Source/core/dom/Position.cpp

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This source file includes following definitions.
nextRenderedEditable
previousRenderedEditable
m_isLegacyEditingPosition
m_isLegacyEditingPosition
m_isLegacyEditingPosition
m_isLegacyEditingPosition
moveToPosition
moveToOffset
containerNode
containerText
computeOffsetInContainerNode
offsetForPositionAfterAnchor
parentAnchoredEquivalent
computeNodeBeforePosition
computeNodeAfterPosition
anchorTypeForLegacyEditingPosition
element
computedStyle
previous
next
uncheckedPreviousOffset
uncheckedPreviousOffsetForBackwardDeletion
uncheckedNextOffset
atFirstEditingPositionForNode
atLastEditingPositionForNode
atEditingBoundary
parentEditingBoundary
atStartOfTree
atEndOfTree
renderedOffset
previousCharacterPosition
nextCharacterPosition
endsOfNodeAreVisuallyDistinctPositions
enclosingVisualBoundary
isStreamer
upstream
downstream
boundingBoxLogicalHeight
hasRenderedNonAnonymousDescendantsWithHeight
nodeIsUserSelectNone
nodeIsUserSelectAll
rootUserSelectAllForNode
isCandidate
inRenderedText
isRenderedCharacter
rendersInDifferentPosition
leadingWhitespacePosition
trailingWhitespacePosition
getInlineBoxAndOffset
isNonTextLeafChild
searchAheadForBetterMatch
downstreamIgnoringEditingBoundaries
upstreamIgnoringEditingBoundaries
getInlineBoxAndOffset
primaryDirection
debugPosition
formatForDebugger
showAnchorTypeAndOffset
showTreeForThis
showTree
showTree
/*
 * Copyright (C) 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "core/dom/Position.h"

#include <stdio.h>
#include "HTMLNames.h"
#include "core/css/CSSComputedStyleDeclaration.h"
#include "core/dom/PositionIterator.h"
#include "core/dom/Text.h"
#include "core/editing/TextIterator.h"
#include "core/editing/VisiblePosition.h"
#include "core/editing/VisibleUnits.h"
#include "core/editing/htmlediting.h"
#include "core/frame/LocalFrame.h"
#include "core/frame/Settings.h"
#include "core/html/HTMLTableElement.h"
#include "core/rendering/InlineIterator.h"
#include "core/rendering/InlineTextBox.h"
#include "core/rendering/RenderBlock.h"
#include "core/rendering/RenderInline.h"
#include "core/rendering/RenderText.h"
#include "platform/Logging.h"
#include "wtf/text/CString.h"
#include "wtf/unicode/CharacterNames.h"

namespace WebCore {

using namespace HTMLNames;

static Node* nextRenderedEditable(Node* node)
{
    while ((node = node->nextLeafNode())) {
        RenderObject* renderer = node->renderer();
        if (!renderer)
            continue;
        if (!node->rendererIsEditable())
            continue;
        if ((renderer->isBox() && toRenderBox(renderer)->inlineBoxWrapper()) || (renderer->isText() && toRenderText(renderer)->firstTextBox()))
            return node;
    }
    return 0;
}

static Node* previousRenderedEditable(Node* node)
{
    while ((node = node->previousLeafNode())) {
        RenderObject* renderer = node->renderer();
        if (!renderer)
            continue;
        if (!node->rendererIsEditable())
            continue;
        if ((renderer->isBox() && toRenderBox(renderer)->inlineBoxWrapper()) || (renderer->isText() && toRenderText(renderer)->firstTextBox()))
            return node;
    }
    return 0;
}

Position::Position(PassRefPtr<Node> anchorNode, LegacyEditingOffset offset)
    : m_anchorNode(anchorNode)
    , m_offset(offset.value())
    , m_anchorType(anchorTypeForLegacyEditingPosition(m_anchorNode.get(), m_offset))
    , m_isLegacyEditingPosition(true)
{
    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement());
}

Position::Position(PassRefPtr<Node> anchorNode, AnchorType anchorType)
    : m_anchorNode(anchorNode)
    , m_offset(0)
    , m_anchorType(anchorType)
    , m_isLegacyEditingPosition(false)
{
    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement());

    ASSERT(anchorType != PositionIsOffsetInAnchor);
    ASSERT(!((anchorType == PositionIsBeforeChildren || anchorType == PositionIsAfterChildren)
        && (m_anchorNode->isTextNode() || editingIgnoresContent(m_anchorNode.get()))));
}

Position::Position(PassRefPtr<Node> anchorNode, int offset, AnchorType anchorType)
    : m_anchorNode(anchorNode)
    , m_offset(offset)
    , m_anchorType(anchorType)
    , m_isLegacyEditingPosition(false)
{
    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement());

    ASSERT(anchorType == PositionIsOffsetInAnchor);
}

Position::Position(PassRefPtr<Text> textNode, unsigned offset)
    : m_anchorNode(textNode)
    , m_offset(static_cast<int>(offset))
    , m_anchorType(PositionIsOffsetInAnchor)
    , m_isLegacyEditingPosition(false)
{
    ASSERT(m_anchorNode);
}

void Position::moveToPosition(PassRefPtr<Node> node, int offset)
{
    ASSERT(!editingIgnoresContent(node.get()));
    ASSERT(anchorType() == PositionIsOffsetInAnchor || m_isLegacyEditingPosition);
    m_anchorNode = node;
    m_offset = offset;
    if (m_isLegacyEditingPosition)
        m_anchorType = anchorTypeForLegacyEditingPosition(m_anchorNode.get(), m_offset);
}
void Position::moveToOffset(int offset)
{
    ASSERT(anchorType() == PositionIsOffsetInAnchor || m_isLegacyEditingPosition);
    m_offset = offset;
    if (m_isLegacyEditingPosition)
        m_anchorType = anchorTypeForLegacyEditingPosition(m_anchorNode.get(), m_offset);
}

