flashes during startup

[tomspeak]

return {
  'f-person/auto-dark-mode.nvim',
  priority = 1000,
  lazy = false,

  config = {
    update_interval = 30000,
    set_dark_mode = function()
      vim.api.nvim_set_option('background', 'dark')
    end,
    set_light_mode = function()
      vim.api.nvim_set_option('background', 'light')
    end,
  },
}

With this configuration, if I am in light mode, on startup it will briefly flash in dark mode, then switch to light mode.

Is there a way for me to make it set to the correct value on startup and not have this flash?

[nekowinston]

AFAIK not really, the best workaround I can offer is to use a transparent background, if your Terminal syncs dark/light as well. That way, you won't get the flash for the background at least.

[bugabinga]

This probably happens because Neovim and/or your color scheme set the background to dark before this plugin has a chance to be loaded.

My workaround looks like this:

return {
  'f-person/auto-dark-mode.nvim',
  lazy = false,
  priority = 9999,
  init = function()
      -- Get the current hour
      local current_hour = tonumber( os.date  '%H'  )

      -- Set the background based on the time of day
      if current_hour >= 9 and current_hour < 17 then
        vim.opt.background = 'light'
      else
        vim.opt.background = 'dark'
      end
  end,
  opts = {
    ...
  },
}

This happens to work for me, because my system also changes between light ad dark mode during those hours.

Another alternative could be to vendor the code of this plugin into your configuration and have it run very early, maybe.

[alycklama]

I was able to fix this on my machine by not setting any theme explicitly. I forgot I manually set the theme when loading the theme in Lazy. By removing this, it no longer flashes.

[connorjs]

Setting the vim color scheme as the “base” scheme seems to fix this enough for me. That scheme seems to use terminal colors, so there is no main background flash. YMMV.

vim.cmd.colorscheme("vim")

[guivictorr]

I was able to fix (but only on macOS 😅) with this init function

    init = function()
      -- Function to determine if macOS is in dark mode
      local function is_dark_mode()
        local handle = io.popen("defaults read -g AppleInterfaceStyle 2>/dev/null")
        local result = handle:read("*a")
        handle:close()
        return result:match("Dark") ~= nil
      end

      -- Set the background based on macOS appearance
      if is_dark_mode() then
        vim.opt.background = "dark"
      else
        vim.opt.background = "light"
      end
    end,

[JacobHayes]

My hack is to generate an extra config file in the set_{light,dark}_mode callbacks that hard codes vim.go.background and then import that from init (or some other config).

This spreads the logic out a bit, but doesn't require specific hours, should work across all systems¹, and is maybe slightly quicker on startup than the alternatives above.

_{1: well, you'd need to refactor around io.open or something instead of os.execute for non-WSL Windows 😅}

---

With LazyVim, I have: ~/.config/nvim/lua/plugins/colorscheme.lua:

return {
  {
    "f-person/auto-dark-mode.nvim",
    event = "VeryLazy",
    init = function()
      require("config.background")
    end,
    opts = {
      update_interval = 1000,
      set_dark_mode = function()
        vim.api.nvim_set_option_value("background", "dark", {})
        os.execute("echo 'vim.go.background = \"dark\"' > ~/.config/nvim/lua/config/background.lua")
      end,
      set_light_mode = function()
        vim.api.nvim_set_option_value("background", "light", {})
        os.execute("echo 'vim.go.background = \"light\"' > ~/.config/nvim/lua/config/background.lua")
      end,
    },
  },
}

[jan-xyz]

After debugging this for a bit on my system, it seems to be a performance problem. executing the query command and parsing the response takes "too long" until the first time that it actually triggers a background change.

[nekowinston]

I'd appreciate if people running into this issue could give the latest updates a try, ideally without any extra caching functions and workarounds. I hope switching to newer APIs made things more responsive.

[uloco]

still flashing for me with the lastest version (macos + ghostty)

[cravingPixels]

I also have the flashing with latest version (c31de12). Currently on macos with wezterm. nvim at 0.11