Ultimately we want to move throttling logic to AnimationCollection and
Animation::Tick (and later to KeyframeEffect::SetParentTime). This is so that
we can support script-generated animations without having to introduce yet
another manager.
To that end this patch introduces a method on AnimationCollection that can be
called from Animation::Tick to perform the necessary notifications needed to
update style.
Later in this patch series we will extend RequestRestyle to incorporate more of
the throttling logic and further extend it to cover some of the other
notifications such as updating layers.
This patch tracks whether or not we have already posted a restyle for animation
to avoid making redundant calls. Calls to nsIDocument::SetNeedStyleFlush are
cheap and more difficult to detect when they have completed so we don't filter
redundant calls in the Restyle::Throttled case.
If mHasPendingAnimationRestyle is set and AnimationCommon::EnsureStyleRuleFor
is *never* called then we could arrive at situation where we fail to make post
further restyles for animation.
I have verified that if we fail to reset mHasPendingAnimationRestyle at the
appropriate point (e.g. resetting it at the end of EnsureStyleRuleFor *after*
the early-returns) then a number of existing tests fail.
Furthermore, I have observed that it is reset by the beginning of each tick
in almost every case except for a few instances of browser mochitests such as
browser/components/customizableui/test/browser_1007336_lwthemes_in_customize_mode.js.
In this case, during the async cleanup of the test, we have an opacity
transition on a vbox element that becomes display:none and appears to be skipped
during restyling. However, even in this case, EnsureStyleRuleFor is called
within one or at most two ticks and mHasPendingAnimationRestyle flag is cleared
(i.e. it does not get stuck).
In FlushTransitions and FlushAnimations we use different mechanisms to see if a
transition/animation can be throttled on the current tick.
FlushTransitions calls Animation::CanThrottle whilst FlushAnimations calls
EnsureStyleRuleFor and checks if the rule has changed or not. These are not as
completely different as they might seem at first since, internally,
EnsureStyleRuleFor calls Animation::CanThrottle.
We would like to unify this behavior and simply use Animation::CanThrottle in
FlushAnimations as we do in FlushTransitions.
First, however, we have to account for the differences in these approaches:
1. Using the result of EnsureStyleRuleFor means we may *not* call
PostRestyleForAnimation if an animation collection's mNeedsRefreshes member
is false.
This member is false when all animations have finished (or there are no
animations in the collection). In this case EnsureStyleRuleFor will not
update the style rule and we will end up assuming the tick can be throttled.
*However*, in the case that all animations are finished
Animation::CanThrottle will *also* return true (technically it will return
false until we compose style for the first time after becoming finished but
beyond that one moment it will return true) so skipping this check by using
Animation::CanThrottle instead of EnsureStyleRuleFor should not
make a significant difference.
2. Using the result of EnsureStyleRuleFor will mean that if we have already
updated the style rule within a given tick we will avoid calling
PostRestyleForAnimation (and call SetNeedStyleFlush instead). This can
happen the first time we call FlushAnimations from
PresShell::FlushPendingNotifications. (When we call FlushAnimations from
nsAnimationManager::WillRefresh mStyleRuleRefreshTime will be stale and we
won't apply this optimization. Furthermore after the first call to
PresShell::FlushPendingNotifications we will typically skip calling
FlushAnimations since PresShell::StyleUpdateForAllAnimationsIsUpToDate will
typically return true).
This seems like a possibly useful optimization although it is surprising we
don't do the same for transitions. Note that this optimization applies
regardless of whether we are performing a throttleable flush or not. That is,
even if we pass CommonAnimationManager::Cannot_Throttle we will still end up
throttling the tick in this case. Furthermore, we will mark the document as
needing a style flush even though this does not appear to be necessary.
This patch copies this optimization (checking if mStyleRuleRefreshTime) to
FlushAnimations so we can maintain this behavior when calling
Animation::CanThrottle instead of EnsureStyleRuleFor. It also applies the
same behavior to FlushTransitions for consistency (and so we can later
combine FlushAnimations and FlushTransitions).
Note that we apply this optimization *before* calling Tick since it should
only apply once we have already Tick'ed the animations in the collection.
We will first hit FlushAnimations as a result of the refresh driver calling
nsAnimationManager/nsTransitionManager::WillRefresh at which point
mStyleRuleRefreshTime should be stale. Using this order not only saves
redundant work but also makes moving the restyle code to Animation later on
more straightforward.
(In future we will divorce WillRefresh and FlushAnimations and only call
Tick in WillRefresh and only perform this optimization FlushAnimations.)
3. Using the result of EnsureStyleRuleFor means that while checking if we can
throttle or not we also update the style rule in FlushAnimations. That seems
like an odd side-effect particularly since FlushTransitions doesn't do the
same thing.
There is no longer anything in FlushTransitions that modifies the set of
transitions. I believe this changed as of bug 960465, specifically changeset
https://hg.mozilla.org/mozilla-central/rev/b2ee72589c18, so that this code is
no longer needed.
By removing this we can further align FlushAnimations and FlushTransitions.
Finished can be determined immediately after mFinished is set, but blocked is
not determined until RecomputeBlocking() has run.
--HG--
extra : rebase_source : e1d919bfbd411b928c25d1f0d428842e17f6fbf8
Notifications are now up to date with processing, and
MediaStream::GetCurrentTime() now returns "the main-thread's view of how much
data has been processed by this stream", as documented.
--HG--
extra : rebase_source : 90eb894f7b5e7cf56c3635e68716fd2514494f7e
This does not affect the target time of the video frames, but may mean that more
frames are displayed.
--HG--
extra : rebase_source : f804f2f58ce5ce2668e047f83adf614d9043f3a2
clang complains about shifting quantities beyond the width of their
type, since that is undefined behavior. Let's fix the problematic
occurrences by adding some casts prior to shifting.
A decoder isn't created until a SPS and PPS NALs have been detected in the stream. The decoder will be initialised instead lazily later during the input process.
A decoder isn't created until a SPS and PPS NALs have been detected in the stream. The decoder will be initialised instead lazily later during the input process.
Brian Birtles
Jean-Yves Avenard
Karl Tomlinson
Nathan Froyd
JW Wang
L. David Baron
Daniel Holbert
Chris Peterson
Jonathan Kew
Sebastian Hengst
Till Schneidereit
Jan de Mooij
Phil Ringnalda
Kartikaya Gupta
Benjamin Bouvier