vim-airline/plugin/airline.vim

" MIT License. Copyright (c) 2013 Bailey Ling.
" vim: et ts=2 sts=2 sw=2

if &cp || v:version < 702 || (exists('g:loaded_airline') && g:loaded_airline)
  finish
endif
let g:loaded_airline = 1

" autocmd VimEnter * call airline#deprecation#check()

let s:airline_initialized = 0
let s:airline_theme_defined = 0
function! s:init()
  if !s:airline_initialized
    let s:airline_initialized = 1

    call airline#init#bootstrap()

    let s:airline_theme_defined = exists('g:airline_theme')
    if s:airline_theme_defined || !airline#switch_matching_theme()
      let g:airline_theme = get(g:, 'airline_theme', 'dark')
      call airline#switch_theme(g:airline_theme)
    endif
  endif
endfunction

function! s:on_window_changed()
  if pumvisible()
    return
  endif
  call <sid>init()
  call airline#update_statusline()
endfunction

function! s:on_colorscheme_changed()
  call <sid>init()
  if !s:airline_theme_defined
    if airline#switch_matching_theme()
      return
    endif
  endif

  " couldn't find a match, or theme was defined, just refresh
  call airline#load_theme()
endfunction

function airline#cmdwinenter(...)
  call airline#extensions#apply_left_override('Command Line', '')
endfunction

function! s:airline_toggle()
  if exists("#airline")
    augroup airline
      au!
    augroup END
    augroup! airline
      if exists("s:stl")
        let &stl = s:stl
      endif
    else
      let s:stl = &stl
      augroup airline
        autocmd!

        autocmd CmdwinEnter *
              \ call airline#add_statusline_func('airline#cmdwinenter')
              \ | call <sid>on_window_changed()
        autocmd CmdwinLeave * call airline#remove_statusline_func('airline#cmdwinenter')

        autocmd ColorScheme * call <sid>on_colorscheme_changed()
        autocmd WinEnter,BufWinEnter,FileType,BufUnload,ShellCmdPost,VimResized *
              \ call <sid>on_window_changed()

        autocmd BufWritePost */autoload/airline/themes/*.vim
              \ exec 'source '.split(globpath(&rtp, 'autoload/airline/themes/'.g:airline_theme.'.vim', 1), "\n")[0]
              \ | call airline#load_theme()
      augroup END
      if s:airline_initialized
        call <sid>on_window_changed()
      endif
    endif
  endfunction

  function! s:get_airline_themes(a, l, p)
    let files = split(globpath(&rtp, 'autoload/airline/themes/'.a:a.'*'), "\n")
    return map(files, 'fnamemodify(v:val, ":t:r")')
  endfunction
  function! s:airline_theme(...)
    if a:0
      call airline#switch_theme(a:1)
    else
      echo g:airline_theme
    endif
  endfunction
  command! -nargs=? -complete=customlist,<sid>get_airline_themes AirlineTheme call <sid>airline_theme(<f-args>)
  command! AirlineToggleWhitespace call airline#extensions#whitespace#toggle()
  command! AirlineToggle call <sid>airline_toggle()

  call <sid>airline_toggle()