Node* Position::containerNode() const
{
    if (!m_anchorNode)
        return 0;

    switch (anchorType()) {
    case PositionIsBeforeChildren:
    case PositionIsAfterChildren:
    case PositionIsOffsetInAnchor:
        return m_anchorNode.get();
    case PositionIsBeforeAnchor:
    case PositionIsAfterAnchor:
        return m_anchorNode->parentNode();
    }
    ASSERT_NOT_REACHED();
    return 0;
}

Text* Position::containerText() const
{
    switch (anchorType()) {
    case PositionIsOffsetInAnchor:
        return m_anchorNode && m_anchorNode->isTextNode() ? toText(m_anchorNode) : 0;
    case PositionIsBeforeAnchor:
    case PositionIsAfterAnchor:
        return 0;
    case PositionIsBeforeChildren:
    case PositionIsAfterChildren:
        ASSERT(!m_anchorNode || !m_anchorNode->isTextNode());
        return 0;
    }
    ASSERT_NOT_REACHED();
    return 0;
}

int Position::computeOffsetInContainerNode() const
{
    if (!m_anchorNode)
        return 0;

    switch (anchorType()) {
    case PositionIsBeforeChildren:
        return 0;
    case PositionIsAfterChildren:
        return lastOffsetInNode(m_anchorNode.get());
    case PositionIsOffsetInAnchor:
        return minOffsetForNode(m_anchorNode.get(), m_offset);
    case PositionIsBeforeAnchor:
        return m_anchorNode->nodeIndex();
    case PositionIsAfterAnchor:
        return m_anchorNode->nodeIndex() + 1;
    }
    ASSERT_NOT_REACHED();
    return 0;
}

int Position::offsetForPositionAfterAnchor() const
{
    ASSERT(m_anchorType == PositionIsAfterAnchor || m_anchorType == PositionIsAfterChildren);
    ASSERT(!m_isLegacyEditingPosition);
    return lastOffsetForEditing(m_anchorNode.get());
}

// Neighbor-anchored positions are invalid DOM positions, so they need to be
// fixed up before handing them off to the Range object.
Position Position::parentAnchoredEquivalent() const
{
    if (!m_anchorNode)
        return Position();

    // FIXME: This should only be necessary for legacy positions, but is also needed for positions before and after Tables
    if (m_offset <= 0 && (m_anchorType != PositionIsAfterAnchor && m_anchorType != PositionIsAfterChildren)) {
        if (m_anchorNode->parentNode() && (editingIgnoresContent(m_anchorNode.get()) || isRenderedTableElement(m_anchorNode.get())))
            return positionInParentBeforeNode(*m_anchorNode);
        return Position(m_anchorNode.get(), 0, PositionIsOffsetInAnchor);
    }
    if (!m_anchorNode->offsetInCharacters()
        && (m_anchorType == PositionIsAfterAnchor || m_anchorType == PositionIsAfterChildren || static_cast<unsigned>(m_offset) == m_anchorNode->countChildren())
        && (editingIgnoresContent(m_anchorNode.get()) || isRenderedTableElement(m_anchorNode.get()))
        && containerNode()) {
        return positionInParentAfterNode(*m_anchorNode);
    }

    return Position(containerNode(), computeOffsetInContainerNode(), PositionIsOffsetInAnchor);
}

Node* Position::computeNodeBeforePosition() const
{
    if (!m_anchorNode)
        return 0;

    switch (anchorType()) {
    case PositionIsBeforeChildren:
        return 0;
    case PositionIsAfterChildren:
        return m_anchorNode->lastChild();
    case PositionIsOffsetInAnchor:
        return m_anchorNode->traverseToChildAt(m_offset - 1); // -1 converts to traverseToChildAt((unsigned)-1) and returns null.
    case PositionIsBeforeAnchor:
        return m_anchorNode->previousSibling();
    case PositionIsAfterAnchor:
        return m_anchorNode.get();
    }
    ASSERT_NOT_REACHED();
    return 0;
}

Node* Position::computeNodeAfterPosition() const
{
    if (!m_anchorNode)
        return 0;

    switch (anchorType()) {
    case PositionIsBeforeChildren:
        return m_anchorNode->firstChild();
    case PositionIsAfterChildren:
        return 0;
    case PositionIsOffsetInAnchor:
        return m_anchorNode->traverseToChildAt(m_offset);
    case PositionIsBeforeAnchor:
        return m_anchorNode.get();
    case PositionIsAfterAnchor:
        return m_anchorNode->nextSibling();
    }
    ASSERT_NOT_REACHED();
    return 0;
}

Position::AnchorType Position::anchorTypeForLegacyEditingPosition(Node* anchorNode, int offset)
{
    if (anchorNode && editingIgnoresContent(anchorNode)) {
        if (offset == 0)
            return Position::PositionIsBeforeAnchor;
        return Position::PositionIsAfterAnchor;
    }
    return Position::PositionIsOffsetInAnchor;
}

// FIXME: This method is confusing (does it return anchorNode() or containerNode()?) and should be renamed or removed
Element* Position::element() const
{
    Node* n = anchorNode();
    while (n && !n->isElementNode())
        n = n->parentNode();
    return toElement(n);
}

PassRefPtr<CSSComputedStyleDeclaration> Position::computedStyle() const
{
    Element* elem = element();
    if (!elem)
        return nullptr;
    return CSSComputedStyleDeclaration::create(elem);
}

Position Position::previous(PositionMoveType moveType) const
{
    Node* node = deprecatedNode();
    if (!node)
        return *this;

    int offset = deprecatedEditingOffset();
    // FIXME: Negative offsets shouldn't be allowed. We should catch this earlier.
    ASSERT(offset >= 0);

    if (offset > 0) {
        if (Node* child = node->traverseToChildAt(offset - 1))
            return lastPositionInOrAfterNode(child);

        // There are two reasons child might be 0:
        //   1) The node is node like a text node that is not an element, and therefore has no children.
        //      Going backward one character at a time is correct.
        //   2) The old offset was a bogus offset like (<br>, 1), and there is no child.
        //      Going from 1 to 0 is correct.
        switch (moveType) {
        case CodePoint:
            return createLegacyEditingPosition(node, offset - 1);
        case Character:
            return createLegacyEditingPosition(node, uncheckedPreviousOffset(node, offset));
        case BackwardDeletion:
            return createLegacyEditingPosition(node, uncheckedPreviousOffsetForBackwardDeletion(node, offset));
        }
    }

    if (ContainerNode* parent = node->parentNode())
        return createLegacyEditingPosition(parent, node->nodeIndex());
    return *this;
}

