/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, 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 Netscape are
 * Copyright (C) 2000 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s): 
 *   Scott Collins <scc@netscape.com>
 */

/* nsISupportsIterators.idl --- IDL defining general purpose iterators */


#include "nsISupports.idl"


  /*
    ...
  */


  /**
   * ...
   */
[scriptable, uuid(7330650e-1dd2-11b2-a0c2-9ff86ee97bed)]
interface nsIOutputIterator : nsISupports
  {
      /**
       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
       * The iterator and the underlying container or sequence cooperate to |Release()|
       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @param anElementToPut the element to place into the underlying container or sequence
       */
    void putElement( in nsISupports anElementToPut );

      /**
       * Advance this iterator to the next position in the underlying container or sequence.
       */
    void stepForward();
  };

  /**
   * ...
   */
[scriptable, uuid(85585e12-1dd2-11b2-a930-f6929058269a)]
interface nsIInputIterator : nsISupports
  {
      /**
       * Retrieve (and |AddRef()|) the element this iterator currently points to.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @result a new reference to the element this iterator currently points to (if any)
       */
    nsISupports getElement();

      /**
       * Advance this iterator to the next position in the underlying container or sequence.
       */
    void stepForward();

      /**
       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
       *
       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
       *
       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
       */
    boolean isEqualTo( in nsISupports anotherIterator );

      /**
       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
       *
       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
       */
    nsISupports clone();
  };

  /**
   * ...
   */
[scriptable, uuid(8da01646-1dd2-11b2-98a7-c7009045be7e)]
interface nsIForwardIterator : nsISupports
  {
      /**
       * Retrieve (and |AddRef()|) the element this iterator currently points to.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @result a new reference to the element this iterator currently points to (if any)
       */
    nsISupports getElement();

      /**
       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
       * The iterator and the underlying container or sequence cooperate to |Release()|
       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @param anElementToPut the element to place into the underlying container or sequence
       */
    void putElement( in nsISupports anElementToPut );

      /**
       * Advance this iterator to the next position in the underlying container or sequence.
       */
    void stepForward();

      /**
       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
       *
       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
       *
       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
       */
    boolean isEqualTo( in nsISupports anotherIterator );

      /**
       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
       *
       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
       */
    nsISupports clone();
  };

  /**
   * ...
   */
[scriptable, uuid(948defaa-1dd1-11b2-89f6-8ce81f5ebda9)]
interface nsIBidirectionalIterator : nsISupports
  {
      /**
       * Retrieve (and |AddRef()|) the element this iterator currently points to.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @result a new reference to the element this iterator currently points to (if any)
       */
    nsISupports getElement();

      /**
       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
       * The iterator and the underlying container or sequence cooperate to |Release()|
       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @param anElementToPut the element to place into the underlying container or sequence
       */
    void putElement( in nsISupports anElementToPut );

      /**
       * Advance this iterator to the next position in the underlying container or sequence.
       */
    void stepForward();

      /**
       * Move this iterator to the previous position in the underlying container or sequence.
       */
    void stepBackward();

      /**
       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
       *
       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
       *
       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
       */
    boolean isEqualTo( in nsISupports anotherIterator );

      /**
       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
       *
       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
       */
    nsISupports clone();
  };

  /**
   * ...
   */
[scriptable, uuid(9bd6fdb0-1dd1-11b2-9101-d15375968230)]
interface nsIRandomAccessIterator : nsISupports
  {
      /**
       * Retrieve (and |AddRef()|) the element this iterator currently points to.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @result a new reference to the element this iterator currently points to (if any)
       */
    nsISupports getElement();

      /**
       * Retrieve (and |AddRef()|) an element at some offset from where this iterator currently points.
       * The offset may be negative.  |getElementAt(0)| is equivalent to |getElement()|.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @param anOffset a |0|-based offset from the position to which this iterator currently points
       * @result a new reference to the indicated element (if any)
       */
    nsISupports getElementAt( in PRInt32 anOffset );

      /**
       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
       * The iterator and the underlying container or sequence cooperate to |Release()|
       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @param anElementToPut the element to place into the underlying container or sequence
       */
    void putElement( in nsISupports anElementToPut );

      /**
       * Put |anElementToPut| into the underlying container or sequence at the position |anOffset| away from that currently pointed to by this iterator.
       * The iterator and the underlying container or sequence cooperate to |Release()|
       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
       * |putElementAt(0, obj)| is equivalent to |putElement(obj)|.
       *
       * The result is undefined if this iterator currently points outside the
       * useful range of the underlying container or sequence.
       *
       * @param anOffset a |0|-based offset from the position to which this iterator currently points
       * @param anElementToPut the element to place into the underlying container or sequence
       */
    void putElementAt( in PRInt32 anOffset, in nsISupports anElementToPut );

      /**
       * Advance this iterator to the next position in the underlying container or sequence.
       */
    void stepForward();

      /**
       * Move this iterator by |anOffset| positions in the underlying container or sequence.
       * |anOffset| may be negative.  |stepForwardBy(1)| is equivalent to |stepForward()|.
       * |stepForwardBy(0)| is a no-op.
       *
       * @param anOffset a |0|-based offset from the position to which this iterator currently points
       */
    void stepForwardBy( in PRInt32 anOffset );

      /**
       * Move this iterator to the previous position in the underlying container or sequence.
       */
    void stepBackward();

      /**
       * Move this iterator backwards by |anOffset| positions in the underlying container or sequence.
       * |anOffset| may be negative.  |stepBackwardBy(1)| is equivalent to |stepBackward()|.
       * |stepBackwardBy(n)| is equivalent to |stepForwardBy(-n)|.  |stepBackwardBy(0)| is a no-op.
       *
       * @param anOffset a |0|-based offset from the position to which this iterator currently points
       */
    void stepBackwardBy( in PRInt32 anOffset );

      /**
       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
       *
       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
       *
       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
       */
    boolean isEqualTo( in nsISupports anotherIterator );

      /**
       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
       *
       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
       */
    nsISupports clone();
  };

%{C++
%}