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 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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#ifndef __nsIContentIterator_h___
#define __nsIContentIterator_h___

#include "nsISupports.h"


class nsIFocusTracker;
class nsIContent;
class nsIDOMRange;

#define NS_ICONTENTITERTOR_IID \
{0xa6cf90e4, 0x15b3, 0x11d2,   \
{0x93, 0x2e, 0x00, 0x80, 0x5f, 0x8a, 0xdd, 0x32} }

// {B4BC9F63-D9BA-11d3-9938-00108301233C}
#define NS_IGENERATEDCONTENTITERTOR_IID \
{ 0xb4bc9f63, 0xd9ba, 0x11d3,  \
{ 0x99, 0x38, 0x0, 0x10, 0x83, 0x1, 0x23, 0x3c } }


class nsIContentIterator : public nsISupports
{
public:
  NS_DEFINE_STATIC_IID_ACCESSOR(NS_ICONTENTITERTOR_IID)

  /* Initializes an iterator for the subtree rooted by the node aRoot
   */
  virtual nsresult Init(nsIContent* aRoot) = 0;

  /* Initializes an iterator for the subtree defined by the range aRange
   */
  virtual nsresult Init(nsIDOMRange* aRange) = 0;

  /** First will reset the list.
   */
  virtual void First() = 0;

  /** Last will reset the list to the end.
   */
  virtual void Last() = 0;

  /** Next will advance the list.
   */
  virtual void Next() = 0;

  /** Prev will decrement the list.
   */
  virtual void Prev() = 0;

  /** CurrentItem will return the current item, or null if the list is empty
   *  @return the current node
   */
  virtual nsIContent *GetCurrentNode() = 0;

  /** return if the collection is at the end. that is the beginning following a call to Prev
   *  and it is the end of the list following a call to next
   *  @return if the iterator is done.
   */
  virtual PRBool IsDone() = 0;

  /** PositionAt will position the iterator to the supplied node
   */
  virtual nsresult PositionAt(nsIContent* aCurNode) = 0;
};

class nsIPresShell;

class nsIGeneratedContentIterator : public nsISupports {
public:

  NS_DEFINE_STATIC_IID_ACCESSOR(NS_IGENERATEDCONTENTITERTOR_IID)

  /* Initializes an iterator for the subtree rooted by the node aRoot
   */
  virtual nsresult Init(nsIPresShell *aShell, nsIDOMRange* aRange) = 0;

  virtual nsresult Init(nsIPresShell *aShell, nsIContent* aContent) = 0;
};


#endif // __nsIContentIterator_h___

