C++ InlineTextBox::start方法代码示例

Position Position::upstream(EStayInBlock stayInBlock) const
{
    Position start = equivalentDeepPosition();
    NodeImpl *startNode = start.node();
    if (!startNode)
        return Position();

    NodeImpl *block = startNode->enclosingBlockFlowOrTableElement();
    Position lastVisible;
    
    PositionIterator it(start);
    for (; !it.atStart(); it.previous()) {
        NodeImpl *currentNode = it.current().node();

        if (stayInBlock) {
            NodeImpl *currentBlock = currentNode->enclosingBlockFlowOrTableElement();
            if (block != currentBlock)
                return it.next();
        }

        RenderObject *renderer = currentNode->renderer();
        if (!renderer)
            continue;

        if (renderer->style()->visibility() != VISIBLE)
            continue;

        lastVisible = it.current();

        if (renderer->isReplaced() || renderer->isBR()) {
            if (it.current().offset() >= renderer->caretMaxOffset())
                return Position(currentNode, renderer->caretMaxOffset());
            else
                continue;
        }

        if (renderer->isText() && static_cast<RenderText *>(renderer)->firstTextBox()) {
            if (currentNode != startNode)
                return Position(currentNode, renderer->caretMaxOffset());

            if (it.current().offset() < 0)
                continue;
            uint textOffset = it.current().offset();

            RenderText *textRenderer = static_cast<RenderText *>(renderer);
            for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                if (textOffset > box->start() && textOffset <= box->start() + box->len())
                    return it.current();
                else if (box != textRenderer->lastTextBox() && 
                         !box->nextOnLine() && 
                         textOffset == box->start() + box->len() + 1)
                    return it.current();
            }
        }
    }
    
    return lastVisible.isNotNull() ? lastVisible : *this;
}

static VisiblePosition logicalEndPositionForLine(const VisiblePosition& c)
{
    if (c.isNull())
        return VisiblePosition();

    RootInlineBox* rootBox = rootBoxForLine(c);
    if (!rootBox) {
        // There are VisiblePositions at offset 0 in blocks without
        // RootInlineBoxes, like empty editable blocks and bordered blocks.
        Position p = c.deepEquivalent();
        if (p.node()->renderer() && p.node()->renderer()->isRenderBlock() && !p.deprecatedEditingOffset())
            return c;
        return VisiblePosition();
    }
    
    InlineBox* logicalEndBox;
    Node* logicalEndNode;
    getLogicalEndBoxAndNode(rootBox, logicalEndBox, logicalEndNode);
    if (!logicalEndNode)
        return VisiblePosition();
    
    int endOffset = 1;
    if (logicalEndNode->hasTagName(brTag))
        endOffset = 0;
    else if (logicalEndBox->isInlineTextBox()) {
        InlineTextBox* endTextBox = static_cast<InlineTextBox*>(logicalEndBox);
        endOffset = endTextBox->start();
        if (!endTextBox->isLineBreak())
            endOffset += endTextBox->len();
    }
    
    return VisiblePosition(logicalEndNode, endOffset, VP_UPSTREAM_IF_POSSIBLE);
}

LayoutRect LayoutSVGInlineText::localCaretRect(InlineBox* box, int caretOffset, LayoutUnit*)
{
    if (!box || !box->isInlineTextBox())
        return LayoutRect();

    InlineTextBox* textBox = toInlineTextBox(box);
    if (static_cast<unsigned>(caretOffset) < textBox->start() || static_cast<unsigned>(caretOffset) > textBox->start() + textBox->len())
        return LayoutRect();

    // Use the edge of the selection rect to determine the caret rect.
    if (static_cast<unsigned>(caretOffset) < textBox->start() + textBox->len()) {
        LayoutRect rect = textBox->localSelectionRect(caretOffset, caretOffset + 1);
        LayoutUnit x = box->isLeftToRightDirection() ? rect.x() : rect.maxX();
        return LayoutRect(x, rect.y(), caretWidth, rect.height());
    }

    LayoutRect rect = textBox->localSelectionRect(caretOffset - 1, caretOffset);
    LayoutUnit x = box->isLeftToRightDirection() ? rect.maxX() : rect.x();
    return LayoutRect(x, rect.y(), caretWidth, rect.height());
}

static IntRect ellipsisRectForBox(const InlineTextBox& box, unsigned start, unsigned end)
{
    unsigned truncation = box.truncation();
    if (truncation == cNoTruncation)
        return IntRect();

    auto ellipsis = box.root().ellipsisBox();
    if (!ellipsis)
        return IntRect();
    
