Unexpected TabNew behavior

Question

I want to create a netrw sidebar whenever I open a new tab. I tried this:

au TabNew,VimEnter *
    \ | :Vex
    \ | :vert res 40

but this makes a layout like this when I :tabe file2:

tab1:          tab2:
netrw|file1    file2|file1

It works fine with TabEnter, but then it opens a new sidebar whenever I switch tabs. How can I fix this?

Answer 1

Not sure why you're having the odd behavior with TabNew...

But one possible way to implement a netrw window per tab is to use a TabEnter event together with the :Lexplore command, and some detection of whether :Lex is already opened in a window using the t:netrw_lexbufnr per-tab variable.

function! OpenLexplore()
  if bufwinid(get(t:, 'netrw_lexbufnr')) >= 0
    " If :Lexplore is already opened in a window
    " in the current tab, do nothing.
    return
  endif

  " Otherwise, open :Lexplore, resize it, and
  " switch the cursor back to the previous window.
  Lexplore
  vertical resize 40
  wincmd p
endfunction

augroup tab_lexplore
  autocmd!
  autocmd TabEnter,VimEnter * call OpenLexplore()
augroup END