qtextdocumentlayout.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

    painter->setRenderHint(QPainter::Antialiasing);

    if (selectionFormat) {
        painter->setPen(QPen(selectionFormat->foreground(), 0));
        painter->fillRect(r, selectionFormat->background());
    } else {
        QBrush fg = charFormat.foreground();
        if (fg == Qt::NoBrush)
            fg = context.palette.text();
        painter->setPen(QPen(fg, 0));
    }

    QBrush brush = context.palette.brush(QPalette::Text);

    switch (style) {
    case QTextListFormat::ListDecimal:
    case QTextListFormat::ListLowerAlpha:
    case QTextListFormat::ListUpperAlpha: {
        QTextLayout layout(itemText, font, q->paintDevice());
        layout.setCacheEnabled(true);
        QTextOption option(Qt::AlignLeft | Qt::AlignAbsolute);
        option.setTextDirection(dir);
        layout.setTextOption(option);
        layout.beginLayout();
        layout.createLine();
        layout.endLayout();
        layout.draw(painter, QPointF(r.left(), pos.y()));
        break;
    }
    case QTextListFormat::ListSquare:
        painter->fillRect(r, brush);
        break;
    case QTextListFormat::ListCircle:
        painter->drawEllipse(r);
        break;
    case QTextListFormat::ListDisc:
        painter->setBrush(brush);
        painter->drawEllipse(r);
        painter->setBrush(Qt::NoBrush);
        break;
    case QTextListFormat::ListStyleUndefined:
        break;
    default:
        break;
    }

    painter->restore();
}

static bool isFrameInCell(const QTextTableCell &cell, QTextFrame *frame)
{
    const int cellStart = cell.firstPosition();
    const int cellEnd = cell.lastPosition();
    const int frameStart = frame->firstPosition();
    const int frameEnd = frame->lastPosition();

    return cellStart <= frameStart && cellStart <= frameEnd
           && cellEnd >= frameStart && cellEnd >= frameEnd;
}

QLayoutStruct QTextDocumentLayoutPrivate::layoutCell(QTextTable *t, const QTextTableCell &cell, qreal width,
                                                    int layoutFrom, int layoutTo)
{
    LDEBUG << "layoutCell";
    QLayoutStruct layoutStruct;
    layoutStruct.frame = t;
    layoutStruct.minimumWidth = 0;
    layoutStruct.maximumWidth = INT_MAX;
    layoutStruct.y = 0;
    layoutStruct.x_left = 0;
    layoutStruct.x_right = width;
    // we get called with different widths all the time (for example for figuring
    // out the min/max widths), so we always have to do the full layout ;(
    // also when for example in a table layoutFrom/layoutTo affect only one cell,
    // making that one cell grow the available width of the other cells may change
    // (shrink) and therefore when layoutCell gets called for them they have to
    // be relayouted, even if layoutFrom/layoutTo is not in their range. Hence
    // this line:
    layoutStruct.fullLayout = true;

    QList<QTextFrame *> floats;

    // ### speed up
    // layout out child frames in that cell first
    for (int i = 0; i < t->childFrames().size(); ++i){
        QTextFrame *frame = t->childFrames().at(i);
        if (isFrameInCell(cell, frame)) {
            QTextFrameData *cd = data(frame);
            cd->sizeDirty = true;
                layoutFrame(frame, frame->firstPosition(), frame->lastPosition(), width, -1);
            layoutStruct.minimumWidth = qMax(layoutStruct.minimumWidth, cd->minimumWidth);
            layoutStruct.maximumWidth = qMin(layoutStruct.maximumWidth, cd->maximumWidth);

            if (cd->flow_position != QTextFrameFormat::InFlow)
                floats.append(frame);
        }
    }

    qreal floatMinWidth = layoutStruct.minimumWidth;

    layoutFlow(cell.begin(), &layoutStruct, layoutFrom, layoutTo);

    // floats that are located inside the text (like inline images) aren't taken into account by
    // layoutFlow with regards to the cell height (layoutStruct->y), so for a safety measure we
    // do that here. For example with <td><img align="right" src="..." />blah</td>
    // when the image happens to be higher than the text
    for (int i = 0; i < floats.size(); ++i)
        layoutStruct.y = qMax(layoutStruct.y, data(floats.at(i))->size.height());

    // constraint the maximumWidth by the minimum width of the fixed size floats, to
    // keep them visible
    layoutStruct.maximumWidth = qMax(layoutStruct.maximumWidth, floatMinWidth);

    // as floats in cells get added to the table's float list but must not affect
    // floats in other cells we must clear the list here.
    data(t)->floats.clear();

