created 2002 · complexity basic · author Simon "neoneye" Strandgaard · version 6.0
Borland behaviour = the cursor keeps the same xy position during pageup/down.
I'm new to Vim scripting, im sure it can be done smarter?
I read VimTip105 and it gave me a clue of how BorlandPageUp/Down could be done.
" i could'nt find any get_number_of_visible_lines function, so i made my own.
function GetNumberOfVisibleLines()
let cur_line = line(".")
let cur_col = virtcol(".")
normal H
let top_line = line(".")
normal L
let bot_line = line(".")
execute "normal " . cur_line . "G"
execute "normal " . cur_col . "|"
return bot_line - top_line
endfunc
" noremap <PageUp> 39<C-U>:set scroll=0<CR>
function! MyPageUp()
let visible_lines = GetNumberOfVisibleLines()
execute "normal " . visible_lines . "\<C-U>:set scroll=0\r"
endfunction
" noremap <PageDown> 39<C-D>:set scroll=0<CR>
function! MyPageDown()
let visible_lines = GetNumberOfVisibleLines()
execute "normal " . visible_lines . "\<C-D>:set scroll=0\r"
endfunction
" BorlandPascal pageup/down behaviour!
" todo: when hitting top/bottom of file, then restore Y to lastY
noremap <PageUp> :call MyPageUp()<CR>
noremap <PageDown> :call MyPageDown()<CR>
Comments
For maintaining the same x coordinate, :help 'startofline'.
And CTRL-U (up), CTRL-D (down) may also be useful for what you want (half page scrolls)
A solution that I use (easier, I would say, but has a small side-effect) is this:
map <PageDown> :set scroll=0<CR>:set scroll^=2<CR>:set scroll-=1<CR><C-D>:set scroll=0<CR> map <PageUp> :set scroll=0<CR>:set scroll^=2<CR>:set scroll-=1<CR><C-U>:set scroll=0<CR>
I found Vim's normal PgUp/PgDn behaviour weird - I think it's different from every other editor I've used and I was unable to get used to it. The above two lines are godsent!
Ditto on the above two lines. They work exactly as I want! (SRS)
See Combining move and scroll. You might find it useful to incorporate the improvements into this tip.
A solution that works in insert and visual modes too:
nnoremap <silent> <PageUp> <C-U><C-U> vnoremap <silent> <PageUp> <C-U><C-U> inoremap <silent> <PageUp> <C-\><C-O><C-U><C-\><C-O><C-U> nnoremap <silent> <PageDown> <C-D><C-D> vnoremap <silent> <PageDown> <C-D><C-D> inoremap <silent> <PageDown> <C-\><C-O><C-D><C-\><C-O><C-D>
It assumes that "scroll" has its default value. Also there is an intermediate redraw, but that could be perceived as a feature, really.
I've spent a whole day trying to simulate sometheing like the <C-\><C-O> command for Visual mode (hoping for the universal solution -- a way to call any normal mode command from any mode), yet it looks like impossible if the command in question is supposed to be a custom movement command, modifying selection.
Another method that does not move cursor from screen position when scrolling, even with long lines that wrap:
function! s:GetNumScroll(num)
let num_rows = winheight(0)
let num_scroll = a:num
if (a:num == -1)
let num_scroll = (num_rows + 1) / 2
elseif (a:num == -2)
let num_scroll = num_rows
endif
if (num_scroll < 1)
let num_scroll = 1
endif
return num_scroll
endfunction
function! s:RtrnToOrig(before_scr_line)
normal H
let delta = a:before_scr_line - winline()
while (delta != 0)
if (delta < 0)
let delta = winline() - a:before_scr_line
let iter = 1
while (iter <= delta)
execute "normal" "gk"
let iter +=1
endwhile
elseif (delta > 0)
let iter = 1
while (iter <= delta)
execute "normal" "gj"
let iter +=1
endwhile
endif
let delta = a:before_scr_line - winline()
endwhile
endfunction
function! s:scrollUP(num)
let num_scroll = <SID>GetNumScroll(a:num)
let num_rows = winheight(0)
" -------------
let before_scr_line = winline()
normal L
let after_scr_line = winline()
let extra = num_rows - after_scr_line
let extra += num_scroll
" move by 1 to prevent over scrolling
let iter = 1
while (iter <= extra)
execute "normal" "gj"
let iter +=1
endwhile
" -------------
call <SID>RtrnToOrig(before_scr_line)
endfunction
function! s:scrollDN(num)
let num_scroll = <SID>GetNumScroll(a:num)
" -------------
let before_scr_line = winline()
normal H
let after_scr_line = line(".")
execute "normal" "gk"
let after_scr2_line = line(".")
if ( (after_scr_line == after_scr2_line) && (after_scr_line > 1) )
execute "normal" "gk"
endif
let extra = (num_scroll - 1)
let extra += (winline() - 1)
" move by 1 to prevent over scrolling
let iter = 1
while (iter <= extra)
execute "normal" "gk"
let iter +=1
endwhile
" -------------
call <SID>RtrnToOrig(before_scr_line)
endfunction
nmap <silent> <C-J> :call <SID>scrollUP(1)<CR>
nmap <silent> <C-K> :call <SID>scrollDN(1)<CR>
nmap <silent> <C-F> :call <SID>scrollUP(-1)<CR>
nmap <silent> <C-B> :call <SID>scrollDN(-1)<CR>
nmap <silent> <PageDown>:call <SID>scrollUP(-2)<CR>
nmap <silent> <PageUp> :call <SID>scrollDN(-2)<CR>