show_windows_numbers.vim

function! ShowWindowNumbers()
  for i in range(1, winnr('$'))
    " Get the buffer and window associated with this number
    let bufnr = winbufnr(i)
    let winid = win_getid(i)
    let figlet_output = system('figlet -f small ' . i )
    let popup_content = split(figlet_output, "\n")
    let popup_height = 5
    let popup_width = 8
    let row = win_screenpos(i)[0] + (winheight(i) - popup_height) / 2
    let col = win_screenpos(i)[1] + (winwidth(i) - popup_width) / 2
    let popup_options = {
        \ 'win': winid,
        \ 'wrap': 0,
        \ 'maxheight': popup_height,
        \ 'maxwidth': popup_width,
        \ 'minheight': popup_height,
        \ 'minwidth': popup_width,
        \ 'line': row,
        \ 'col': col,
        \ 'time': 3000,
        \ 'style': 'minimal',
        \ 'title': 'Window ' . i,
        \ 'border': [],
        \ }
    call popup_create(popup_content, popup_options)
  endfor
endfunction

nnoremap <silent> <C-w>n :call ShowWindowNumbers()<CR>