Position Position::next(PositionMoveType moveType) const
{
    ASSERT(moveType != BackwardDeletion);

    Node* node = deprecatedNode();
    if (!node)
        return *this;

    int offset = deprecatedEditingOffset();
    // FIXME: Negative offsets shouldn't be allowed. We should catch this earlier.
    ASSERT(offset >= 0);

    if (Node* child = node->traverseToChildAt(offset))
        return firstPositionInOrBeforeNode(child);

    if (!node->hasChildren() && offset < lastOffsetForEditing(node)) {
        // There are two reasons child might be 0:
        //   1) The node is node like a text node that is not an element, and therefore has no children.
        //      Going forward one character at a time is correct.
        //   2) The new offset is a bogus offset like (<br>, 1), and there is no child.
        //      Going from 0 to 1 is correct.
        return createLegacyEditingPosition(node, (moveType == Character) ? uncheckedNextOffset(node, offset) : offset + 1);
    }

    if (ContainerNode* parent = node->parentNode())
        return createLegacyEditingPosition(parent, node->nodeIndex() + 1);
    return *this;
}

int Position::uncheckedPreviousOffset(const Node* n, int current)
{
    return n->renderer() ? n->renderer()->previousOffset(current) : current - 1;
}

int Position::uncheckedPreviousOffsetForBackwardDeletion(const Node* n, int current)
{
    return n->renderer() ? n->renderer()->previousOffsetForBackwardDeletion(current) : current - 1;
}

int Position::uncheckedNextOffset(const Node* n, int current)
{
    return n->renderer() ? n->renderer()->nextOffset(current) : current + 1;
}

bool Position::atFirstEditingPositionForNode() const
{
    if (isNull())
        return true;
    // FIXME: Position before anchor shouldn't be considered as at the first editing position for node
    // since that position resides outside of the node.
    switch (m_anchorType) {
    case PositionIsOffsetInAnchor:
        return m_offset <= 0;
    case PositionIsBeforeChildren:
    case PositionIsBeforeAnchor:
        return true;
    case PositionIsAfterChildren:
    case PositionIsAfterAnchor:
        return !lastOffsetForEditing(deprecatedNode());
    }
    ASSERT_NOT_REACHED();
    return false;
}

bool Position::atLastEditingPositionForNode() const
{
    if (isNull())
        return true;
    // FIXME: Position after anchor shouldn't be considered as at the first editing position for node
    // since that position resides outside of the node.
    return m_anchorType == PositionIsAfterAnchor || m_anchorType == PositionIsAfterChildren || m_offset >= lastOffsetForEditing(deprecatedNode());
}

// A position is considered at editing boundary if one of the following is true:
// 1. It is the first position in the node and the next visually equivalent position
//    is non editable.
// 2. It is the last position in the node and the previous visually equivalent position
//    is non editable.
// 3. It is an editable position and both the next and previous visually equivalent
//    positions are both non editable.
bool Position::atEditingBoundary() const
{
    Position nextPosition = downstream(CanCrossEditingBoundary);
    if (atFirstEditingPositionForNode() && nextPosition.isNotNull() && !nextPosition.deprecatedNode()->rendererIsEditable())
        return true;

    Position prevPosition = upstream(CanCrossEditingBoundary);
    if (atLastEditingPositionForNode() && prevPosition.isNotNull() && !prevPosition.deprecatedNode()->rendererIsEditable())
        return true;

    return nextPosition.isNotNull() && !nextPosition.deprecatedNode()->rendererIsEditable()
        && prevPosition.isNotNull() && !prevPosition.deprecatedNode()->rendererIsEditable();
}

Node* Position::parentEditingBoundary() const
{
    if (!m_anchorNode)
        return 0;

    Node* documentElement = m_anchorNode->document().documentElement();
    if (!documentElement)
        return 0;

    Node* boundary = m_anchorNode.get();
    while (boundary != documentElement && boundary->nonShadowBoundaryParentNode() && m_anchorNode->rendererIsEditable() == boundary->parentNode()->rendererIsEditable())
        boundary = boundary->nonShadowBoundaryParentNode();

    return boundary;
}


bool Position::atStartOfTree() const
{
    if (isNull())
        return true;
    return !deprecatedNode()->parentNode() && m_offset <= 0;
}

bool Position::atEndOfTree() const
{
    if (isNull())
        return true;
    return !deprecatedNode()->parentNode() && m_offset >= lastOffsetForEditing(deprecatedNode());
}

int Position::renderedOffset() const
{
    if (!deprecatedNode()->isTextNode())
        return m_offset;

    if (!deprecatedNode()->renderer())
        return m_offset;

    int result = 0;
    RenderText* textRenderer = toRenderText(deprecatedNode()->renderer());
    for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
        int start = box->start();
        int end = box->start() + box->len();
        if (m_offset < start)
            return result;
        if (m_offset <= end) {
            result += m_offset - start;
            return result;
        }
        result += box->len();
    }
    return result;
}

// return first preceding DOM position rendered at a different location, or "this"
Position Position::previousCharacterPosition(EAffinity affinity) const
{
    if (isNull())
        return Position();

    Node* fromRootEditableElement = deprecatedNode()->rootEditableElement();

    bool atStartOfLine = isStartOfLine(VisiblePosition(*this, affinity));
    bool rendered = isCandidate();

    Position currentPos = *this;
    while (!currentPos.atStartOfTree()) {
        currentPos = currentPos.previous();

        if (currentPos.deprecatedNode()->rootEditableElement() != fromRootEditableElement)
            return *this;

        if (atStartOfLine || !rendered) {
            if (currentPos.isCandidate())
                return currentPos;
        } else if (rendersInDifferentPosition(currentPos))
            return currentPos;
    }

    return *this;
}

// return first following position rendered at a different location, or "this"
Position Position::nextCharacterPosition(EAffinity affinity) const
{
    if (isNull())
        return Position();

