         it != end; ++it)
        if (it.value() == from.property(it.key()))
            diff.clearProperty(it.key());

    return diff;
}

QTextHtmlExporter::QTextHtmlExporter(const QTextDocument *_doc)
    : doc(_doc), fragmentMarkers(false)
{
    const QFont defaultFont = doc->defaultFont();
    defaultCharFormat.setFont(defaultFont);
}

QString QTextHtmlExporter::toHtml(const QByteArray &encoding)
{
    html = QLatin1String("<html><head><meta name=\"qrichtext\" content=\"1\" />");
    html.reserve(doc->docHandle()->length());

    if (!encoding.isEmpty())
        html += QString::fromLatin1("<meta http-equiv=\"Content-Type\" content=\"text/html; charset=%1\" />").arg(QString::fromAscii(encoding));

    QString title  = doc->metaInformation(QTextDocument::DocumentTitle);
    if (!title.isEmpty())
        html += QString::fromLatin1("<title>") + title + QString::fromLatin1("</title>");
    html += QLatin1String("<style type=\"text/css\">\n");
    html += QLatin1String("p, li { white-space: pre-wrap; }\n");
    html += QLatin1String("</style>");
    html += QLatin1String("</head><body style=\"");

    html += QLatin1String(" font-family:'");
    html += defaultCharFormat.fontFamily();
    html += QLatin1String("';");

    if (defaultCharFormat.hasProperty(QTextFormat::FontPointSize)) {
        html += QLatin1String(" font-size:");
        html += QString::number(defaultCharFormat.fontPointSize());
        html += QLatin1String("pt;");
    }

    html += QLatin1String(" font-weight:");
    html += QString::number(defaultCharFormat.fontWeight() * 8);
    html += QLatin1Char(';');

    html += QLatin1String(" font-style:");
    html += (defaultCharFormat.fontItalic() ? QLatin1String("italic") : QLatin1String("normal"));
    html += QLatin1Char(';');

    {
        html += QLatin1String(" text-decoration:");
        bool atLeastOneDecorationSet = false;

        if (defaultCharFormat.fontUnderline()) {
            html += QLatin1String(" underline");
            atLeastOneDecorationSet = true;
        }

        if (defaultCharFormat.fontOverline()) {
            html += QLatin1String(" overline");
            atLeastOneDecorationSet = true;
        }

        if (defaultCharFormat.fontStrikeOut()) {
            html += QLatin1String(" line-through");
            atLeastOneDecorationSet = true;
        }

        if (!atLeastOneDecorationSet)
            html += QLatin1String("none");
        html += QLatin1Char(';');
    }
    html += QLatin1Char('\"');

    const QTextFrameFormat fmt = doc->rootFrame()->frameFormat();
    QBrush bg = fmt.background();
    if (bg != Qt::NoBrush)
        emitAttribute("bgcolor", bg.color().name());

    html += QLatin1Char('>');

    emitFrame(doc->rootFrame()->begin());
    html += QLatin1String("</body></html>");
    return html;
}

void QTextHtmlExporter::emitAttribute(const char *attribute, const QString &value)
{
    html += QLatin1Char(' ');
    html += QLatin1String(attribute);
    html += QLatin1String("=\"");
    html += value;
    html += QLatin1Char('"');
}

bool QTextHtmlExporter::emitCharFormatStyle(const QTextCharFormat &format)
{
    bool attributesEmitted = false;

    {
        const QString family = format.fontFamily();
        if (!family.isEmpty() && family != defaultCharFormat.fontFamily()) {
            html += QLatin1String(" font-family:'");
            html += family;
            html += QLatin1String("';");
            attributesEmitted = true;
        }
    }

    if (format.hasProperty(QTextFormat::FontPointSize)
        && format.fontPointSize() != defaultCharFormat.fontPointSize()) {
        html += QLatin1String(" font-size:");
        html += QString::number(format.fontPointSize());
        html += QLatin1String("pt;");
        attributesEmitted = true;
    } else if (format.hasProperty(QTextFormat::FontSizeAdjustment)) {
        static const char * const sizeNames[] = {
            "small", "medium", "large", "x-large", "xx-large"
        };
        const char *name = 0;
        const int idx = format.intProperty(QTextFormat::FontSizeAdjustment) + 1;
        if (idx >= 0 && idx <= 4) {
            name = sizeNames[idx];
        }
        if (name) {
            html += QLatin1String(" font-size:");
            html += QLatin1String(name);
            html += QLatin1Char(';');
            attributesEmitted = true;
        }
    }

    if (format.fontWeight() != defaultCharFormat.fontWeight()) {
        html += QLatin1String(" font-weight:");
        html += QString::number(format.fontWeight() * 8);
        html += QLatin1Char(';');
        attributesEmitted = true;
    }

    if (format.fontItalic() != defaultCharFormat.fontItalic()) {
        html += QLatin1String(" font-style:");
        html += (format.fontItalic() ? QLatin1String("italic") : QLatin1String("normal"));
        html += QLatin1Char(';');
        attributesEmitted = true;
    }

