1247604 - [animation][w3c spec needed] support for re-set timestatus for reversed animation

Status: NEW

(Core :: CSS Parsing and Computation, enhancement)

Description

[Robert Utasi [:hunboy]]

Attachment: reverse animation timing issue testcase

per discuss on chat just filing a w3c discussion bug for animation.
The issue is - based on the attached testcase:

1. We have a paused animation with the time position I say x.
2. We set up the animation as reversed
3. The problem is: the time position is still x and not 1-x
4. Other problem is: we don't have animationPaused event either to catch this issue via javascript somehow.

In the testcase I use the anchor active selector for moving the layer as forward or rewind.

Comment 1

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

I really don't understand this bug.  What is it that you would like to be different from the way it is today?

Comment 2

[Brian Birtles (:birtles)]

The animation appears to only be reversed while a:active matches, hence why it doesn't appear in the reversed position while paused. I don't understand what the bug is.

Comment 3

[Robert Utasi [:hunboy]]

the problem is, when we set up the animation reversed during the animation period, that will display the animation time position is still x and not 1-x so the animation repositions itself instead of staying at that graphical position we need. I don't think this is a "bug" whilst all of browsers do this in this way as firefox. So this is the reason why I set it up as spec "bug".

Other anomaly: if we simply reverse the time-position when the animation is at start position we cannot reverse this to the end position anyway the animation never runs in reverse mode. So the time position always can be in [0...1) range exculding the 1 value.

Comment 4

[Robert Utasi [:hunboy]]

Attachment: testcase 2 - simplified

Press the "button" to make the animation as reversed. currently it graphically "repositions" itself instead of "staying" at that graphical position where we press the button.

Comment 5

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

It sounds like you want a way to change (to negative) the rate at which time advances on the timeline, instead of the current reverse feature which changes the mapping from time to animation position.

Comment 6

[Robert Utasi [:hunboy]]

Attachment: emulation presentation showcase

This is what I want to do by reversing the animation in at some time position. this is a presentation only, see the testcase 2 for the issue.