    Node* fromRootEditableElement = deprecatedNode()->rootEditableElement();

    bool atEndOfLine = isEndOfLine(VisiblePosition(*this, affinity));
    bool rendered = isCandidate();

    Position currentPos = *this;
    while (!currentPos.atEndOfTree()) {
        currentPos = currentPos.next();

        if (currentPos.deprecatedNode()->rootEditableElement() != fromRootEditableElement)
            return *this;

        if (atEndOfLine || !rendered) {
            if (currentPos.isCandidate())
                return currentPos;
        } else if (rendersInDifferentPosition(currentPos))
            return currentPos;
    }

    return *this;
}

// Whether or not [node, 0] and [node, lastOffsetForEditing(node)] are their own VisiblePositions.
// If true, adjacent candidates are visually distinct.
// FIXME: Disregard nodes with renderers that have no height, as we do in isCandidate.
// FIXME: Share code with isCandidate, if possible.
static bool endsOfNodeAreVisuallyDistinctPositions(Node* node)
{
    if (!node || !node->renderer())
        return false;

    if (!node->renderer()->isInline())
        return true;

    // Don't include inline tables.
    if (isHTMLTableElement(*node))
        return false;

    // A Marquee elements are moving so we should assume their ends are always
    // visibily distinct.
    if (isHTMLMarqueeElement(*node))
        return true;

    // There is a VisiblePosition inside an empty inline-block container.
    return node->renderer()->isReplaced() && canHaveChildrenForEditing(node) && toRenderBox(node->renderer())->height() != 0 && !node->firstChild();
}

static Node* enclosingVisualBoundary(Node* node)
{
    while (node && !endsOfNodeAreVisuallyDistinctPositions(node))
        node = node->parentNode();

    return node;
}

// upstream() and downstream() want to return positions that are either in a
// text node or at just before a non-text node.  This method checks for that.
static bool isStreamer(const PositionIterator& pos)
{
    if (!pos.node())
        return true;

    if (isAtomicNode(pos.node()))
        return true;

    return pos.atStartOfNode();
}

// This function and downstream() are used for moving back and forth between visually equivalent candidates.
// For example, for the text node "foo     bar" where whitespace is collapsible, there are two candidates
// that map to the VisiblePosition between 'b' and the space.  This function will return the left candidate
// and downstream() will return the right one.
// Also, upstream() will return [boundary, 0] for any of the positions from [boundary, 0] to the first candidate
// in boundary, where endsOfNodeAreVisuallyDistinctPositions(boundary) is true.
Position Position::upstream(EditingBoundaryCrossingRule rule) const
{
    Node* startNode = deprecatedNode();
    if (!startNode)
        return Position();

    // iterate backward from there, looking for a qualified position
    Node* boundary = enclosingVisualBoundary(startNode);
    // FIXME: PositionIterator should respect Before and After positions.
    PositionIterator lastVisible = m_anchorType == PositionIsAfterAnchor ? createLegacyEditingPosition(m_anchorNode.get(), caretMaxOffset(m_anchorNode.get())) : *this;
    PositionIterator currentPos = lastVisible;
    bool startEditable = startNode->rendererIsEditable();
    Node* lastNode = startNode;
    bool boundaryCrossed = false;
    for (; !currentPos.atStart(); currentPos.decrement()) {
        Node* currentNode = currentPos.node();

        // Don't check for an editability change if we haven't moved to a different node,
        // to avoid the expense of computing rendererIsEditable().
        if (currentNode != lastNode) {
            // Don't change editability.
            bool currentEditable = currentNode->rendererIsEditable();
            if (startEditable != currentEditable) {
                if (rule == CannotCrossEditingBoundary)
                    break;
                boundaryCrossed = true;
            }
            lastNode = currentNode;
        }

        // If we've moved to a position that is visually distinct, return the last saved position. There
        // is code below that terminates early if we're *about* to move to a visually distinct position.
        if (endsOfNodeAreVisuallyDistinctPositions(currentNode) && currentNode != boundary)
            return lastVisible;

        // skip position in unrendered or invisible node
        RenderObject* renderer = currentNode->renderer();
        if (!renderer || renderer->style()->visibility() != VISIBLE)
            continue;

        if (rule == CanCrossEditingBoundary && boundaryCrossed) {
            lastVisible = currentPos;
            break;
        }

        // track last visible streamer position
        if (isStreamer(currentPos))
            lastVisible = currentPos;

        // Don't move past a position that is visually distinct.  We could rely on code above to terminate and
        // return lastVisible on the next iteration, but we terminate early to avoid doing a nodeIndex() call.
        if (endsOfNodeAreVisuallyDistinctPositions(currentNode) && currentPos.atStartOfNode())
            return lastVisible;

        // Return position after tables and nodes which have content that can be ignored.
        if (editingIgnoresContent(currentNode) || isRenderedTableElement(currentNode)) {
            if (currentPos.atEndOfNode())
                return positionAfterNode(currentNode);
            continue;
        }

        // return current position if it is in rendered text
        if (renderer->isText() && toRenderText(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 createLegacyEditingPosition(currentNode, renderer->caretMaxOffset());
            }

            unsigned textOffset = currentPos.offsetInLeafNode();
            RenderText* textRenderer = toRenderText(renderer);
            InlineTextBox* lastTextBox = textRenderer->lastTextBox();
            for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                if (textOffset <= box->start() + box->len()) {
                    if (textOffset > box->start())
                        return currentPos;
                    continue;
                }

                if (box == lastTextBox || textOffset != box->start() + box->len() + 1)
                    continue;

                // The text continues on the next line only if the last text box is not on this line and
                // none of the boxes on this line have a larger start offset.