    IntRect rect;
    unsigned ellipsisStartPosition = start > box.start() ? start - box.start() : 0;
    ASSERT(end >= box.start());
    unsigned ellipsisEndPosition = std::min(end - box.start(), box.len());
    
    // The ellipsis should be considered to be selected if the end of
    // the selection is past the beginning of the truncation and the
    // beginning of the selection is before or at the beginning of the truncation.
    if (ellipsisEndPosition < truncation && ellipsisStartPosition > truncation)
        return IntRect();
    return ellipsis->selectionRect();
}

static void writeTextRun(TextStream& ts, const RenderText& o, const InlineTextBox& run)
{
    // FIXME: Table cell adjustment is temporary until results can be updated.
    int y = run.m_y;
    if (o.containingBlock()->isTableCell())
        y -= toRenderTableCell(o.containingBlock())->intrinsicPaddingTop();
    ts << "text run at (" << run.m_x << "," << y << ") width " << run.m_width;
    if (run.direction() == RTL || run.m_dirOverride) {
        ts << (run.direction() == RTL ? " RTL" : " LTR");
        if (run.m_dirOverride)
            ts << " override";
    }
    ts << ": "
        << quoteAndEscapeNonPrintables(String(o.text()).substring(run.start(), run.len()))
        << "\n";
}

static VisiblePosition endPositionForLine(const VisiblePosition& c)
{
    if (c.isNull())
        return VisiblePosition();

    RootInlineBox *rootBox = rootBoxForLine(c);
    if (!rootBox) {
        // There are VisiblePositions at offset 0 in blocks without
        // RootInlineBoxes, like empty editable blocks and bordered blocks.
        Position p = c.deepEquivalent();
        if (p.node()->renderer() && p.node()->renderer()->isRenderBlock() && p.deprecatedEditingOffset() == 0)
            return c;
        return VisiblePosition();
    }
    
    // Generated content (e.g. list markers and CSS :before and :after
    // pseudoelements) have no corresponding DOM element, and so cannot be
    // represented by a VisiblePosition.  Use whatever precedes instead.
    Node *endNode;
    InlineBox *endBox = rootBox->lastLeafChild();
    while (1) {
        if (!endBox)
            return VisiblePosition();

        RenderObject *endRenderer = endBox->renderer();
        if (!endRenderer)
            return VisiblePosition();

        endNode = endRenderer->node();
        if (endNode)
            break;
        
        endBox = endBox->prevLeafChild();
    }
    
    int endOffset = 1;
    if (endNode->hasTagName(brTag)) {
        endOffset = 0;
    } else if (endBox->isInlineTextBox()) {
        InlineTextBox *endTextBox = static_cast<InlineTextBox *>(endBox);
        endOffset = endTextBox->start();
        if (!endTextBox->isLineBreak())
            endOffset += endTextBox->len();
    }
    
    return VisiblePosition(endNode, endOffset, VP_UPSTREAM_IF_POSSIBLE);
}

static VisiblePosition startPositionForLine(const VisiblePosition& c)
{
    if (c.isNull())
        return VisiblePosition();

    RootInlineBox *rootBox = rootBoxForLine(c);
    if (!rootBox) {
        // There are VisiblePositions at offset 0 in blocks without
        // RootInlineBoxes, like empty editable blocks and bordered blocks.
        Position p = c.deepEquivalent();
        if (p.node()->renderer() && p.node()->renderer()->isRenderBlock() && p.deprecatedEditingOffset() == 0)
            return positionAvoidingFirstPositionInTable(c);
        
        return VisiblePosition();
    }
    
    // Generated content (e.g. list markers and CSS :before and :after
    // pseudoelements) have no corresponding DOM element, and so cannot be
    // represented by a VisiblePosition.  Use whatever follows instead.
    InlineBox *startBox = rootBox->firstLeafChild();
    Node *startNode;
    while (1) {
        if (!startBox)
            return VisiblePosition();

