C++ InlineTextBox::len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);
}

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);
}

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 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 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: 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";
}

void SVGTextChunkLayoutInfo::recursiveBuildTextChunks(InlineFlowBox* start)
{
#if DEBUG_CHUNK_BUILDING > 1
    fprintf(stderr, " -> buildTextChunks(start=%p)\n", start);
#endif

    for (InlineBox* curr = start->firstChild(); curr; curr = curr->nextOnLine()) {
        if (curr->renderer()->isText()) {
            InlineTextBox* textBox = static_cast<InlineTextBox*>(curr);

            unsigned length = textBox->len();
            ASSERT(length > 0);

#if DEBUG_CHUNK_BUILDING > 1
            fprintf(stderr, " -> Handle inline text box (%p) with %i characters (start: %i, end: %i), handlingTextPath=%i\n",
                            textBox, length, textBox->start(), textBox->end(), (int) m_handlingTextPath);
#endif

            RenderText* text = textBox->textRenderer();
            ASSERT(text);
            ASSERT(text->node());

            SVGTextContentElement* textContent = 0;
            Node* node = text->node()->parent();
            while (node && node->isSVGElement() && !textContent) {
                if (static_cast<SVGElement*>(node)->isTextContent())
                    textContent = static_cast<SVGTextContentElement*>(node);
                else
                    node = node->parentNode();
            }
            ASSERT(textContent);

            // Start new character range for the first chunk
            bool isFirstCharacter = m_svgTextChunks.isEmpty() && m_chunk.start == m_charsIt && m_chunk.start == m_chunk.end;
            if (isFirstCharacter) {
                ASSERT(m_chunk.boxes.isEmpty());
                m_chunk.boxes.append(SVGInlineBoxCharacterRange());
            } else
                ASSERT(!m_chunk.boxes.isEmpty());

            // Walk string to find out new chunk positions, if existent
            for (unsigned i = 0; i < length; ++i) {
                ASSERT(m_charsIt != m_charsEnd);

                SVGInlineBoxCharacterRange& range = m_chunk.boxes.last();
                if (range.isOpen()) {
                    range.box = curr;
                    range.startOffset = !i ? 0 : i - 1;

#if DEBUG_CHUNK_BUILDING > 1
                    fprintf(stderr, " | -> Range is open! box=%p, startOffset=%i\n", range.box, range.startOffset);
#endif
                }

                // If a new (or the first) chunk has been started, record it's text-anchor and writing mode.
                if (m_assignChunkProperties) {
                    m_assignChunkProperties = false;

                    m_chunk.isVerticalText = isVerticalWritingMode(text->style()->svgStyle());
                    m_chunk.isTextPath = m_handlingTextPath;
                    m_chunk.anchor = text->style()->svgStyle()->textAnchor();
                    m_chunk.textLength = textContent->textLength().value(textContent);
                    m_chunk.lengthAdjust = (ELengthAdjust) textContent->lengthAdjust();

#if DEBUG_CHUNK_BUILDING > 1
                    fprintf(stderr, " | -> Assign chunk properties, isVerticalText=%i, anchor=%i\n", m_chunk.isVerticalText, m_chunk.anchor);
#endif
                }

                if (i > 0 && !isFirstCharacter && m_charsIt->newTextChunk) {
                    // Close mid chunk & character range
                    ASSERT(!range.isOpen());
                    ASSERT(!range.isClosed());

                    range.endOffset = i;
                    closeTextChunk();

#if DEBUG_CHUNK_BUILDING > 1
                    fprintf(stderr, " | -> Close mid-text chunk, at endOffset: %i and starting new mid chunk!\n", range.endOffset);
#endif
    
                    // Prepare for next chunk, if we're not at the end
                    startTextChunk();
                    if (i + 1 == length) {
#if DEBUG_CHUNK_BUILDING > 1
                        fprintf(stderr, " | -> Record last chunk of inline text box!\n");
#endif

                        startTextChunk();
                        SVGInlineBoxCharacterRange& range = m_chunk.boxes.last();

                        m_assignChunkProperties = false;
                        m_chunk.isVerticalText = isVerticalWritingMode(text->style()->svgStyle());
                        m_chunk.isTextPath = m_handlingTextPath;
                        m_chunk.anchor = text->style()->svgStyle()->textAnchor();
                        m_chunk.textLength = textContent->textLength().value(textContent);
                        m_chunk.lengthAdjust = (ELengthAdjust) textContent->lengthAdjust();

                        range.box = curr;
                        range.startOffset = i;
//.........这里部分代码省略.........