                bool continuesOnNextLine = true;
                InlineBox* otherBox = box;
                while (continuesOnNextLine) {
                    otherBox = otherBox->nextLeafChild();
                    if (!otherBox)
                        break;
                    if (otherBox == lastTextBox || (otherBox->renderer() == textRenderer && toInlineTextBox(otherBox)->start() > textOffset))
                        continuesOnNextLine = false;
                }

                otherBox = box;
                while (continuesOnNextLine) {
                    otherBox = otherBox->prevLeafChild();
                    if (!otherBox)
                        break;
                    if (otherBox == lastTextBox || (otherBox->renderer() == textRenderer && toInlineTextBox(otherBox)->start() > textOffset))
                        continuesOnNextLine = false;
                }

                if (continuesOnNextLine)
                    return currentPos;
            }
        }
    }

    return lastVisible;
}

// This function and upstream() are used for moving back and forth between visually equivalent candidates.
// For example, for the text node "foo     bar" where whitespace is collapsible, there are two candidates
// that map to the VisiblePosition between 'b' and the space.  This function will return the right candidate
// and upstream() will return the left one.
// Also, downstream() will return the last position in the last atomic node in boundary for all of the positions
// in boundary after the last candidate, where endsOfNodeAreVisuallyDistinctPositions(boundary).
// FIXME: This function should never be called when the line box tree is dirty. See https://bugs.webkit.org/show_bug.cgi?id=97264
Position Position::downstream(EditingBoundaryCrossingRule rule) const
{
    Node* startNode = deprecatedNode();
    if (!startNode)
        return Position();

    // iterate forward from there, looking for a qualified position
    Node* boundary = enclosingVisualBoundary(startNode);
    // FIXME: PositionIterator should respect Before and After positions.
    PositionIterator lastVisible = m_anchorType == PositionIsAfterAnchor ? createLegacyEditingPosition(m_anchorNode.get(), caretMaxOffset(m_anchorNode.get())) : *this;
    PositionIterator currentPos = lastVisible;
    bool startEditable = startNode->rendererIsEditable();
    Node* lastNode = startNode;
    bool boundaryCrossed = false;
    for (; !currentPos.atEnd(); currentPos.increment()) {
        Node* currentNode = currentPos.node();

        // Don't check for an editability change if we haven't moved to a different node,
        // to avoid the expense of computing rendererIsEditable().
        if (currentNode != lastNode) {
            // Don't change editability.
            bool currentEditable = currentNode->rendererIsEditable();
            if (startEditable != currentEditable) {
                if (rule == CannotCrossEditingBoundary)
                    break;
                boundaryCrossed = true;
            }

            lastNode = currentNode;
        }

        // stop before going above the body, up into the head
        // return the last visible streamer position
        if (isHTMLBodyElement(*currentNode) && currentPos.atEndOfNode())
            break;

        // Do not move to a visually distinct position.
        if (endsOfNodeAreVisuallyDistinctPositions(currentNode) && currentNode != boundary)
            return lastVisible;
        // Do not move past a visually disinct position.
        // Note: The first position after the last in a node whose ends are visually distinct
        // positions will be [boundary->parentNode(), originalBlock->nodeIndex() + 1].
        if (boundary && boundary->parentNode() == currentNode)
            return lastVisible;

        // skip position in unrendered or invisible node
        RenderObject* renderer = currentNode->renderer();
        if (!renderer || renderer->style()->visibility() != VISIBLE)
            continue;

        if (rule == CanCrossEditingBoundary && boundaryCrossed) {
            lastVisible = currentPos;
            break;
        }

        // track last visible streamer position
        if (isStreamer(currentPos))
            lastVisible = currentPos;

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

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

            unsigned textOffset = currentPos.offsetInLeafNode();
            RenderText* textRenderer = toRenderText(renderer);
            InlineTextBox* lastTextBox = textRenderer->lastTextBox();
            for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                if (textOffset <= box->end()) {
                    if (textOffset >= box->start())
                        return currentPos;
                    continue;
                }

                if (box == lastTextBox || textOffset != box->start() + box->len())
                    continue;

                // The text continues on the next line only if the last text box is not on this line and
                // none of the boxes on this line have a larger start offset.

                bool continuesOnNextLine = true;
                InlineBox* otherBox = box;
                while (continuesOnNextLine) {
                    otherBox = otherBox->nextLeafChild();
                    if (!otherBox)
                        break;
                    if (otherBox == lastTextBox || (otherBox->renderer() == textRenderer && toInlineTextBox(otherBox)->start() >= textOffset))
                        continuesOnNextLine = false;
                }

                otherBox = box;
                while (continuesOnNextLine) {
                    otherBox = otherBox->prevLeafChild();
                    if (!otherBox)
                        break;
                    if (otherBox == lastTextBox || (otherBox->renderer() == textRenderer && toInlineTextBox(otherBox)->start() >= textOffset))
                        continuesOnNextLine = false;
                }

                if (continuesOnNextLine)
                    return currentPos;
            }
        }
    }

    return lastVisible;
}

static int boundingBoxLogicalHeight(RenderObject *o, const IntRect &rect)
{
    return o->style()->isHorizontalWritingMode() ? rect.height() : rect.width();
}

bool Position::hasRenderedNonAnonymousDescendantsWithHeight(RenderObject* renderer)
{
    RenderObject* stop = renderer->nextInPreOrderAfterChildren();
    for (RenderObject *o = renderer->firstChild(); o && o != stop; o = o->nextInPreOrder())
        if (o->nonPseudoNode()) {
            if ((o->isText() && boundingBoxLogicalHeight(o, toRenderText(o)->linesBoundingBox()))
                || (o->isBox() && toRenderBox(o)->pixelSnappedLogicalHeight())
                || (o->isRenderInline() && isEmptyInline(o) && boundingBoxLogicalHeight(o, toRenderInline(o)->linesBoundingBox())))
                return true;
        }
    return false;
}

bool Position::nodeIsUserSelectNone(Node* node)
{
    return node && node->renderer() && !node->renderer()->isSelectable();
}

bool Position::nodeIsUserSelectAll(const Node* node)
{
    return RuntimeEnabledFeatures::userSelectAllEnabled() && node && node->renderer() && node->renderer()->style()->userSelect() == SELECT_ALL;
}

Node* Position::rootUserSelectAllForNode(Node* node)
{
    if (!node || !nodeIsUserSelectAll(node))
        return 0;
    Node* parent = node->parentNode();
    if (!parent)
        return node;

