This patch adjusts GetComputedTimingAt to set the time fraction and current
iteration fields of the output computed timing correctly for animations with
zero iteration duration. Care must be taken to handle cases such as animations
that have zero duration but repeat infinitely.
The code is significantly re-arranged to more closely align with the naming and
algorithms defined in Web Animations.
A couple of tests in test_animations.html have been tweaked to account for
floating-point error. This is not because the new code is less precise but
actually the opposite. These tests fall on the transition point of step-timing
functions. The new code uses the closest possible floating-point representation
of these times which happens to cause them to fall on the opposite side of the
transition point.
For example, in evaluating a point 3s into a reversed interval the old code
would give us an intermediate time fraction of:
0.29999999999999982
When we reverse that by subtracting from 1.0 we get: 0.70000000000000018
With the code in this patch we get an intermediate time fraction of:
0.29999999999999999
When we reverse that by subtracting from 1.0 we get: 0.69999999999999996
Hence we fall on the opposite side of the transition boundary.
This patch also makes ElementAnimation::ActiveDuration a static method that
takes timing parameters as an argument. This is so that this method can be
used within ElementAnimations::GetComputedTimingAt (a static method) in a
future patch.
We could also make ActiveDuration() a method of AnimationTiming. I suspect
this logic belongs together in ElementAnimation however.
In a future patch we could also add the active duration to the ComputedTiming
struct which would simplify the only other place this is currently used
which is ElementAnimations::GetEventsAt.
This patch simply moves the code from ElementAnimations to ElementAnimation so
that it can later be used in transitions code and so we can later move
EnsureStyleRuleFor to ElementAnimation.
Introduces a struct to store timing parameters for passing to
GetPositionInIteration. In future this struct is expected to be expanded to
include other timing parameters as well (based roughly on Web Animations'
"Timing" interface, hence the name AnimationTiming).
We currently have mozilla::StyleAnimation as well as nsStyleAnimation. This
patch renames StyleAnimation back to ElementAnimation.
Although ElementAnimation is very similar to ElementAnimations, in the near
future we expect to retire ElementAnimations and replace it with a common
AnimationSet-like structure that is covers the features of ElementAnimations and
ElementTransitions.
We need a basic representation of animations from which we can derive subclasses
to represent specific cases such as transitions. For now we will retrofit
ElementAnimation for that purpose hence renaming it to StyleAnimation.
This patch removes the "using namespace mozilla::layers" line from
AnimationCommon.cpp since the unified build system concatenates several files
together before compiling making using declarations like this leak into other
files potentially creating ambiguities. Previously, when we were calling
ElementAnimation, 'Animation', there were ambiguities between
mozilla::layers::Animation and this new 'Animation' class. In general, it is
probably a good idea to limit the scope of these using declarations so I've kept
that change.
This patch relocates ElementAnimation from nsAnimationManager.{h,cpp} to
AnimationCommon.{h,cpp} and in the process moves it into the mozilla::css
namespace.
I've been wanting to remove this code for a while. I think this code is
problematic for three reasons:
(1) It's in the middle of code where it doesn't belong, and which ought
to be handling purely-style-system things. (This is blocking me
from reusing that code elsewhere, e.g., in bug 977991 and
bug 960465, both of which could use it in some form.)
(2) It defeats the optimization from bug 790505 whenever we do a
miniflush (in other words, whenever we have any style change,
whether or not it's related)
(3) It means the conditions for when we decide to ship a new set of
animation data to a layer doesn't cover all the cases the layer
needs it. In particular, we only run this miniflush code when we
have a currently running animation or transition that's running on
the compositor thread. On the other hand, the UpdateTransformLayer
style change handling in DoApplyRenderingChangeToTree depends on
whether the frame currently has a transform layer, which can
continue to be true for a bit after the animation stops. So if we
need to send animations to the layer because of a transform style
change that happens soon after an animation completes, our style
change handling will find the existing layer and call its
SetBaseTransformForNextTransaction method but never do anything
that triggers layer construction. The style throttling code, in
turn, will never stop doing main thread updates because the
animation generation on the layer is out-of-date, and these main
thread updates will keep the layer active, but they'll never show
up because the stale animation data overrides the new transform
that we've been setting. (At least, I think that's what was
happening; it makes sense to me and matches the behavior I was
observing. I didn't verify which main thread updates and which
layer updates were actually happening, though.)
This shows up, for example, in the animation in attachment 8384813
just halting at a corner if I'm careful not to disturb it. (I'm
testing on Linux, with both accelerated layers and OMT animations
explicitly enabled.)
I think there are probably some other things that can be removed as
followups to removing this code, because I think we made some boundary
conditions intentionally incorrect so that problem (3) above wouldn't be
as bad as it otherwise would have been.
This moves restyling management out of nsCSSFrameConstructor (thus
reducing its size), and keeps the restyling code closer together.
This is the first of two big chunks of code moved in this patch series.
A later patch in this series will move related code from nsFrameManager
into the same destination file.
The fixes to the miniflush code
(nsTransitionManager::UpdateThrottledStyle and UpdateAllThrottledStyles)
fix the case where we constructed totally incorrect style contexts for
outer table frames (which have special style contexts inheriting from
the table frame) during the miniflush, leading to inconsistent style
data and other bad things, when we should have been touching the style
on the table frame instead.
The fixes to the other OMTA codepaths lead to layer tests being
performed on the same frame that the styles will be applied to, and
probably fix real bugs (which would occur when animating opacity or
transform on a table).
The fixes to the miniflush code
(nsTransitionManager::UpdateThrottledStyle and UpdateAllThrottledStyles)
fix the case where we constructed totally incorrect style contexts for
outer table frames (which have special style contexts inheriting from
the table frame) during the miniflush, leading to inconsistent style
data and other bad things, when we should have been touching the style
on the table frame instead.
The fixes to the other OMTA codepaths lead to layer tests being
performed on the same frame that the styles will be applied to, and
probably fix real bugs (which would occur when animating opacity or
transform on a table).
