gecko/dom/animation/AnimationPlayer.h
Brian Birtles 94984390c8 Bug 1052147 - Initialize AnimationPlayer::mPlayState to running state; r=dbaron
The assertion in nsTimeStamp::operator >= occasionally fails due to a null RHS
timestamp when called from AnimationPlayer::GetCurrentTimeDuration, which, in
turn, is called from AnimationPlayer::SetSource.

The issue appears to be that we're not correctly initializing
AnimationPlayer.mPlayState. This value can be running (0) or paused (1) but we
only ever compare against the paused state (i.e. every other value is
effectively treated as running). If we don't initialize this we can end
up in the paused state but with mPauseStart not set to a valid (non-null)
TimeStamp. This creates an inconsistent state since we assume that when we're
paused mPauseStart is non-null, hence the assertion fails.

This gets tickled because, since bug 1040543, we call
AnimationPlayer::SetSource from nsAnimationManager::BuildAnimations *before* we
set mPlayState and mPauseStart.

This patch initializes mPlayState to the running state so we don't accidentally
end up in an inconsistent state.

It also removes some (now unnecessary) initialization of mPlayState and
mPauseStart from nsTransitionManager::ConsiderStartingTransition.

In future we could also consider reworking nsAnimationManager::BuildAnimations
so that we call SetSource on the new animation player *after* setting up its
play state. That may be more correct and would further avoid this problem but
may not be necessary since all that code is likely to change in the near future.
2014-08-13 18:21:45 +09:00

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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 <algorithm> // for std::max
#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/AnimationTimeline.h" // for AnimationTimeline
#include "nsCSSProperty.h" // for nsCSSProperty
// X11 has a #define for CurrentTime.
#ifdef CurrentTime
#undef CurrentTime
#endif
struct JSContext;
namespace mozilla {
namespace dom {
class AnimationPlayer MOZ_FINAL : public nsWrapperCache
{
protected:
virtual ~AnimationPlayer() { }
public:
explicit AnimationPlayer(AnimationTimeline* aTimeline)
: mPlayState(NS_STYLE_ANIMATION_PLAY_STATE_RUNNING)
, mIsRunningOnCompositor(false)
, mTimeline(aTimeline)
{
SetIsDOMBinding();
}
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;
// AnimationPlayer methods
Animation* GetSource() const { return mSource; }
AnimationTimeline* Timeline() const { return mTimeline; }
double StartTime() const;
double CurrentTime() const;
void SetSource(Animation* aSource);
void Tick();
bool IsPaused() const {
return mPlayState == NS_STYLE_ANIMATION_PLAY_STATE_PAUSED;
}
bool IsRunning() const;
bool IsCurrent() const;
// Return the duration since the start time of the player, taking into
// account the pause state. May be negative.
// Returns a null value if the timeline associated with this object has a
// current timestamp that is null or if the start time of this object is
// null.
Nullable<TimeDuration> GetCurrentTimeDuration() const {
const TimeStamp& timelineTime = mTimeline->GetCurrentTimeStamp();
// FIXME: In order to support arbitrary timelines we will need to fix
// the pause logic to handle the timeline time going backwards.
MOZ_ASSERT(timelineTime.IsNull() || !IsPaused() ||
timelineTime >= mPauseStart,
"if paused, any non-null value of aTime must be at least"
" mPauseStart");
Nullable<TimeDuration> result; // Initializes to null
if (!timelineTime.IsNull() && !mStartTime.IsNull()) {
result.SetValue((IsPaused() ? mPauseStart : timelineTime) - mStartTime);
}
return result;
}
nsString mName;
// The beginning of the delay period.
TimeStamp mStartTime;
TimeStamp mPauseStart;
uint8_t mPlayState;
bool mIsRunningOnCompositor;
nsRefPtr<AnimationTimeline> mTimeline;
nsRefPtr<Animation> mSource;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_AnimationPlayer_h