Ability to easily toggle between a set of themes (light/dark)

[EriKWDev]

Describe your feature request

I usually use helix on my laptop and when it is bright outside it is nice to use a light theme. At home, in the dark, it is much nicer with a darker theme.

It would be nice if there was some simple binding to toggle between themes that I have defined.

# config.toml
themes = [ "monokai_pro_spectrum", "catppuccin_latte" ] # ...or more

With proposed bindings:

• Next theme <Space> <t> <n>
• Previous themes: <Space> <t> <p>
• Select theme #n: <Space> <t> <0/1/2/3/4/5/6/7/8/9>

It would be nice if this decision was saved between sessions

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We could keep compatability by making the old theme = "..." still work unless the new themes is present. I would not mind other bindings if you come up with better ones, but I think the proposed ones seem to align with others.

I also prefer this over something like having two dark-theme = "...", light-theme = "..." since this approach is more general.

[the-mikedavis]

This might fall under #2849 but it seems slightly different since it's about configuration directly rather than enabling/disabling features.

Persisting between sessions I think is covered by #401.

I think it would be really elegant if this could be accomplished with custom keymaps. That would need a more general purpose configuration language (TOML is temporary).

As a workaround, you can hack at least the <space>t<0/1/2/3...> part with

# ~/.config/helix/config.toml
[keys.normal.space.t]
"1" = ":theme monokai_pro_spectrum"
"2" = ":theme catppuccin_latte"
# ...

You can also remove all themes from the ~/.config/helix/runtime/themes except the ones you would like to toggle between and then :theme <tab><tab>.... That would remove most of the friction from the current setup.

Overall though this seems like a somewhat specific use-case and I'm not sure it warrants building a feature around it. I may be out of touch on this but I don't imagine many people switch themes very often.

[EriKWDev]

Ye I don't know how niche this is either, but those keybindings will help a bit.

[kirawi]

Seems like a duplicate of #2158

[the-mikedavis]

I think it's subtley different: this one is more about manual toggling. But it's possible that the use-case would be served equally well by #2158