qtextdocumentlayout.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

        td->minimumWidth += td->minWidths.at(i) + td->border + cellSpacing + td->border;
    }
    td->minimumWidth += margin - td->border;

    td->maximumWidth = td->columnPositions.at(0);
    for (int i = 0; i < columns; ++i)
        if (td->maxWidths.at(i) != INT_MAX)
            td->maximumWidth += td->maxWidths.at(i) + td->border + cellSpacing + td->border;
    td->maximumWidth += margin - td->border;

    td->rowPositionsBeforePageBreak = td->rowPositions;

    td->updateSize();
    td->sizeDirty = false;
    return QRectF(); // invalid rect -> update everything
}

void QTextDocumentLayoutPrivate::positionFloat(QTextFrame *frame, QTextLine *currentLine)
{
    QTextFrameData *fd = data(frame);

    QTextFrame *parent = frame->parentFrame();
    Q_ASSERT(parent);
    QTextFrameData *pd = data(parent);
    Q_ASSERT(pd && pd->currentLayoutStruct);

    if (!pd->floats.contains(frame))
        pd->floats.append(frame);
    fd->layoutDirty = true;
    Q_ASSERT(!fd->sizeDirty);

//     qDebug() << "positionFloat:" << frame << "width=" << fd->size.width();
    qreal y = pd->currentLayoutStruct->y;
    if (currentLine) {
        qreal left, right;
        floatMargins(y, pd->currentLayoutStruct, &left, &right);
//         qDebug() << "have line: right=" << right << "left=" << left << "textWidth=" << currentLine->textWidth();
        if (right - left < currentLine->naturalTextWidth() + fd->size.width()) {
            pd->currentLayoutStruct->pendingFloats.append(frame);
//             qDebug() << "    adding to pending list";
            return;
        }
    }

    if (!parent->parentFrame() /* float in root frame */
        && y + fd->size.height() > pd->currentLayoutStruct->pageBottom) {
        y = pd->currentLayoutStruct->pageBottom;
    }

    y = findY(y, pd->currentLayoutStruct, fd->size.width());

    qreal left, right;
    floatMargins(y, pd->currentLayoutStruct, &left, &right);

    if (fd->flow_position == QTextFrameFormat::FloatLeft)
        fd->position = QPointF(left, y);
    else
        fd->position = QPointF(right - fd->size.width(), y);

//     qDebug()<< "float positioned at " << fd->position;
    fd->layoutDirty = false;
}

QRectF QTextDocumentLayoutPrivate::layoutFrame(QTextFrame *f, int layoutFrom, int layoutTo)
{
    LDEBUG << "layoutFrame (pre)";
    Q_ASSERT(data(f)->sizeDirty);
//     qDebug("layouting frame (%d--%d), parent=%p", f->firstPosition(), f->lastPosition(), f->parentFrame());

    QTextFrameFormat fformat = f->frameFormat();

    QTextFrame *parent = f->parentFrame();
    const QTextFrameData *pd = parent ? data(parent) : 0;

    const qreal maximumWidth = pd ? pd->contentsWidth : q_func()->document()->pageSize().width();

    const qreal width = fformat.width().value(maximumWidth);

    QTextLength height = fformat.height();
    qreal h = height.value(pd ? pd->contentsHeight : -1);

    return layoutFrame(f, layoutFrom, layoutTo, width, h);
}

QRectF QTextDocumentLayoutPrivate::layoutFrame(QTextFrame *f, int layoutFrom, int layoutTo, qreal frameWidth, qreal frameHeight)
{
    LDEBUG << "layoutFrame from=" << layoutFrom << "to=" << layoutTo;
    Q_Q(QTextDocumentLayout);
    Q_ASSERT(data(f)->sizeDirty);
//     qDebug("layouting frame (%d--%d), parent=%p", f->firstPosition(), f->lastPosition(), f->parentFrame());

    QTextFrameData *fd = data(f);

    {
        QTextFrameFormat fformat = f->frameFormat();
        // set sizes of this frame from the format
        fd->margin = fformat.margin();
        fd->border = fformat.border();
        fd->padding = fformat.padding();

        fd->contentsWidth = frameWidth - 2*(fd->margin + fd->border + fd->padding);

        if (frameHeight != -1) {
            fd->contentsHeight = frameHeight - 2*(fd->margin + fd->border + fd->padding);
        } else {
            fd->contentsHeight = frameHeight;
        }

        fd->flow_position = fformat.position();
    }

    int startPos = f->firstPosition();
    int endPos = f->lastPosition();
    if (startPos > endPos) {
        // inline image
        QTextCharFormat format = q->format(startPos - 1);
        QTextObjectInterface *iface = q->handlerForObject(format.objectType());
        if (iface)
            fd->size = iface->intrinsicSize(q->document(), startPos - 1, format).toSize();
        fd->sizeDirty = false;
        return QRectF();
    }

    if (QTextTable *table = qobject_cast<QTextTable *>(f)) {
        return layoutTable(table, layoutFrom, layoutTo);
    }

