1" Vim plugin for showing matching parens
2" Maintainer:  Bram Moolenaar <[email protected]>
3" Last Change: 2008 Feb 27
4
5" Exit quickly when:
6" - this plugin was already loaded (or disabled)
7" - when 'compatible' is set
8" - the "CursorMoved" autocmd event is not availble.
9if exists("g:loaded_matchparen") || &cp || !exists("##CursorMoved")
10  finish
11endif
12let g:loaded_matchparen = 1
13
14augroup matchparen
15  " Replace all matchparen autocommands
16  autocmd! CursorMoved,CursorMovedI,WinEnter * call s:Highlight_Matching_Pair()
17augroup END
18
19" Skip the rest if it was already done.
20if exists("*s:Highlight_Matching_Pair")
21  finish
22endif
23
24let cpo_save = &cpo
25set cpo-=C
26
27" The function that is invoked (very often) to define a ":match" highlighting
28" for any matching paren.
29function! s:Highlight_Matching_Pair()
30  " Remove any previous match.
31  if exists('w:paren_hl_on') && w:paren_hl_on
32    3match none
33    let w:paren_hl_on = 0
34  endif
35
36  " Avoid that we remove the popup menu.
37  " Return when there are no colors (looks like the cursor jumps).
38  if pumvisible() || (&t_Co < 8 && !has("gui_running"))
39    return
40  endif
41
42  " Get the character under the cursor and check if it's in 'matchpairs'.
43  let c_lnum = line('.')
44  let c_col = col('.')
45  let before = 0
46
47  let c = getline(c_lnum)[c_col - 1]
48  let plist = split(&matchpairs, '.\zs[:,]')
49  let i = index(plist, c)
50  if i < 0
51    " not found, in Insert mode try character before the cursor
52    if c_col > 1 && (mode() == 'i' || mode() == 'R')
53      let before = 1
54      let c = getline(c_lnum)[c_col - 2]
55      let i = index(plist, c)
56    endif
57    if i < 0
58      " not found, nothing to do
59      return
60    endif
61  endif
62
63  " Figure out the arguments for searchpairpos().
64  if i % 2 == 0
65    let s_flags = 'nW'
66    let c2 = plist[i + 1]
67  else
68    let s_flags = 'nbW'
69    let c2 = c
70    let c = plist[i - 1]
71  endif
72  if c == '['
73    let c = '\['
74    let c2 = '\]'
75  endif
76
77  " Find the match.  When it was just before the cursor move it there for a
78  " moment.
79  if before > 0
80    let save_cursor = winsaveview()
81    call cursor(c_lnum, c_col - before)
82  endif
83
84  " When not in a string or comment ignore matches inside them.
85  let s_skip ='synIDattr(synID(line("."), col("."), 0), "name") ' .
86	\ '=~?  "string\\|character\\|singlequote\\|comment"'
87  execute 'if' s_skip '| let s_skip = 0 | endif'
88
89  " Limit the search to lines visible in the window.
90  let stoplinebottom = line('w$')
91  let stoplinetop = line('w0')
92  if i % 2 == 0
93    let stopline = stoplinebottom
94  else
95    let stopline = stoplinetop
96  endif
97
98  try
99    " Limit the search time to 300 msec to avoid a hang on very long lines.
100    " This fails when a timeout is not supported.
101    let [m_lnum, m_col] = searchpairpos(c, '', c2, s_flags, s_skip, stopline, 300)
102  catch /E118/
103    " Can't use the timeout, restrict the stopline a bit more to avoid taking
104    " a long time on closed folds and long lines.
105    " The "viewable" variables give a range in which we can scroll while
106    " keeping the cursor at the same position.
107    " adjustedScrolloff accounts for very large numbers of scrolloff.
108    let adjustedScrolloff = min([&scrolloff, (line('w$') - line('w0')) / 2])
109    let bottom_viewable = min([line('$'), c_lnum + &lines - adjustedScrolloff - 2])
110    let top_viewable = max([1, c_lnum-&lines+adjustedScrolloff + 2])
111    " one of these stoplines will be adjusted below, but the current values are
112    " minimal boundaries within the current window
113    if i % 2 == 0
114      if has("byte_offset") && has("syntax_items") && &smc > 0
115	let stopbyte = min([line2byte("$"), line2byte(".") + col(".") + &smc * 2])
116	let stopline = min([bottom_viewable, byte2line(stopbyte)])
117      else
118	let stopline = min([bottom_viewable, c_lnum + 100])
119      endif
120      let stoplinebottom = stopline
121    else
122      if has("byte_offset") && has("syntax_items") && &smc > 0
123	let stopbyte = max([1, line2byte(".") + col(".") - &smc * 2])
124	let stopline = max([top_viewable, byte2line(stopbyte)])
125      else
126	let stopline = max([top_viewable, c_lnum - 100])
127      endif
128      let stoplinetop = stopline
129    endif
130    let [m_lnum, m_col] = searchpairpos(c, '', c2, s_flags, s_skip, stopline)
131  endtry
132
133  if before > 0
134    call winrestview(save_cursor)
135  endif
136
137  " If a match is found setup match highlighting.
138  if m_lnum > 0 && m_lnum >= stoplinetop && m_lnum <= stoplinebottom
139    exe '3match MatchParen /\(\%' . c_lnum . 'l\%' . (c_col - before) .
140	  \ 'c\)\|\(\%' . m_lnum . 'l\%' . m_col . 'c\)/'
141    let w:paren_hl_on = 1
142  endif
143endfunction
144
145" Define commands that will disable and enable the plugin.
146command! NoMatchParen windo 3match none | unlet! g:loaded_matchparen |
147	  \ au! matchparen
148command! DoMatchParen runtime plugin/matchparen.vim | windo doau CursorMoved
149
150let &cpo = cpo_save
151