author Andrew Osmond <>
Mon, 04 Jun 2018 08:29:50 -0400
changeset 442380 453d21db2a306f4800e8be4d77f6d61000cb9a0c
parent 310055 cfb1f1eeceb36952195fd255d5a7a5f017771cbd
child 448947 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1465619 - Part 10. Re-add support for discarding animated image frames. r=tnikkel AnimatedFrameDiscardingQueue subclasses AnimationFrameBuffer to allow a cleaner abstraction over the behaviour change when we cross the threshold of too high a memory footprint for an animated image. The next patch will build on top of this to provide an abstraction to reuse the discarded frames. Differential Revision:

/* -*- 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 */

#ifndef mozilla_image_PlaybackType_h
#define mozilla_image_PlaybackType_h

#include "imgIContainer.h"

namespace mozilla {
namespace image {

 * PlaybackType identifies a surface cache entry as either a static surface or
 * an animation. Note that a specific cache entry is one or the other, but
 * images may be associated with both types of cache entries, since in some
 * circumstances we may want to treat an animated image as if it were static.
enum class PlaybackType : uint8_t
  eStatic,   // Calls to DrawableRef() will always return the same surface.
  eAnimated  // An animation; calls to DrawableRef() may return different
             // surfaces at different times.

 * Given an imgIContainer FRAME_* value, returns the corresponding PlaybackType
 * for use in surface cache lookups.
inline PlaybackType
ToPlaybackType(uint32_t aWhichFrame)
  MOZ_ASSERT(aWhichFrame == imgIContainer::FRAME_FIRST ||
             aWhichFrame == imgIContainer::FRAME_CURRENT);
  return aWhichFrame == imgIContainer::FRAME_CURRENT
       ? PlaybackType::eAnimated
       : PlaybackType::eStatic;

} // namespace image
} // namespace mozilla

#endif // mozilla_image_PlaybackType_h