Question

I have my Vim window set to 90 columns using set columns=90, but this causes problems when commands (pyunit-vim, in particular) open new vertical splits, because each window then only has 45 columns, which is far too narrow. Ideally, I’d like to add splits to the existing width, rather than impinge upon it. Is there some way to specify this behaviour?

Answer 1

EDIT: just noticed possible duplicate comment, after I’d entered this answer. That code there looks a bit better and more general purpose than mine (mine is targeted at OP who was dealing with one wide or two-wide splits). Also, I think you could delete WinLeave autocmd in mine, since leaving a window will be paired with entering a different window in scenarios I can think of.

I think you can get close to what you want by assigning autocmds to WinEnter and WinLeave. The code below sets things up to call a size-adjusting function whenever you enter or leave a window. A better event for entry, I think, may be BufWinEnter. You may need to tweak, but code similar to this in your vimrc would work, I think:

autocmd WinEnter * call AdjustSize()
autocmd WinLeave * call AdjustSize()
function! AdjustSize()
    if (winwidth('%')<50) && (&columns<=90)
        set columns = 2 * &columns
        "then make widths the same
        exe "normal! \<c-w>="
    else 
        set columns=90
        " or adjust size only if window isnt' huge...
        " if columns >= 150
        "     set columns = 90
        " endif
    endif
endfunction