gecko-dev/image/decoders/nsIconDecoder.cpp

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4.9 KiB
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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):
* Scott MacGregor <mscott@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
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* decision by deleting the provisions above and replace them with the notice
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* ***** END LICENSE BLOCK ***** */
#include "nsIconDecoder.h"
#include "nsIInputStream.h"
#include "RasterImage.h"
#include "imgIContainerObserver.h"
#include "nspr.h"
#include "nsRect.h"
#include "ImageErrors.h"
namespace mozilla {
namespace image {
nsIconDecoder::nsIconDecoder(RasterImage &aImage, imgIDecoderObserver* aObserver)
: Decoder(aImage, aObserver),
mWidth(-1),
mHeight(-1),
mPixBytesRead(0),
mPixBytesTotal(0),
mImageData(nsnull),
mState(iconStateStart)
{
// Nothing to do
}
nsIconDecoder::~nsIconDecoder()
{ }
void
nsIconDecoder::WriteInternal(const char *aBuffer, PRUint32 aCount)
{
NS_ABORT_IF_FALSE(!HasError(), "Shouldn't call WriteInternal after error!");
// We put this here to avoid errors about crossing initialization with case
// jumps on linux.
PRUint32 bytesToRead = 0;
nsresult rv;
// Performance isn't critical here, so our update rectangle is
// always the full icon
nsIntRect r(0, 0, mWidth, mHeight);
// Loop until the input data is gone
while (aCount > 0) {
switch (mState) {
case iconStateStart:
// Grab the width
mWidth = (PRUint8)*aBuffer;
// Book Keeping
aBuffer++;
aCount--;
mState = iconStateHaveHeight;
break;
case iconStateHaveHeight:
// Grab the Height
mHeight = (PRUint8)*aBuffer;
// Post our size to the superclass
PostSize(mWidth, mHeight);
if (HasError()) {
// Setting the size lead to an error; this can happen when for example
// a multipart channel sends an image of a different size.
mState = iconStateFinished;
return;
}
// If We're doing a size decode, we're done
if (IsSizeDecode()) {
mState = iconStateFinished;
break;
}
// Add the frame and signal
rv = mImage.EnsureFrame(0, 0, 0, mWidth, mHeight,
gfxASurface::ImageFormatARGB32,
&mImageData, &mPixBytesTotal);
if (NS_FAILED(rv)) {
PostDecoderError(rv);
return;
}
// Tell the superclass we're starting a frame
PostFrameStart();
// Book Keeping
aBuffer++;
aCount--;
mState = iconStateReadPixels;
break;
case iconStateReadPixels:
// How many bytes are we reading?
bytesToRead = NS_MIN(aCount, mPixBytesTotal - mPixBytesRead);
// Copy the bytes
memcpy(mImageData + mPixBytesRead, aBuffer, bytesToRead);
// Invalidate
PostInvalidation(r);
// Book Keeping
aBuffer += bytesToRead;
aCount -= bytesToRead;
mPixBytesRead += bytesToRead;
// If we've got all the pixel bytes, we're finished
if (mPixBytesRead == mPixBytesTotal) {
PostFrameStop();
PostDecodeDone();
mState = iconStateFinished;
}
break;
case iconStateFinished:
// Consume all excess data silently
aCount = 0;
break;
}
}
}
} // namespace image
} // namespace mozilla