1 files changed, 680 insertions, 0 deletions
diff --git a/src/3rdparty/webkit/WebCore/editing/VisiblePosition.cpp b/src/3rdparty/webkit/WebCore/editing/VisiblePosition.cpp
new file mode 100644
index 0000000..9ecc4d8
--- /dev/null
+++ b/src/3rdparty/webkit/WebCore/editing/VisiblePosition.cpp
@@ -0,0 +1,680 @@
+/*
+ * Copyright (C) 2004 Apple Computer, 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 "VisiblePosition.h"
+
+#include "CString.h"
+#include "Document.h"
+#include "Element.h"
+#include "FloatRect.h"
+#include "HTMLNames.h"
+#include "InlineTextBox.h"
+#include "Logging.h"
+#include "Range.h"
+#include "Text.h"
+#include "htmlediting.h"
+#include "visible_units.h"
+#include <stdio.h>
+
+namespace WebCore {
+
+using namespace HTMLNames;
+
+VisiblePosition::VisiblePosition(const Position &pos, EAffinity affinity)
+{
+    init(pos, affinity);
+}
+
+VisiblePosition::VisiblePosition(Node *node, int offset, EAffinity affinity)
+{
+    ASSERT(offset >= 0);
+    init(Position(node, offset), affinity);
+}
+
+void VisiblePosition::init(const Position& position, EAffinity affinity)
+{
+    m_affinity = affinity;
+    
+    m_deepPosition = canonicalPosition(position);
+    
+    // When not at a line wrap, make sure to end up with DOWNSTREAM affinity.
+    if (m_affinity == UPSTREAM && (isNull() || inSameLine(VisiblePosition(position, DOWNSTREAM), *this)))
+        m_affinity = DOWNSTREAM;
+}
+
+VisiblePosition VisiblePosition::next(bool stayInEditableContent) const
+{
+    VisiblePosition next(nextVisuallyDistinctCandidate(m_deepPosition), m_affinity);
+    
+    if (!stayInEditableContent)
+        return next;
+    
+    return honorEditableBoundaryAtOrAfter(next);
+}
+
+VisiblePosition VisiblePosition::previous(bool stayInEditableContent) const
+{
+    // find first previous DOM position that is visible
+    Position pos = previousVisuallyDistinctCandidate(m_deepPosition);
+    
+    // return null visible position if there is no previous visible position
+    if (pos.atStart())
+        return VisiblePosition();
+        
+    VisiblePosition prev = VisiblePosition(pos, DOWNSTREAM);
+    ASSERT(prev != *this);
+    
+#ifndef NDEBUG
+    // we should always be able to make the affinity DOWNSTREAM, because going previous from an
+    // UPSTREAM position can never yield another UPSTREAM position (unless line wrap length is 0!).
+    if (prev.isNotNull() && m_affinity == UPSTREAM) {
+        VisiblePosition temp = prev;
+        temp.setAffinity(UPSTREAM);
+        ASSERT(inSameLine(temp, prev));
+    }
+#endif
+
+    if (!stayInEditableContent)
+        return prev;
+    
+    return honorEditableBoundaryAtOrBefore(prev);
+}
+
+Position VisiblePosition::leftVisuallyDistinctCandidate() const
+{
+    Position p = m_deepPosition;
+    if (!p.node())
+        return Position();
+
+    Position downstreamStart = p.downstream();
+    TextDirection primaryDirection = LTR;
+    for (RenderObject* r = p.node()->renderer(); r; r = r->parent()) {
+        if (r->isBlockFlow()) {
+            primaryDirection = r->style()->direction();
+            break;
+        }
+    }
+
+    while (true) {
+        InlineBox* box;
+        int offset;
+        p.getInlineBoxAndOffset(m_affinity, primaryDirection, box, offset);
+        if (!box)
+            return primaryDirection == LTR ? previousVisuallyDistinctCandidate(m_deepPosition) : nextVisuallyDistinctCandidate(m_deepPosition);
+
+        RenderObject* renderer = box->object();
+
+        while (true) {
+            if ((renderer->isReplaced() || renderer->isBR()) && offset == box->caretRightmostOffset())
+                return box->direction() == LTR ? previousVisuallyDistinctCandidate(m_deepPosition) : nextVisuallyDistinctCandidate(m_deepPosition);
+
+            offset = box->direction() == LTR ? renderer->previousOffset(offset) : renderer->nextOffset(offset);
+
+            int caretMinOffset = box->caretMinOffset();
+            int caretMaxOffset = box->caretMaxOffset();
+
+            if (offset > caretMinOffset && offset < caretMaxOffset)
+                break;
+
+            if (box->direction() == LTR ? offset < caretMinOffset : offset > caretMaxOffset) {
+                // Overshot to the left.
