1668029 - Amazon overlays a transparent link on top of image, causing it to display invisible in high contrast mode

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[msradel]

Attachment: FF HC - Amazon.jpg

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0

Steps to reproduce:

https://www.amazon.com/stores/Bose/page/9E24AFD5-B420-4859-BD2F-A993BA579B20

See related Bug 1666059 - Plex overlays a transparent button on top of text, causing invisible text in high contrast mode

Actual results:

See screen shots.

FIle name Schema - FF = Firefox, IE = Internet Explorer, HC = Hight Contrast Mode

1. Firefox with High Contrast Mode
2. Firefox without High Contrast Mode
3. IE with High Contrast Mode

Expected results:

I should be able to view ALL images on the page.

Comment 1

[msradel]

Attachment: FF - Amazon.jpg

Comment 2

[msradel]

Attachment: IE HC - Amazon.jpg

Comment 3

[Emilio Cobos Álvarez [:emilio]]

Attachment: testcase

So this is because they effectively have a semi-transparent, absolutely-positioned link overlaid on top of the image, and we make it fully opaque.

Comment 5

[Emilio Cobos Álvarez [:emilio]]

So it seems clear we need to deal with transparency in HCM somehow, not just resetting all backgrounds to the default one as we've done historically.

https://drafts.csswg.org/css-color-adjust-1/#forced-colors-properties seems to suggest we should just respect the alpha value and set the other components to the default background. Does that seem sensible? I suspect we should really set them to the "reverted" background in some cases, to make stuff like bug 1625036 work with backplating...

Thoughts?

Comment 6

[Morgan Reschenberg [:morgan]]

(In reply to Emilio Cobos Álvarez (:emilio) from comment #5)

So it seems clear we need to deal with transparency in HCM somehow, not just resetting all backgrounds to the default one as we've done historically.

https://drafts.csswg.org/css-color-adjust-1/#forced-colors-properties seems to suggest we should just respect the alpha value and set the other components to the default background. Does that seem sensible? I suspect we should really set them to the "reverted" background in some cases, to make stuff like bug 1625036 work with backplating...

Thoughts?

Yeah, I agree with you. I saw the plex bug and was thinking the same thing.

Comment 7

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1668029 - When resetting background color for high contrast, preserve alpha channel appropriately. r=morgan

But discard it when backplating behind text, so that text is readable.

This should be uncontroversial... Dealing with widgets is a bit harder
so TBD.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f1130dfcdbc4
When resetting background color for high contrast, preserve alpha channel appropriately. r=morgan

Comment 9

[Razvan Maries]

Backed out for perma failures.

Push with failure: https://treeherder.mozilla.org/#/jobs?repo=autoland&selectedTaskRun=K5fMJ7fnRLuSWq3RdOl_4w.0&resultStatus=pending%2Crunning%2Csuccess%2Ctestfailed%2Cbusted%2Cexception&searchStr=windows%2C10%2Cx64%2Cdebug%2Creftests%2Ctest-windows10-64%2Fdebug-reftest-e10s%2Cr3&revision=f1130dfcdbc4288385aa97c3c388be90d26d1c8e

Log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=317078867&repo=autoland&lineNumber=8168

Backout: https://hg.mozilla.org/integration/autoland/rev/6c41ddbfb5874ed68fb542662208b89791edfaa1

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/eaa908b5583c
When resetting background color for high contrast, preserve alpha channel appropriately. r=morgan

Comment 11

[James Teh [:Jamie] (away returning 12 Jan)]

Leaving this in (both of) your very capable hands. :) Thanks.

Comment 12

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/eaa908b5583c

Comment 13

[msradel]

Thank you all for the quick research and resolution. It will make a huge difference for me and other who use high contrast.