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.
This patch adds a means of terminating an animation so that is has no effect.
The procedure is defined by Web Animations:
http://w3c.github.io/web-animations/#cancelling-a-player-section
We don't implement all of this, however, since we don't currently support the
finished promise or custom effects.
In a later bug we will expose this as the cancel() method on AnimationPlayer.
We call this method for terminated animations in nsAnimationManager and
nsTransitionManager to ensure they get removed from the pending player tracker
and so that, for example, the ready promise of CSS Animation player objects is
rejected when the corresponding item is removed from animation-name.
