refactor: refactor setup() function, handle old configuration and update highlights

[xeluxee]

Fix #37

Changes introduced with this PR:

• The configuration is kept in the global variable vim.g.onedark_config, to make it accessible from vimscript
• refactor setup(): now it accepts an argument, a dictionary containing options. Note: setup() only manages configuration, it doesn't load the colorscheme. To load the colorscheme you can :colo onedark

Example:

require('onedark').setup {
  style = 'deep',
  toggle_style_key = '<leader>o',
  diagnostics = {
    darker = false,
    background = false,
  },
}

Of course it can be called without any argument: require('onedark').setup(), and the default configuration will be used

• colors/onedark.vim -> colors/onedark.lua
• lua/onedark/config.lua -> lua/onedark/old_config.lua, since this file is used to parse old configuration (if found it prints deprecation messages)
• highlights: deprecate bold, underline, undercurl, italic and reverse options in favor of fmt, a string that is ready to be used in highlight command. Example: ErrorMsg = {fg = c.red, fmt = "bold,italic"}. To see all the available attributes :h attr-list or here (they are the same for cterm and gui)
• highlights: trying to improve markdown highlights (TS markdown has no highlighting #41), trough groups TSTitle, TSURI, TSTextReference
• highlights: update nvim-cmp highlights to support new kind icon colors
• highlights: improve hop highlights
• highlights: for C and C++ TSOperator is purple now, it looks better. I think we should consider colouring TSOperator for other languages too
• highlights: implemented code_style customization for various elements (comments, keywords, functions, strings and variables)
• colors: allow user to define custom colors or to overwrite existing ones.
• highlights: allow user to define custom highlights or to overwrite existing ones. Dollar prefix means a color from the colorscheme must be used. Example:

require('onedark').setup {
  colors = {
    bright_orange = "#ff8800",    -- define a new color
    green = '#00ffaa',            -- redefine an existing color
  },
  highlights = {
    TSKeyword = {fg = '$green'},
    TSString = {fg = '$bright_orange', bg = '#00ff00', fmt = 'bold'},
    TSFunction = {fg = '#0000ff', sp = '$cyan', fmt = 'underline,italic'},
  }
}

Usage

NOTE: all configurations must be done before setting the colorscheme

Vimscript

let g:onedark_config = {
  \ 'style': 'deep',
  \ 'toggle_style_key': '<leader>ts',
  \ 'ending_tildes': v:true,
  \ 'diagnostics': {
    \ 'darker': v:false,
    \ 'background': v:false,
  \ },
\ }
colorscheme onedark

Note: when using vimscript boolean values must be set with v:true and v:false, not 0 and 1

Lua

require('onedark').setup {
  style = 'warmer',
  toggle_style_key = '<leader>t',
  code_style = {
    comment = 'italic',
    keywords = 'bold,italic',
    strings = 'italic',
  },
  diagnostics = {
    darker = false,
    background = false,
  },
}
vim.api.nvim_command('colorscheme onedark')

Full config

default_config = {
    -- Main options --
    style = 'dark',    -- choose between 'dark', 'darker', 'cool', 'deep', 'warm', 'warmer' and 'light'
    toggle_style_key = '<leader>ts',
    toggle_style_list = { 'dark', 'darker', 'cool', 'deep', 'warm', 'warmer', 'light' },
    transparent = false,     -- don't set background
    term_colors = true,      -- if true enable the terminal
    ending_tildes = false,    -- show the end-of-buffer tildes

    -- Changing Formats --
    code_style = {
        comments = 'italic',
        keywords = 'none',
        functions = 'none',
        strings = 'none',
        variables = 'none'
    },

    -- Custom Highlights --
    colors = {}, -- Override default colors
    highlights = {}, -- Override highlight groups

    -- Plugins Related --
    diagnostics = {
        darker = true, -- darker colors for diagnostic
        undercurl = true,   -- use undercurl for diagnostics
        background = true,    -- use background color for virtual text
    },
}

[xeluxee]

@navarasu now this PR is ready to be merged
Should we consider using stylua or something like that to format lua code?

[navarasu]

Thanks @xeluxee for your valuable. contribution. I will pull this code and will check in my local with all cases. Also will update the doc and merge tomorrow.

[xeluxee]

@navarasu I've just pushed a bugfix commit, please give another pull before checking

[navarasu]

I pulled it in local and verified. Legacy vim syntax works. But when I call lua option in the init.nvim, it is not enabling the scheme

lua <<EOF
require('onedark').setup {
  style = 'warmer'
  }
EOF

[navarasu]

We need to call M.colorscheme() at last in setup. But I called vim.api.nvim_command('colorscheme onedark') to fix #28

[xeluxee]

We need to call M.colorscheme() at last in setup. But I called vim.api.nvim_command('colorscheme onedark') to fix #28

@navarasu I don't agree, since setup function shouldn't load the colorscheme: other Neovim colorschemes uses setup only to configure theme options.
For example I don't always use onedark, but I want it to be configured in my init.lua trough setup(). So if later I want to switch to onedark I can simply :colo onedark without calling setup again with all the settings

Actually #28 can be solved only calling :colo onedark (or vim.api.nvim_command("colo onedark") from lua) since autocmd is triggered only on command :colorscheme. Indeed if we update highlight groups directly with M.colorscheme() everything will work except autocommands, that won't be triggered.

[navarasu]

@xeluxee Yes, I agree. There is some suggestion from one user #46