    // needed for child frames with a minimum width that is
    // more than what we can offer
    qreal newContentsWidth = fd->contentsWidth;

    // layout child frames
    QList<QTextFrame *> children = f->childFrames();
    for (int i = 0; i < children.size(); ++i) {
        QTextFrame *c = children.at(i);
        QTextFrameData *cd = data(c);
        if (cd->sizeDirty) {
            layoutFrame(c, layoutFrom, layoutTo);
        }
        newContentsWidth = qMax(newContentsWidth, cd->size.width());
    }

    qreal margin = fd->margin + fd->border;
    QLayoutStruct layoutStruct;
    layoutStruct.frame = f;
    layoutStruct.x_left = margin + fd->padding;
    layoutStruct.x_right = margin + fd->contentsWidth - fd->padding;
    layoutStruct.y = margin + fd->padding;
    layoutStruct.contentsWidth = 0;
    layoutStruct.minimumWidth = 0;
    layoutStruct.maximumWidth = INT_MAX;
    layoutStruct.fullLayout = fd->contentsWidth != newContentsWidth;
    layoutStruct.updateRect = QRectF(QPointF(0, 0), QSizeF(INT_MAX, INT_MAX));
    LDEBUG << "layoutStruct: x_left" << layoutStruct.x_left << "x_right" << layoutStruct.x_right
           << "fullLayout" << layoutStruct.fullLayout;

    fd->contentsWidth = newContentsWidth;

    if (!f->parentFrame()) {
        layoutStruct.pageHeight = q->document()->pageSize().height();
        layoutStruct.pageBottom = layoutStruct.pageHeight - fd->margin;
        layoutStruct.pageMargin = fd->margin;
    }

    QTextFrame::Iterator it = f->begin();
    layoutFlow(it, &layoutStruct, layoutFrom, layoutTo);

    fd->contentsWidth = qMax(fd->contentsWidth, layoutStruct.contentsWidth);
    fd->minimumWidth = layoutStruct.minimumWidth;
    fd->maximumWidth = layoutStruct.maximumWidth;

    qreal height = fd->contentsHeight == -1
                 ? layoutStruct.y + margin + fd->padding
                 : fd->contentsHeight + 2*margin;
    fd->size = QSizeF(fd->contentsWidth + 2*margin, height);
    fd->sizeDirty = false;
    return layoutStruct.updateRect;
}

void QTextDocumentLayoutPrivate::layoutFlow(QTextFrame::Iterator it, QLayoutStruct *layoutStruct,
                                            int layoutFrom, int layoutTo)
{
    Q_Q(QTextDocumentLayout);
    LDEBUG << "layoutFlow from=" << layoutFrom << "to=" << layoutTo;
    QTextFrameData *fd = data(layoutStruct->frame);

    fd->currentLayoutStruct = layoutStruct;

    QTextFrame::Iterator previousIt;

    const bool inRootFrame = (it.parentFrame() == q->document()->rootFrame());
    if (inRootFrame) {
        bool redoCheckPoints = layoutStruct->fullLayout || checkPoints.isEmpty();

        if (!redoCheckPoints) {
            QVector<QCheckPoint>::Iterator checkPoint = qLowerBound(checkPoints.begin(), checkPoints.end(), layoutFrom);
            if (checkPoint != checkPoints.end()) {
                if (checkPoint != checkPoints.begin())
                    --checkPoint;

                layoutStruct->y = checkPoint->y;
                layoutStruct->minimumWidth = checkPoint->minimumWidth;
                layoutStruct->maximumWidth = checkPoint->maximumWidth;
                layoutStruct->contentsWidth = checkPoint->contentsWidth;

                if (layoutStruct->pageHeight > 0.0) {
                    int page = int(layoutStruct->y / layoutStruct->pageHeight);
                    layoutStruct->pageBottom = (page + 1) * layoutStruct->pageHeight - layoutStruct->pageMargin;
                }

                it = iteratorForTextPosition(checkPoint->positionInFrame);
                checkPoints.resize(checkPoint - checkPoints.begin() + 1);

