[vim] Respect g:fzf_colors

Close #711

README.md

@@ -319,7 +319,7 @@ Note that the environment variables `FZF_DEFAULT_COMMAND` and
 `FZF_DEFAULT_OPTS` also apply here. Refer to [the wiki page][fzf-config] for
 customization.
 
-[fzf-config]: https://github.com/junegunn/fzf/wiki/Configuring-FZF-command-(vim)
+[fzf-config]: https://github.com/junegunn/fzf/wiki/Configuring-Vim-plugin
 
 #### `fzf#run`
 
@@ -347,7 +347,8 @@ page](https://github.com/junegunn/fzf/wiki/Examples-(vim)).
 
 `fzf#wrap([name string,] [opts dict,] [fullscreen boolean])` is a helper
 function that decorates the options dictionary so that it understands
-`g:fzf_layout`, `g:fzf_action`, and `g:fzf_history_dir` like `:FZF`.
+`g:fzf_layout`, `g:fzf_action`, `g:fzf_colors`, and `g:fzf_history_dir` like
+`:FZF`.
 
 ```vim
 command! -bang MyStuff

plugin/fzf.vim

@@ -159,6 +159,22 @@ function! s:common_sink(action, lines) abort
   endtry
 endfunction
 
+function! s:get_color(attr, ...)
+  for group in a:000
+    let code = synIDattr(synIDtrans(hlID(group)), a:attr, 'cterm')
+    if code =~ '^[0-9]\+$'
+      return code
+    endif
+  endfor
+  return ''
+endfunction
+
+function! s:defaults()
+  let rules = copy(get(g:, 'fzf_colors', {}))
+  let colors = join(map(items(filter(map(rules, 'call("s:get_color", v:val)'), '!empty(v:val)')), 'join(v:val, ":")'), ',')
+  return empty(colors) ? '' : ('--color='.colors)
+endfunction
+
 " [name string,] [opts dict,] [fullscreen boolean]
 function! fzf#wrap(...)
   let args = ['', {}, 0]
@@ -190,8 +206,10 @@ function! fzf#wrap(...)
     endif
   endif
 
+  " Colors: g:fzf_colors
+  let opts.options = s:defaults() .' '. get(opts, 'options', '')
+
   " History: g:fzf_history_dir
-  let opts.options = get(opts, 'options', '')
   if len(name) && len(get(g:, 'fzf_history_dir', ''))
     let dir = expand(g:fzf_history_dir)
     if !isdirectory(dir)

test/fzf.vader

@@ -143,6 +143,10 @@ Execute (fzf#wrap):
   Assert opts.options =~ '--history /tmp/foobar'
   Assert opts.options =~ '--color light'
 
+  let g:fzf_colors = { 'fg': ['fg', 'Error'] }
+  let opts = fzf#wrap({})
+  Assert opts.options =~ '^--color=fg:'
+
 Execute (Cleanup):
   unlet g:dir
   Restore