USE AT YOUR OWN RISK

LightSwitch

A neovim plugin to easily switch between the light and dark variants of colorschemes in a unified way.

There is no need to stop using :colorscheme name if you know the name of the colorscheme you want to switch to. LightSwitch is there for you if you don't remember the name of an appropriate colorscheme of the other brightness or when you specifically look for a theme with certain brightness!

Colorschemes need to be registered before they work with this plugin:

-- First create a themegroup for your colorscheme:
local nightfox_group = {
  variants = {
    light = { 'dayfox', 'dawnfox' },
    dark = { 'nightfox', 'duskfox', 'nordfox', 'terafox', 'carbonfox' },
  },
-- Select the initial variants you want to use:
  selected = { light = 'dayfox', dark = 'nightfox' },
}
-- Then register them with the setup function:
require('lightswitch').setup({
  dayfox = nightfox_group, dawnfox = nightfox_group,
  nightfox = nightfox_group, duskfox = nightfox_group,
  nordfox = nightfox_group, terafox = nightfox_group,
  carbonfox = nightfox_group,
})

If the colorscheme is a bit special you can account for that with a custom switch function:

-- A theme that uses the same name for light and dark variant or that
-- uses an unusual way of changing between dark and light:
local vscode_group = {
    variants = { dark = {'vscode'}, light = {'vscode'} },
    selected = { dark = 'vscode', light = 'vscode' },
    custom_switch = {
        -- This is the default behaviour for dual brightness themes and
        -- thus unnecessary to specify:
        --vscode = function(light_or_dark)
        --    vim.cmd('colorscheme vscode')
        --    vim.cmd('set background=' .. light_or_dark)
        --end,

        -- If the theme does not react to changes of 'bg' or for some
        -- reason does not set the correct 'bg' value you need to set
        -- 'bg' and the brightness value known to LightSwitch yourself.
        vscode = function(light_or_dark)
            -- Make sure theme is active
            vim.cmd('colorscheme vscode')
            -- Unusual way of switching:
            require('vscode').load(light_or_dark)
            -- Fix LightSwitch state if necessary
            require('lightswitch').setstate(light_or_dark)
        end,
    },
}

Commands

variant   | of current             | of any
----------|------------------------|--------------------------
light     | `LightsOn name`²       | `LightSwitchOn name`²
dark      | `LightsOff name`²      | `LightSwitchOff name`²
opposite¹ | `LightsToggle name`²   | `LightSwitchToggle name`²

¹ ...of currently active theme's brightness (= `&bg` for unknown themes)
² Missing name defaults to current theme's last used variant (=selected)

Tips

• To avoid having to add/remove colorscheme names and groups in your config every time you un/install a theme, you might want to register them conditionally like so:

  -- YOURCONFIG/THEMES.lua
  return {}

  -- YOURCONFIG/sometheme_config.lua
  -- ...
  local themes = require('YOURCONFIG.THEMES')
  local group = {
      selected = { light = 'name1', dark = 'name2' },
      variants = { light ={'name1'},dark ={'name2'}},
  }
  themes['name1'] = group
  themes['name2'] = group

  Now, only if the theme's config is loaded, it is added to the table in YOURCONFIG/THEMES.lua . Call setup() with this table after all available themes were added:

  require('lightswitch').setup(require('YOURCONFIG.THEMES'))

• Lazy loading plugins, or using the conditional registration trick from above requires some caution; here exemplified with lazy.nvim :

  require('lazy').setup{
    { 'foo/sometheme',
      config = function() require('YOURCONFIG.sometheme_config') end,
      -- if you conditionally populate the table of themenames/-groups
      -- to register with LightSwitch:
      lazy=false              -- MAKES SURE THE CONFIG RUNS IMMEDIATELY
    },
    { 'herrvonvoid/lightswitch',
      config = function()
        require('lightswitch').setup(require('YOURCONFIG.THEMES'))
      end,
      -- if you did not use hardcoded themenames/-groups above:
      event= 'User LazyDone', -- ENSURES CONFIG RUNS AFTER THEME-CONFIGS
    }
  }

Troubleshooting

• Theme not found error / Shows uninstalled themes:

  • Did you spell the theme name correctly (check capitalization)?
  • Is the theme really called this way?
  • Did you accidentally register a theme with LightSwitch which is not installed? Consider registering themes, as described above, from their config (which wont be loaded if the theme is not installed) with some table which is imported by the LightSwitch config.

• Installed themes don't show up:

  • Did you register them?
  • As the correct brightness?
  • If you conditionally populate the table passed to setup(): Were all themes added to the table before setup() was called?
  • Are you using the correct command ("Lights<On|Off|Toggle>" only show themes from the same group)?

• Does not switch to the correct previous variant:

  • Were groups and theme names registered correctly?
  • Colorscheme changes before LightSwitch was loaded are not known to it; thus it should be loaded as soon as possible (for example with lazy.nvim's event="User LazyDone").