When scrolling or searching through a large file, it can be convenient to keep the cursor line near the middle of the screen (vertically centered within the window). This tip introduces the scrolloff
option, and shows another possible technique using the zz
command.
Scrolloff option[]
The 'scrolloff'
(scroll offset) option determines the number of context lines you would like to see above and below the cursor. The following command scrolls the text so that (when possible) there are always at least five lines visible above the cursor, and five lines visible below the cursor:
:set scrolloff=5
The above command can be abbreviated as :set so=5
. Entering :set so=0
restores the default behavior so the cursor can be moved to any line in the window without scrolling.
Centering with scrolloff[]
Setting 'scrolloff'
to a large value causes the cursor to stay in the middle line when possible:
:set so=999
To restore normal behavior, enter:
:set so=0
If you change 'scrolloff'
frequently, you may want to use a mapping. With the following in your vimrc, and assuming the default backslash leader key, you can type \zz
to toggle the value of 'scrolloff'
between 0
and 999
:
:nnoremap <Leader>zz :let &scrolloff=999-&scrolloff<CR>
In an expression, &scrolloff
refers to the value of the 'scrolloff'
option. The :let
command assigns a value to 'scrolloff'
; that value is 999-0
if 'scrolloff'
was 0
, and is 999-999
if 'scrolloff'
was 999
.
Centering automatically with autocmds[]
Setting scrolloff
to 999 can have undesired consequences, however. For
example, a script that processes text at the end of your file can
cause those last lines (and your cursor, if it’s on them) to disappear from view
at the bottom of the page. Avoid this by using autocmds.
If you almost always prefer to have your cursor centered vertically on the screen, add this to your vimrc
:
augroup VCenterCursor au! au BufEnter,WinEnter,WinNew,VimResized *,*.* \ let &scrolloff=winheight(win_getid())/2 augroup END
This will keep your cursor centered when you start up, move to another window, add or remove windows or tabs, or resize the GUI. You can disable it during your session with
au! VCenterCursor
win_getid()
returns the ID number of the active window, and winheight(win_getid())
returns the active window’s height in visual lines visible above its status line, if it has one. Dividing the window’s height by 2 gives the number of visual lines on either side of the center line if the height is odd, the greater by 1 if even.
If you prefer to toggle scrolloff
with the <leader>zz
mapping as suggested above (“<leader>
” is the backslash character “\
” by default),
add this to your vimrc
:
set scrolloff=<any startup value you like> if !exists('*VCenterCursor') augroup VCenterCursor au! au OptionSet *,*.* \ if and( expand("<amatch>")=='scrolloff' , \ exists('#VCenterCursor#WinEnter,WinNew,VimResized') )| \ au! VCenterCursor WinEnter,WinNew,VimResized| \ endif augroup END function VCenterCursor() if !exists('#VCenterCursor#WinEnter,WinNew,VimResized') let s:default_scrolloff=&scrolloff let &scrolloff=winheight(win_getid())/2 au VCenterCursor WinEnter,WinNew,VimResized *,*.* \ let &scrolloff=winheight(win_getid())/2 else au! VCenterCursor WinEnter,WinNew,VimResized let &scrolloff=s:default_scrolloff endif endfunction endif nnoremap <leader>zz :call VCenterCursor()<CR>
The function VCenterCursor()
toggles between automatically centering your
cursor and setting scrolloff
to the last value that you manually set. If you
manually set a new scrolloff
value, the OptionSet
autocmd detects this and stops the other autocmds from setting scrolloff
until you call the function again
with <leader>zz
.
Currently it is not possible to set scrolloff
locally (tested on MS
Windows 7 with GVIM 64-bit, version 8.0.271). Furthermore, autocmd
detection fails when you resize the active window without resizing the GUI;
leave and reenter that window or do <leader>zz
twice to get the right value.
Mapping wanted keys[]
An alternative to setting 'scrolloff'
would be to remap some commands so that they vertically center the cursor, for example, when moving down or up with j
and k
. Remap the commands like this:
:nnoremap j jzz :nnoremap k kzz