    Node* candidateRoot = node;
    while (parent) {
        if (!parent->renderer()) {
            parent = parent->parentNode();
            continue;
        }
        if (!nodeIsUserSelectAll(parent))
            break;
        candidateRoot = parent;
        parent = candidateRoot->parentNode();
    }
    return candidateRoot;
}

bool Position::isCandidate() const
{
    if (isNull())
        return false;

    RenderObject* renderer = deprecatedNode()->renderer();
    if (!renderer)
        return false;

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

    if (renderer->isBR())
        // FIXME: The condition should be m_anchorType == PositionIsBeforeAnchor, but for now we still need to support legacy positions.
        return !m_offset && m_anchorType != PositionIsAfterAnchor && !nodeIsUserSelectNone(deprecatedNode()->parentNode());

    if (renderer->isText())
        return !nodeIsUserSelectNone(deprecatedNode()) && inRenderedText();

    if (isRenderedTableElement(deprecatedNode()) || editingIgnoresContent(deprecatedNode()))
        return (atFirstEditingPositionForNode() || atLastEditingPositionForNode()) && !nodeIsUserSelectNone(deprecatedNode()->parentNode());

    if (isHTMLHtmlElement(*m_anchorNode))
        return false;

    if (renderer->isRenderBlockFlow()) {
        if (toRenderBlock(renderer)->logicalHeight() || isHTMLBodyElement(*m_anchorNode)) {
            if (!Position::hasRenderedNonAnonymousDescendantsWithHeight(renderer))
                return atFirstEditingPositionForNode() && !Position::nodeIsUserSelectNone(deprecatedNode());
            return m_anchorNode->rendererIsEditable() && !Position::nodeIsUserSelectNone(deprecatedNode()) && atEditingBoundary();
        }
    } else {
        LocalFrame* frame = m_anchorNode->document().frame();
        bool caretBrowsing = frame->settings() && frame->settings()->caretBrowsingEnabled();
        return (caretBrowsing || m_anchorNode->rendererIsEditable()) && !Position::nodeIsUserSelectNone(deprecatedNode()) && atEditingBoundary();
    }

    return false;
}

bool Position::inRenderedText() const
{
    if (isNull() || !deprecatedNode()->isTextNode())
        return false;

    RenderObject* renderer = deprecatedNode()->renderer();
    if (!renderer)
        return false;

    RenderText *textRenderer = toRenderText(renderer);
    for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
        if (m_offset < static_cast<int>(box->start()) && !textRenderer->containsReversedText()) {
            // The offset we're looking for is before this node
            // this means the offset must be in content that is
            // not rendered. Return false.
            return false;
        }
        if (box->containsCaretOffset(m_offset))
            // Return false for offsets inside composed characters.
            return m_offset == 0 || m_offset == textRenderer->nextOffset(textRenderer->previousOffset(m_offset));
    }

    return false;
}

bool Position::isRenderedCharacter() const
{
    if (isNull() || !deprecatedNode()->isTextNode())
        return false;

    RenderObject* renderer = deprecatedNode()->renderer();
    if (!renderer)
        return false;

    RenderText* textRenderer = toRenderText(renderer);
    for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
        if (m_offset < static_cast<int>(box->start()) && !textRenderer->containsReversedText()) {
            // The offset we're looking for is before this node
            // this means the offset must be in content that is
            // not rendered. Return false.
            return false;
        }
        if (m_offset >= static_cast<int>(box->start()) && m_offset < static_cast<int>(box->start() + box->len()))
            return true;
    }

    return false;
}

bool Position::rendersInDifferentPosition(const Position &pos) const
{
    if (isNull() || pos.isNull())
        return false;

    RenderObject* renderer = deprecatedNode()->renderer();
    if (!renderer)
        return false;

    RenderObject* posRenderer = pos.deprecatedNode()->renderer();
    if (!posRenderer)
        return false;

    if (renderer->style()->visibility() != VISIBLE ||
        posRenderer->style()->visibility() != VISIBLE)
        return false;

    if (deprecatedNode() == pos.deprecatedNode()) {
        if (isHTMLBRElement(*deprecatedNode()))
            return false;

        if (m_offset == pos.deprecatedEditingOffset())
            return false;

        if (!deprecatedNode()->isTextNode() && !pos.deprecatedNode()->isTextNode()) {
            if (m_offset != pos.deprecatedEditingOffset())
                return true;
        }
    }

    if (isHTMLBRElement(*deprecatedNode()) && pos.isCandidate())
        return true;

    if (isHTMLBRElement(*pos.deprecatedNode()) && isCandidate())
        return true;

    if (deprecatedNode()->enclosingBlockFlowElement() != pos.deprecatedNode()->enclosingBlockFlowElement())
        return true;

    if (deprecatedNode()->isTextNode() && !inRenderedText())
        return false;

    if (pos.deprecatedNode()->isTextNode() && !pos.inRenderedText())
        return false;

    int thisRenderedOffset = renderedOffset();
    int posRenderedOffset = pos.renderedOffset();

    if (renderer == posRenderer && thisRenderedOffset == posRenderedOffset)
        return false;

    int ignoredCaretOffset;
    InlineBox* b1;
    getInlineBoxAndOffset(DOWNSTREAM, b1, ignoredCaretOffset);
    InlineBox* b2;
    pos.getInlineBoxAndOffset(DOWNSTREAM, b2, ignoredCaretOffset);

    WTF_LOG(Editing, "renderer:               %p [%p]\n", renderer, b1);
    WTF_LOG(Editing, "thisRenderedOffset:         %d\n", thisRenderedOffset);
    WTF_LOG(Editing, "posRenderer:            %p [%p]\n", posRenderer, b2);
    WTF_LOG(Editing, "posRenderedOffset:      %d\n", posRenderedOffset);
    WTF_LOG(Editing, "node min/max:           %d:%d\n", caretMinOffset(deprecatedNode()), caretMaxOffset(deprecatedNode()));
    WTF_LOG(Editing, "pos node min/max:       %d:%d\n", caretMinOffset(pos.deprecatedNode()), caretMaxOffset(pos.deprecatedNode()));
    WTF_LOG(Editing, "----------------------------------------------------------------------\n");

    if (!b1 || !b2) {
        return false;
    }

    if (b1->root() != b2->root()) {
        return true;
    }

    if (nextRenderedEditable(deprecatedNode()) == pos.deprecatedNode()
        && thisRenderedOffset == caretMaxOffset(deprecatedNode()) && !posRenderedOffset) {
        return false;
    }

    if (previousRenderedEditable(deprecatedNode()) == pos.deprecatedNode()
        && !thisRenderedOffset && posRenderedOffset == caretMaxOffset(pos.deprecatedNode())) {
        return false;
    }

    return true;
}

// This assumes that it starts in editable content.
Position Position::leadingWhitespacePosition(EAffinity affinity, bool considerNonCollapsibleWhitespace) const
{
    ASSERT(isEditablePosition(*this, ContentIsEditable, DoNotUpdateStyle));
    if (isNull())
        return Position();

    if (isHTMLBRElement(*upstream().deprecatedNode()))
        return Position();

