Move Node/ContainerNode's traverseToChildAt() to NodeTraversal

Source/core/dom/Position.cpp

 /*
  * 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
@@ skipping 216 matching lines @@
 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.
+        return m_offset ? NodeTraversal::childAt(*m_anchorNode, m_offset - 1) : 0;
     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);
+        return NodeTraversal::childAt(*m_anchorNode, 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)
@@ skipping 27 matching lines @@
 {
     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))
+        if (Node* child = NodeTraversal::childAt(*node, 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);
@@ skipping 14 matching lines @@
     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))
+    if (Node* child = NodeTraversal::childAt(*node, 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);
     }
@@ skipping 952 matching lines @@
     pos.showTreeForThis();
 }
 
 void showTree(const blink::Position* pos)
 {
     if (pos)
         pos->showTreeForThis();
 }
 
 #endif