    QLatin1String decorationTag(" text-decoration:");
    html += decorationTag;
    bool hasDecoration = false;
    bool atLeastOneDecorationSet = false;

    if (format.fontUnderline() != defaultCharFormat.fontUnderline()) {
        hasDecoration = true;
        if (format.fontUnderline()) {
            html += QLatin1String(" underline");
            atLeastOneDecorationSet = true;
        }
    }

    if (format.fontOverline() != defaultCharFormat.fontOverline()) {
        hasDecoration = true;
        if (format.fontOverline()) {
            html += QLatin1String(" overline");
            atLeastOneDecorationSet = true;
        }
    }

    if (format.fontStrikeOut() != defaultCharFormat.fontStrikeOut()) {
        hasDecoration = true;
        if (format.fontStrikeOut()) {
            html += QLatin1String(" line-through");
            atLeastOneDecorationSet = true;
        }
    }

    if (hasDecoration) {
        if (!atLeastOneDecorationSet)
            html += QLatin1String("none");
        html += QLatin1Char(';');
        attributesEmitted = true;
    } else {
        html.chop(qstrlen(decorationTag.latin1()));
    }

    if (format.foreground() != defaultCharFormat.foreground()
        && format.foreground().style() != Qt::NoBrush) {
        html += QLatin1String(" color:");
        html += format.foreground().color().name();
        html += QLatin1Char(';');
        attributesEmitted = true;
    }

    if (format.background() != defaultCharFormat.background()
        && format.background().style() != Qt::NoBrush) {
        html += QLatin1String(" background-color:");
        html += format.background().color().name();
        html += QLatin1Char(';');
        attributesEmitted = true;
    }

    if (format.verticalAlignment() != defaultCharFormat.verticalAlignment()) {
        html += QLatin1String(" vertical-align:");

        QTextCharFormat::VerticalAlignment valign = format.verticalAlignment();
        if (valign == QTextCharFormat::AlignSubScript)
            html += QLatin1String("sub");
        else if (valign == QTextCharFormat::AlignSuperScript)
            html += QLatin1String("super");

        html += QLatin1Char(';');
        attributesEmitted = true;
    }

    return attributesEmitted;
}

void QTextHtmlExporter::emitTextLength(const char *attribute, const QTextLength &length)
{
    if (length.type() == QTextLength::VariableLength) // default
        return;

    html += QLatin1Char(' ');
    html += QLatin1String(attribute);
    html += QLatin1String("=\"");
    html += QString::number(length.rawValue());

    if (length.type() == QTextLength::PercentageLength)
        html += QLatin1String("%\"");
    else
        html += QLatin1String("\"");
}

void QTextHtmlExporter::emitAlignment(Qt::Alignment align)
{
    if (align & Qt::AlignLeft)
        return;
    else if (align & Qt::AlignRight)
        html += QLatin1String(" align=\"right\"");
    else if (align & Qt::AlignHCenter)
        html += QLatin1String(" align=\"center\"");
    else if (align & Qt::AlignJustify)
        html += QLatin1String(" align=\"justify\"");
}

void QTextHtmlExporter::emitFloatStyle(QTextFrameFormat::Position pos, StyleMode mode)
{
    if (pos == QTextFrameFormat::InFlow)
        return;

    if (mode == EmitStyleTag)
        html += QLatin1String(" style=\"float:");
    else
        html += QLatin1String(" float:");

    if (pos == QTextFrameFormat::FloatLeft)
        html += QLatin1String(" left;");
    else if (pos == QTextFrameFormat::FloatRight)
        html += QLatin1String(" right;");
    else
        Q_ASSERT_X(0, "QTextHtmlExporter::emitFloatStyle()", "pos should be a valid enum type");

    if (mode == EmitStyleTag)
        html += QLatin1Char('\"');
}

void QTextHtmlExporter::emitMargins(const QString &top, const QString &bottom, const QString &left, const QString &right)
{
    html += QLatin1String(" margin-top:");
    html += top;
    html += QLatin1String("px;");

