This patch is the first part in preparing the way to merge ElementTransitions
with CommonElementAnimationData (which we'll eventually rename to something
nicer).
Here we move mTiming from CommonElementAnimationData to the AnimationTiming
struct. While this is not strictly necessary in order to do the later
refactoring it makes it simpler since it:
- Divides time calculation into calculation based on dynamic play state (the
responsibility of animation players in Web Animations terms) and static
author-specified timing parameters (a property of animations in Web Animations
terms).
- In future we will probably put animations on the compositor during their
delay phase so we will want the delay to be present in the AnimationTiming
struct then.
- Makes AnimationTiming line up with the dictionary of the same name in Web
Animations.
In the IPC Animation struct used in layers code we have a member called
'numIterations' where 'iterate forever' is represented by -1.
In layout/style however we have an AnimationTiming struct with an
mIterationCount member where 'iterate forever' is represented by
NS_IEEEPositiveInfinity().
This patch renames 'numIterations' to 'iterationCount' and uses infinity to
represent 'iterate forever'.
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.
This patch makes ElementAnimations::GetPositionInIteration return
a ComputedTiming object instead of just a time portion (time fraction).
Since the ComputedTiming object includes phase information, we can fix those
parts of EnsureStyleRule and GetEventsAt that were temporarily using the time
portion to guess if the animation might have finished or not.
This patch moves event queuing out of EnsureStyleRuleFor into a separate method.
This is a preparatory step towards making GetPositionInIteration into a more
generic method for calculating the current time fraction.
In order to achieve this, GetPositionInIteration needs to be able to calculate
the correct time portion for times outside the range [0, 1] even when it is not
passed a ElementAnimation object. Specifically, it needs the fill mode of the
animation to be passed in.
(Rather than using FillForwards/FillBackwards this patch just compares the
NS_STYLE_ANIMATION_FILL_MODE_* values directly but FillForwards/FillBackwards
are restored in a subsequent patch when they are added to the struct used to
lump the timing parameters together.)
There are a number of places where positionInIteration is used to determine if
the current sample occurs in the active phase or after. This is sub-optimal but
is fixed in a subsequent patch in this series.
The actual work of removing event queuing from GetPositionInIteration is
deferred to a subsequent patch in order to keep the changes as small as
possible. This patch simply makes separate calls to GetPositionInIteration for
interpolating and for event queuing.