        RenderObject *startRenderer = startBox->renderer();
        if (!startRenderer)
            return VisiblePosition();

        startNode = startRenderer->node();
        if (startNode)
            break;
        
        startBox = startBox->nextLeafChild();
    }
    
    int startOffset = 0;
    if (startBox->isInlineTextBox()) {
        InlineTextBox *startTextBox = static_cast<InlineTextBox *>(startBox);
        startOffset = startTextBox->start();
    }
  
    VisiblePosition visPos = VisiblePosition(startNode, startOffset, DOWNSTREAM);
    return positionAvoidingFirstPositionInTable(visPos);
}

static void writeTextRun(TextStream& ts, const RenderText& o, const InlineTextBox& run)
{
    // FIXME: For now use an "enclosingIntRect" model for x, y and logicalWidth, although this makes it harder
    // to detect any changes caused by the conversion to floating point. :(
    int x = run.x();
    int y = run.y();
    int logicalWidth = ceilf(run.left() + run.logicalWidth()) - x;

    ts << "text run at (" << x << "," << y << ") width " << logicalWidth;
    if (!run.isLeftToRightDirection() || run.dirOverride()) {
        ts << (!run.isLeftToRightDirection() ? " RTL" : " LTR");
        if (run.dirOverride())
            ts << " override";
    }
    ts << ": "
        << quoteAndEscapeNonPrintables(String(o.text()).substring(run.start(), run.len()));
    if (run.hasHyphen())
        ts << " + hyphen string " << quoteAndEscapeNonPrintables(o.style()->hyphenString());
    ts << "\n";
}

static void writeTextRun(TextStream& ts, const RenderText& o, const InlineTextBox& run)
{
    // FIXME: For now use an "enclosingIntRect" model for x, y and logicalWidth, although this makes it harder
    // to detect any changes caused by the conversion to floating point. :(
    int x = run.m_x;
    int y = run.m_y;
    int logicalWidth = ceilf(run.m_x + run.m_logicalWidth) - x;

    // FIXME: Table cell adjustment is temporary until results can be updated.
    if (o.containingBlock()->isTableCell())
        y -= toRenderTableCell(o.containingBlock())->intrinsicPaddingBefore();
        
    ts << "text run at (" << x << "," << y << ") width " << logicalWidth;
    if (!run.isLeftToRightDirection() || run.m_dirOverride) {
        ts << (!run.isLeftToRightDirection() ? " RTL" : " LTR");
        if (run.m_dirOverride)
            ts << " override";
    }
    ts << ": "
        << quoteAndEscapeNonPrintables(String(o.text()).substring(run.start(), run.len()));
    if (run.hasHyphen())
        ts << " + hyphen string " << quoteAndEscapeNonPrintables(o.style()->hyphenString());
    ts << "\n";
}

// P.downstream() returns the end of the range of positions that map to the same VisiblePosition as P.
Position Position::downstream() const
{
    Node* startNode = node();
    if (!startNode)
        return Position();

    // iterate forward from there, looking for a qualified position
    Node* block = enclosingBlock(startNode);
    PositionIterator lastVisible = *this;
    PositionIterator currentPos = lastVisible;
    Node* originalRoot = node()->rootEditableElement();
    for (; !currentPos.atEnd(); currentPos.increment()) {   
        Node* currentNode = currentPos.node();
        
        if (currentNode->rootEditableElement() != originalRoot)
            break;

        // stop before going above the body, up into the head
        // return the last visible streamer position
        if (currentNode->hasTagName(bodyTag) && currentPos.atEndOfNode())
            break;
            
        // Do not enter a new enclosing block flow or table element, and don't leave the original one.
        if (block != enclosingBlock(currentNode))
            return lastVisible;

        // skip position in unrendered or invisible node
        RenderObject* renderer = currentNode->renderer();
        if (!renderer || renderer->style()->visibility() != VISIBLE)
            continue;
            
        // track last visible streamer position
        if (isStreamer(currentPos))
            lastVisible = currentPos;

        // Return position before brs, tables, and nodes which have content that can be ignored.
        if (editingIgnoresContent(currentNode) || renderer->isBR() || isTableElement(currentNode)) {
            if (currentPos.offsetInLeafNode() <= renderer->caretMinOffset())
                return Position(currentNode, renderer->caretMinOffset());
            continue;
        }

        // return current position if it is in rendered text
        if (renderer->isText() && static_cast<RenderText*>(renderer)->firstTextBox()) {
            if (currentNode != startNode) {
                ASSERT(currentPos.atStartOfNode());
                return Position(currentNode, renderer->caretMinOffset());
            }

            unsigned textOffset = currentPos.offsetInLeafNode();

