826670 - Animated opacity change can make printed version invisible

Status: RESOLVED WORKSFORME

(Core :: Printing: Output, defect, P3)

Description

[adam.taylor]

Attachment: animationPrint.html; embedded CSS to demo issue

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/20100101 Firefox/18.0
Build ID: 20121231071231

Steps to reproduce:

HTML5 page with an animated fade-in (via CSS3 animation; opacity goes from 0 to 1 over 1 sec).

The CSS is applied to all media types, including print.


Actual results:

The page prints blank, as if the print has 'snapshot' the page at a state before the animation has completed. 

Alternatively, with a larger page weight, the page prints, but with faded text, I assume because the opacity animation has *partially* completed.


Expected results:

If animation is applied to print media, it should be ignored entirely.

Comment 1

[Loic]

Attachment: Reporter's testcase with 10 sec of fading

Testcase with longer duration of fading.

Comment 2

[Daniel Holbert [:dholbert]]

(In reply to adam.taylor from comment #0)

Expected results:

If animation is applied to print media, it should be ignored entirely.

It looks like we implemented this behavior at some point (ignoring animations for print media).

Unfortunately, that causes other problems when the site is depending on the animation to show elements whose underlying style is to make them invisible -- see bug 1564128.

However, this bug as-filed (and its testcase) is effectively WORKSFORME - we now match the expected behavior here and produce the expected result for the testcase.