gecko/modules/libpr0n/public/imgIDecoder.idl

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* ***** 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 mozilla.org 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):
* Stuart Parmenter <pavlov@netscape.com>
* Bobby Holley <bobbyholley@gmail.com>
*
* 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
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsISupports.idl"
interface nsIInputStream;
interface imgIContainer;
interface imgIDecoderObserver;
/**
* imgIDecoder interface
*
* @author Stuart Parmenter <pavlov@netscape.com>
* @version 0.2
* @see imagelib2
*/
[scriptable, uuid(139c6f97-cd2f-4a4f-890d-8d9f4a693682)]
interface imgIDecoder : nsISupports
{
/**
* Bits that can be passed to the decoder to affect decoding.
* @name decodeflags
*
* Meanings:
*
* DECODER_FLAG_NONE: No flags
*
* DECODER_FLAG_HEADERONLY: Read basic data from the image in order to
* set up the image container, but don't read any actual image data.
*/
const long DECODER_FLAG_NONE = 0x0;
const long DECODER_FLAG_HEADERONLY = 0x1;
/**
* Initialize an image decoder.
* @param aContainer The image container to decode to.
* @param aObserver The observer for decode notification events.
* @param aFlags Flags for the decoder
*
* @note The decoder should always pass NULL as the
* first two parameters to all of the imgIDecoderObserver APIs.
*/
void init(in imgIContainer aImage, in imgIDecoderObserver aObserver,
in unsigned long aFlags);
/**
* Closes the stream.
* @param aFlags Close flags of the CLOSE_FLAG_* Variety
*
* Resources are always freed with this call. If notifications are sent,
* OnStopDecode is guaranteed to be called if it hasn't been called already.
*
* CLOSE_FLAG_DONTNOTIFY - Don't send any observer notifications, and don't
* call imgIContainer::decodingComplete().
*/
const long CLOSE_FLAG_DONTNOTIFY = 0x01;
void close(in PRUint32 aFlags);
/**
* Flushes the stream.
*/
void flush();
/**
* Writes data into the stream from an input stream.
*
* For Header-Only decodes, OnStartContainer is the only notification
* fired.
*
* If a decoding error occurs, an internal flag is set and an error is
* returned. Each subsequent call to writeFrom will fail immediately
* for the lifetime of the decoder. Shutdown notifications of the OnStopX
* variety, as well as DecodingComplete(), are guaranteed not to be called
* if a decoding error occurs.
*
* Implementer's note: This method is defined by this interface in order
* to allow the output stream to efficiently copy the data from the input
* stream into its internal buffer (if any). If this method was provide
* as an external facility, a separate char* buffer would need to be used
* in order to call the output stream's other Write method.
* @param fromStream the stream from which the data is read
* @param count the maximun number of bytes to write
*/
void writeFrom(in nsIInputStream inStr, in unsigned long count);
};