/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998, 1999 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

#ifndef nsMsgTxn_h__
#define nsMsgTxn_h__

#include "nsITransaction.h"
#include "msgCore.h"

#define NS_MESSAGETRANSACTION_IID \
{ /* da621b30-1efc-11d3-abe4-00805f8ac968 */ \
    0xda621b30, 0x1efc, 0x11d3, \
	{ 0xab, 0xe4, 0x00, 0x80, 0x5f, 0x8a, 0xc9, 0x68 } }
/**
 * base class for all message undo/redo transactions.
 */
class NS_MSG_BASE nsMsgTxn : public nsITransaction
{
    NS_DECL_ISUPPORTS 

    nsMsgTxn();
    virtual ~nsMsgTxn();

    NS_IMETHOD Do(void);
    
    NS_IMETHOD Undo(void) = 0;
    
    NS_IMETHOD Redo(void) = 0;
    
    NS_IMETHOD GetIsTransient(PRBool *aIsTransient);

    NS_IMETHOD Merge(PRBool *aDidMerge, nsITransaction *aTransaction);

    NS_IMETHOD Write(nsIOutputStream *aOutputStream);

    NS_IMETHOD GetUndoString(nsString *aString);

    NS_IMETHOD GetRedoString(nsString *aString);

};

#endif