1408122 - Dark theme should apply dark colors to about:blank background to avoid white flashes

Status: VERIFIED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Jared Wein [:jaws] (please needinfo? me)]

+++ This bug was initially created as a clone of Bug #1408121 +++

Enabling the dark theme changes the colors of the toolbars to be dark, but the background of tabs flashes white when opening a new tab or loading a new page.

Using a dark background will help users who may have chosen the Dark theme due to light sensitivity (using the browser in the dark).

Comment 2

[Kestrel]

Bug 1402312 did not fix the about:blank case.

Comment 5

[Kestrel]

Bug 1488384 is specifically about the white flashes due to #tabbrowser-tabpanels which is part of the underlying browser chrome. This bug is for theming the in-content about:blank page which is more closely related to Bug 1519547. Also since about:blank can be set as the new tab page it is not just an issue of white flashes (Bug 1471402).

Comment 6

[Tim Nguyen :ntim]

In case someone is interested in implementing this, about:blank is implemented in C++: https://searchfox.org/mozilla-central/source/netwerk/protocol/about/nsAboutBlank.cpp

Comment 7

[Kestrel]

Attachment: Bug 1408122 - Add stylesheet to about:blank for in-content dark mode background

Stylesheet needs to be added in two places for different parsing methods, direct about:blank pages use nsHTMLContentSink while indirect (eg about:newtab displaying about:blank) use Html5Parser and require the nsAboutBlank input stream to be filled.

Comment 10

[Brandon_Davison]

This seems like an interesting defect. Would I be able to attempt it?

Comment 11

[Gian-Carlo Pascutto [:gcp]]

This seems like an interesting defect. Would I be able to attempt it?

There's a patch attached to the bug with discussion in it, which reveals some of the unexpected complexities.

Comment 12

[Gian-Carlo Pascutto [:gcp]]

I've hidden the original description, because that was talking about [blank], which was "fixed" in bug 1488384, at least if the user has the OS dark theme enabled - a distinction that seems to be generating no end of confusion. Comment 2 then morphed this bug into being about about:blank. That should be clearer now.

Comment 13

[Andrei Petcu]

Is this still being reproduced?

Comment 14

[Starbeamrainbowlabs]

(In reply to petcuandrei from comment #13)

Is this still being reproduced?

I'm still seeing it in Firefox Beta 73.0b6 (64-bit).

Comment 15

[Mehmet]

(In reply to petcuandrei from comment #13)

Is this still being reproduced?

Yes, it is! Nightly 74.0a1 (2020-01-20) (64-Bit).

Comment 19

[OptionallyNamed]

My eyes hurt so much every time I restart a page or load a new page. It is weird that dark themes do not make loading pages dark, because obviously the users of dark themes need everything dark. Now my only choice is to squint my eyes or close the screen with my hand. Please, fix it. :-(

Comment 20

[OptionallyNamed]

My eyes hurt so much every time I restart a page or load a new page. It is weird that dark themes do not make loading pages dark, because obviously the users of dark themes need everything dark. Now my only choice is to squint my eyes or close the screen with my hand. Please, fix it. :-( p.s. Another problem with dark theme is that the scrollbars become so dark that I cannot scroll pages. This is so counter-productive.

Comment 21

[Tim Nguyen :ntim]

(In reply to OptionallyNamed from comment #20)

Another problem with dark theme is that the scrollbars become so dark that I cannot scroll pages. This is so counter-productive.

Please file a new bug for this.

Comment 22

[OptionallyNamed]

Please file a new bug for this.

Please, file this bug for me because I am not a sofware enthusiast. please.

Comment 23

[Tom S [:evilpie]]

Attachment: Bug 1408122 - Apply prefers-color-scheme: dark to top-level about:blank. r?emilio

I think during the All Hands in Berlin you might have suggested to do this in nsPresContext::DefaultBackgroundColor,
but this seems a bit more targeted and not a header.

I haven't try tested this yet, so this more of a feedback?

Comment 24

[Tim Nguyen :ntim]

(In reply to OptionallyNamed from comment #22)

Please file a new bug for this.

Please, file this bug for me because I am not a sofware enthusiast. please.

It would be helpful if you could provide a screenshot of what's wrong with the scrollbars on your side, because I'm not seeing this bug on macOS. I can't really file a bug without much context. Thanks :)

Comment 25

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d2722b645439
Apply prefers-color-scheme: dark to top-level about:blank. r=emilio,bzbarsky

Comment 26

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/d2722b645439

Comment 27

[Ciprian Georgiu, Desktop QA]

Reproduced the issue using an affected Nightly build from 2020-02-03, on macOS 10.14.

I have verified that the dark colors are successfully applied while the OS dark theme is enabled. Tested on macOS 10.14, Ubuntu 18.04 and Windows 10 x64, running Beta 75.0b7.

Comment 28

[Guo Yunhe]

I can still reproduce it in Firefox 75 on openSUSE Tumbleweed.

Comment 29

[Tom S [:evilpie]]

(In reply to Guo Yunhe from comment #28)

I can still reproduce it in Firefox 75 on openSUSE Tumbleweed.

Do you have privacy.resistFingerprinting enabled? Somebody opened bug 1634602 that this isn't working.

Comment 30

[Guo Yunhe]

(In reply to Tom Schuster [:evilpie] from comment #29)

(In reply to Guo Yunhe from comment #28)

I can still reproduce it in Firefox 75 on openSUSE Tumbleweed.

Do you have privacy.resistFingerprinting enabled? Somebody opened bug 1634602 that this isn't working.

No, I don't.

Comment 32

[L]

On mac, nightly 89, this still occurs.

Easy way to reproduce:
Holding command, click the down arrow next to any user on this page, then click "profile".
about:blank should open in a new tab with a white background, at least for a second or two before opening the profile page.

Comment 33

[Emilio Cobos Álvarez (:emilio)]

Yeah, that case is a bit harder, because that window has an opener (and thus is web-observable).