Instructions to change the dark mode code block styling don't work

[gilch]

URL: https://pradyunsg.me/furo/customisation/colors/#code-block-styling

What is missing or inaccurate about the content on this page?

Not sure if this is a doc issue or a bug. Instructions to change the dark mode code block styling don't work. (They do work for light mode.) Tested using Sphinx==3.3.1 and furo==2020.12.9b21, the latest versions released on PyPI.

I pasted these lines in my docs/conf.py used by Sphinx.

pygments_style = "sphinx"
pygments_dark_style = "monokai"

Changing pygments_style to another valid Pygments style affects the syntax highlighting in light mode when I rebuild the docs with Sphinx, but changing pygments_dark_style doesn't do anything. Dark mode is always the same style.

[pradyunsg]

HUH! Indeed.

https://github.com/sphinx-doc/sphinx/blob/9cf28264917800534e56a92c1fa5c1196c73e73f/sphinx/builders/html/__init__.py#L264

Looks like I've read the Sphinx code wrong! Sphinx doesn't seem to allow customising the dark color theme out-of-the-box. I might need to start getting hacky about this. :o

[pradyunsg]

Fixed in d5df1d4. :)

[gilch]

@pradyunsg I updated to furo==2020.12.28b23 and it's still not working for me. The dark style is still locked on native.

I tried deleting the build folder and loading the page with no browser cache. No luck. I double-checked site-packages and it appears to have your changes. E.g. __init__.py has the from sphinx.highlighting import PygmentsBridge and def _builder_inited(app):

[pradyunsg]

I think I reproduced the behaviour you're describing and released a fix in beta24. Try that out and lemme know if it works! :)

[gilch]

@pradyunsg Updated to furo==2020.12.30.beta24. No luck. I'm still locked on native in dark mode.

[pradyunsg]

Try cleaning up the previous build's artifacts? I'm unable to reproduce this.

If it's still happening, could you provide a reproducer for this (and reopen the issue as well)? :)

[gilch]

Do you mean open a new issue for the same issue? I don't have the permissions to have a reopen button for this one.

I tried in a fresh virtual environment. pip install -r requirements.txt containing:

sphinx==3.1.2
furo==2020.12.30.beta24

I did a sphinx-quickstart in an empty directory with default settings and Furo for the required ones.
I opened the generated conf.py and replaced the line

html_theme = 'alabaster'

with

html_theme = 'furo'
pygments_style = "sphinx"
pygments_dark_style = "monokai"

I appended the lines

.. code-block:: Python

   def foo(a=1,b='b'): pass

to the generated index.rst to have some code to highlight.

I ran make html.
I found the generated pages in _build/html/ and served the index.html in PyCharm by using the "open with Edge" button. The dark style is still native, not monokai.

---

The browser and server don't seem relevant however. I double-checked the _build/html/static/pygments_dark.css and it's identical to the file loaded by Edge. Monokai isn't in the build.

I manually changed the line

.highlight .k { color: #6ab825; font-weight: bold } /* Keyword */

in pygments_dark.css to

.highlight .k { color: #fff; font-weight: bold } /* Keyword */

and the highlighting color changed, so this is the stylesheet that is definitely being applied in dark mode.

I checked site-packages/furo/__init__.py, and it contains __version__ = "2020.12.30.beta24".

I appended the line

import furo; print("Furo:", furo.__version__)

to conf.py and it prints out Furo: 2020.12.30.beta24 when I run make html.

I added a breakpoint() to the end of _builder_inited() in site-packages:

(Pdb) app.config.pygments_dark_style
'native'

That looks wrong. I changed it like so:

(Pdb) builder.dark_highlighter = PygmentsBridge("html",'monokai')
(Pdb) c

Now the built dark highlighter isn't native when I load it in the browser.

[pradyunsg]

app.config.pygments_dark_style
'native'

Well well well. What happens on newer versions of Sphinx? This might be an environment management bug in the older Sphinx version, maybe?

[gilch]

Updated to sphinx==3.4.1 in my project and it didn't help. I'll try it in a fresh environment.

[gilch]

Fresh environment is the same. Debugger inspection is the same. app.config.pygments_dark_style is 'native'.

[pradyunsg]

This should be resolved with beta25. Could you try again?

[gilch]

Fresh environment with new versions

sphinx==3.5.1
furo==2021.2.21.b25

is the same.

(Pdb) app.config.pygments_dark_style
'native'
(Pdb) __version__
'2021.02.21.beta25'

And again, I can manually set builder.dark_highlighter = PygmentsBridge("html",'monokai') in the debugger to get the right colors, but it seems to be ignoring the pygments_dark_style in conf.py.

[pradyunsg]

What is Sphinx doing...

[pradyunsg]

Okay, with 784a670, this is definitely done now. You should be able to try this by using pip install furo==2021.3.20b31 (which I also yanked, coz... reasons that aren't related to this).

[gilch]

Maybe a separate issue, but I've noticed that formatting for a light pygments theme (tango) bled through to the formatting for a dark theme (monokai). It works fine if I use the same theme for both. Anything the dark theme left unspecified was set by the light theme. E.g. for number literals, the color worked as expected, but became bold text in the dark theme only when I had tango as the light theme.

[pradyunsg]

Hiya! Please file a new discussion for this. Making comments on closed issues makes things harder for me to keep up with.