This patch removes a lot of code involved with observing the refresh driver from
nsAnimationManager and nsTransitionManager now that we no longer need to do
this.
The one piece it does not remove, however, is
AnimationCollection::mNeedsRefreshes since this flag actually serves a secondary
purpose in telling us when the animation style has not changed and so does
not need to be updated. A subsequent patch in this series will rename this
and update the code that makes use of it.
This patch also reworks the dispatch of events in nsRefreshDriver. Previously
the refresh driver would dispatch the transition events for all subdocuments
then the animation events. This arrangement is complicated and not obviously
necessary. This patch simplifies this arrangement by dispatching transition
events and animation events for each document before proceeding to
subdocuments.
In order to sort between events that have the same timestamp we use the
sort order of the corresponding animations so we need to store a pointer
to the animation along with the event.
This patch makes FlushAnimations purely responsible for posting restyles. All
ticking behavior is performed in response to an actual refresh driver tick
(currently CommonAnimationManager::WillRefresh).
When updating the cascade results between transitions and animations, if we
detect a change we force an update by taking the following steps:
a. Updating the animation generation on the restyle manager
b. Updating the animation generation on the collection
c. Iterating over all the properties animated by the collection and, for
each property that we can animate on the compositor, posting a restyle
event with the appropriate change hint (nsChangeHint_UpdateTransformLayer
or nsChangeHint_UpdateTransformOpacity)
d. Marking the collection as needing refreshes
e. Clearing the style rule refresh time so we generate a new style rule in
EnsureStyleRuleFor
As it turns out, the newly-added
AnimationCollection::RequestRestyle(RestyleType::Layer) already performs a, b,
d, and e. It also:
* Ensures we are observing the refresh driver if need be (should have no effect
in this case)
* Clears the last animation style update time on the pres context so that
subsequent calls to FlushPendingNotifications will update animation style
(it seems like we probably should have been doing this for changes to cascade
results anyway)
* Posts a restyle event with restyle hint eRestyle_CSSTransitions or
eRestyle_CSSAnimations
* Marks the document as needing a style flush (irrelevant since posting
a restyle event does this anyway)
The only missing piece that would prevent using RequestRestyle in place of this
code when updating cascade results is (c) from the list above. However, (c)
should not be necessary since ElementRestyler::AddLayerChangesForAnimation()
explicitly checks for out-of-date layer animation generation numbers and adds
the appropriate change hints (nsChangeHint_UpdateTransformLayer etc.) to the
change list.
We currently have a series of methods that clobber various bits of animation
state to force animations on layers to be updated. This aligns closely with
the restyle code introduced in this patch series.
By re-using RequestRestyle when updating animations on layers, not only should
we be able to simplify the code somewhat but, in future, we should also be able
to have Animation objects use the same mechanism to update layers during
a regular tick.
For example, currently we have a bug where when an animation starts after
a delay with the same value as the backwards fill then we don't send the
animation to the compositor right away (see
https://dxr.mozilla.org/mozilla-central/rev/d6ea652c579992daa9041cc9718bb7c6abefbc91/layout/style/test/test_animations_omta.html#287).
By adding this Restyle::Layer value we should be able to fix that in future.
EnsureStyleRuleFor contains logic for performing throttled updates to the style
rule but it is only used in one case: inside
nsTransitionManager::UpdateCascadeResults to determine what properties are
being animated by CSS animations.
We would like to remove throttling logic from EnsureStyleRuleFor altogether but
if that one case where it is currently used is run on every tick then removing
this logic could effectively mean we end up updating the style rule on every
tick. Fortunately nsTransitionManager::UpdateCascadeResults is only called
in the following cases:
1. From nsTransitionManager::StyleContextChanged (via
TransitionManager::UpdateCascadeResultsWithTransitions), when we are
processing style changes for transitions.
2. From AnimationCollection::EnsureStyleRuleFor (via
nsAnimationManager::MaybeUpdateCascadeResults and
nsTransitionManager::UpdateCascadeResultsWithAnimations), when we are
updating the animation style rule from CSS animations.