    html += QLatin1String(" margin-bottom:");
    html += bottom;
    html += QLatin1String("px;");

    html += QLatin1String(" margin-left:");
    html += left;
    html += QLatin1String("px;");

    html += QLatin1String(" margin-right:");
    html += right;
    html += QLatin1String("px;");
}

void QTextHtmlExporter::emitFragment(const QTextFragment &fragment)
{
    const QTextCharFormat format = fragment.charFormat();

    bool closeAnchor = false;

    if (format.isAnchor()) {
        const QString name = format.anchorName();
        if (!name.isEmpty()) {
            html += QLatin1String("<a name=\"");
            html += name;
            html += QLatin1String("\"></a>");
        }
        const QString href = format.anchorHref();
        if (!href.isEmpty()) {
            html += QLatin1String("<a href=\"");
            html += href;
            html += QLatin1String("\">");
            closeAnchor = true;
        }
    }

    QLatin1String styleTag("<span style=\"");
    html += styleTag;

    const bool attributesEmitted = emitCharFormatStyle(format);
    if (attributesEmitted)
        html += QLatin1String("\">");
    else
        html.chop(qstrlen(styleTag.latin1()));

    QString txt = fragment.text();
    if (txt.count() == 1 && txt.at(0) == QChar::ObjectReplacementCharacter) {
        if (format.isImageFormat()) {
            QTextImageFormat imgFmt = format.toImageFormat();

            html += QLatin1String("<img");

            if (imgFmt.hasProperty(QTextFormat::ImageName))
                emitAttribute("src", imgFmt.name());

            if (imgFmt.hasProperty(QTextFormat::ImageWidth))
                emitAttribute("width", QString::number(imgFmt.width()));

            if (imgFmt.hasProperty(QTextFormat::ImageHeight))
                emitAttribute("height", QString::number(imgFmt.height()));

            if (QTextFrame *imageFrame = qobject_cast<QTextFrame *>(doc->objectForFormat(imgFmt)))
                emitFloatStyle(imageFrame->frameFormat().position());

            html += QLatin1String(" />");
        }
    } else {
        Q_ASSERT(!txt.contains(QChar::ObjectReplacementCharacter));

        txt = Qt::escape(txt);

        // split for [\n{LineSeparator}]
        QString forcedLineBreakRegExp = QString::fromLatin1("[\\na]");
        forcedLineBreakRegExp[3] = QChar::LineSeparator;

        const QStringList lines = txt.split(QRegExp(forcedLineBreakRegExp));
        for (int i = 0; i < lines.count(); ++i) {
            if (i > 0)
                html += QLatin1String("<br />"); // space on purpose for compatibility with Netscape, Lynx & Co.
            html += lines.at(i);
        }
    }

    if (attributesEmitted)
        html += QLatin1String("</span>");

    if (closeAnchor)
        html += QLatin1String("</a>");
}

static bool isOrderedList(int style)
{
    return style == QTextListFormat::ListDecimal || style == QTextListFormat::ListLowerAlpha
           || style == QTextListFormat::ListUpperAlpha;
}

void QTextHtmlExporter::emitBlockAttributes(const QTextBlock &block)
{
    QTextBlockFormat format = block.blockFormat();
    emitAlignment(format.alignment());

    Qt::LayoutDirection dir = format.layoutDirection();
    if (dir == Qt::LeftToRight) {
        // assume default to not bloat the html too much
        // html += QLatin1String(" dir='ltr'");
    } else {
        html += QLatin1String(" dir='rtl'");
    }

    QLatin1String style(" style=\"");
    html += style;

    if (block.begin().atEnd()) {
        html += QLatin1String("-qt-paragraph-type:empty;");
    }

    emitMargins(QString::number(format.topMargin()),
                QString::number(format.bottomMargin()),
                QString::number(format.leftMargin()),
                QString::number(format.rightMargin()));

    html += QLatin1String(" -qt-block-indent:");
    html += QString::number(format.indent());
    html += QLatin1Char(';');

    html += QLatin1String(" text-indent:");
    html += QString::number(format.indent());
    html += QLatin1String("px;");

    QTextCharFormat diff = formatDifference(defaultCharFormat, block.charFormat()).toCharFormat();
    if (!diff.properties().isEmpty())
        emitCharFormatStyle(diff);

    html += QLatin1Char('"');

