Persistent highlighting of a passage in Vim

Question

I use Vim for presentations and note-taking.

I would like to be able to highlight a portion of text in a buffer , split the window, go to the bottom of the buffer, and carry on typing the notes, whilst keeping the highlight on.

If I use , say , shift-V to highlight a line, then the highlight disappears when I resume the note-taking.

Of course, I will want to clear the highlights at some point.

How can I achieve the persistent highlight described above ?

Answer 1

If by "persisted" you mean only in a current vim session (not stored with text file), then :h textprop API might be what you want.

Here is the proof of the concept:

func! Markline(line)
    " check if 'markline' text property exists
    if empty(prop_type_get("markline"))
        " define Markline highlight group to be used for ... highlighting
        hi! Markline guibg=#C0C0C0 guifg=#000000 ctermbg=253 ctermfg=0
        " define 'markline' property that should use 'Markline' highlight
        call prop_type_add('markline', {'highlight': 'Markline'})
    endif
    " add 'markline' property for a line passed into function with a length of the passed line
    call prop_add(a:line, 1, {'length': len(getline(a:line)), 'type': 'markline'})
endfunc
"mapping to mark current line
nnoremap <space>m :call Markline(line('.'))<CR>
"mapping to remove marks from ALL lines
nnoremap <space>d :call prop_remove({"id": "markline"})<CR>

It is possible to make it work for an arbitrary visual selection or a text objects but this minimal example should be enough to get started.