+                InlineBox* prevBox = box->prevLeafChild();
+                if (!prevBox)
+                    return primaryDirection == LTR ? previousVisuallyDistinctCandidate(m_deepPosition) : nextVisuallyDistinctCandidate(m_deepPosition);
+
+                // Reposition at the other logical position corresponding to our edge's visual position and go for another round.
+                box = prevBox;
+                renderer = box->object();
+                offset = prevBox->caretRightmostOffset();
+                continue;
+            }
+
+            ASSERT(offset == box->caretLeftmostOffset());
+
+            unsigned char level = box->bidiLevel();
+            InlineBox* prevBox = box->prevLeafChild();
+
+            if (box->direction() == primaryDirection) {
+                if (!prevBox || prevBox->bidiLevel() >= level)
+                    break;
+
+                level = prevBox->bidiLevel();
+
+                InlineBox* nextBox = box;
+                do {
+                    nextBox = nextBox->nextLeafChild();
+                } while (nextBox && nextBox->bidiLevel() > level);
+
+                if (nextBox && nextBox->bidiLevel() == level)
+                    break;
+
+                while (InlineBox* prevBox = box->prevLeafChild()) {
+                    if (prevBox->bidiLevel() < level)
+                        break;
+                    box = prevBox;
+                }
+                renderer = box->object();
+                offset = box->caretRightmostOffset();
+                if (box->direction() == primaryDirection)
+                    break;
+                continue;
+            }
+
+            if (prevBox) {
+                box = prevBox;
+                renderer = box->object();
+                offset = box->caretRightmostOffset();
+                if (box->bidiLevel() > level) {
+                    do {
+                        prevBox = box->prevLeafChild();
+                    } while (prevBox && prevBox->bidiLevel() > level);
+
+                    if (!prevBox || prevBox->bidiLevel() < level)
+                        continue;
+                }
+            } else {
+                // Trailing edge of a secondary run. Set to the leading edge of the entire run.
+                while (true) {
+                    while (InlineBox* nextBox = box->nextLeafChild()) {
+                        if (nextBox->bidiLevel() < level)
+                            break;
+                        box = nextBox;
+                    }
+                    if (box->bidiLevel() == level)
+                        break;
+                    level = box->bidiLevel();
+                    while (InlineBox* prevBox = box->prevLeafChild()) {
+                        if (prevBox->bidiLevel() < level)
+                            break;
+                        box = prevBox;
+                    }
+                    if (box->bidiLevel() == level)
+                        break;
+                    level = box->bidiLevel();
+                }
+                renderer = box->object();
+                offset = primaryDirection == LTR ? box->caretMinOffset() : box->caretMaxOffset();
+            }
+            break;
+        }
+
+        p = Position(renderer->element(), offset);
+
+        if (p.isCandidate() && p.downstream() != downstreamStart || p.atStart() || p.atEnd())
+            return p;
+    }
+}
+
+VisiblePosition VisiblePosition::left(bool stayInEditableContent) const
+{
+    Position pos = leftVisuallyDistinctCandidate();
+    if (pos.atStart() || pos.atEnd())
+        return VisiblePosition();
+
+    VisiblePosition left = VisiblePosition(pos, DOWNSTREAM);
+    ASSERT(left != *this);
+
+    if (!stayInEditableContent)
+        return left;
+
+    // FIXME: This may need to do something different from "before".