//    qDebug() << "layoutCell done";

    return layoutStruct;
}

QRectF QTextDocumentLayoutPrivate::layoutTable(QTextTable *table, int layoutFrom, int layoutTo)
{
    LDEBUG << "layoutTable";
    QTextTableData *td = static_cast<QTextTableData *>(data(table));
    Q_ASSERT(td->sizeDirty);
    const int rows = table->rows();
    const int columns = table->columns();

    const QTextTableFormat fmt = table->format();

    QVector<QTextLength> columnWidthConstraints = fmt.columnWidthConstraints();
    if (columnWidthConstraints.size() != columns)
        columnWidthConstraints.resize(columns);
    Q_ASSERT(columnWidthConstraints.count() == columns);

    const qreal cellSpacing = td->cellSpacing = fmt.cellSpacing();
    td->cellPadding = fmt.cellPadding();
    const qreal margin = td->margin + td->border + td->padding;

    qreal totalWidth = fmt.width().value(td->contentsWidth);
    // two (vertical) borders per cell per column
    totalWidth -= columns * 2 * td->border;
    // inter-cell spacing
    totalWidth -= (columns - 1) * cellSpacing;
    // cell spacing at the left and right hand side
    totalWidth -= 2 * cellSpacing;
    // remember the width used to distribute to percentaged columns
    qreal initialTotalWidth = totalWidth;

    td->widths.resize(columns);
    td->widths.fill(0);

    td->minWidths.resize(columns);
    // start with a minimum width of 0. totally empty
    // cells of default created tables are invisible otherwise
    // and therefore hardly editable
    td->minWidths.fill(1);

    td->maxWidths.resize(columns);
    td->maxWidths.fill(INT_MAX);

    td->rowPageBreaks.clear();

    // calculate minimum and maximum sizes of the columns
    for (int i = 0; i < columns; ++i) {
        for (int row = 0; row < rows; ++row) {
            const QTextTableCell cell = table->cellAt(row, i);
            const int cspan = cell.columnSpan();

            if (cspan > 1 && i != cell.column())
                continue;

            // to figure out the min and the max width lay out the cell at
            // maximum width. otherwise the maxwidth calculation sometimes
            // returns wrong values
            QLayoutStruct layoutStruct = layoutCell(table, cell, INT_MAX, layoutFrom, layoutTo);

            // distribute the minimum width over all columns the cell spans
            qreal widthToDistribute = layoutStruct.minimumWidth + 2 * td->cellPadding;
            for (int n = 0; n < cspan; ++n) {
                const int col = i + n;
                qreal w = widthToDistribute / (cspan - n);
                td->minWidths[col] = qMax(td->minWidths.at(col), w);
                widthToDistribute -= td->minWidths.at(col);
                if (widthToDistribute <= 0)
                    break;
            }

            // ### colspans
            qreal maxW = td->maxWidths.at(i);
            if (layoutStruct.maximumWidth != INT_MAX) {
                if (maxW == INT_MAX)
                    maxW = layoutStruct.maximumWidth + 2 * td->cellPadding;
                else
                    maxW = qMax(maxW, layoutStruct.maximumWidth + 2 * td->cellPadding);
            }
            td->maxWidths[i] = qMax(td->minWidths.at(i), maxW);
        }
    }

    // set fixed values, figure out total percentages used and number of
    // variable length cells. Also assign the minimum width for variable columns.
    qreal totalPercentage = 0;
    int variableCols = 0;
    for (int i = 0; i < columns; ++i) {
        const QTextLength &length = columnWidthConstraints.at(i);
        if (length.type() == QTextLength::FixedLength) {
            td->widths[i] = qMax(length.rawValue(), td->minWidths.at(i));
            totalWidth -= td->widths.at(i);
        } else if (length.type() == QTextLength::PercentageLength) {
            totalPercentage += length.rawValue();
        } else if (length.type() == QTextLength::VariableLength) {
            variableCols++;

            td->widths[i] = td->minWidths.at(i);
            totalWidth -= td->minWidths.at(i);
        }
    }

    // set percentage values
    {
        const qreal totalPercentagedWidth = initialTotalWidth * totalPercentage / 100;
        for (int i = 0; i < columns; ++i)
            if (columnWidthConstraints.at(i).type() == QTextLength::PercentageLength) {
                const qreal percentWidth = totalPercentagedWidth * columnWidthConstraints.at(i).rawValue() / totalPercentage;
                td->widths[i] = qMax(percentWidth, td->minWidths.at(i));
                totalWidth -= td->widths.at(i);
            }
    }

