qtextdocumentfragment.cpp

奇趣公司比较新的qt/emd版本

    When inserting such a fragment into a QTextDocument the current char format of
    the QTextCursor used for insertion is used as format for the text.
*/
QTextDocumentFragment QTextDocumentFragment::fromPlainText(const QString &plainText)
{
    QTextDocumentFragment res;

    res.d = new QTextDocumentFragmentPrivate;
    res.d->importedFromPlainText = true;
    QTextCursor cursor(res.d->doc);
    cursor.insertText(plainText);
    return res;
}

QTextHtmlImporter::QTextHtmlImporter(QTextDocument *_doc, const QString &_html, ImportMode mode, const QTextDocument *resourceProvider)
    : indent(0), doc(_doc), importMode(mode)
{
    cursor = QTextCursor(doc);
    compressNextWhitespace = false;
    wsm = QTextHtmlParserNode::WhiteSpaceNormal;

    QString html = _html;
    const int startFragmentPos = html.indexOf(QLatin1String("<!--StartFragment-->"));
    if (startFragmentPos != -1) {
        const int endFragmentPos = html.indexOf(QLatin1String("<!--EndFragment-->"));
        if (startFragmentPos < endFragmentPos)
            html = html.mid(startFragmentPos, endFragmentPos - startFragmentPos);
        else
            html = html.mid(startFragmentPos);

        html.prepend(QLatin1String("<meta name=\"qrichtext\" content=\"1\" />"));
    }

    parse(html, resourceProvider ? resourceProvider : doc);
//    dumpHtml();
}

static QTextListFormat::Style nextListStyle(QTextListFormat::Style style)
{
    if (style == QTextListFormat::ListDisc)
        return QTextListFormat::ListCircle;
    else if (style == QTextListFormat::ListCircle)
        return QTextListFormat::ListSquare;
    return style;
}

void QTextHtmlImporter::import()
{
    cursor.beginEditBlock();
    hasBlock = true;
    forceBlockMerging = false;
    compressNextWhitespace = !textEditMode;
    blockTagClosed = false;
    for (currentNodeIdx = 0; currentNodeIdx < count(); ++currentNodeIdx) {
        currentNode = &at(currentNodeIdx);
        wsm = textEditMode ? QTextHtmlParserNode::WhiteSpacePreWrap : currentNode->wsm;

        /*
         * process each node in three stages:
         * 1) check if the hierarchy changed and we therefore passed the
         *    equivalent of a closing tag -> we may need to finish off
         *    some structures like tables
         *
         * 2) check if the current node is a special node like a
         *    <table>, <ul> or <img> tag that requires special processing
         *
         * 3) if the node should result in a QTextBlock create one and
         *    finally insert text that may be attached to the node
         */

        /* emit 'closing' table blocks or adjust current indent level
         * if we
         *  1) are beyond the first node
         *  2) the current node not being a child of the previous node
         *      means there was a tag closing in the input html
         */
        if (currentNodeIdx > 0 && (currentNode->parent != currentNodeIdx - 1)) {
            blockTagClosed = closeTag();
            // visually collapse subsequent block tags, but if the element after the closed block tag
            // is for example an inline element (!isBlock) we have to make sure we start a new paragraph by setting
            // hasBlock to false.
            if (blockTagClosed
                && !currentNode->isBlock()
                && currentNode->id != Html_unknown)
                hasBlock = false;
        }

        if (currentNode->displayMode == QTextHtmlElement::DisplayNone) {
            if (currentNode->id == Html_title)
                doc->setMetaInformation(QTextDocument::DocumentTitle, currentNode->text);
            // ignore explicitly 'invisible' elements
            continue;
        }

        if (processSpecialNodes() == ContinueWithNextNode)
            continue;

        // make sure there's a block for 'Blah' after <ul><li>foo</ul>Blah
        if (blockTagClosed
            && !hasBlock
            && !currentNode->isBlock()
            && !currentNode->text.isEmpty() && !currentNode->hasOnlyWhitespace()
            && currentNode->displayMode == QTextHtmlElement::DisplayInline) {