                if (checkPoint != checkPoints.begin()) {
                    previousIt = it;
                    --previousIt;
                }
            } else {
                redoCheckPoints = true;
            }
        }

        if (redoCheckPoints) {
            checkPoints.clear();
            QCheckPoint cp;
            cp.y = layoutStruct->y;
            cp.positionInFrame = 0;
            cp.minimumWidth = layoutStruct->minimumWidth;
            cp.maximumWidth = layoutStruct->maximumWidth;
            cp.contentsWidth = layoutStruct->contentsWidth;
            checkPoints.append(cp);
        }
    }
                
    while (!it.atEnd()) {
        QTextFrame *c = it.currentFrame();

        if (inRootFrame) {
            int docPos;
            if (it.currentFrame())
                docPos = it.currentFrame()->firstPosition();
            else
                docPos = it.currentBlock().position();

            if (qAbs(layoutStruct->y - checkPoints.last().y) > 2000) {
                qreal left, right;
                floatMargins(layoutStruct->y, layoutStruct, &left, &right);
                if (left == layoutStruct->x_left && right == layoutStruct->x_right) {
                    QCheckPoint p;
                    p.y = layoutStruct->y;
                    p.positionInFrame = docPos;
                    p.minimumWidth = layoutStruct->minimumWidth;
                    p.maximumWidth = layoutStruct->maximumWidth;
                    p.contentsWidth = layoutStruct->contentsWidth;
                    checkPoints.append(p);

                    if (currentLazyLayoutPosition != -1
                        && docPos > currentLazyLayoutPosition + lazyLayoutStepSize)
                        break;

                    if (layoutTo != -1
                        && docPos > layoutTo)
                        break;
                }
            }
        }

        if (c) {
            // position child frame
            QTextFrameData *cd = data(c);
            Q_ASSERT(!cd->sizeDirty);
            if (cd->flow_position == QTextFrameFormat::InFlow) {
                qreal left, right;
                floatMargins(layoutStruct->y, layoutStruct, &left, &right);
                left = qMax(left, layoutStruct->x_left);
                right = qMin(right, layoutStruct->x_right);

                if (right - left < cd->size.width()) {
                    layoutStruct->y = findY(layoutStruct->y, layoutStruct, cd->size.width());
                    floatMargins(layoutStruct->y, layoutStruct, &left, &right);
                }

                QPointF pos(left, layoutStruct->y);

                Qt::Alignment align = Qt::AlignLeft;

                QTextTable *table = qobject_cast<QTextTable *>(c);

                if (table)
                    align = table->format().alignment() & Qt::AlignHorizontal_Mask;

                // align only if there is space for alignment
                if (right - left > cd->size.width()) {
                    if (align == Qt::AlignRight)
                        pos.rx() += layoutStruct->x_right - cd->size.width();
                    else if (align == Qt::AlignHCenter)
                        pos.rx() += (layoutStruct->x_right - cd->size.width()) / 2;
                }

                cd->position = pos;
                layoutStruct->y += cd->size.height();
                cd->layoutDirty = false;

                if (table) {
                    QTextTableData *td = static_cast<QTextTableData *>(data(table));
                    // if the table was previously broken across a page boundary
                    // (due to lazy layouting) then we need to reset the row positions
                    // and the table height (from the row positions) and call
                    // pageBreakInsideTable again.
                    if (!td->rowPageBreaks.isEmpty()) {
                        td->rowPageBreaks.clear();
                        td->rowPositions = td->rowPositionsBeforePageBreak;
                        td->updateSize();
                    }
                }

                if (inRootFrame
                    && cd->position.y() + cd->size.height() > layoutStruct->pageBottom
                   ) {

                    if (table && cd->size.height() > layoutStruct->pageHeight / 2) {
                        pageBreakInsideTable(table, layoutStruct);
                    } else {
                        layoutStruct->newPage();
                        cd->position.setY(layoutStruct->y);
                        layoutStruct->y += cd->size.height();
                    }
                }
            } else {
                positionFloat(c);
            }
            previousIt = it;
            ++it;
        } else {
            QTextFrame::Iterator lastIt;
            if (!previousIt.atEnd())
                lastIt = previousIt;
            previousIt = it;
            QTextBlock block = it.currentBlock();
            ++it;

            const qreal origY = layoutStruct->y;

            // layout and position child block
            layoutBlock(block, layoutStruct, layoutFrom, layoutTo, lastIt.currentBlock());

            // if the block right before a table is empty 'hide' it by
            // positioning it into the table border
            if (isEmptyBlockBeforeTable(block, it)) {
                layoutStruct->y = origY;
                continue;
            }