text: /*
   * Copyright (C) 2007, 2008 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 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 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. 
   */
  
  #ifndef PositionIterator_h
  #define PositionIterator_h
  
  #include "Node.h"
  #include "Position.h"
  
  namespace WebCore {
  
  // A Position iterator with constant-time
  // increment, decrement, and several predicates on the Position it is at.
  // Conversion to/from Position is O(n) in the offset.
  class PositionIterator {
  public:
      PositionIterator()
          : m_anchorNode(0)
          , m_nodeAfterPositionInAnchor(0)
          , m_offsetInAnchor(0)
      {
      }
  
      PositionIterator(const Position& pos)
          : m_anchorNode(pos.anchorNode())
          , m_nodeAfterPositionInAnchor(m_anchorNode->childNode(pos.deprecatedEditingOffset()))
          , m_offsetInAnchor(m_nodeAfterPositionInAnchor ? 0 : pos.deprecatedEditingOffset())
      {
      }
      operator Position() const;
  
      void increment();
      void decrement();
  
      Node* node() const { return m_anchorNode; }
      int offsetInLeafNode() const { return m_offsetInAnchor; }
  
      bool atStart() const;
      bool atEnd() const;
      bool atStartOfNode() const;
      bool atEndOfNode() const;
      bool isCandidate() const;
  
  private:
      Node* m_anchorNode;
      Node* m_nodeAfterPositionInAnchor; // If this is non-null, m_nodeAfterPositionInAnchor->parentNode() == m_anchorNode;
      int m_offsetInAnchor;
  };
  
  } // namespace WebCore
  
  #endif // PositionIterator_h
  