CSS WG Blog CSS Transitions draft updated

CSS Transitions draft updated

The CSS Working Group has published an updated Working Draft of CSS Transitions. CSS Transitions allows property changes in CSS values to occur smoothly over a specified duration.

This contains a number of significant changes relative to the previous working draft. The most significant changes are in two areas:

1. The specification now defines how transitions start much more clearly. This will require updates to all shipping implementations, which all disagree, and most or all of which had behaviors that even their implementors thought were undesirable.
2. The rules for faster reversing of partially completed transitions now match Gecko’s shipping behavior, rather than an alternative proposal that involved reversing timing functions.

We’re particularly interested in feedback on these changes, but also in other feedback about the spec.

I’m hoping that there won’t be a need for any further changes of this magnitude, and that the specification can go to last call relatively soon. I’m aware that there are some issues that need to be addressed before that happens, but I’m expecting that the changes
needed for these issues will be smaller. Any proposals for new features will almost certainly be postponed to the next level of the specification.

A more complete list of significant changes since the last working draft is in the changes section of the draft.

As always, please send feedback to the (archived) public mailing list www-style@w3.org with the spec code ([css3-transitions]) and your comment topic in the subject line.

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