Add opt-out configuration for BufEnter and FocusGained.

README.mkd

@@ -78,6 +78,8 @@ You can customise:
 * Line highlights
 * Whether or not vim-gitgutter is on initially (defaults to on)
 * Whether or not line highlighting is on initially (defaults to off)
+* Whether or not vim-gitgutter runs on `BufEnter` (defaults to yes)
+* Whether or not vim-gitgutter runs for all buffers on `FocusGained` (defaults to yes)
 
 Please note that vim-gitgutter won't override any colours or highlights you've set in your colorscheme.
 
@@ -133,6 +135,26 @@ Add `let g:gitgutter_enabled = 0` to your `~/.vimrc`.
 Add `let g:gitgutter_highlight_lines = 1` to your `~/.vimrc`.
 
 
+#### To stop vim-gitgutter running on `BufEnter`
+
+This is on by default but causes a noticeable lag for some people.  To turn it off, add this to your ~/.vimrc`:
+
+```
+let g:gitgutter_on_bufenter = 0
+```
+
+
+#### To stop vim-gitgutter running for all buffers on `FocusGained`
+
+This is on by default but causes a noticeable lag for some people.  To turn it off, add this to your `~/.vimrc`:
+
+```
+let g:gitgutter_all_on_focusgained = 0
+```
+
+Note that this is always off with gVim on Windows due to a Vim/shell bug causing an infinite loop.
+
+
 ### FAQ
 
 > Why are the colours in the sign column weird?

doc/gitgutter.txt

@@ -96,6 +96,9 @@ You can customise:
 - Line highlights
 - Whether or not vim-gitgutter is on initially (defaults to on)
 - Whether or not line highlighting is on initially (defaults to off)
+- Whether or not vim-gitgutter runs on `BufEnter` (defaults to yes)
+- Whether or not vim-gitgutter runs for all buffers on `FocusGained` (defaults
+  to yes)
 
 Please note that vim-gitgutter won't override any colours or highlights you've
 set in your colorscheme.
@@ -147,7 +150,6 @@ LINE HIGHLIGHTS
 
 Similarly to the signs' colours, set up the following highlight groups in your
 colorscheme or |vimrc|:
-
 >
   GitGutterAddLine          " default: links to DiffAdd
   GitGutterChangeLine       " default: links to DiffChange
@@ -157,11 +159,31 @@ colorscheme or |vimrc|:
 
 TO TURN OFF VIM-GITGUTTER BY DEFAULT
 
-Add `let g:gitgutter_enabled = 0` to your |vimrc|.
+Add to your |vimrc|
+>
+  let g:gitgutter_enabled = 0
+<
 
 TO TURN ON LINE HIGHLIGHTING BY DEFAULT
 
-Add `let g:gitgutter_highlight_lines = 1` to your |vimrc|.
+Add to your |vimrc|
+>
+  let g:gitgutter_highlight_lines = 1
+<
+
+TO STOP VIM-GITGUTTER RUNNING ON |BUFENTER|
+
+Add to your |vimrc|
+>
+  let g:gitgutter_on_bufenter = 0
+<
+
+TO STOP VIM-GITGUTTER RUNNING ON |FOCUSGAINED|
+
+Add to your |vimrc|
+>
+  let g:gitgutter_all_on_focusgained = 0
+<
 
 
 ===============================================================================

plugin/gitgutter.vim

@@ -18,6 +18,14 @@ if !exists('g:gitgutter_sign_column_always')
   let g:gitgutter_sign_column_always = 0
 endif
 
+if !exists('g:gitgutter_on_bufenter')
+  let g:gitgutter_on_bufenter = 1
+endif
+
+if !exists('g:gitgutter_all_on_focusgained')
+  let g:gitgutter_all_on_focusgained = 1
+endif
+
 let s:file = ''
 
 function! s:init()
@@ -500,7 +508,10 @@ endfunction
 augroup gitgutter
   autocmd!
   autocmd BufReadPost,BufWritePost,FileReadPost,FileWritePost * call GitGutter(s:current_file())
-  if !has('gui_win32')
+  if g:gitgutter_on_bufenter
+    autocmd BufEnter * call GitGutter(s:current_file())
+  endif
+  if g:gitgutter_all_on_focusgained && !has('gui_win32')
     autocmd FocusGained * call GitGutterAll()
   endif
 augroup END