            RenderText* textRenderer = static_cast<RenderText*>(renderer);
            for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                if (textOffset >= box->start() && textOffset <= box->end())
                    return currentPos;
                
                if (box != textRenderer->lastTextBox() && 
                     !box->nextOnLine() &&
                     textOffset == box->start() + box->len()) {
                    return currentPos;
                }
            }
        }
    }
    
    return lastVisible;
}

static VisiblePosition createVisiblePositionAfterAdjustingOffsetForBiDi(const InlineTextBox& box, int offset, ShouldAffinityBeDownstream shouldAffinityBeDownstream)
{
    ASSERT(offset >= 0);

    if (offset && static_cast<unsigned>(offset) < box.len())
        return createVisiblePositionForBox(box, box.start() + offset, shouldAffinityBeDownstream);

    bool positionIsAtStartOfBox = !offset;
    if (positionIsAtStartOfBox == box.isLeftToRightDirection()) {
        // offset is on the left edge

        const InlineBox* prevBox = box.prevLeafChildIgnoringLineBreak();
        if ((prevBox && prevBox->bidiLevel() == box.bidiLevel())
            || box.renderer().containingBlock()->style().direction() == box.direction()) // FIXME: left on 12CBA
            return createVisiblePositionForBox(box, box.caretLeftmostOffset(), shouldAffinityBeDownstream);

        if (prevBox && prevBox->bidiLevel() > box.bidiLevel()) {
            // e.g. left of B in aDC12BAb
            const InlineBox* leftmostBox;
            do {
                leftmostBox = prevBox;
                prevBox = leftmostBox->prevLeafChildIgnoringLineBreak();
            } while (prevBox && prevBox->bidiLevel() > box.bidiLevel());
            return createVisiblePositionForBox(*leftmostBox, leftmostBox->caretRightmostOffset(), shouldAffinityBeDownstream);
        }

        if (!prevBox || prevBox->bidiLevel() < box.bidiLevel()) {
            // e.g. left of D in aDC12BAb
            const InlineBox* rightmostBox;
            const InlineBox* nextBox = &box;
            do {
                rightmostBox = nextBox;
                nextBox = rightmostBox->nextLeafChildIgnoringLineBreak();
            } while (nextBox && nextBox->bidiLevel() >= box.bidiLevel());
            return createVisiblePositionForBox(*rightmostBox,
                box.isLeftToRightDirection() ? rightmostBox->caretMaxOffset() : rightmostBox->caretMinOffset(), shouldAffinityBeDownstream);
        }

        return createVisiblePositionForBox(box, box.caretRightmostOffset(), shouldAffinityBeDownstream);
    }

    const InlineBox* nextBox = box.nextLeafChildIgnoringLineBreak();
    if ((nextBox && nextBox->bidiLevel() == box.bidiLevel())
        || box.renderer().containingBlock()->style().direction() == box.direction())
        return createVisiblePositionForBox(box, box.caretRightmostOffset(), shouldAffinityBeDownstream);

    // offset is on the right edge
    if (nextBox && nextBox->bidiLevel() > box.bidiLevel()) {
        // e.g. right of C in aDC12BAb
        const InlineBox* rightmostBox;
        do {
            rightmostBox = nextBox;
            nextBox = rightmostBox->nextLeafChildIgnoringLineBreak();
        } while (nextBox && nextBox->bidiLevel() > box.bidiLevel());
        return createVisiblePositionForBox(*rightmostBox, rightmostBox->caretLeftmostOffset(), shouldAffinityBeDownstream);
    }

    if (!nextBox || nextBox->bidiLevel() < box.bidiLevel()) {
        // e.g. right of A in aDC12BAb
        const InlineBox* leftmostBox;
        const InlineBox* prevBox = &box;
        do {
            leftmostBox = prevBox;
            prevBox = leftmostBox->prevLeafChildIgnoringLineBreak();
        } while (prevBox && prevBox->bidiLevel() >= box.bidiLevel());
        return createVisiblePositionForBox(*leftmostBox,
            box.isLeftToRightDirection() ? leftmostBox->caretMinOffset() : leftmostBox->caretMaxOffset(), shouldAffinityBeDownstream);
    }

    return createVisiblePositionForBox(box, box.caretLeftmostOffset(), shouldAffinityBeDownstream);
}

