1912426 - Popovers with @starting-style and transition-behavior: discrete do not have exit animations

Status: NEW

(Core :: CSS Transitions and Animations, defect)

Description

[er.yd37]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:130.0) Gecko/20100101 Firefox/130.0

Steps to reproduce:

1. Visited the mdn page about @starting-style and scrolled down to the examples showing animation of a popover: https://developer.mozilla.org/en-US/docs/Web/CSS/@starting-style#animating_a_popover
2. Clicked to show, and then hide the popover

Reproduced in Firefox 129.0 and Firefox Developer Edition 130.0b2

Actual results:

The popover animates when appearing, but when disappearing, it just blinks away. The backdrop is not animated at all.

Expected results:

The popover and its backdrop should animate both when appearing, and when disappearing. Open the mdn page in Chrome to see how it animates.

Comment 1

[er.yd37]

Attachment: The bug shown in Firefox

Comment 2

[er.yd37]

Attachment: Intended behaviour as shown in Chrome

Comment 3

[Mayank Bansal]

Attachment: standalone_testcase.html

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Boris I think this is known (about animating display discretely right?)

Comment 5

[Boris Chiou [:boris]]

Yes. In this case, when changing the display property to none, we destroy all animations/transitions immediately because we don't support discrete animation on display property (i.e. it changes to none immediately).