            QTextBlockFormat block = currentNode->blockFormat;
            block.setIndent(indent);

            appendBlock(block, currentNode->charFormat);

            hasBlock = true;
        }

        if (currentNode->isBlock()) {
            if (processBlockNode() == ContinueWithNextNode)
                continue;
        }

        if (currentNode->charFormat.isAnchor() && !currentNode->charFormat.anchorName().isEmpty()) {
            namedAnchors.append(currentNode->charFormat.anchorName());
        }

        if (appendNodeText())
            hasBlock = false; // if we actually appended text then we don't
                              // have an empty block anymore
    }

    cursor.endEditBlock();
}

static bool isPreservingWhitespaceMode(QTextHtmlParserNode::WhiteSpaceMode mode)
{
    return mode == QTextHtmlParserNode::WhiteSpacePre
           || mode == QTextHtmlParserNode::WhiteSpacePreWrap
           ;
}

bool QTextHtmlImporter::appendNodeText()
{
    const int initialCursorPosition = cursor.position();
    QTextCharFormat format = currentNode->charFormat;

    if (isPreservingWhitespaceMode(wsm))
        compressNextWhitespace = false;

    QString text = currentNode->text;

    QString textToInsert;
    textToInsert.reserve(text.size());

    for (int i = 0; i < text.length(); ++i) {
        QChar ch = text.at(i);

        if (ch.isSpace()
            && ch != QChar::Nbsp
            && ch != QChar::ParagraphSeparator) {

            if (compressNextWhitespace)
                continue;

            if (wsm == QTextHtmlParserNode::WhiteSpacePre
                || textEditMode
               ) {
                if (ch == QLatin1Char('\n')) {
                    if (textEditMode)
                        continue;
                } else if (ch == QLatin1Char('\r')) {
                    continue;
                }
            } else if (wsm != QTextHtmlParserNode::WhiteSpacePreWrap) {
                compressNextWhitespace = true;
                if (wsm == QTextHtmlParserNode::WhiteSpaceNoWrap)
                    ch = QChar::Nbsp;
                else
                    ch = QLatin1Char(' ');
            }
        } else {
            compressNextWhitespace = false;
        }

        if (ch == QLatin1Char('\n')
            || ch == QChar::ParagraphSeparator) {

            if (!textToInsert.isEmpty()) {
                cursor.insertText(textToInsert, format);
                textToInsert.clear();
            }

            QTextBlockFormat fmt = cursor.blockFormat();

            if (fmt.hasProperty(QTextFormat::BlockBottomMargin)) {
                QTextBlockFormat tmp = fmt;
                tmp.clearProperty(QTextFormat::BlockBottomMargin);
                cursor.setBlockFormat(tmp);
            }

            fmt.clearProperty(QTextFormat::BlockTopMargin);
            appendBlock(fmt, cursor.charFormat());
        } else {
            if (!namedAnchors.isEmpty()) {
                if (!textToInsert.isEmpty()) {
                    cursor.insertText(textToInsert, format);
                    textToInsert.clear();
                }

                format.setAnchor(true);
                format.setAnchorNames(namedAnchors);
                cursor.insertText(ch, format);
                namedAnchors.clear();
                format.clearProperty(QTextFormat::IsAnchor);
                format.clearProperty(QTextFormat::AnchorName);
            } else {
                textToInsert += ch;
            }
        }
    }

    if (!textToInsert.isEmpty()) {
        cursor.insertText(textToInsert, format);
    }

    return cursor.position() != initialCursorPosition;
}

QTextHtmlImporter::ProcessNodeResult QTextHtmlImporter::processSpecialNodes()
{
    switch (currentNode->id) {
        case Html_body:
            if (currentNode->charFormat.background().style() != Qt::NoBrush) {
                QTextFrameFormat fmt = doc->rootFrame()->frameFormat();
                fmt.setBackground(currentNode->charFormat.background());
                doc->rootFrame()->setFrameFormat(fmt);
                const_cast<QTextHtmlParserNode *>(currentNode)->charFormat.clearProperty(QTextFormat::BackgroundBrush);
            }
            break;

        case Html_ol:
        case Html_ul: {
            QTextListFormat::Style style = currentNode->listStyle;

            if (currentNode->id == Html_ul && !currentNode->hasOwnListStyle && currentNode->parent) {
                const QTextHtmlParserNode *n = &at(currentNode->parent);
                while (n) {
                    if (n->id == Html_ul) {
                        style = nextListStyle(currentNode->listStyle);
                    }
                    if (n->parent)
                        n = &at(n->parent);
                    else
                        n = 0;
                }
            }