3. From nsAnimationManager::CheckAnimationRule (via
TransitionManager::UpdateCascadeResultsWithAnimationsToBeDestroyed), when
we are processing style changes for CSS animations.
None of these things should be happenning on a regular throttle-able tick so by
removing this logic we shouldn't be causing any additional work.
I have verified, using a test case that combines transitions and animations on
the same property, that we have the same behavior with regard to calling
EnsureStyleRuleFor both before and after this patch (specifically we avoid
calling it altogether while running only the transition but when the animation
starts and clobbers the transition we end up calling EnsureStyleRuleFor once on
each tick).
nsTransitionManager::WillRefresh and nsAnimationManager::WillRefresh are now
identical and all methods they call exist on CommonAnimationManager so we
can unify them there.
The implementations of FlushAnimations and FlushTransitions should now be all
but equivalent so this patch combines them into a single implementation on
CommonAnimationManager.
Regarding some of the minor differences between the two methods:
* The combined implementation drops the check for an empty list of collections
found only in FlushTransitions. This seems like a very minor optimization
that could possibly cause us to fail to unregister from the refresh driver
if we forgot to do so when removing the last collection.
* The combined implementation uses the loop implementation from FlushAnimations
since it is more compact.
This patch also removes the extra nested scope since it doesn't seem necessary.
This patch moves the additional checks (beyond those of Animation::CanThrottle)
from FlushAnimations/FlushTransitions to AnimationCollection::RequestRestyle.
These checks are on a per-collection basis hence it makes sense for the
collection to perform them. This also moves logic out of the managers which is
needed if we want to support script-based animations without introducing another
manager.
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).
AnimationCollection::HasAnimationOfProperty uses IsFinishedTransition to filter
out transitions that should otherwise be ignored. This is used in the following
places:
1. nsLayoutUtils::HasAnimations
The is only used by nsIFrame::BuildDisplayListForStackingContext to see if
there are any opacity animations
For this case, simply returning *current* animations would be sufficient
(since finished but filling animations should have already filled in the
display opacity)
2. CommonAnimationManager::GetAnimationsForCompositor
This should really only return *current* animations--that is, animations that
are running or scheduled to run. Finished animations never run on the
compositor. Indeed, only *playing* animations run on the compositor but, as
we will see in some of the cases below, it is sometimes useful to know that
an animation *will* run on the compositor in the near future (e.g. so we can
pre-render content).
The places where GetAnimationsForCompositor is used are:
- When building layers to add animations to layers in nsDisplayList--in this
case we skip any animations that aren't playing so if
GetAnimationsForCompositor only returned current animations that would be
more than sufficient.
- In nsLayoutUtils::HasAnimationsForCompositor. This in turn is used:
- In ChooseScaleAndSetTransform to see if the transform is being animated
on the compositor. If so, it calls
nsLayoutUtils::ComputeSuitableScaleForAnimation (which also calls
GetAnimationsForCompositor) and passes the result to
GetMinAndMaxScaleForAnimationProperty which we have already adjusted in
part 4 of this patch series to only deal with *relevant* animations
Relevant animations include both current animations and in effect
animations but we don't run forwards-filling animations on the compositor
so GetAnimationsForCompositor should NOT return them. Current animations
should be enough. In fact, playing animations should be enough but we
might want to pre-render layers at a suitable size during their delay
phase so returning current animations is probably ok.
- In nsDisplayListBuilder::MarkOutOfFlowFrameForDisplay to add a fuzz
factor to the overflow rect for frames undergoing a transform animation
on the compositor. In this case too current animations should be
sufficient.
- In nsDisplayOpacity::NeedsActiveLayer to say "yes" if we are animating
opacity on the compositor. Presumably in this case it would be good to
say "yes" if the animation is in the delay phase too (as it currently
does). After the animation is finished, we should drop the layer, i.e.
current animations should be sufficient.
- In nsDisplayTransform::ShouldPrerenderTransformedContent. As with
nsDisplayOpacity::NeedsActiveLayer, we only need to pre-render
transformed content for animations that are current.
