Bug 20995 – Rewrite keyframe resolution to be like styleForElement()

• Component: CSS
• Status: RESOLVED FIXED

[Chris Marrin]

Today, I resolve style when the style sheet is read. This has several problems, most notably that it can't resolve physical units, like ems. So it needs to change.

Hyatt suggests:

1) In addKeyframeStyle, just store the CSSStyleDeclarations for each keyframe
2) Create a new method (keyframeStyleForElement?) which resolves keyframes given an element and animation name
3) When starting an animation, use this method to get the list of RenderStyles for each keyframe, caching them for the duration of the animation, and using them as today to run the animation.

[Chris Marrin]

That's actually keyframeStylesForElement() since it collects style for all keyframes at once

Raising to P1 because of dependent bug 21043.

[Chris Marrin]

Created attachment 23821 [details]
Patch, including LayoutTest file

[Chris Marrin]

The fix is as outlines above. I ended up duplicating the element's RenderStyle into each keyframe RenderStyle, so they had full information for doing things like lineheight and other font metrics (and possibly others). This makes the RenderStyles a bit more heavyweight in some cases, but I think the model is right.

The submitted testcase tests the line-height property, which was borked before this change.

[Dave Hyatt]

Comment on attachment 23821 [details]
Patch, including LayoutTest file

r=me

[Simon Fraser (smfr)]

Committed r37077
	M	WebCore/rendering/style/KeyframeList.cpp
	M	WebCore/rendering/style/StyleRareNonInheritedData.h
	M	WebCore/rendering/style/StyleRareNonInheritedData.cpp
	M	WebCore/rendering/style/Animation.h
	M	WebCore/rendering/style/Animation.cpp
	M	WebCore/rendering/style/KeyframeList.h
	M	WebCore/rendering/style/RenderStyle.h
	M	WebCore/ChangeLog
	M	WebCore/css/CSSStyleSelector.cpp
	M	WebCore/css/CSSStyleSelector.h
	M	WebCore/page/animation/CompositeAnimation.cpp
	M	WebCore/page/animation/KeyframeAnimation.cpp
	M	WebCore/page/animation/KeyframeAnimation.h
	M	LayoutTests/ChangeLog
	A	LayoutTests/animations/lineheight-animation.html
	A	LayoutTests/animations/lineheight-animation-expected.txt
r37077 = e979de02d997b41646bbf7c704ca6bc0c6c3bfdb (trunk)

[Chris Marrin]

*** Bug 20148 has been marked as a duplicate of this bug. ***