    QBrush bg = format.background();
    if (bg != Qt::NoBrush)
        emitAttribute("bgcolor", bg.color().name());
}

void QTextHtmlExporter::emitBlock(const QTextBlock &block)
{
    if (block.begin().atEnd()) {
        // ### HACK, remove once QTextFrame::Iterator is fixed
        int p = block.position();
        if (p > 0)
            --p;
        QTextDocumentPrivate::FragmentIterator frag = doc->docHandle()->find(p);
        QChar ch = doc->docHandle()->buffer().at(frag->stringPosition);
        if (ch == QTextBeginningOfFrame
            || ch == QTextEndOfFrame)
            return;
    }

    html += QLatin1Char('\n');

    // save and later restore, in case we 'change' the default format by
    // emitting block char format information
    QTextCharFormat oldDefaultCharFormat = defaultCharFormat;

    QTextList *list = block.textList();
    if (list) {
        if (list->itemNumber(block) == 0) { // first item? emit <ul> or appropriate
            const QTextListFormat format = list->format();
            const int style = format.style();
            switch (style) {
                case QTextListFormat::ListDecimal: html += QLatin1String("<ol"); break;
                case QTextListFormat::ListDisc: html += QLatin1String("<ul"); break;
                case QTextListFormat::ListCircle: html += QLatin1String("<ul type=\"circle\""); break;
                case QTextListFormat::ListSquare: html += QLatin1String("<ul type=\"square\""); break;
                case QTextListFormat::ListLowerAlpha: html += QLatin1String("<ol type=\"a\""); break;
                case QTextListFormat::ListUpperAlpha: html += QLatin1String("<ol type=\"A\""); break;
                default: html += QLatin1String("<ul"); // ### should not happen
            }

            if (format.hasProperty(QTextFormat::ListIndent)) {
                html += QLatin1String(" style=\"-qt-list-indent: ");
                html += QString::number(format.indent());
                html += QLatin1String(";\"");
            }

            html += QLatin1Char('>');
        }

        html += QLatin1String("<li");

        const QTextCharFormat blockFmt = formatDifference(defaultCharFormat, block.charFormat()).toCharFormat();
        if (!blockFmt.properties().isEmpty()) {
            html += QLatin1String(" style=\"");
            emitCharFormatStyle(blockFmt);
            html += QLatin1Char('\"');

            defaultCharFormat.merge(block.charFormat());
        }
    }

    const QTextBlockFormat blockFormat = block.blockFormat();
    if (blockFormat.hasProperty(QTextFormat::BlockTrailingHorizontalRulerWidth)) {
        html += QLatin1String("<hr");

        QTextLength width = blockFormat.lengthProperty(QTextFormat::BlockTrailingHorizontalRulerWidth);
        if (width.type() != QTextLength::VariableLength)
            emitTextLength("width", width);
        else
            html += QLatin1Char(' ');

        html += QLatin1String("/>");
        return;
    }

    const bool pre = blockFormat.nonBreakableLines();
    if (pre) {
        if (list)
            html += QLatin1Char('>');
        html += QLatin1String("<pre");
    } else if (!list) {
        html += QLatin1String("<p");
    }

    emitBlockAttributes(block);

    html += QLatin1Char('>');

    const QTextCharFormat blockCharFmt = block.charFormat();
    const QTextCharFormat diff = formatDifference(defaultCharFormat, blockCharFmt).toCharFormat();

    defaultCharFormat.merge(blockCharFmt);

    QTextBlock::Iterator it = block.begin();
    if (fragmentMarkers && !it.atEnd() && block == doc->begin())
        html += QLatin1String("<!--StartFragment-->");

    for (; !it.atEnd(); ++it)
        emitFragment(it.fragment());

    if (fragmentMarkers && block.position() + block.length() == doc->docHandle()->length())
        html += QLatin1String("<!--EndFragment-->");

    if (pre)
        html += QLatin1String("</pre>");
    else if (list)
        html += QLatin1String("</li>");
    else
        html += QLatin1String("</p>");

    if (list) {
        if (list->itemNumber(block) == list->count() - 1) { // last item? close list
            if (isOrderedList(list->format().style()))
                html += QLatin1String("</ol>");
            else
                html += QLatin1String("</ul>");
        }
    }

    defaultCharFormat = oldDefaultCharFormat;
}

void QTextHtmlExporter::emitTable(const QTextTable *table)
{
    QTextTableFormat format = table->format();

    html += QLatin1String("\n<table");

    if (format.hasProperty(QTextFormat::FrameBorder))
        emitAttribute("border", QString::number(format.border()));

    emitFloatStyle(format.position());
    emitAlignment(format.alignment());
    emitTextLength("width", format.width());

    if (format.hasProperty(QTextFormat::TableCellSpacing))
        emitAttribute("cellspacing", QString::number(format.cellSpacing()));
    if (format.hasProperty(QTextFormat::TableCellPadding))
        emitAttribute("cellpadding", QString::number(format.cellPadding()));

