How do I stop the colorcolumn from breaking into multiple pieces when there are wrapped lines?

Question

The colorcolumn works well when there are no wrapped lines. set colorcolumn=80:

However, when there are long lines that are wrapped, the colorcolumn breaks into multiple pieces:

Is there a way to make it such that the colorcolumn will always be a single unbroken line?

Answer 1

The colorcolumn setting accepts multiple values, for example set colorcolumn=30,60 will highlight column 30 and 60.

We can use this to display a single unbroken line for wrapped lines; for example for a 130-column line on a 40 column wide display you would use set colorcolumn=30,70,110 to highlight the first three columns.

You can set this automatically with a little command:

command! -nargs=1 WrappedCC let &colorcolumn = join(map(range(10), {i -> &columns * i + <args>}), ',')

This uses &columns to get the screen width, and adds the first ten colour columns at the correct place.

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You can also hook in to OptionSet autocommand to automatically do this whenever colorcolumn is set, so you don't need a new command; you can just use set cc=80 instead of WrappedCC 80. You can still use set cc= to clear the highlight, or set cc=80,120 to only set those two columns.

fun s:wrapped_cc()
    let &colorcolumn = join(map(range(10), {i -> &columns * i + str2nr(&cc)}), ',')
endfun

augroup wrappedcc
    autocmd!
    autocmd OptionSet  colorcolumn  if &cc != '' && &cc !~ ','       | call s:wrapped_cc() | endif
    autocmd VimEnter   *            if &cc != '' && &cc !~ ','       | call s:wrapped_cc() | endif
    autocmd VimResized *            if len(matchlist(&cc, ',')) >= 4 | call s:wrapped_cc() | endif
augroup end

This also needs to hook in to the VimEnter because OptionSet isn't triggered on startup; otherwise set colorcolumn=80 from your vimrc won't work; since the VimEnter is triggered after reading all the vimrc you can put the set colorcolumn= anywhere in your vimrc (it doesn't need to be after the autocmd).

Also need to hook in to the VimResized to re-calculate the column positions because they need to be adjusted after the window is resized. This assumes that anything with more than four columns is a "wrapped column".