gecko-dev/dom/animation/AnimationPlayer.h

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/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* 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_dom_AnimationPlayer_h
#define mozilla_dom_AnimationPlayer_h
#include "nsWrapperCache.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/Attributes.h"
#include "mozilla/TimeStamp.h" // for TimeStamp, TimeDuration
#include "mozilla/dom/Animation.h" // for Animation
#include "mozilla/dom/AnimationPlayerBinding.h" // for AnimationPlayState
#include "mozilla/dom/AnimationTimeline.h" // for AnimationTimeline
#include "nsCSSProperty.h" // for nsCSSProperty
// X11 has a #define for CurrentTime.
#ifdef CurrentTime
#undef CurrentTime
#endif
struct JSContext;
class nsCSSPropertySet;
class nsIDocument;
class nsPresContext;
namespace mozilla {
namespace css {
class AnimValuesStyleRule;
class CommonAnimationManager;
} // namespace css
class CSSAnimationPlayer;
class CSSTransitionPlayer;
namespace dom {
class AnimationPlayer : public nsWrapperCache
{
protected:
virtual ~AnimationPlayer() { }
public:
explicit AnimationPlayer(AnimationTimeline* aTimeline)
: mTimeline(aTimeline)
, mIsPaused(false)
, mIsRunningOnCompositor(false)
Bug 1078122 part 6 - Store the previous finished state; r=dholbert AnimationPlayer::CanThrottle determines if an animation player has just finished by inspecting the value of mLastNotification. This is problematic for two reasons: 1. mLastNotification is intended to be used for events (as the XXX comment notes) 2. mLastNotification is specific to CSS Animations and should be moved to CSSAnimationPlayer. To address this, this patch adds an extra member mIsPreviousStateFinished. The Web Animations spec already defines animation players as having such a member: http://w3c.github.io/web-animations/#previous-finished-state We set it to true when we calculate the style for an animation that has finished. This differs slightly from the code it is replacing as explained below. In the case of CSS Animations we perform the following sequence of steps on each sample. 1. EnsureStyleRuleFor (calls CanThrottle, and maybe ComposeStyle) 2. GetEventsForCurrentTime In the existing code, we update mLastNotification in (2) which happens on every sample, even throttled samples. In this patch, however, we update mIsPreviousStateFinished in (1) during the ComposeStyle step which only happens for unthrottled samples. So, as of this patch, in CanThrottle, we ask "have we newly entered the finished state since the last *unthrottled* sample?", whereas previously we simply looked for a change since the last sample, throttled or not. However, if the answer to the question is "yes", then we'll run an unthrottled sample and update mIsPreviousStateFinished so these should be functionally equivalent. Another subtle difference is that this patch looks at the player's finished state rather than the animation phase of its source content, and these will produce different results in the case where the player is paused. However, since paused animations are not run on the compositor, this should not matter. In the case of CSS Transitions, AnimationPlayer::CanThrottle() is not currently used and so mIsPreviousStateFinished is irrelevant. Ultimately, both the existing and the new code is somewhat fragile but hopefully this will be addressed by: * Replacing mIsPreviousStateFinished with inspecting whether the finished promise is settled (bug 1074630), * Merging more of the code in nsAnimationManager and nsTransitionManager and applying a unified approach to sampling that better accommodates these considerations.
2014-10-20 04:55:47 +00:00
, mIsPreviousStateFinished(false)
{
}
NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AnimationPlayer)
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(AnimationPlayer)
AnimationTimeline* GetParentObject() const { return mTimeline; }
virtual JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE;
virtual CSSAnimationPlayer* AsCSSAnimationPlayer() { return nullptr; }
virtual CSSTransitionPlayer* AsCSSTransitionPlayer() { return nullptr; }
// Temporary flags to control restyle behavior until bug 1073336
// provides a better solution.
enum UpdateFlags {
eNoUpdate,
eUpdateStyle
};
// AnimationPlayer methods
Animation* GetSource() const { return mSource; }
AnimationTimeline* Timeline() const { return mTimeline; }
Nullable<double> GetStartTime() const;
Nullable<TimeDuration> GetCurrentTime() const;
AnimationPlayState PlayState() const;
virtual void Play(UpdateFlags aUpdateFlags);
virtual void Pause(UpdateFlags aUpdateFlags);
bool IsRunningOnCompositor() const { return mIsRunningOnCompositor; }
// Wrapper functions for AnimationPlayer DOM methods when called
// from script. We often use the same methods internally and from
// script but when called from script we perform extra steps such
// as flushing style or converting the return type.
