gecko-dev/dom/animation/AnimationPlayer.h
Brian Birtles 7a9094aa6e Bug 1112480 part 7 - Add checking for orphaned players; r=jwatt
When a player is made pending, we rely on it being added to a pending player
tracker that will eventually start the player. However, there are a few
situations where this might not happen. For example, we can't find a pending
player tracker (e.g. there's no source content or the source content isn't
attached to a document), or the pending player tracker disappeared.

In these cases we still want to ensure that such a player does actually get
started. This patch attempts to detect such situations and start players
accordingly.

There are, unfortunately, currently no tests for this. I have been unsuccessful
in recreating any of the situations these tests are supposed to cover.
2015-01-09 07:57:58 +09:00

239 lines
9.2 KiB
C++

/* 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 "mozilla/dom/Promise.h" // for Promise
#include "nsCSSProperty.h" // for nsCSSProperty
// X11 has a #define for CurrentTime.
#ifdef CurrentTime
#undef CurrentTime
#endif
// GetCurrentTime is defined in winbase.h as zero argument macro forwarding to
// GetTickCount().
#ifdef GetCurrentTime
#undef GetCurrentTime
#endif
struct JSContext;
class nsCSSPropertySet;
class nsIDocument;
class nsPresContext;
namespace mozilla {
struct AnimationPlayerCollection;
namespace css {
class AnimValuesStyleRule;
class CommonAnimationManager;
} // namespace css
class CSSAnimationPlayer;
class CSSTransitionPlayer;
namespace dom {
class AnimationPlayer : public nsISupports,
public nsWrapperCache
{
protected:
virtual ~AnimationPlayer() { }
public:
explicit AnimationPlayer(AnimationTimeline* aTimeline)
: mTimeline(aTimeline)
, mIsPending(false)
, mIsRunningOnCompositor(false)
, mIsPreviousStateFinished(false)
{
}
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(AnimationPlayer)
AnimationTimeline* GetParentObject() const { return mTimeline; }
virtual JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE;
virtual CSSAnimationPlayer* AsCSSAnimationPlayer() { return nullptr; }
virtual CSSTransitionPlayer* AsCSSTransitionPlayer() { return nullptr; }
// AnimationPlayer methods
Animation* GetSource() const { return mSource; }
AnimationTimeline* Timeline() const { return mTimeline; }
Nullable<TimeDuration> GetStartTime() const { return mStartTime; }
Nullable<TimeDuration> GetCurrentTime() const;
AnimationPlayState PlayState() const;
virtual Promise* GetReady(ErrorResult& aRv);
virtual void Play();
virtual void Pause();
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 (or one of our subclasses) perform
// extra steps such as flushing style or converting the return type.
Nullable<double> GetStartTimeAsDouble() const;
Nullable<double> GetCurrentTimeAsDouble() const;
virtual AnimationPlayState PlayStateFromJS() const { return PlayState(); }
virtual void PlayFromJS() { Play(); }
// PauseFromJS is currently only here for symmetry with PlayFromJS but
// in future we will likely have to flush style in
// CSSAnimationPlayer::PauseFromJS so we leave it for now.
void PauseFromJS() { Pause(); }
void SetSource(Animation* aSource);
void Tick();
/**
* Typically, when a player is played, it does not start immediately but is
* added to a table of pending players on the document of its source content.
* In the meantime it sets its hold time to the time from which playback
* should begin.
*
* When the document finishes painting, any pending players in its table
* are marked as being ready to start by calling StartOnNextTick.
* The moment when the paint completed is also recorded, converted to a
* timeline time, and passed to StartOnTick. This is so that when these
* players do start, they can be timed from the point when painting
* completed.
*
* After calling StartOnNextTick, players remain in the pending state until
* the next refresh driver tick. At that time they transition out of the
* pending state using the time passed to StartOnNextTick as the effective
* time at which they resumed.
*
* This approach means that any setup time required for performing the
* initial paint of an animation such as layerization is not deducted from
* the running time of the animation. Without this we can easily drop the
* first few frames of an animation, or, on slower devices, the whole
* animation.
*
* Furthermore:
*
* - Starting the player immediately when painting finishes is problematic
* because the start time of the player will be ahead of its timeline
* (since the timeline time is based on the refresh driver time).
* That's a problem because the player is playing but its timing suggests
* it starts in the future. We could update the timeline to match the start
* time of the player but then we'd also have to update the timing and style
* of all animations connected to that timeline or else be stuck in an
* inconsistent state until the next refresh driver tick.
*
* - If we simply use the refresh driver time on its next tick, the lag
* between triggering an animation and its effective start is unacceptably
* long.
*
* Note that the caller of this method is responsible for removing the player
* from any PendingPlayerTracker it may have been added to.
*/
void StartOnNextTick(const Nullable<TimeDuration>& aReadyTime);
// Testing only: Start a pending player using the current timeline time.
// This is used to support existing tests that expect animations to begin
// immediately. Ideally we would rewrite the those tests and get rid of this
// method, but there are a lot of them.
//
// As with StartOnNextTick, the caller of this method is responsible for
// removing the player from any PendingPlayerTracker it may have been added
// to.
void StartNow();
void Cancel();
const nsString& Name() const {
return mSource ? mSource->Name() : EmptyString();
}
bool IsPaused() const { return PlayState() == AnimationPlayState::Paused; }
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);
protected:
void DoPlay();
void DoPause();
void ResumeAt(const TimeDuration& aResumeTime);
void UpdateSourceContent();
void FlushStyle() const;
void PostUpdate();
// Remove this player from the pending player tracker and resets mIsPending
// as necessary. The caller is responsible for resolving or aborting the
// mReady promise as necessary.
void CancelPendingPlay();
bool IsPossiblyOrphanedPendingPlayer() const;
StickyTimeDuration SourceContentEnd() const;
nsIDocument* GetRenderedDocument() const;
nsPresContext* GetPresContext() const;
virtual css::CommonAnimationManager* GetAnimationManager() const = 0;
AnimationPlayerCollection* GetCollection() const;
nsRefPtr<AnimationTimeline> mTimeline;
nsRefPtr<Animation> mSource;
// The beginning of the delay period.
Nullable<TimeDuration> mStartTime; // Timeline timescale
Nullable<TimeDuration> mHoldTime; // Player timescale
Nullable<TimeDuration> mPendingReadyTime; // Timeline timescale
// A Promise that is replaced on each call to Play() (and in future Pause())
// and fulfilled when Play() is successfully completed.
// This object is lazily created by GetReady.
nsRefPtr<Promise> mReady;
// Indicates if the player is in the pending state. We use this rather
// than checking if this player is tracked by a PendingPlayerTracker.
// This is because the PendingPlayerTracker is associated with the source
// content's document but we need to know if we're pending even if the
// source content loses association with its document.
bool mIsPending;
bool mIsRunningOnCompositor;
// 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