gecko-dev/gfx/layers/client/ImageClient.h

/* -*- Mode: C++; tab-width: 20; 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_GFX_IMAGECLIENT_H
#define MOZILLA_GFX_IMAGECLIENT_H

#include <stdint.h>                     // for uint32_t, uint64_t
#include <sys/types.h>                  // for int32_t
#include "mozilla/Attributes.h"         // for MOZ_OVERRIDE
#include "mozilla/RefPtr.h"             // for RefPtr, TemporaryRef
#include "mozilla/gfx/Types.h"          // for SurfaceFormat
#include "mozilla/layers/CompositableClient.h"  // for CompositableClient
#include "mozilla/layers/CompositorTypes.h"  // for CompositableType, etc
#include "mozilla/layers/LayersSurfaces.h"  // for SurfaceDescriptor
#include "mozilla/layers/TextureClient.h"  // for TextureClient, etc
#include "mozilla/mozalloc.h"           // for operator delete
#include "nsCOMPtr.h"                   // for already_AddRefed
#include "nsRect.h"                     // for nsIntRect

namespace mozilla {
namespace layers {

class CompositableForwarder;
class Image;
class ImageContainer;
class ShadowableLayer;

/**
 * Image clients are used by basic image layers on the content thread, they
 * always match with an ImageHost on the compositor thread. See
 * CompositableClient.h for information on connecting clients to hosts.
 */
class ImageClient : public CompositableClient
{
public:
  /**
   * Creates, configures, and returns a new image client. If necessary, a
   * message will be sent to the compositor to create a corresponding image
   * host.
   */
  static TemporaryRef<ImageClient> CreateImageClient(CompositableType aImageHostType,
                                                     CompositableForwarder* aFwd,
                                                     TextureFlags aFlags);

  virtual ~ImageClient() {}

  /**
   * Update this ImageClient from aContainer in aLayer
   * returns false if this is the wrong kind of ImageClient for aContainer.
   * Note that returning true does not necessarily imply success
   */
  virtual bool UpdateImage(ImageContainer* aContainer, uint32_t aContentFlags) = 0;

  /**
   * The picture rect is the area of the texture which makes up the image. That
   * is, the area that should be composited. In texture space.
   */
  virtual void UpdatePictureRect(nsIntRect aPictureRect);

  virtual already_AddRefed<Image> CreateImage(ImageFormat aFormat) = 0;

  /**
   * Synchronously remove all the textures used by the image client.
   */
  virtual void FlushAllImages(bool aExceptFront) {}

protected:
  ImageClient(CompositableForwarder* aFwd, TextureFlags aFlags,
              CompositableType aType);

  CompositableType mType;
  int32_t mLastPaintedImageSerial;
  nsIntRect mPictureRect;
};

/**
 * An image client which uses a single texture client.
 */
class ImageClientSingle : public ImageClient
{
public:
  ImageClientSingle(CompositableForwarder* aFwd,
                    TextureFlags aFlags,
                    CompositableType aType);

  virtual bool UpdateImage(ImageContainer* aContainer, uint32_t aContentFlags);

  virtual void OnDetach() MOZ_OVERRIDE;

  virtual bool AddTextureClient(TextureClient* aTexture) MOZ_OVERRIDE;

  virtual TextureInfo GetTextureInfo() const MOZ_OVERRIDE;

  virtual already_AddRefed<Image> CreateImage(ImageFormat aFormat) MOZ_OVERRIDE;

  virtual void FlushAllImages(bool aExceptFront) MOZ_OVERRIDE;

protected:
  virtual bool UpdateImageInternal(ImageContainer* aContainer, uint32_t aContentFlags, bool* aIsSwapped);

protected:
  RefPtr<TextureClient> mFrontBuffer;
};

/**
 * An image client which uses two texture clients.
 */
class ImageClientBuffered : public ImageClientSingle
{
public:
  ImageClientBuffered(CompositableForwarder* aFwd,
                      TextureFlags aFlags,
                      CompositableType aType);

  virtual bool UpdateImage(ImageContainer* aContainer, uint32_t aContentFlags);

  virtual void OnDetach() MOZ_OVERRIDE;

  virtual void FlushAllImages(bool aExceptFront) MOZ_OVERRIDE;

protected:
  RefPtr<TextureClient> mBackBuffer;
};

/**
 * Image class to be used for async image uploads using the image bridge
 * protocol.
 * We store the ImageBridge id in the TextureClientIdentifier.
 */
class ImageClientBridge : public ImageClient
{
public:
  ImageClientBridge(CompositableForwarder* aFwd,
                    TextureFlags aFlags);

  virtual bool UpdateImage(ImageContainer* aContainer, uint32_t aContentFlags);
  virtual bool Connect() { return false; }
  virtual void Updated() {}
  void SetLayer(ShadowableLayer* aLayer)
  {
    mLayer = aLayer;
  }

  virtual TextureInfo GetTextureInfo() const MOZ_OVERRIDE
  {
    return TextureInfo(mType);
  }

  virtual void SetIPDLActor(CompositableChild* aChild) MOZ_OVERRIDE
  {
    MOZ_ASSERT(!aChild, "ImageClientBridge should not have IPDL actor");
  }

  virtual already_AddRefed<Image> CreateImage(ImageFormat aFormat) MOZ_OVERRIDE
  {
    NS_WARNING("Should not create an image through an ImageClientBridge");
    return nullptr;
  }

protected:
  uint64_t mAsyncContainerID;
  ShadowableLayer* mLayer;
};

}
}

#endif