    // for variable columns distribute the remaining space
    if (variableCols > 0 && totalWidth > 0) {
        QVarLengthArray<int> columnsWithProperMaxSize;
        for (int i = 0; i < columns; ++i)
            if (columnWidthConstraints.at(i).type() == QTextLength::VariableLength
                && td->maxWidths.at(i) != INT_MAX)
                columnsWithProperMaxSize.append(i);

        qreal lastTotalWidth = totalWidth;
        while (totalWidth > 0) {
            for (int k = 0; k < columnsWithProperMaxSize.count(); ++k) {
                const int col = columnsWithProperMaxSize[k];
                const int colsLeft = columnsWithProperMaxSize.count() - k;
                const qreal w = qMin(td->maxWidths.at(col) - td->widths.at(col), totalWidth / colsLeft);
                td->widths[col] += w;
                totalWidth -= w;
            }
            if (totalWidth == lastTotalWidth)
                break;
            lastTotalWidth = totalWidth;
        }

        if (totalWidth > 0
            // don't unnecessarily grow variable length sized tables
            && fmt.width().type() != QTextLength::VariableLength) {
            const qreal widthPerAnySizedCol = totalWidth / variableCols;
            for (int col = 0; col < columns; ++col) {
                if (columnWidthConstraints.at(col).type() == QTextLength::VariableLength)
                    td->widths[col] += widthPerAnySizedCol;
            }
        }
    }


    td->columnPositions.resize(columns);
    td->columnPositions[0] = margin /*includes table border*/ + cellSpacing + td->border;

    for (int i = 1; i < columns; ++i)
        td->columnPositions[i] = td->columnPositions.at(i-1) + td->widths.at(i-1) + td->border + cellSpacing + td->border;

    td->heights.resize(rows);
    td->heights.fill(0);

    td->rowPositions.resize(rows);
    td->rowPositions[0] = margin /*includes table border*/ + cellSpacing + td->border;

    bool haveRowSpannedCells = false;

    // now that we have the column widths we can lay out all cells with the right
    // width, to calculate the row heights. we have to use two passes though, cells
    // which span more than one row have to be processed later to avoid them enlarging
    // other calls too much
    //
    // ### this could be made faster by iterating over the cells array of QTextTable
    for (int r = 0; r < rows; ++r) {
        td->calcRowPosition(r);

        for (int c = 0; c < columns; ++c) {
            QTextTableCell cell = table->cellAt(r, c);
            const int rspan = cell.rowSpan();
            const int cspan = cell.columnSpan();

            if (cspan > 1 && cell.column() != c)
                continue;

            if (rspan > 1) {
                haveRowSpannedCells = true;
                continue;
            }

            const qreal width = td->cellWidth(c, cspan);
//            qDebug() << "layoutCell for cell at row" << r << "col" << c;
            QLayoutStruct layoutStruct = layoutCell(table, cell, width, layoutFrom, layoutTo);

            td->heights[r] = qMax(td->heights.at(r), layoutStruct.y + 2 * td->cellPadding);
        }
    }

    if (haveRowSpannedCells) {
        for (int r = 0; r < rows; ++r) {
            td->calcRowPosition(r);

            for (int c = 0; c < columns; ++c) {
                QTextTableCell cell = table->cellAt(r, c);
                const int rspan = cell.rowSpan();
                const int cspan = cell.columnSpan();

                if (cspan > 1 && cell.column() != c)
                    continue;

                if (rspan == 1)
                    continue;

                if (cell.row() != r)
                    continue;

                const qreal width = td->cellWidth(c, cspan);
                QLayoutStruct layoutStruct = layoutCell(table, cell, width, layoutFrom, layoutTo);

                // the last row gets all the remaining space
                qreal heightToDistribute = layoutStruct.y + 2 * td->cellPadding;
                for (int n = 0; n < rspan - 1; ++n) {
                    const int row = r + n;
                    heightToDistribute -= td->heights.at(row) + td->border + cellSpacing + td->border;
                    if (heightToDistribute <= 0)
                        break;
                }

                if (heightToDistribute > 0) {
                    const int lastRow = r + rspan - 1;
                    td->heights[lastRow] = qMax(td->heights.at(lastRow), heightToDistribute);
                }
            }
        }
    }

    // - margin to compensate the + margin in columnPositions[0]
//    td->contentsWidth = qMax(td->contentsWidth,
//                             td->columnPositions.last() + td->widths.last() + td->padding + td->border + cellSpacing - margin);
    td->contentsWidth = td->columnPositions.last() + td->widths.last() + td->padding + td->border + cellSpacing - margin;

    td->minimumWidth = td->columnPositions.at(0);
    for (int i = 0; i < columns; ++i) {