VisiblePosition RenderTextLineBoxes::positionForPoint(const RenderText& renderer, const LayoutPoint& point) const
{
    if (!m_first || !renderer.textLength())
        return renderer.createVisiblePosition(0, DOWNSTREAM);

    LayoutUnit pointLineDirection = m_first->isHorizontal() ? point.x() : point.y();
    LayoutUnit pointBlockDirection = m_first->isHorizontal() ? point.y() : point.x();
    bool blocksAreFlipped = renderer.style().isFlippedBlocksWritingMode();

    InlineTextBox* lastBox = nullptr;
    for (auto box = m_first; box; box = box->nextTextBox()) {
        if (box->isLineBreak() && !box->prevLeafChild() && box->nextLeafChild() && !box->nextLeafChild()->isLineBreak())
            box = box->nextTextBox();

        auto& rootBox = box->root();
        LayoutUnit top = std::min(rootBox.selectionTop(), rootBox.lineTop());
        if (pointBlockDirection > top || (!blocksAreFlipped && pointBlockDirection == top)) {
            LayoutUnit bottom = rootBox.selectionBottom();
            if (rootBox.nextRootBox())
                bottom = std::min(bottom, rootBox.nextRootBox()->lineTop());

            if (pointBlockDirection < bottom || (blocksAreFlipped && pointBlockDirection == bottom)) {
                ShouldAffinityBeDownstream shouldAffinityBeDownstream;
#if PLATFORM(IOS)
                if (pointLineDirection != box->logicalLeft() && point.x() < box->x() + box->logicalWidth()) {
                    int half = box->x() + box->logicalWidth() / 2;
                    EAffinity affinity = point.x() < half ? DOWNSTREAM : VP_UPSTREAM_IF_POSSIBLE;
                    return renderer.createVisiblePosition(box->offsetForPosition(pointLineDirection) + box->start(), affinity);
                }
#endif
                if (lineDirectionPointFitsInBox(pointLineDirection, *box, shouldAffinityBeDownstream))
                    return createVisiblePositionAfterAdjustingOffsetForBiDi(*box, box->offsetForPosition(pointLineDirection), shouldAffinityBeDownstream);
            }
        }
        lastBox = box;
    }

    if (lastBox) {
        ShouldAffinityBeDownstream shouldAffinityBeDownstream;
        lineDirectionPointFitsInBox(pointLineDirection, *lastBox, shouldAffinityBeDownstream);
        return createVisiblePositionAfterAdjustingOffsetForBiDi(*lastBox, lastBox->offsetForPosition(pointLineDirection) + lastBox->start(), shouldAffinityBeDownstream);
    }
    return renderer.createVisiblePosition(0, DOWNSTREAM);
}

void RenderNamedFlowThread::getRanges(Vector<RefPtr<Range> >& rangeObjects, const RenderRegion* region) const
{
    LayoutUnit logicalTopForRegion;
    LayoutUnit logicalBottomForRegion;

    // extend the first region top to contain everything up to its logical height
    if (region->isFirstRegion())
        logicalTopForRegion = LayoutUnit::min();
    else
        logicalTopForRegion =  region->logicalTopForFlowThreadContent();

    // extend the last region to contain everything above its y()
    if (region->isLastRegion())
        logicalBottomForRegion = LayoutUnit::max();
    else
        logicalBottomForRegion = region->logicalBottomForFlowThreadContent();

    Vector<Node*> nodes;
    // eliminate the contentNodes that are descendants of other contentNodes
    for (NamedFlowContentNodes::const_iterator it = contentNodes().begin(); it != contentNodes().end(); ++it) {
        Node* node = *it;
        if (!isContainedInNodes(nodes, node))
            nodes.append(node);
    }

    for (size_t i = 0; i < nodes.size(); i++) {
        Node* contentNode = nodes.at(i);
        if (!contentNode->renderer())
            continue;

        RefPtr<Range> range = Range::create(contentNode->document());
        bool foundStartPosition = false;
        bool startsAboveRegion = true;
        bool endsBelowRegion = true;
        bool skipOverOutsideNodes = false;
        Node* lastEndNode = 0;

        for (Node* node = contentNode; node; node = nextNodeInsideContentNode(node, contentNode)) {
            RenderObject* renderer = node->renderer();
            if (!renderer)
                continue;