            QTextListFormat listFmt;
            listFmt.setStyle(style);

            ++indent;
            if (currentNode->hasCssListIndent)
                listFmt.setIndent(currentNode->cssListIndent);
            else
                listFmt.setIndent(indent);

            List l;
            l.format = listFmt;
            l.listNode = currentNodeIdx;
            lists.append(l);
            compressNextWhitespace = true;

            // broken html: <ul>Text here<li>Foo
            const QString simpl = currentNode->text.simplified();
            if (simpl.isEmpty() || simpl.at(0).isSpace())
                return ContinueWithNextNode;
            break;
        }

        case Html_table: {
            Table t = scanTable(currentNodeIdx);
            tables.append(t);
            hasBlock = false;
            return ContinueWithNextNode;
        }

        case Html_tr:
            return ContinueWithNextNode;

        case Html_img: {
            QTextImageFormat fmt;
            fmt.setName(currentNode->imageName);

            fmt.merge(currentNode->charFormat);

            if (currentNode->imageWidth >= 0)
                fmt.setWidth(currentNode->imageWidth);
            if (currentNode->imageHeight >= 0)
                fmt.setHeight(currentNode->imageHeight);

            cursor.insertImage(fmt, QTextFrameFormat::Position(currentNode->cssFloat));

            cursor.movePosition(QTextCursor::Left, QTextCursor::KeepAnchor);
            cursor.mergeCharFormat(currentNode->charFormat);
            cursor.movePosition(QTextCursor::Right);

            hasBlock = false;
            return ContinueWithNextNode;
        }

        case Html_hr: {
            QTextBlockFormat blockFormat = currentNode->blockFormat;
            blockFormat.setTopMargin(topMargin(currentNodeIdx));
            blockFormat.setBottomMargin(bottomMargin(currentNodeIdx));
            blockFormat.setProperty(QTextFormat::BlockTrailingHorizontalRulerWidth, currentNode->width);
            if (hasBlock && importMode == ImportToDocument)
                cursor.mergeBlockFormat(blockFormat);
            else
                appendBlock(blockFormat);
            hasBlock = false;
            return ContinueWithNextNode;
        }

        default: break;
    }
    return ContinueWithCurrentNode;
}

// returns true if a block tag was closed
bool QTextHtmlImporter::closeTag()
{
    const QTextHtmlParserNode *closedNode = &at(currentNodeIdx - 1);
    const int endDepth = depth(currentNodeIdx) - 1;
    int depth = this->depth(currentNodeIdx - 1);
    bool blockTagClosed = false;

    while (depth > endDepth) {
        Table *t = 0;
        if (!tables.isEmpty())
            t = &tables.last();

        switch (closedNode->id) {
            case Html_tr:
                if (t && !t->isTextFrame) {
                    ++t->currentRow;

                    // for broken html with rowspans but missing tr tags
                    while (!t->currentCell.atEnd() && t->currentCell.row < t->currentRow)
                        ++t->currentCell;
                }

                blockTagClosed = true;
                break;

            case Html_table:
                if (!t)
                    break;
                indent = t->lastIndent;

                tables.resize(tables.size() - 1);
                t = 0;

                if (tables.isEmpty()) {
                    cursor = doc->rootFrame()->lastCursorPosition();
                } else {
                    t = &tables.last();
                    if (t->isTextFrame)
                        cursor = t->frame->lastCursorPosition();
                    else if (!t->currentCell.atEnd())
                        cursor = t->currentCell.cell().lastCursorPosition();
                }

                // we don't need an extra block after tables, so we don't
                // claim to have closed one for the creation of a new one
                // in import()
                blockTagClosed = false;
                compressNextWhitespace = true;
                break;

            case Html_th:
            case Html_td:
                if (t && !t->isTextFrame)
                    ++t->currentCell;
                blockTagClosed = true;
                compressNextWhitespace = true;
                break;