+    return honorEditableBoundaryAtOrBefore(left);
+}
+
+Position VisiblePosition::rightVisuallyDistinctCandidate() const
+{
+    Position p = m_deepPosition;
+    if (!p.node())
+        return Position();
+
+    Position downstreamStart = p.downstream();
+    TextDirection primaryDirection = LTR;
+    for (RenderObject* r = p.node()->renderer(); r; r = r->parent()) {
+        if (r->isBlockFlow()) {
+            primaryDirection = r->style()->direction();
+            break;
+        }
+    }
+
+    while (true) {
+        InlineBox* box;
+        int offset;
+        p.getInlineBoxAndOffset(m_affinity, primaryDirection, box, offset);
+        if (!box)
+            return primaryDirection == LTR ? nextVisuallyDistinctCandidate(m_deepPosition) : previousVisuallyDistinctCandidate(m_deepPosition);
+
+        RenderObject* renderer = box->object();
+
+        while (true) {
+            if ((renderer->isReplaced() || renderer->isBR()) && offset == box->caretLeftmostOffset())
+                return box->direction() == LTR ? nextVisuallyDistinctCandidate(m_deepPosition) : previousVisuallyDistinctCandidate(m_deepPosition);
+
+            offset = box->direction() == LTR ? renderer->nextOffset(offset) : renderer->previousOffset(offset);
+
+            int caretMinOffset = box->caretMinOffset();
+            int caretMaxOffset = box->caretMaxOffset();
+
+            if (offset > caretMinOffset && offset < caretMaxOffset)
+                break;
+
+            if (box->direction() == LTR ? offset > caretMaxOffset : offset < caretMinOffset) {
+                // Overshot to the right.
+                InlineBox* nextBox = box->nextLeafChild();
+                if (!nextBox)
+                    return primaryDirection == LTR ? nextVisuallyDistinctCandidate(m_deepPosition) : previousVisuallyDistinctCandidate(m_deepPosition);
+
+                // Reposition at the other logical position corresponding to our edge's visual position and go for another round.
+                box = nextBox;
+                renderer = box->object();
+                offset = nextBox->caretLeftmostOffset();
+                continue;
+            }
+
+            ASSERT(offset == box->caretRightmostOffset());
+
+            unsigned char level = box->bidiLevel();
+            InlineBox* nextBox = box->nextLeafChild();
+
+            if (box->direction() == primaryDirection) {
+                if (!nextBox || nextBox->bidiLevel() >= level)
+                    break;
+
+                level = nextBox->bidiLevel();
+
+                InlineBox* prevBox = box;
+                do {
+                    prevBox = prevBox->prevLeafChild();
+                } while (prevBox && prevBox->bidiLevel() > level);
+
+                if (prevBox && prevBox->bidiLevel() == level)   // For example, abc FED 123 ^ CBA
+                    break;
+
+                // For example, abc 123 ^ CBA
+                while (InlineBox* nextBox = box->nextLeafChild()) {
+                    if (nextBox->bidiLevel() < level)
+                        break;
+                    box = nextBox;
+                }
+                renderer = box->object();
+                offset = box->caretLeftmostOffset();
+                if (box->direction() == primaryDirection)
+                    break;
+                continue;
+            }
+
+            if (nextBox) {
+                box = nextBox;
+                renderer = box->object();
+                offset = box->caretLeftmostOffset();
+                if (box->bidiLevel() > level) {
+                    do {
+                        nextBox = box->nextLeafChild();
+                    } while (nextBox && nextBox->bidiLevel() > level);
+
+                    if (!nextBox || nextBox->bidiLevel() < level)
+                        continue;
+                }
+            } else {
+                // Trailing edge of a secondary run. Set to the leading edge of the entire run.