    Position prev = previousCharacterPosition(affinity);
    if (prev != *this && prev.deprecatedNode()->inSameContainingBlockFlowElement(deprecatedNode()) && prev.deprecatedNode()->isTextNode()) {
        String string = toText(prev.deprecatedNode())->data();
        UChar c = string[prev.deprecatedEditingOffset()];
        if (considerNonCollapsibleWhitespace ? (isSpaceOrNewline(c) || c == noBreakSpace) : isCollapsibleWhitespace(c))
            if (isEditablePosition(prev))
                return prev;
    }

    return Position();
}

// This assumes that it starts in editable content.
Position Position::trailingWhitespacePosition(EAffinity, bool considerNonCollapsibleWhitespace) const
{
    ASSERT(isEditablePosition(*this, ContentIsEditable, DoNotUpdateStyle));
    if (isNull())
        return Position();

    VisiblePosition v(*this);
    UChar c = v.characterAfter();
    // The space must not be in another paragraph and it must be editable.
    if (!isEndOfParagraph(v) && v.next(CannotCrossEditingBoundary).isNotNull())
        if (considerNonCollapsibleWhitespace ? (isSpaceOrNewline(c) || c == noBreakSpace) : isCollapsibleWhitespace(c))
            return *this;

    return Position();
}

void Position::getInlineBoxAndOffset(EAffinity affinity, InlineBox*& inlineBox, int& caretOffset) const
{
    getInlineBoxAndOffset(affinity, primaryDirection(), inlineBox, caretOffset);
}

static bool isNonTextLeafChild(RenderObject* object)
{
    if (object->firstChild())
        return false;
    if (object->isText())
        return false;
    return true;
}

static InlineTextBox* searchAheadForBetterMatch(RenderObject* renderer)
{
    RenderBlock* container = renderer->containingBlock();
    RenderObject* next = renderer;
    while ((next = next->nextInPreOrder(container))) {
        if (next->isRenderBlock())
            return 0;
        if (next->isBR())
            return 0;
        if (isNonTextLeafChild(next))
            return 0;
        if (next->isText()) {
            InlineTextBox* match = 0;
            int minOffset = INT_MAX;
            for (InlineTextBox* box = toRenderText(next)->firstTextBox(); box; box = box->nextTextBox()) {
                int caretMinOffset = box->caretMinOffset();
                if (caretMinOffset < minOffset) {
                    match = box;
                    minOffset = caretMinOffset;
                }
            }
            if (match)
                return match;
        }
    }
    return 0;
}

static Position downstreamIgnoringEditingBoundaries(Position position)
{
    Position lastPosition;
    while (position != lastPosition) {
        lastPosition = position;
        position = position.downstream(CanCrossEditingBoundary);
    }
    return position;
}

static Position upstreamIgnoringEditingBoundaries(Position position)
{
    Position lastPosition;
    while (position != lastPosition) {
        lastPosition = position;
        position = position.upstream(CanCrossEditingBoundary);
    }
    return position;
}

void Position::getInlineBoxAndOffset(EAffinity affinity, TextDirection primaryDirection, InlineBox*& inlineBox, int& caretOffset) const
{
    caretOffset = deprecatedEditingOffset();
    RenderObject* renderer = deprecatedNode()->renderer();

    if (!renderer->isText()) {
        inlineBox = 0;
        if (canHaveChildrenForEditing(deprecatedNode()) && renderer->isRenderBlockFlow() && hasRenderedNonAnonymousDescendantsWithHeight(renderer)) {
            // Try a visually equivalent position with possibly opposite editability. This helps in case |this| is in
            // an editable block but surrounded by non-editable positions. It acts to negate the logic at the beginning
            // of RenderObject::createVisiblePosition().
            Position equivalent = downstreamIgnoringEditingBoundaries(*this);
            if (equivalent == *this) {
                equivalent = upstreamIgnoringEditingBoundaries(*this);
                if (equivalent == *this || downstreamIgnoringEditingBoundaries(equivalent) == *this)
                    return;
            }

            equivalent.getInlineBoxAndOffset(UPSTREAM, primaryDirection, inlineBox, caretOffset);
            return;
        }
        if (renderer->isBox()) {
            inlineBox = toRenderBox(renderer)->inlineBoxWrapper();
            if (!inlineBox || (caretOffset > inlineBox->caretMinOffset() && caretOffset < inlineBox->caretMaxOffset()))
                return;
        }
    } else {
        RenderText* textRenderer = toRenderText(renderer);

