modules/libpr0n/src/imgTools.cpp
author Bobby Holley <bobbyholley@gmail.com>
Sun, 12 Sep 2010 08:22:26 -0700
changeset 53660 dbdd01fabe455d0497143136fc68264279f00f1f
parent 51248 3d3fd377d82e34d6f3f3740aa1c969698880cde5
child 70762 0417dfeeb4407948353f331368e8e433f61e0019
permissions -rw-r--r--
Bug 593489 - Make Image hold onto its URI.r=joe,a=blockerblocker

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
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 *
 * 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 Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2007
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Justin Dolske <dolske@mozilla.com> (original author)
 *
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 * 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"),
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#include "imgTools.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "ImageErrors.h"
#include "imgIContainer.h"
#include "imgIEncoder.h"
#include "imgIDecoderObserver.h"
#include "imgIContainerObserver.h"
#include "gfxContext.h"
#include "nsStringStream.h"
#include "nsComponentManagerUtils.h"
#include "nsWeakReference.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsStreamUtils.h"
#include "nsNetUtil.h"
#include "RasterImage.h"

using namespace mozilla::imagelib;

/* ========== imgITools implementation ========== */



NS_IMPL_ISUPPORTS1(imgTools, imgITools)

imgTools::imgTools()
{
  /* member initializers and constructor code */
}

imgTools::~imgTools()
{
  /* destructor code */
}


NS_IMETHODIMP imgTools::DecodeImageData(nsIInputStream* aInStr,
                                        const nsACString& aMimeType,
                                        imgIContainer **aContainer)
{
  nsresult rv;
  RasterImage* image;  // convenience alias for *aContainer

  NS_ENSURE_ARG_POINTER(aInStr);

  // If the caller didn't provide an imgIContainer, create one.
  if (*aContainer) {
    NS_ABORT_IF_FALSE((*aContainer)->GetType() == imgIContainer::TYPE_RASTER,
                      "wrong type of imgIContainer for decoding into");
    image = static_cast<RasterImage*>(*aContainer);
  } else {
    *aContainer = image = new RasterImage();
    NS_ADDREF(image);
  }

  // Initialize the Image. If we're using the one from the caller, we
  // require that it not be initialized.
  nsCString mimeType(aMimeType);
  rv = image->Init(nsnull, mimeType.get(), "<unknown>", Image::INIT_FLAG_NONE);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIInputStream> inStream = aInStr;
  if (!NS_InputStreamIsBuffered(aInStr)) {
    nsCOMPtr<nsIInputStream> bufStream;
    rv = NS_NewBufferedInputStream(getter_AddRefs(bufStream), aInStr, 1024);
    if (NS_SUCCEEDED(rv))
      inStream = bufStream;
  }

  // Figure out how much data we've been passed
  PRUint32 length;
  rv = inStream->Available(&length);
  NS_ENSURE_SUCCESS(rv, rv);

  // Send the source data to the Image. WriteToRasterImage always
  // consumes everything it gets.
  PRUint32 bytesRead;
  rv = inStream->ReadSegments(RasterImage::WriteToRasterImage,
                              static_cast<void*>(image),
                              length, &bytesRead);
  NS_ENSURE_SUCCESS(rv, rv);
  NS_ABORT_IF_FALSE(bytesRead == length, "WriteToRasterImage should consume everything!");


  // Let the Image know we've sent all the data
  rv = image->SourceDataComplete();
  NS_ENSURE_SUCCESS(rv, rv);

  // All done
  return NS_OK;
}


NS_IMETHODIMP imgTools::EncodeImage(imgIContainer *aContainer,
                                    const nsACString& aMimeType,
                                    nsIInputStream **aStream)
{
    return EncodeScaledImage(aContainer, aMimeType, 0, 0, aStream);
}


NS_IMETHODIMP imgTools::EncodeScaledImage(imgIContainer *aContainer,
                                          const nsACString& aMimeType,
                                          PRInt32 aScaledWidth,
                                          PRInt32 aScaledHeight,
                                          nsIInputStream **aStream)
{
  nsresult rv;
  PRBool doScaling = PR_TRUE;
  PRUint8 *bitmapData;
  PRUint32 bitmapDataLength, strideSize;

  // If no scaled size is specified, we'll just encode the image at its
  // original size (no scaling).
  if (aScaledWidth == 0 && aScaledHeight == 0) {
    doScaling = PR_FALSE;
  } else {
    NS_ENSURE_ARG(aScaledWidth > 0);
    NS_ENSURE_ARG(aScaledHeight > 0);
  }

  // Get an image encoder for the media type
  nsCAutoString encoderCID(
    NS_LITERAL_CSTRING("@mozilla.org/image/encoder;2?type=") + aMimeType);

  nsCOMPtr<imgIEncoder> encoder = do_CreateInstance(encoderCID.get());
  if (!encoder)
    return NS_IMAGELIB_ERROR_NO_ENCODER;

  // Use frame 0 from the image container.
  nsRefPtr<gfxImageSurface> frame;
  rv = aContainer->CopyFrame(imgIContainer::FRAME_CURRENT, PR_TRUE,
                             getter_AddRefs(frame));
  NS_ENSURE_SUCCESS(rv, rv);
  if (!frame)
    return NS_ERROR_NOT_AVAILABLE;

  PRInt32 w = frame->Width(), h = frame->Height();
  if (!w || !h)
    return NS_ERROR_FAILURE;

  nsRefPtr<gfxImageSurface> dest;

  if (!doScaling) {
    // If we're not scaling the image, use the actual width/height.
    aScaledWidth  = w;
    aScaledHeight = h;

    bitmapData = frame->Data();
    if (!bitmapData)
      return NS_ERROR_FAILURE;

    strideSize = frame->Stride();
    bitmapDataLength = aScaledHeight * strideSize;

  } else {
    // Prepare to draw a scaled version of the image to a temporary surface...

    // Create a temporary image surface
    dest = new gfxImageSurface(gfxIntSize(aScaledWidth, aScaledHeight),
                               gfxASurface::ImageFormatARGB32);
    if (!dest)
      return NS_ERROR_OUT_OF_MEMORY;

    gfxContext ctx(dest);

    // Set scaling
    gfxFloat sw = (double) aScaledWidth / w;
    gfxFloat sh = (double) aScaledHeight / h;
    ctx.Scale(sw, sh);

    // Paint a scaled image
    ctx.SetOperator(gfxContext::OPERATOR_SOURCE);
    ctx.SetSource(frame);
    ctx.Paint();

    bitmapData = dest->Data();
    strideSize = dest->Stride();
    bitmapDataLength = aScaledHeight * strideSize;
  }

  // Encode the bitmap
  rv = encoder->InitFromData(bitmapData, bitmapDataLength,
                             aScaledWidth, aScaledHeight, strideSize,
                             imgIEncoder::INPUT_FORMAT_HOSTARGB, EmptyString());

  NS_ENSURE_SUCCESS(rv, rv);

  return CallQueryInterface(encoder, aStream);
}