Automatic dark mode

[jagot]

Feature description

On some modern operating systems, there is support for automatically switching to a dark theme at sunset and a light theme at sunrise. I would like to be able to specify two themes, a light one and a dark one, and have GLMakie automatically switch between the two, when the desktop theme changes.

Example programs:

• Emacs using auto-dark mode
• iTerm2

[asinghvi17]

On MacOS, you can detect this by running:

defaults read -g AppleInterfaceStyle

which will print "Dark" if dark mode is on, and an error message otherwise.

From there, you can check this at startup:

is_dark_mode = contains( read(`defaults read -g AppleInterfaceStyle`, String), "Dark")

and set the Makie theme appropriately:

is_dark_mode && Makie.set_theme!(Makie.theme_dark())

I don't think it makes sense to upstream this, since plotting would become quite unpredictable :D - but a small startup package could be nice.

You could also run some async task that queries the dark-mode status every minute or so, and performs the switch if necessary!

[jagot]

I created a small package that forks out to dark-notify to capture the theme switches on macOS:

I assume one could do similar things on e.g. Gnome.

This way, one could conceivably do something like

using GLMakie
using AutoDark

auto_dark() do theme
    println("Setting theme: ", theme)
    set_theme!(theme == :light ? theme_light() : theme_dark())
end

x = range(0, stop=1, length=1000)

fig = Figure()
ax = Axis(fig[1,1])

lines!(ax, x, sinpi.(2x))
fig

but the problem is that it does not change the theme of already displayed figure (which is what I am after).

[asinghvi17]

Ah, that's not really possible with Makie at the moment I think - you would have to create a new Figure, and that would pick up the current theme. A lot of theme expansion/inheritance is done at the time of plot creation so it's pretty difficult to have that cascade downwards after the fact.

[jagot]

I completely understand that this is a hairy feature to implement and get right, but it would be so nice I still wished to make the feature request :)