image/DecoderFlags.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_image_DecoderFlags_h
   7 #define mozilla_image_DecoderFlags_h
   8
   9 #include "mozilla/TypedEnumBits.h"
  10
  11 namespace mozilla {
  12 namespace image {
  13
  14 /**
  15  * Flags that influence decoder behavior. Note that these flags *don't*
  16  * influence the logical content of the surfaces that the decoder generates, so
  17  * they're not in a factor in SurfaceCache lookups and the like. These flags
  18  * instead either influence which surfaces are generated at all or the tune the
  19  * decoder's behavior for a particular scenario.
  20  */
  21 enum class DecoderFlags : uint8_t {
  22   FIRST_FRAME_ONLY = 1 << 0,
  23   IS_REDECODE = 1 << 1,
  24   IMAGE_IS_TRANSIENT = 1 << 2,
  25   ASYNC_NOTIFY = 1 << 3,
  26
  27   /**
  28    * By default, a surface is considered substitutable. That means callers are
  29    * willing to accept a less than ideal match to display. If a caller requires
  30    * a specific size and won't accept alternatives, then this flag should be
  31    * set.
  32    */
  33   CANNOT_SUBSTITUTE = 1 << 4,
  34 };
  35 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(DecoderFlags)
  36
  37 /**
  38  * @return the default set of decode flags.
  39  */
  40 inline DecoderFlags DefaultDecoderFlags() { return DecoderFlags(); }
  41
  42 }  // namespace image
  43 }  // namespace mozilla
  44
  45 #endif  // mozilla_image_DecoderFlags_h