+                while (true) {
+                    while (InlineBox* prevBox = box->prevLeafChild()) {
+                        if (prevBox->bidiLevel() < level)
+                            break;
+                        box = prevBox;
+                    }
+                    if (box->bidiLevel() == level)
+                        break;
+                    level = box->bidiLevel();
+                    while (InlineBox* nextBox = box->nextLeafChild()) {
+                        if (nextBox->bidiLevel() < level)
+                            break;
+                        box = nextBox;
+                    }
+                    if (box->bidiLevel() == level)
+                        break;
+                    level = box->bidiLevel();
+                }
+                renderer = box->object();
+                offset = primaryDirection == LTR ? box->caretMaxOffset() : box->caretMinOffset();
+            }
+            break;
+        }
+
+        p = Position(renderer->element(), offset);
+
+        if (p.isCandidate() && p.downstream() != downstreamStart || p.atStart() || p.atEnd())
+            return p;
+    }
+}
+
+VisiblePosition VisiblePosition::right(bool stayInEditableContent) const
+{
+    Position pos = rightVisuallyDistinctCandidate();
+    if (pos.atStart() || pos.atEnd())
+        return VisiblePosition();
+
+    VisiblePosition right = VisiblePosition(pos, DOWNSTREAM);
+    ASSERT(right != *this);
+
+    if (!stayInEditableContent)
+        return right;
+
+    // FIXME: This may need to do something different from "after".
+    return honorEditableBoundaryAtOrAfter(right);
+}
+
+VisiblePosition VisiblePosition::honorEditableBoundaryAtOrBefore(const VisiblePosition &pos) const
+{
+    if (pos.isNull())
+        return pos;
+    
+    Node* highestRoot = highestEditableRoot(deepEquivalent());
+    
+    // Return empty position if pos is not somewhere inside the editable region containing this position
+    if (highestRoot && !pos.deepEquivalent().node()->isDescendantOf(highestRoot))
+        return VisiblePosition();
+        
+    // Return pos itself if the two are from the very same editable region, or both are non-editable
+    // FIXME: In the non-editable case, just because the new position is non-editable doesn't mean movement
+    // to it is allowed.  Selection::adjustForEditableContent has this problem too.
+    if (highestEditableRoot(pos.deepEquivalent()) == highestRoot)
+        return pos;
+  
+    // Return empty position if this position is non-editable, but pos is editable
+    // FIXME: Move to the previous non-editable region.
+    if (!highestRoot)
+        return VisiblePosition();
+
+    // Return the last position before pos that is in the same editable region as this position
+    return lastEditablePositionBeforePositionInRoot(pos.deepEquivalent(), highestRoot);
+}
+
+VisiblePosition VisiblePosition::honorEditableBoundaryAtOrAfter(const VisiblePosition &pos) const
+{
+    if (pos.isNull())
+        return pos;
+    
+    Node* highestRoot = highestEditableRoot(deepEquivalent());
+    
+    // Return empty position if pos is not somewhere inside the editable region containing this position
+    if (highestRoot && !pos.deepEquivalent().node()->isDescendantOf(highestRoot))
+        return VisiblePosition();
+    
+    // Return pos itself if the two are from the very same editable region, or both are non-editable
+    // FIXME: In the non-editable case, just because the new position is non-editable doesn't mean movement
+    // to it is allowed.  Selection::adjustForEditableContent has this problem too.
+    if (highestEditableRoot(pos.deepEquivalent()) == highestRoot)
+        return pos;
+
+    // Return empty position if this position is non-editable, but pos is editable
+    // FIXME: Move to the next non-editable region.
+    if (!highestRoot)
+        return VisiblePosition();
+
+    // Return the next position after pos that is in the same editable region as this position
+    return firstEditablePositionAfterPositionInRoot(pos.deepEquivalent(), highestRoot);
+}
+
+Position canonicalizeCandidate(const Position& candidate)
+{
+    if (candidate.isNull())
+        return Position();
+    ASSERT(candidate.isCandidate());
+    Position upstream = candidate.upstream();
+    if (upstream.isCandidate())
+        return upstream;
+    return candidate;
+}
+
+Position VisiblePosition::canonicalPosition(const Position& position)
+{
+    // FIXME (9535):  Canonicalizing to the leftmost candidate means that if we're at a line wrap, we will 
+    // ask renderers to paint downstream carets for other renderers.