    QBrush bg = format.background();
    if (bg != Qt::NoBrush)
        emitAttribute("bgcolor", bg.color().name());

    html += QLatin1Char('>');

    const int rows = table->rows();
    const int columns = table->columns();

    QVector<QTextLength> columnWidths = format.columnWidthConstraints();
    if (columnWidths.isEmpty()) {
        columnWidths.resize(columns);
        columnWidths.fill(QTextLength());
    }
    Q_ASSERT(columnWidths.count() == columns);

    QVarLengthArray<bool> widthEmittedForColumn(columns);
    for (int i = 0; i < columns; ++i)
        widthEmittedForColumn[i] = false;

    const int headerRowCount = qMin(format.headerRowCount(), rows);
    if (headerRowCount > 0)
        html += QLatin1String("<thead>");

    for (int row = 0; row < rows; ++row) {
        html += QLatin1String("\n<tr>");

        for (int col = 0; col < columns; ++col) {
            const QTextTableCell cell = table->cellAt(row, col);

            // for col/rowspans
            if (cell.row() != row)
                continue;

            if (cell.column() != col)
                continue;

            html += QLatin1String("\n<td");

            if (!widthEmittedForColumn[col]) {
                emitTextLength("width", columnWidths.at(col));
                widthEmittedForColumn[col] = true;
            }

            if (cell.columnSpan() > 1)
                emitAttribute("colspan", QString::number(cell.columnSpan()));

            if (cell.rowSpan() > 1)
                emitAttribute("rowspan", QString::number(cell.rowSpan()));

            const QTextCharFormat cellFormat = cell.format();
            QBrush bg = cellFormat.background();
            if (bg != Qt::NoBrush)
                emitAttribute("bgcolor", bg.color().name());

            html += QLatin1Char('>');

            emitFrame(cell.begin());

            html += QLatin1String("</td>");
        }

        html += QLatin1String("</tr>");
        if (headerRowCount > 0 && row == headerRowCount - 1)
            html += QLatin1String("</thead>");
    }

    html += QLatin1String("</table>");
}

void QTextHtmlExporter::emitFrame(QTextFrame::Iterator frameIt)
{
    if (!frameIt.atEnd()) {
        QTextFrame::Iterator next = frameIt;
        ++next;
        if (next.atEnd()
            && frameIt.currentFrame() == 0
            && frameIt.parentFrame() != doc->rootFrame()
            && frameIt.currentBlock().begin().atEnd())
            return;
    }

    for (QTextFrame::Iterator it = frameIt;
         !it.atEnd(); ++it) {
        if (QTextFrame *f = it.currentFrame()) {
            if (QTextTable *table = qobject_cast<QTextTable *>(f)) {
                emitTable(table);
            } else {
                html += QLatin1String("\n<table");
                QTextFrameFormat format = f->frameFormat();

                if (format.hasProperty(QTextFormat::FrameBorder))
                    emitAttribute("border", QString::number(format.border()));

                html += QLatin1String(" style=\"-qt-table-type: frame;");
                emitFloatStyle(format.position(), OmitStyleTag);

                if (format.hasProperty(QTextFormat::FrameMargin)) {
                    const QString margin = QString::number(format.margin());
                    emitMargins(margin, margin, margin, margin);
                }

                html += QLatin1Char('\"');

                emitTextLength("width", format.width());
                emitTextLength("height", format.height());

                QBrush bg = format.background();
                if (bg != Qt::NoBrush)
                    emitAttribute("bgcolor", bg.color().name());

                html += QLatin1Char('>');
                html += QLatin1String("\n<tr>\n<td style=\"border: none;\">");
                emitFrame(f->begin());
                html += QLatin1String("</td></tr></table>");
            }
        } else if (it.currentBlock().isValid()) {
            emitBlock(it.currentBlock());
        }
    }
}

QString QTextDocument::toHtml(const QByteArray &encoding) const
{
    return QTextHtmlExporter(this).toHtml(encoding);
}

QVector<QTextFormat> QTextDocument::allFormats() const
{
    Q_D(const QTextDocument);
    return d->formatCollection()->formats;
}


QTextDocumentPrivate *QTextDocument::docHandle() const
{
    Q_D(const QTextDocument);
    return const_cast<QTextDocumentPrivate *>(d);
}

---