Make ElementTraversal / NodeTraversal classes for clarity

Source/core/dom/NodeTraversal.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
+ * Copyright (C) 2014 Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef NodeTraversal_h
 #define NodeTraversal_h
 
 #include "core/dom/Node.h"
 
 namespace WebCore {
 
-namespace NodeTraversal {
+class NodeTraversal {
+public:
+    // Does a pre-order traversal of the tree to find the next node after this one.
+    // This uses the same order that tags appear in the source file. If the stayWithin
+    // argument is non-null, the traversal will stop once the specified node is reached.
+    // This can be used to restrict traversal to a particular sub-tree.
+    static Node* next(const Node& current) { return traverseNextTemplate(current); }
+    static Node* next(const ContainerNode& current) { return traverseNextTemplate(current); }
+    static Node* next(const Node& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
+    static Node* next(const ContainerNode& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
 
-// Does a pre-order traversal of the tree to find the next node after this one.
-// This uses the same order that tags appear in the source file. If the stayWithin
-// argument is non-null, the traversal will stop once the specified node is reached.
-// This can be used to restrict traversal to a particular sub-tree.
-Node* next(const Node&);
-Node* next(const Node&, const Node* stayWithin);
-Node* next(const ContainerNode&);
-Node* next(const ContainerNode&, const Node* stayWithin);
+    // Like next, but skips children and starts with the next sibling.
+    static Node* nextSkippingChildren(const Node& current) { return traverseNextSkippingChildrenTemplate(current); }
+    static Node* nextSkippingChildren(const ContainerNode& current) { return traverseNextSkippingChildrenTemplate(current); }
+    static Node* nextSkippingChildren(const Node& current, const Node* stayWithin) { return traverseNextSkippingChildrenTemplate(current, stayWithin); }
+    static Node* nextSkippingChildren(const ContainerNode& current, const Node* stayWithin) { return traverseNextSkippingChildrenTemplate(current, stayWithin); }
 
-// Like next, but skips children and starts with the next sibling.
-Node* nextSkippingChildren(const Node&);
-Node* nextSkippingChildren(const Node&, const Node* stayWithin);
-Node* nextSkippingChildren(const ContainerNode&);
-Node* nextSkippingChildren(const ContainerNode&, const Node* stayWithin);
+    // Does a reverse pre-order traversal to find the node that comes before the current one in document order
+    static Node* previous(const Node&, const Node* stayWithin = 0);
 
-// Does a reverse pre-order traversal to find the node that comes before the current one in document order
-Node* previous(const Node&, const Node* stayWithin = 0);
+    // Like previous, but skips children and starts with the next sibling.
+    static Node* previousSkippingChildren(const Node&, const Node* stayWithin = 0);
 
-// Like previous, but skips children and starts with the next sibling.
-Node* previousSkippingChildren(const Node&, const Node* stayWithin = 0);
+    // Like next, but visits parents after their children.
+    static Node* nextPostOrder(const Node&, const Node* stayWithin = 0);
 
-// Like next, but visits parents after their children.
-Node* nextPostOrder(const Node&, const Node* stayWithin = 0);
+    // Like previous, but visits parents before their children.
+    static Node* previousPostOrder(const Node&, const Node* stayWithin = 0);
 
-// Like previous, but visits parents before their children.
-Node* previousPostOrder(const Node&, const Node* stayWithin = 0);
+    // Pre-order traversal including the pseudo-elements.
+    static Node* previousIncludingPseudo(const Node&, const Node* stayWithin = 0);
+    static Node* nextIncludingPseudo(const Node&, const Node* stayWithin = 0);
+    static Node* nextIncludingPseudoSkippingChildren(const Node&, const Node* stayWithin = 0);
 
-// Pre-order traversal including the pseudo-elements.
-Node* previousIncludingPseudo(const Node&, const Node* stayWithin = 0);
-Node* nextIncludingPseudo(const Node&, const Node* stayWithin = 0);
-Node* nextIncludingPseudoSkippingChildren(const Node&, const Node* stayWithin = 0);
+    static Node* nextAncestorSibling(const Node&);
+    static Node* nextAncestorSibling(const Node&, const Node* stayWithin);
 
-Node* nextAncestorSibling(const Node&);
-Node* nextAncestorSibling(const Node&, const Node* stayWithin);
+private:
+    template <class NodeType>
+    static Node* traverseNextTemplate(NodeType&);
+    template <class NodeType>
+    static Node* traverseNextTemplate(NodeType&, const Node* stayWithin);
+    template <class NodeType>
+    static Node* traverseNextSkippingChildrenTemplate(NodeType&);
+    template <class NodeType>
+    static Node* traverseNextSkippingChildrenTemplate(NodeType&, const Node* stayWithin);
+};
 
 template <class NodeType>
-inline Node* traverseNextTemplate(NodeType& current)
+inline Node* NodeTraversal::traverseNextTemplate(NodeType& current)
 {
     if (current.firstChild())
         return current.firstChild();
     if (current.nextSibling())
         return current.nextSibling();
     return nextAncestorSibling(current);
 }
-inline Node* next(const Node& current) { return traverseNextTemplate(current); }
-inline Node* next(const ContainerNode& current) { return traverseNextTemplate(current); }
 
 template <class NodeType>
-inline Node* traverseNextTemplate(NodeType& current, const Node* stayWithin)
+inline Node* NodeTraversal::traverseNextTemplate(NodeType& current, const Node* stayWithin)
 {
     if (current.firstChild())
         return current.firstChild();
     if (current == stayWithin)
         return 0;
     if (current.nextSibling())
         return current.nextSibling();
     return nextAncestorSibling(current, stayWithin);
 }
-inline Node* next(const Node& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
-inline Node* next(const ContainerNode& current, const Node* stayWithin) { return traverseNextTemplate(current, stayWithin); }
 
 template <class NodeType>
-inline Node* traverseNextSkippingChildrenTemplate(NodeType& current)
+inline Node* NodeTraversal::traverseNextSkippingChildrenTemplate(NodeType& current)
 {
     if (current.nextSibling())
         return current.nextSibling();
     return nextAncestorSibling(current);
 }
-inline Node* nextSkippingChildren(const Node& current) { return traverseNextSkippingChildrenTemplate(current); }
-inline Node* nextSkippingChildren(const ContainerNode& current) { return traverseNextSkippingChildrenTemplate(current); }
 
 template <class NodeType>
-inline Node* traverseNextSkippingChildrenTemplate(NodeType& current, const Node* stayWithin)
+inline Node* NodeTraversal::traverseNextSkippingChildrenTemplate(NodeType& current, const Node* stayWithin)
 {
     if (current == stayWithin)
         return 0;
     if (current.nextSibling())
         return current.nextSibling();
     return nextAncestorSibling(current, stayWithin);
 }
-inline Node* nextSkippingChildren(const Node& current, const Node* stayWithin) { return traverseNextSkippingChildrenTemplate(current, stayWithin); }
-inline Node* nextSkippingChildren(const ContainerNode& current, const Node* stayWithin) { return traverseNextSkippingChildrenTemplate(current, stayWithin); }
 
-}
-
-}
+} // namespace WebCore
 
 #endif