/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISerializable.idl"
#include "nsIEnumerator.idl"

[scriptable, uuid(83b6019c-cbc4-11d2-8cca-0060b0fc14a3)]
interface nsICollection : nsISerializable
{

  PRUint32 Count();
  nsISupports GetElementAt(in PRUint32 index);
  void QueryElementAt(in PRUint32 index, in nsIIDRef uuid, 
                      [iid_is(uuid),retval] out nsQIResult result);
  void SetElementAt(in PRUint32 index, in nsISupports item);
  void AppendElement(in nsISupports item);
  void RemoveElement(in nsISupports item);

  nsIEnumerator Enumerate();

  void Clear();

};

%{C++

#ifndef nsCOMPtr_h__
#include "nsCOMPtr.h"
#endif

class nsQueryElementAt : public nsCOMPtr_helper
  {
    public:
      nsQueryElementAt( nsICollection* aCollection, PRUint32 aIndex, nsresult* aErrorPtr )
          : mCollection(aCollection),
            mIndex(aIndex),
            mErrorPtr(aErrorPtr)
        {
          // nothing else to do here
        }

      virtual nsresult NS_FASTCALL operator()( const nsIID& aIID, void** ) const;

    private:
      nsICollection*  mCollection;
      PRUint32        mIndex;
      nsresult*       mErrorPtr;
  };

inline
const nsQueryElementAt
do_QueryElementAt( nsICollection* aCollection, PRUint32 aIndex, nsresult* aErrorPtr = 0 )
  {
    return nsQueryElementAt(aCollection, aIndex, aErrorPtr);
  }

%}