        InlineTextBox* box;
        InlineTextBox* candidate = 0;

        for (box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
            int caretMinOffset = box->caretMinOffset();
            int caretMaxOffset = box->caretMaxOffset();

            if (caretOffset < caretMinOffset || caretOffset > caretMaxOffset || (caretOffset == caretMaxOffset && box->isLineBreak()))
                continue;

            if (caretOffset > caretMinOffset && caretOffset < caretMaxOffset) {
                inlineBox = box;
                return;
            }

            if (((caretOffset == caretMaxOffset) ^ (affinity == DOWNSTREAM))
                || ((caretOffset == caretMinOffset) ^ (affinity == UPSTREAM))
                || (caretOffset == caretMaxOffset && box->nextLeafChild() && box->nextLeafChild()->isLineBreak()))
                break;

            candidate = box;
        }
        if (candidate && candidate == textRenderer->lastTextBox() && affinity == DOWNSTREAM) {
            box = searchAheadForBetterMatch(textRenderer);
            if (box)
                caretOffset = box->caretMinOffset();
        }
        inlineBox = box ? box : candidate;
    }

    if (!inlineBox)
        return;

    unsigned char level = inlineBox->bidiLevel();

    if (inlineBox->direction() == primaryDirection) {
        if (caretOffset == inlineBox->caretRightmostOffset()) {
            InlineBox* nextBox = inlineBox->nextLeafChild();
            if (!nextBox || nextBox->bidiLevel() >= level)
                return;

            level = nextBox->bidiLevel();
            InlineBox* prevBox = inlineBox;
            do {
                prevBox = prevBox->prevLeafChild();
            } while (prevBox && prevBox->bidiLevel() > level);

            if (prevBox && prevBox->bidiLevel() == level)   // For example, abc FED 123 ^ CBA
                return;

            // For example, abc 123 ^ CBA
            while (InlineBox* nextBox = inlineBox->nextLeafChild()) {
                if (nextBox->bidiLevel() < level)
                    break;
                inlineBox = nextBox;
            }
            caretOffset = inlineBox->caretRightmostOffset();
        } else {
            InlineBox* prevBox = inlineBox->prevLeafChild();
            if (!prevBox || prevBox->bidiLevel() >= level)
                return;

            level = prevBox->bidiLevel();
            InlineBox* nextBox = inlineBox;
            do {
                nextBox = nextBox->nextLeafChild();
            } while (nextBox && nextBox->bidiLevel() > level);

            if (nextBox && nextBox->bidiLevel() == level)
                return;

            while (InlineBox* prevBox = inlineBox->prevLeafChild()) {
                if (prevBox->bidiLevel() < level)
                    break;
                inlineBox = prevBox;
            }
            caretOffset = inlineBox->caretLeftmostOffset();
        }
        return;
    }

    if (caretOffset == inlineBox->caretLeftmostOffset()) {
        InlineBox* prevBox = inlineBox->prevLeafChildIgnoringLineBreak();
        if (!prevBox || prevBox->bidiLevel() < level) {
            // Left edge of a secondary run. Set to the right edge of the entire run.
            while (InlineBox* nextBox = inlineBox->nextLeafChildIgnoringLineBreak()) {
                if (nextBox->bidiLevel() < level)
                    break;
                inlineBox = nextBox;
            }
            caretOffset = inlineBox->caretRightmostOffset();
        } else if (prevBox->bidiLevel() > level) {
            // Right edge of a "tertiary" run. Set to the left edge of that run.
            while (InlineBox* tertiaryBox = inlineBox->prevLeafChildIgnoringLineBreak()) {
                if (tertiaryBox->bidiLevel() <= level)
                    break;
                inlineBox = tertiaryBox;
            }
            caretOffset = inlineBox->caretLeftmostOffset();
        }
    } else {
        InlineBox* nextBox = inlineBox->nextLeafChildIgnoringLineBreak();
        if (!nextBox || nextBox->bidiLevel() < level) {
            // Right edge of a secondary run. Set to the left edge of the entire run.
            while (InlineBox* prevBox = inlineBox->prevLeafChildIgnoringLineBreak()) {
                if (prevBox->bidiLevel() < level)
                    break;
                inlineBox = prevBox;
            }
            caretOffset = inlineBox->caretLeftmostOffset();
        } else if (nextBox->bidiLevel() > level) {
            // Left edge of a "tertiary" run. Set to the right edge of that run.
            while (InlineBox* tertiaryBox = inlineBox->nextLeafChildIgnoringLineBreak()) {
                if (tertiaryBox->bidiLevel() <= level)
                    break;
                inlineBox = tertiaryBox;
            }
            caretOffset = inlineBox->caretRightmostOffset();
        }
    }
}

TextDirection Position::primaryDirection() const
{
    TextDirection primaryDirection = LTR;
    for (const RenderObject* r = m_anchorNode->renderer(); r; r = r->parent()) {
        if (r->isRenderBlockFlow()) {
            primaryDirection = r->style()->direction();
            break;
        }
    }

    return primaryDirection;
}


void Position::debugPosition(const char* msg) const
{
    if (isNull())
        fprintf(stderr, "Position [%s]: null\n", msg);
    else
        fprintf(stderr, "Position [%s]: %s [%p] at %d\n", msg, deprecatedNode()->nodeName().utf8().data(), deprecatedNode(), m_offset);
}

#ifndef NDEBUG

void Position::formatForDebugger(char* buffer, unsigned length) const
{
    StringBuilder result;

    if (isNull())
        result.appendLiteral("<null>");
    else {
        char s[1024];
        result.appendLiteral("offset ");
        result.appendNumber(m_offset);
        result.appendLiteral(" of ");
        deprecatedNode()->formatForDebugger(s, sizeof(s));
        result.append(s);
    }

    strncpy(buffer, result.toString().utf8().data(), length - 1);
}

void Position::showAnchorTypeAndOffset() const
{
    if (m_isLegacyEditingPosition)
        fputs("legacy, ", stderr);
    switch (anchorType()) {
    case PositionIsOffsetInAnchor:
        fputs("offset", stderr);
        break;
    case PositionIsBeforeChildren:
        fputs("beforeChildren", stderr);
        break;
    case PositionIsAfterChildren:
        fputs("afterChildren", stderr);
        break;
    case PositionIsBeforeAnchor:
        fputs("before", stderr);
        break;
    case PositionIsAfterAnchor:
        fputs("after", stderr);
        break;
    }
    fprintf(stderr, ", offset:%d\n", m_offset);
}

void Position::showTreeForThis() const
{
    if (anchorNode()) {
        anchorNode()->showTreeForThis();
        showAnchorTypeAndOffset();
    }
}

#endif



} // namespace WebCore

#ifndef NDEBUG

void showTree(const WebCore::Position& pos)
{
    pos.showTreeForThis();
}

void showTree(const WebCore::Position* pos)
{
    if (pos)
        pos->showTreeForThis();
}

#endif
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root/Source/core/dom/Position.cpp

DEFINITIONS
