gecko/dom/file/AsyncHelper.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* 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/. */
#ifndef mozilla_dom_file_asynchelper_h__
#define mozilla_dom_file_asynchelper_h__
#include "FileCommon.h"
#include "nsIRequest.h"
#include "nsIRunnable.h"
class nsIRequestObserver;
BEGIN_FILE_NAMESPACE
/**
* Must be subclassed. The subclass must implement DoStreamWork.
* Async operations that are not supported in necko (truncate, flush, etc.)
* should use this helper. Call AsyncWork to invoke the operation.
*/
class AsyncHelper : public nsIRunnable,
public nsIRequest
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIRUNNABLE
NS_DECL_NSIREQUEST
nsresult
AsyncWork(nsIRequestObserver* aObserver, nsISupports* aCtxt);
protected:
AsyncHelper(nsISupports* aStream)
: mStream(aStream),
mStatus(NS_OK)
{ }
virtual ~AsyncHelper()
{ }
virtual nsresult
DoStreamWork(nsISupports* aStream) = 0;
private:
nsCOMPtr<nsISupports> mStream;
nsCOMPtr<nsIRequestObserver> mObserver;
nsresult mStatus;
};
END_FILE_NAMESPACE
#endif // mozilla_dom_file_asynchelper_h__