"
" Intelligently navigate tmux panes and Vim splits using the same keys.
" This also supports SSH tunnels where Vim is running on a remote host.
"
" See https://sunaku.github.io/tmux-select-pane.html for documentation.

function! TmuxNavigateDirections() abort
  let [y, x] = win_screenpos('.')
  let h = winheight('.')
  let w = winwidth('.')

  let can_go_up    = y > 2 " +1 for the tabline
  let can_go_down  = y + h < &lines - &laststatus
  let can_go_left  = x > 1
  let can_go_right = x + w < &columns

  return
        \ (can_go_up    ? 'U' : '') .
        \ (can_go_down  ? 'D' : '') .
        \ (can_go_left  ? 'L' : '') .
        \ (can_go_right ? 'R' : '')
endfunction

let progname = substitute($VIM, '.*[/\\]', '', '')
set title titlestring=%{progname}\ %f\ #%{TmuxNavigateDirections()}

" enable support for setting the window title in regular Vim under tmux
if &term =~ '^screen' && !has('nvim')
  execute "set t_ts=\e]2; t_fs=\7"
endif