Earlier in this patch series we divided keyframe processing into two stages:
(1) Turning javascript objects into an array of Keyframe objects
(2) Calculating AnimationProperty arrays from the Keyframe objects
This patch creates a SetFrames method so that CSS animations and
CSS transitions can skip (1) and pass the frames constructed from CSS syntax
into (2).
It also adds the following additional processing:
a. Notifying animation mutation observers when the set of frames has changed.
This is currently performed by nsAnimationManager but ultimately we should
encapsulate this logic inside the effect itself. Furthermore, it will be
needed when we implement effect.setFrames() (i.e. the Javascript-facing
wrapper for this method).
b. Preserving the mWinsInCascade and mIsRunningOnCompositor state on properties
when updating them.
This is currently performed by:
bool KeyframeEffectReadOnly::UpdateProperties(
const InfallibleTArray<AnimationProperty>& aProperties)
which is what nsAnimationManager currently uses. We will ultimately remove
the above method and here we are just moving this code to the new version
of UpdateProperties.
c. Requesting a restyle when the set of AnimationProperty objects has changed.
Again, this is currently performed by the existing UpdateProperties method
so we are just moving it here. This behavior will also be required when
we implement effect.setFrames() and when we call UpdateProperties from
elsewhere in restyling code.
This is bug 1235002 but we fix it here and leave that bug to just do further
cleanup work (e.g. re-instating the check for an empty property set before
requesting a restyle in NotifyAnimationTimingUpdated).
d. Marking the cascade as needing an update when the set of AnimationProperty
objects has changed.
This is in preparation for calling UpdateProperties from elsewhere in
restyling (e.g. when the nsStyleContext is updated).
MozReview-Commit-ID: 2ll26lsWZTm
StyleAnimationValue::ComputeValue(s) will automatically look up the style
context of the supplied element. This is mostly fine, but when we start using
this method in scenarios where we are building the initial style context
(as happens later in this patch series) it can easily land us in a situation
where we iterate indefinitely.
It would be better, instead, to just explicitly pass in the style context we
want to use, as we already do for StyleAnimationValue::ExtractComputedValue.
MozReview-Commit-ID: ZoVBlBRRBI
