Add a method for downcasting from an ElementAnimation to an
ElementPropertyTransition (when the underlying object is an
ElementPropertyTransition).
This, unfortunately, adds a vtable to ElementAnimation but in the long term
I hope we will be able to isolate transition-specific code to a specific kind of
TransitionEffect that hangs off ElementAnimation and put the vtable on
AnimationEffect instead. (The AnimationEffect concept is part of the Web
Animations API.)
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.
This patch takes StyleAnimation and makes it ref-counted heap object. This
should allow us to store StyleAnimation and its subclasses (transitions only
currently) in a consistent fashion (an array of base-class pointers).
Furthermore, this will be helpful if we want these things to be pointed to
from Javascript objects that may, for example, preserve their lifetime beyond
that of the element that currently owns them.
This patch also introduces a typedef for an array of refptrs to StyleAnimation
objects (and similarly for the subclass ElementPropertyTransition) to simplify
the code somewhat.
Two comments in AnimationCommon.h refer to 'mFlushCount' which was presumably
the old name for mAnimationGeneration. Also, one comment says
nsCSSFrameConstructor tracks this. This patch adjusts the comments to refer
to mAnimationGeneration and RestyleManager.
(The reference to nsTransitionManager::UpdateAllThrottleStyles() is still valid
since there is useful documentation accompanying that method despite the fact
that the relevant code is mostly contained in AnimationCommon.h since bug
914847. Eventually we will unify the structures of transitions and
animations to the the point that we can replace the
IMPL_UPDATE_ALL_THROTTLED_STYLES_INTERNAL macro in AnimationCommon.h with an
actual method. At that point we can move the documentation accompanying
nsTransitionManager::UpdateAllThrottleStyles and its references to
AnimationCommon.)
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.