//.........这里部分代码省略.........
                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
                // for elements that start inside the region, set the start position to be before them. If we found one, we will just skip the others until
                // the range is closed.
                if (startsAboveRegion) {
                    startsAboveRegion = false;
                    range->setStartBefore(node, IGNORE_EXCEPTION);
                }
            }
            skipOverOutsideNodes  = false;
            foundStartPosition = true;

            // end position
            if (logicalBottomForRegion < logicalBottomForRenderer && (endsBelowRegion || (!endsBelowRegion && !node->isDescendantOf(lastEndNode)))) {
                // for Text elements, just find just find the last textbox that is contained inside the region and use its start()+len() offset as end position
                if (renderer->isText()) { // Text crosses region bottom
                    RenderText* textRenderer = toRenderText(renderer);
                    InlineTextBox* lastBox = 0;
                    for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                        if ((offsetTop + box->logicalTop()) < logicalBottomForRegion) {
                            lastBox = box;
                            continue;
                        }
                        ASSERT(lastBox);
                        if (lastBox)
                            range->setEnd(Position(toText(node), lastBox->start() + lastBox->len()));
                        break;
                    }
                    endsBelowRegion = false;
                    lastEndNode = node;
                } else { // node crosses region bottom
                    // for all elements, except Text, just set the start position to be after their children
                    range->setEnd(Position(node, Position::PositionIsAfterChildren));
                    endsBelowRegion = true;
                    lastEndNode = node;
                }
            } else { // node ends inside region
                // for elements that ends inside the region, set the end position to be after them
                // allow this end position to be changed only by other elements that are not descendants of the current end node
                if (endsBelowRegion || (!endsBelowRegion && !node->isDescendantOf(lastEndNode))) {
                    range->setEndAfter(node, IGNORE_EXCEPTION);
                    endsBelowRegion = false;
                    lastEndNode = node;
                }
            }
        }
        if (foundStartPosition || skipOverOutsideNodes)
            rangeObjects.append(range);
    }
}

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;
}

// 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;
}

// p.upstream() returns the start of the range of positions that map to the same VisiblePosition as P.
Position Position::upstream() const
{
    Node* startNode = node();
    if (!startNode)
        return Position();
    
    // iterate backward from there, looking for a qualified position
    Node* block = enclosingBlock(startNode);
    PositionIterator lastVisible = *this;
    PositionIterator currentPos = lastVisible;
    Node* originalRoot = node()->rootEditableElement();
    for (; !currentPos.atStart(); currentPos.decrement()) {
        Node* currentNode = currentPos.node();
        
        if (currentNode->rootEditableElement() != originalRoot)
            break;

        // Don't enter a new enclosing block flow or table element.  There is code below that
        // terminates early if we're about to leave an enclosing block flow or table element.
        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;
        
        // Don't leave a block flow or table element.  We could rely on code above to terminate and 
        // return lastVisible on the next iteration, but we terminate early.
        if (currentNode == enclosingBlock(currentNode) && currentPos.atStartOfNode())
            return lastVisible;
            
        // Return position after brs, tables, and nodes which have content that can be ignored.
        if (editingIgnoresContent(currentNode) || renderer->isBR() || isTableElement(currentNode)) {
            if (currentPos.atEndOfNode())
                return Position(currentNode, maxDeepOffset(currentNode));
            continue;
        }

        // return current position if it is in rendered text
        if (renderer->isText() && static_cast<RenderText*>(renderer)->firstTextBox()) {
            if (currentNode != startNode) {
                // This assertion fires in layout tests in the case-transform.html test because
                // of a mix-up between offsets in the text in the DOM tree with text in the
                // render tree which can have a different length due to case transformation.
                // Until we resolve that, disable this so we can run the layout tests!
                //ASSERT(currentOffset >= renderer->caretMaxOffset());
                return Position(currentNode, renderer->caretMaxOffset());
            }

            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->start() + box->len())
                    return currentPos;
                    
                if (box != textRenderer->lastTextBox() && 
                    !box->nextOnLine() && 
                    textOffset == box->start() + box->len() + 1)
                    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);
}