            LayoutRect boundingBox;
            if (renderer->isRenderInline())
                boundingBox = toRenderInline(renderer)->linesBoundingBox();
            else if (renderer->isText())
                boundingBox = toRenderText(renderer)->linesBoundingBox();
            else {
                boundingBox =  toRenderBox(renderer)->frameRect();
                if (toRenderBox(renderer)->isRelPositioned())
                    boundingBox.move(toRenderBox(renderer)->relativePositionLogicalOffset());
            }

            LayoutUnit offsetTop = renderer->containingBlock()->offsetFromLogicalTopOfFirstPage();
            const LayoutPoint logicalOffsetFromTop(isHorizontalWritingMode() ? LayoutUnit() :  offsetTop,
                isHorizontalWritingMode() ? offsetTop : LayoutUnit());

            boundingBox.moveBy(logicalOffsetFromTop);

            LayoutUnit logicalTopForRenderer = region->logicalTopOfFlowThreadContentRect(boundingBox);
            LayoutUnit logicalBottomForRenderer = region->logicalBottomOfFlowThreadContentRect(boundingBox);

            // if the bounding box of the current element doesn't intersect the region box
            // close the current range only if the start element began inside the region,
            // otherwise just move the start position after this node and keep skipping them until we found a proper start position.
            if (!boxIntersectsRegion(logicalTopForRenderer, logicalBottomForRenderer, logicalTopForRegion, logicalBottomForRegion)) {
                if (foundStartPosition) {
                    if (!startsAboveRegion) {
                        if (range->intersectsNode(node, IGNORE_EXCEPTION))
                            range->setEndBefore(node, IGNORE_EXCEPTION);
                        rangeObjects.append(range->cloneRange(IGNORE_EXCEPTION));
                        range = Range::create(contentNode->document());
                        startsAboveRegion = true;
                    } else
                        skipOverOutsideNodes = true;
                }
                if (skipOverOutsideNodes)
                    range->setStartAfter(node, IGNORE_EXCEPTION);
                foundStartPosition = false;
                continue;
            }

            // start position
            if (logicalTopForRenderer < logicalTopForRegion && startsAboveRegion) {
                if (renderer->isText()) { // Text crosses region top
                    // for Text elements, just find the last textbox that is contained inside the region and use its start() offset as start position
                    RenderText* textRenderer = toRenderText(renderer);
                    for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                        if (offsetTop + box->logicalBottom() < logicalTopForRegion)
                            continue;
                        range->setStart(Position(toText(node), box->start()));
                        startsAboveRegion = false;
                        break;
                    }
                } else { // node crosses region top
                    // for all elements, except Text, just set the start position to be before their children
                    startsAboveRegion = true;
                    range->setStart(Position(node, Position::PositionIsBeforeChildren));
                }
            } else { // node starts inside region
//.........这里部分代码省略.........

static int placePositionedBoxesHorizontally(InlineFlowBox* flow, int x, int& leftPosition, int& rightPosition, int& leftAlign, int& rightAlign, bool& needsWordSpacing, int xPos, bool positioned)
{
    int mn = INT_MAX;
    int mx = INT_MIN;
    int amn = INT_MAX;
    int amx = INT_MIN;
    int startx = x;
    bool seenPositionedElement = false;
    flow->setXPos(x);
    for (InlineBox* curr = flow->firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->object()->isText()) {
            mn = min(mn, x);
            amn = min(amn, x);
            InlineTextBox* text = static_cast<InlineTextBox*>(curr);
            RenderText* rt = static_cast<RenderText*>(text->object());
            if (rt->textLength()) {
                if (needsWordSpacing && DeprecatedChar(rt->characters()[text->start()]).isSpace())
                    x += rt->style(flow->isFirstLineStyle())->font().wordSpacing();
                needsWordSpacing = !DeprecatedChar(rt->characters()[text->end()]).isSpace();
            }
            text->setXPos(x);
            x += text->width();
            mx = max(mx, x);
            amx = max(amx, x);
        } else if (curr->object()->isInlineFlow()) {
            InlineFlowBox* flow = static_cast<InlineFlowBox*>(curr);
            if (flow->object()->element()->hasTagName(aTag)) {
                x = placePositionedBoxesHorizontally(flow, x, mn, mx, amn, amx, needsWordSpacing, xPos, false);
            } else {
                SVGTextPositioningElement* text = static_cast<SVGTextPositioningElement*>(flow->object()->element());
                x += (int)(text->dx()->getFirst().value());
                if (text->x()->numberOfItems() > 0)
                    x = (int)(text->x()->getFirst().value() - xPos);
                if (text->x()->numberOfItems() > 0 || text->y()->numberOfItems() > 0 ||
                    text->dx()->numberOfItems() > 0 || text->dy()->numberOfItems() > 0) {
                    seenPositionedElement = true;
                    needsWordSpacing = false;
                    int ignoreX, ignoreY;
                    x = placePositionedBoxesHorizontally(flow, x, mn, mx, ignoreX, ignoreY, needsWordSpacing, xPos, true);
                } else if (seenPositionedElement) {
                    int ignoreX, ignoreY;
                    x = placePositionedBoxesHorizontally(flow, x, mn, mx, ignoreX, ignoreY, needsWordSpacing, xPos, false);
                } else
                    x = placePositionedBoxesHorizontally(flow, x, mn, mx, amn, amx, needsWordSpacing, xPos, false);
            }
        }
    }