+    // To fix this, we need to either a) add code to all paintCarets to pass the responsibility off to
+    // the appropriate renderer for VisiblePosition's like these, or b) canonicalize to the rightmost candidate
+    // unless the affinity is upstream.
+    Node* node = position.node();
+    if (!node)
+        return Position();
+
+    node->document()->updateLayoutIgnorePendingStylesheets();
+
+    Position candidate = position.upstream();
+    if (candidate.isCandidate())
+        return candidate;
+    candidate = position.downstream();
+    if (candidate.isCandidate())
+        return candidate;
+
+    // When neither upstream or downstream gets us to a candidate (upstream/downstream won't leave 
+    // blocks or enter new ones), we search forward and backward until we find one.
+    Position next = canonicalizeCandidate(nextCandidate(position));
+    Position prev = canonicalizeCandidate(previousCandidate(position));
+    Node* nextNode = next.node();
+    Node* prevNode = prev.node();
+
+    // The new position must be in the same editable element. Enforce that first.
+    // Unless the descent is from a non-editable html element to an editable body.
+    if (node->hasTagName(htmlTag) && !node->isContentEditable())
+        return next.isNotNull() ? next : prev;
+
+    Node* editingRoot = editableRootForPosition(position);
+        
+    // If the html element is editable, descending into its body will look like a descent 
+    // from non-editable to editable content since rootEditableElement() always stops at the body.
+    if (editingRoot && editingRoot->hasTagName(htmlTag) || position.node()->isDocumentNode())
+        return next.isNotNull() ? next : prev;
+        
+    bool prevIsInSameEditableElement = prevNode && editableRootForPosition(prev) == editingRoot;
+    bool nextIsInSameEditableElement = nextNode && editableRootForPosition(next) == editingRoot;
+    if (prevIsInSameEditableElement && !nextIsInSameEditableElement)
+        return prev;
+        
+    if (nextIsInSameEditableElement && !prevIsInSameEditableElement)
+        return next;
+        
+    if (!nextIsInSameEditableElement && !prevIsInSameEditableElement)
+        return Position();
+
+    // The new position should be in the same block flow element. Favor that.
+    Node *originalBlock = node->enclosingBlockFlowElement();
+    bool nextIsOutsideOriginalBlock = !nextNode->isDescendantOf(originalBlock) && nextNode != originalBlock;
+    bool prevIsOutsideOriginalBlock = !prevNode->isDescendantOf(originalBlock) && prevNode != originalBlock;
+    if (nextIsOutsideOriginalBlock && !prevIsOutsideOriginalBlock)
+        return prev;
+        
+    return next;
+}
+
+UChar VisiblePosition::characterAfter() const
+{
+    // We canonicalize to the first of two equivalent candidates, but the second of the two candidates
+    // is the one that will be inside the text node containing the character after this visible position.
+    Position pos = m_deepPosition.downstream();
+    Node* node = pos.node();
+    if (!node || !node->isTextNode())
+        return 0;
+    Text* textNode = static_cast<Text*>(pos.node());
+    int offset = pos.offset();
+    if ((unsigned)offset >= textNode->length())
+        return 0;
+    return textNode->data()[offset];
+}
+
+IntRect VisiblePosition::localCaretRect(RenderObject*& renderer) const
+{
+    Node* node = m_deepPosition.node();
+    if (!node) {
+        renderer = 0;
+        return IntRect();
+    }
+    
+    renderer = node->renderer();
+    if (!renderer)
+        return IntRect();
+
+    InlineBox* inlineBox;
+    int caretOffset;
+    getInlineBoxAndOffset(inlineBox, caretOffset);
+
+    if (inlineBox)
+        renderer = inlineBox->object();
+
+    return renderer->localCaretRect(inlineBox, caretOffset);
+}
+
+IntRect VisiblePosition::absoluteCaretBounds() const
+{
+    RenderObject* renderer;
+    IntRect localRect = localCaretRect(renderer);
+    if (localRect.isEmpty() || !renderer)
+        return IntRect();
+
+    return renderer->localToAbsoluteQuad(FloatRect(localRect)).enclosingBoundingBox();
+}
+
+int VisiblePosition::xOffsetForVerticalNavigation() const
+{
+    RenderObject* renderer;
+    IntRect localRect = localCaretRect(renderer);
+    if (localRect.isEmpty() || !renderer)
+        return 0;
+
+    // This ignores transforms on purpose, for now. Vertical navigation is done
+    // without consulting transforms, so that 'up' in transformed text is 'up'
+    // relative to the text, not absolute 'up'.
