"post locked" info animation doesn't work as expected

[afercia]

Follow up to #24553

The CSS animation added in #24553 doesn't work as expected for a couple reasons:

• height "auto" can't be animated with CSS
• jQuery delay() works only for the jQuery effects queue, not for other methods like empty()

The original intent of this animation was to make the "user is currently editing" info smoothly slide in and out, avoiding "jumps" in the UI that could be disturbing for users.

I'd say either the leftover code related to the animation should be removed or the animation should be fixed.

Created at WordCamp Roma 2018 contributors day.

/Cc @johnbillion

[afercia]

Relevant changesets:
[24576]
[24906]

For reference, the "locked info" was moved to the first line in #38185

[afercia]

44946.diff​ is a POC to fix the animation with 2 drawbacks:

• magic number for min-height
• setTimeout()

[afercia]

Looking back at this ticket, I'd lean towards just removing the dead code originally meant for the animation. In 6 years no one complained for the missing animation, so looks like some clean-up is preferable.

[afercia]

Also: the content of .locked-indicator is hidden only visually. Its text is announced by screen readers even when a post is not locked, which is definitely misleading (see attached screenshot).

I'd consider this a bug, as incorrect information is communicated to assistive technology users. I'd like to propose to:

• really hide both .locked-indicator and .locked-info using display: none: this will effectively hide their content also from assistive technologies
• when a post is locked, reveal these elements without animation

[afercia]

Locked info not hidden from assistive technologies

[afercia]

44946.2.diff​ :

• really hides the locked information both visually and from assistive technologies
• removes dead code originally meant for the CSS animation

[afercia]

Animated GIF with 44946.2.diff​ applied

[afercia]

In 45417:

Accessibility: Improve toggling the "Post locked" information visibility.

• effectively hides the "Post locked" information from assistive technologies
• when a post is locked, reveals the "Post locked" information without CSS animation
• the height CSS animation didn't work anyways after [24906]

See #24553.
Fixes #44946.