- In nsDisplayTransform::GetLayerState. As with
nsDisplayOpacity::NeedsActiveLayer, we only need to return active here
for current animations.
- In nsIFrame::IsTransformed. Here we test the display style to see if
there is a transform and also check if transform is being animated on the
compositor. As a result, we really only need HasAnimationsForCompositor
to return true for animations that are playing--otherwise the display
style will tell us if we're transformed or not. Returning true for all
current compositor animations (which is a superset of playing), however,
should not cause problems (we already return true for even more than
that).
- In nsIFrame::HasOpacityInternal which is much the same as
nsIFrame::IsTransformed and hence current should be fine.
3. AnimationCollection::CanThrottleAnimation
Here, HasAnimationOfProperty is used when looking for animations that would
disqualify us from throttling the animation by having an out-of-date layer
generation or being a transform animation that affects scroll and so requires
that we do the occasional main thread sample to update scrollbars.
It would seem like current animations are enough here too. One interesting
case is where we *had* a compositor animation but it has finished or been
cancelled. In that case, the animation won't be current and we should not
throttle the animation since we need to take it off its layer.
It turns out checking for current animations is still ok in this case too.
The reasoning is as follows:
- If the animation is newly-finished, we'll pick that up in
Animation::CanThrottle and return false then.
- If the animation is newly-idle then there are two cases:
If the cancelled animation was the only compositor animation then
AnimationCollection::CanPerformOnCompositorThread will notice that there
are no playing compositor animations and return false and
AnimationCollection::CanThrottleAnimation will never be called.
If there are other compositor animations running, then
AnimationCollection::CanThrottleAnimation will still return false because
whatever cancelled the animation will update the animation generation and
we'll notice the mismatch between the layer animation generation and the
animation generation on the collection.
Based on the above analysis it appears that making
AnimationCollection::HasAnimationOfProperty return only current animations (and
simulatneously renaming it to HasCurrentAnimationOfProperty) is safe. Indeed, in
effect, we already do this for transitions but not for animations. This patch
generalizes this behavior to all animations.
This patch also updates test_animations_omta.html since it was incorrectly
testing that a finished opacity animation was still running on the compositor.
Finished animations should not run on the compositor and the changes in this
patch cause that to happen. The reason we don't just update this test to check
for RunningOn.MainThread is that for opacity animations, unlike transform
animations, we can't detect if an opacity on a layer was set by animation or
not. As a result, for opacity animations we typically test the opacity on
either the main thread or compositor in order to allow for the case where an
animation-set opacity is still lingering on the compositor.
Prior to this patch, CSSAnimation defined a method for converting an
nsCSSPseudoElements::Type to a nsString (but only for the set of
pseudo-elements that can have animations). We would like to re-use this
when setting up transition events so this patch moves it to
AnimationCollection. Re-using this method more widely means we can make
a few further simplifications to the code.
This patch extracts a utility class for queueing up a series of EventInfo
objects (of templated type) and then dispatching them. This covers the event
queuing behavior in nsAnimationManager so that we can reuse it in
nsTransitionManager.
The long-term plan is to drop the mozilla::css namespace altogether. Before we
go to much further with refactoring code in AnimationCommon, we should drop
usage of the mozilla::css namespace. Specifically, this patch moves the
CommonAnimationManager and AnimValuesStyleRule classes to the mozilla namespace.
This patch prepares the way for script-generated events by making
event dispatch a separate process that happens after sampling animations.
This will allow us to sample animations from their associated timeline
(removing the need for a further manager to tracker script-generated
animations).
Furthermore, once we sample animations from timelines the order in which they
are sampled is likely to be more or less random so by making event dispatch at
separate step, we have an opportunity to sort the events and dispatch in
a consistent and sensible order. It also ensures that event callbacks will
not be run until all animations (including transitions) have been updated
ensuring they see a consistent view of timing properties.
This patch only affects event handling for CSS animations. Transitions will
be dealt with in a subsequent patch.