Nullable<double> GetCurrentTimeAsDouble() const;
virtual AnimationPlayState PlayStateFromJS() const { return PlayState(); }
virtual void PlayFromJS();
void PauseFromJS();
void SetSource(Animation* aSource);
void Tick();
const nsString& Name() const {
return mSource ? mSource->Name() : EmptyString();
}
bool IsPaused() const { return mIsPaused; }
bool IsRunning() const;
bool HasCurrentSource() const {
return GetSource() && GetSource()->IsCurrent();
}
bool HasInEffectSource() const {
return GetSource() && GetSource()->IsInEffect();
}
void SetIsRunningOnCompositor() { mIsRunningOnCompositor = true; }
void ClearIsRunningOnCompositor() { mIsRunningOnCompositor = false; }
// Returns true if this animation does not currently need to update
// style on the main thread (e.g. because it is empty, or is
// running on the compositor).
bool CanThrottle() const;
// Updates |aStyleRule| with the animation values of this player's source
// content, if any.
// Any properties already contained in |aSetProperties| are not changed. Any
// properties that are changed are added to |aSetProperties|.
// |aNeedsRefreshes| will be set to true if this player expects to update
// the style rule on the next refresh driver tick as well (because it
// is running and has source content to sample).
void ComposeStyle(nsRefPtr<css::AnimValuesStyleRule>& aStyleRule,
nsCSSPropertySet& aSetProperties,
bool& aNeedsRefreshes);
// The beginning of the delay period.
Nullable<TimeDuration> mStartTime; // Timeline timescale
protected:
void FlushStyle() const;
void MaybePostRestyle() const;
StickyTimeDuration SourceContentEnd() const;
nsIDocument* GetRenderedDocument() const;
nsPresContext* GetPresContext() const;
virtual css::CommonAnimationManager* GetAnimationManager() const = 0;
nsRefPtr<AnimationTimeline> mTimeline;
nsRefPtr<Animation> mSource;
Nullable<TimeDuration> mHoldTime; // Player timescale
bool mIsPaused;
bool mIsRunningOnCompositor;
Bug 1078122 part 6 - Store the previous finished state; r=dholbert AnimationPlayer::CanThrottle determines if an animation player has just finished by inspecting the value of mLastNotification. This is problematic for two reasons: 1. mLastNotification is intended to be used for events (as the XXX comment notes) 2. mLastNotification is specific to CSS Animations and should be moved to CSSAnimationPlayer. To address this, this patch adds an extra member mIsPreviousStateFinished. The Web Animations spec already defines animation players as having such a member: http://w3c.github.io/web-animations/#previous-finished-state We set it to true when we calculate the style for an animation that has finished. This differs slightly from the code it is replacing as explained below. In the case of CSS Animations we perform the following sequence of steps on each sample. 1. EnsureStyleRuleFor (calls CanThrottle, and maybe ComposeStyle) 2. GetEventsForCurrentTime In the existing code, we update mLastNotification in (2) which happens on every sample, even throttled samples. In this patch, however, we update mIsPreviousStateFinished in (1) during the ComposeStyle step which only happens for unthrottled samples. So, as of this patch, in CanThrottle, we ask "have we newly entered the finished state since the last *unthrottled* sample?", whereas previously we simply looked for a change since the last sample, throttled or not. However, if the answer to the question is "yes", then we'll run an unthrottled sample and update mIsPreviousStateFinished so these should be functionally equivalent. Another subtle difference is that this patch looks at the player's finished state rather than the animation phase of its source content, and these will produce different results in the case where the player is paused. However, since paused animations are not run on the compositor, this should not matter. In the case of CSS Transitions, AnimationPlayer::CanThrottle() is not currently used and so mIsPreviousStateFinished is irrelevant. Ultimately, both the existing and the new code is somewhat fragile but hopefully this will be addressed by: * Replacing mIsPreviousStateFinished with inspecting whether the finished promise is settled (bug 1074630), * Merging more of the code in nsAnimationManager and nsTransitionManager and applying a unified approach to sampling that better accommodates these considerations.
2014-10-20 04:55:47 +00:00
// Indicates whether we were in the finished state during our
// most recent unthrottled sample (our last ComposeStyle call).
// FIXME: When we implement the finished promise (bug 1074630) we can
// probably remove this and check if the promise has been settled yet
// or not instead.
bool mIsPreviousStateFinished; // Spec calls this "previous finished state"
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_AnimationPlayer_h