gecko-dev/image/DecoderFlags.h
Andrew Osmond 186b24b666 Bug 1370412 - Part 8a. Add "substitutable" flag to ISurfaceProvider state to indicate when the caller won't accept substitutes. r=tnikkel
When SurfaceCache::Lookup is called to access surface data, it indicates
that the caller will not accept substitutes as in the case of
SurfaceCache::LookupBestMatch. As such, we need to be careful not to
remove those surfaces from our cache when pruning (in part 8b). This is
the marker used to track that, at some point, there was a caller which
got this surface that would accept no other (e.g. factor of 2 mode must
make an accept for this particular surface).
2017-09-05 07:58:45 -04:00

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/* -*- 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_DecoderFlags_h
#define mozilla_image_DecoderFlags_h
#include "mozilla/TypedEnumBits.h"
namespace mozilla {
namespace image {
/**
* Flags that influence decoder behavior. Note that these flags *don't*
* influence the logical content of the surfaces that the decoder generates, so
* they're not in a factor in SurfaceCache lookups and the like. These flags
* instead either influence which surfaces are generated at all or the tune the
* decoder's behavior for a particular scenario.
*/
enum class DecoderFlags : uint8_t
{
FIRST_FRAME_ONLY = 1 << 0,
IS_REDECODE = 1 << 1,
IMAGE_IS_TRANSIENT = 1 << 2,
ASYNC_NOTIFY = 1 << 3,
/**
* By default, a surface is considered substitutable. That means callers are
* willing to accept a less than ideal match to display. If a caller requires
* a specific size and won't accept alternatives, then this flag should be
* set.
*/
CANNOT_SUBSTITUTE = 1 << 4
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(DecoderFlags)
/**
* @return the default set of decode flags.
*/
inline DecoderFlags
DefaultDecoderFlags()
{
return DecoderFlags();
}
} // namespace image
} // namespace mozilla
#endif // mozilla_image_DecoderFlags_h