Prior to this patch, CSSAnimation defined a method for converting an
nsCSSPseudoElements::Type to a nsString (but only for the set of
pseudo-elements that can have animations). We would like to re-use this
when setting up transition events so this patch moves it to
AnimationCollection. Re-using this method more widely means we can make
a few further simplifications to the code.
This patch extracts a utility class for queueing up a series of EventInfo
objects (of templated type) and then dispatching them. This covers the event
queuing behavior in nsAnimationManager so that we can reuse it in
nsTransitionManager.
The long-term plan is to drop the mozilla::css namespace altogether. Before we
go to much further with refactoring code in AnimationCommon, we should drop
usage of the mozilla::css namespace. Specifically, this patch moves the
CommonAnimationManager and AnimValuesStyleRule classes to the mozilla namespace.
This patch prepares the way for script-generated events by making
event dispatch a separate process that happens after sampling animations.
This will allow us to sample animations from their associated timeline
(removing the need for a further manager to tracker script-generated
animations).
Furthermore, once we sample animations from timelines the order in which they
are sampled is likely to be more or less random so by making event dispatch at
separate step, we have an opportunity to sort the events and dispatch in
a consistent and sensible order. It also ensures that event callbacks will
not be run until all animations (including transitions) have been updated
ensuring they see a consistent view of timing properties.
This patch only affects event handling for CSS animations. Transitions will
be dealt with in a subsequent patch.
The bulk of this commit was generated by running:
run-clang-tidy.py \
-checks='-*,llvm-namespace-comment' \
-header-filter=^/.../mozilla-central/.* \
-fix
Prior to this patch we cancel animations in AnimationCollection::Destroy but
this is not called automatically when the property holding the collection is
destroyed via its destructor. When an element is unbound from the tree we
destroy its animation properties but don't call AnimationCollection::Destroy.
This means, that in such circumstances:
* We won't create animation mutation records for the removed animations
* Once we start registering animations with a timeline they won't have a
chance to remove themselves from the timeline (meaning
document.timeline.getAnimations()) will keep returning them
* Once we go to implement the animationcancel and transitioncancel events we
won't fire them in this case (assuming we implement the queueing/dispatch of
those events as part of the cancel code)
This patch addresses this by moving the call to cancel each animations to the
property destructor for the animation properties.
We do this first so we can land this change separately to ease bisecting any
regressions it might trigger.
This patch makes Cancel() call PostUpdate which clobbers certain state in style
so that animated style is correctly flushed when an animation is cancelled.
The main difficulty with this is that we *don't* want to call this when we're
cancelling an animation as a result of a style update or else we'll trigger
needless work. The pattern elsewhere has been to define a *FromStyle() method
for this case (e.g. CSSAnimation::PlayFromStyle, PauseFromStyle). This isn't
ideal because there's always the danger we will forget to call the appropriate
*FromStyle method. It is, however, consistent. Hopefully in bug 1151731 we'll
find a better way of expressing this.
This patch is a fairly minimal rename of the AnimationPlayer interface. It
leaves a bunch of local variables and helper classes still using the word
"player". These will be addressed in subsequent patches that don't require DOM
peer review.
This patch adds an options flag to GetAnimationsForCompositor for two reasons.
a) We want to reuse this functionality in nsLayoutUtils.cpp rather than
duplicating the same logic. To do that and maintain the existing behavior,
however, we need to *not* update the active layer tracker when calling this
from nsLayoutUtils.cpp.
b) It's surprising that GetAnimationsForCompositor also has this side effect of
updating the active layer tracker. Adding this as an option makes it clear at
the call site that this is what will happen.
This is the main patch for the bug; it makes us use the mechanism added
in bug 1125455 to avoid sending animations that aren't currently
applying to the compositor.
Patch 7 is needed to make this code rerun in all the cases where we need
to rerun it, though.
This does somewhat less work than PostRestyleForAnimation, although I
believe PostRestyleForAnimation would be a sufficient alternative.
This is used in patch 6.
