View text file in two columns

Tip 1615 Printable Monobook Previous Next

created 2009 · complexity basic · author Nsg · version 7.0

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When reading text, it can be useful to make a wide window, then split it vertically so two consecutive pages of text can be seen in the left and right windows.

With a large monitor, you might enter :set columns=160 to make the screen 160 columns wide. This tip can then be used to split the screen to show two windows, with the 'scrollbind' option set so that scrolling one window also scrolls the other window.

Mapping

Enter the following command (or put in your vimrc):

:noremap <silent> <Leader>vs :<C-u>let @z=&so<CR>:set so=0 noscb<CR>:bo vs<CR>Ljzt:setl scb<CR><C-w>p:setl scb<CR>:let &so=@z<CR>

With the default leader, you can now press \vs to vertically split the screen into two windows with 'scrollbind' set. To display only a single window, press Ctrl-W then o.

The mapping performs these operations:

:<C-u>              " clear command line (if in visual mode)
let @z=&so          " save scrolloff in register z
:set so=0 noscb     " set scrolloff to 0 and clear scrollbind
:bo vs              " split window vertically, new window on right
Ljzt                " jump to bottom of window + 1, scroll to top
:setl scb           " setlocal scrollbind in right window
<C-w>p              " jump to previous window
:setl scb           " setlocal scrollbind in left window
:let &so=@z         " restore scrolloff

The mapping clears 'scrollbind' before manipulating the windows so that the position of the second window can be adjusted without scrolling the first window. Setting 'scrolloff' to 0 allows the cursor to be positioned at the bottom of the screen (with command L).

Problems

• If the cursor is in the last line when the mapping is executed, the mapping fails because j cannot move the cursor down (and the remaining commands are not executed).
• Register z is changed.

See also

• vim_use discussion
• MPage plugin that supports multiple windows (two or more) with sequential text

Comments

I put this into a function:

noremap <silent> <Leader>ac :exe AddColumn()<CR>
function! AddColumn()
  exe "norm \<C-u>"
  let @z=&so
  set noscb so=0
  bo vs
  exe "norm \<PageDown>"
  setl scrollbind
  wincmd p
  setl scrollbind
  let &so=@z
endfunction

Except when I try to scroll one of the buffer windows by one line or more. In that case, the line-difference between each buffer is reduced to zero. Curiously, this works perfectly when done by hand in the command prompt.

I have read that that line-difference is meant for 2 different files. However, we are using the same file, but in two different windows. Then, how do I keep that line difference valid between the windows on_scroll?