/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla 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/MPL/
 *
 * 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 TransforMiiX XSLT processor code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Peter Van der Beken <peterv@propagandism.org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * 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"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * ***** END LICENSE BLOCK ***** */

#ifndef nsXPathExpression_h__
#define nsXPathExpression_h__

#include "nsIDOMXPathExpression.h"
#include "nsIDOMNSXPathExpression.h"
#include "txIXPathContext.h"
#include "txResultRecycler.h"
#include "nsAutoPtr.h"
#include "nsCycleCollectionParticipant.h"

class Expr;
class txXPathNode;

/**
 * A class for evaluating an XPath expression string
 */
class nsXPathExpression : public nsIDOMXPathExpression,
                          public nsIDOMNSXPathExpression
{
public:
    nsXPathExpression(nsAutoPtr<Expr>& aExpression, txResultRecycler* aRecycler,
                      nsIDOMDocument *aDocument);

    // nsISupports interface
    NS_DECL_CYCLE_COLLECTING_ISUPPORTS
    NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsXPathExpression,
                                             nsIDOMXPathExpression)

    // nsIDOMXPathExpression interface
    NS_DECL_NSIDOMXPATHEXPRESSION

    // nsIDOMNSXPathExpression interface
    NS_DECL_NSIDOMNSXPATHEXPRESSION

private:
    nsAutoPtr<Expr> mExpression;
    nsRefPtr<txResultRecycler> mRecycler;
    nsCOMPtr<nsIDOMDocument> mDocument;

    class EvalContextImpl : public txIEvalContext
    {
    public:
        EvalContextImpl(const txXPathNode& aContextNode,
                        PRUint32 aContextPosition, PRUint32 aContextSize,
                        txResultRecycler* aRecycler)
            : mContextNode(aContextNode),
              mContextPosition(aContextPosition),
              mContextSize(aContextSize),
              mLastError(NS_OK),
              mRecycler(aRecycler)
        {
        }

        nsresult getError()
        {
            return mLastError;
        }

        TX_DECL_EVAL_CONTEXT;

    private:
        const txXPathNode& mContextNode;
        PRUint32 mContextPosition;
        PRUint32 mContextSize;
        nsresult mLastError;
        nsRefPtr<txResultRecycler> mRecycler;
    };
};

#endif