    if (mn > mx)
        mn = mx = startx;
    if (amn > amx)
        amn = amx = startx;

    int width = mx - mn;
    flow->setWidth(width);

    int awidth = amx - amn;
    int dx = 0;
    if (positioned) {
        switch (flow->object()->style()->svgStyle()->textAnchor()) {
            case TA_MIDDLE:
                translateBox(flow, dx = -awidth / 2, 0, true);
                break;
            case TA_END:
                translateBox(flow, dx = -awidth, 0, true);
                break;
            case TA_START:
            default:
                break;
        }

        if (dx) {
            x += dx;
            mn += dx;
            mx += dx;
        }
    }

    leftPosition = min(leftPosition, mn);
    rightPosition = max(rightPosition, mx);
    leftAlign = min(leftAlign, amn);
    rightAlign = max(rightAlign, amx);

    return x;
}

Position Position::downstream(EStayInBlock stayInBlock) const
{
    Position start = equivalentDeepPosition();
    NodeImpl *startNode = start.node();
    if (!startNode)
        return Position();

    NodeImpl *block = startNode->enclosingBlockFlowOrTableElement();
    Position lastVisible;
    
    PositionIterator it(start);            
    for (; !it.atEnd(); it.next()) {   
        NodeImpl *currentNode = it.current().node();

        if (stayInBlock) {
            NodeImpl *currentBlock = currentNode->enclosingBlockFlowOrTableElement();
            if (block != currentBlock)
                return it.previous();
        }

        RenderObject *renderer = currentNode->renderer();
        if (!renderer)
            continue;

        if (renderer->style()->visibility() != VISIBLE)
            continue;

        lastVisible = it.current();

        if (currentNode != startNode && renderer->isBlockFlow()) {
            if (it.current().offset() == 0) {
                // If no first child, or first visible child is a not a block, return; otherwise continue.
                if (!currentNode->firstChild())
                    return Position(currentNode, 0);
                for (NodeImpl *child = currentNode->firstChild(); child; child = child->nextSibling()) {
                    RenderObject *r = child->renderer();
                    if (r && r->style()->visibility() == VISIBLE) {
                         if (r->isBlockFlow())
                            break; // break causes continue code below to run.
                         else
                            return Position(child, 0);
                    }
                }
                continue;
            }
        }

        if (renderer->isReplaced() || renderer->isBR()) {
            if (it.current().offset() <= renderer->caretMinOffset())
                return Position(currentNode, renderer->caretMinOffset());
            else
                continue;
        }

        if (renderer->isText() && static_cast<RenderText *>(renderer)->firstTextBox()) {
            if (currentNode != start.node())
                return Position(currentNode, renderer->caretMinOffset());

            if (it.current().offset() < 0)
                continue;
            uint textOffset = it.current().offset();

            RenderText *textRenderer = static_cast<RenderText *>(renderer);
            for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                if (textOffset >= box->start() && textOffset <= box->end())
                    return it.current();
                else if (box != textRenderer->lastTextBox() && 
                         !box->nextOnLine() && 
                         textOffset == box->start() + box->len())
                    return it.current();
            }
        }
    }
    
    return lastVisible.isNotNull() ? lastVisible : *this;
}