image/ImageOps.h
author Carsten "Tomcat" Book <cbook@mozilla.com>
Wed, 10 Feb 2016 11:47:34 +0100
changeset 283775 7042e8a19f94d6e075ec149567aea74dfd06c392
parent 255729 4d7cd400d799e73e54c7d81d8379df7c097fb3c4
child 287144 5d03f2103664bbc4b024fe73213883f32afe8535
permissions -rw-r--r--
merge mozilla-inbound to mozilla-central a=merge

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * 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_image_ImageOps_h
#define mozilla_image_ImageOps_h

#include "nsCOMPtr.h"
#include "nsRect.h"

class gfxDrawable;
class imgIContainer;
class nsIInputStream;

namespace mozilla {

namespace gfx {
class SourceSurface;
}

namespace image {

class Image;
struct Orientation;

class ImageOps
{
public:
  /**
   * Creates a version of an existing image which does not animate and is frozen
   * at the first frame.
   *
   * @param aImage         The existing image.
   */
  static already_AddRefed<Image> Freeze(Image* aImage);
  static already_AddRefed<imgIContainer> Freeze(imgIContainer* aImage);

  /**
   * Creates a clipped version of an existing image. Animation is unaffected.
   *
   * @param aImage         The existing image.
   * @param aClip          The rectangle to clip the image against.
   */
  static already_AddRefed<Image> Clip(Image* aImage, nsIntRect aClip);
  static already_AddRefed<imgIContainer> Clip(imgIContainer* aImage,
                                              nsIntRect aClip);

  /**
   * Creates a version of an existing image which is rotated and/or flipped to
   * the specified orientation.
   *
   * @param aImage         The existing image.
   * @param aOrientation   The desired orientation.
   */
  static already_AddRefed<Image> Orient(Image* aImage,
                                        Orientation aOrientation);
  static already_AddRefed<imgIContainer> Orient(imgIContainer* aImage,
                                                Orientation aOrientation);

  /**
   * Creates an image from a gfxDrawable.
   *
   * @param aDrawable      The gfxDrawable.
   */
  static already_AddRefed<imgIContainer>
  CreateFromDrawable(gfxDrawable* aDrawable);

  /**
   * Decodes an image from an nsIInputStream directly into a SourceSurface,
   * without ever creating an Image or imgIContainer (which are mostly
   * main-thread-only). That means that this function may be called
   * off-main-thread.
   *
   * @param aInputStream An input stream containing an encoded image.
   * @param aMimeType The MIME type of the image.
   * @param aFlags Flags of the imgIContainer::FLAG_DECODE_* variety.
   * @return A SourceSurface containing the first frame of the image at its
   *         intrinsic size, or nullptr if the image cannot be decoded.
   */
  static already_AddRefed<gfx::SourceSurface>
  DecodeToSurface(nsIInputStream* aInputStream,
                  const nsACString& aMimeType,
                  uint32_t aFlags);

private:
  // This is a static utility class, so disallow instantiation.
  virtual ~ImageOps() = 0;
};

} // namespace image
} // namespace mozilla

#endif // mozilla_image_ImageOps_h