+    return renderer->localToAbsolute(localRect.location()).x();
+}
+
+void VisiblePosition::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, m_deepPosition.node()->nodeName().utf8().data(), m_deepPosition.node(), m_deepPosition.offset());
+}
+
+#ifndef NDEBUG
+
+void VisiblePosition::formatForDebugger(char* buffer, unsigned length) const
+{
+    m_deepPosition.formatForDebugger(buffer, length);
+}
+
+void VisiblePosition::showTreeForThis() const
+{
+    m_deepPosition.showTreeForThis();
+}
+
+#endif
+
+PassRefPtr<Range> makeRange(const VisiblePosition &start, const VisiblePosition &end)
+{
+    Position s = rangeCompliantEquivalent(start);
+    Position e = rangeCompliantEquivalent(end);
+    return Range::create(s.node()->document(), s.node(), s.offset(), e.node(), e.offset());
+}
+
+VisiblePosition startVisiblePosition(const Range *r, EAffinity affinity)
+{
+    int exception = 0;
+    return VisiblePosition(r->startContainer(exception), r->startOffset(exception), affinity);
+}
+
+VisiblePosition endVisiblePosition(const Range *r, EAffinity affinity)
+{
+    int exception = 0;
+    return VisiblePosition(r->endContainer(exception), r->endOffset(exception), affinity);
+}
+
+bool setStart(Range *r, const VisiblePosition &visiblePosition)
+{
+    if (!r)
+        return false;
+    Position p = rangeCompliantEquivalent(visiblePosition);
+    int code = 0;
+    r->setStart(p.node(), p.offset(), code);
+    return code == 0;
+}
+
+bool setEnd(Range *r, const VisiblePosition &visiblePosition)
+{
+    if (!r)
+        return false;
+    Position p = rangeCompliantEquivalent(visiblePosition);
+    int code = 0;
+    r->setEnd(p.node(), p.offset(), code);
+    return code == 0;
+}
+
+Node *enclosingBlockFlowElement(const VisiblePosition &visiblePosition)
+{
+    if (visiblePosition.isNull())
+        return NULL;
+
+    return visiblePosition.deepEquivalent().node()->enclosingBlockFlowElement();
+}
+
+bool isFirstVisiblePositionInNode(const VisiblePosition &visiblePosition, const Node *node)
+{
+    if (visiblePosition.isNull())
+        return false;
+    
+    if (!visiblePosition.deepEquivalent().node()->isDescendantOf(node))
+        return false;
+        
+    VisiblePosition previous = visiblePosition.previous();
+    return previous.isNull() || !previous.deepEquivalent().node()->isDescendantOf(node);
+}
+
+bool isLastVisiblePositionInNode(const VisiblePosition &visiblePosition, const Node *node)
+{
+    if (visiblePosition.isNull())
+        return false;
+    
+    if (!visiblePosition.deepEquivalent().node()->isDescendantOf(node))
+        return false;
+                
+    VisiblePosition next = visiblePosition.next();
+    return next.isNull() || !next.deepEquivalent().node()->isDescendantOf(node);
+}
+
+}  // namespace WebCore
+
+#ifndef NDEBUG
+
+void showTree(const WebCore::VisiblePosition* vpos)
+{
+    if (vpos)
+        vpos->showTreeForThis();
+}
+
+void showTree(const WebCore::VisiblePosition& vpos)
+{
+    vpos.showTreeForThis();
+}
+
+#endif