Adding the g:ycm_auto_trigger option

Toggling this option off turns off the identifier completer and the semantic
triggers.

Fixes #597

README.md

@@ -678,6 +678,21 @@ Default: `0`
 
     let g:ycm_min_num_identifier_candidate_chars = 0
 
+### The `g:ycm_auto_trigger` option
+
+When set to `0`, this option turns off YCM's identifier completer (the
+as-you-type popup) _and_ the semantic triggers (the popup you'd get after typing
+`.` or `->` in say C++). The Syntastic integration remains working and you can
+still force semantic completion with the `<C-Space>` shortcut.
+
+If you want to just turn off the identifier completer but keep the semantic
+triggers, you should set `g:ycm_min_num_of_chars_for_completion` to a high
+number like `99`.
+
+Default: `1`
+
+    let g:ycm_auto_trigger = 1
+
 ### The `g:ycm_filetype_whitelist` option
 
 This option controls for which Vim filetypes (see `:h filetype`) should YCM be

autoload/youcompleteme.vim

@@ -366,7 +366,10 @@ function! s:OnCursorMovedInsertMode()
   if g:ycm_autoclose_preview_window_after_completion
     call s:ClosePreviewWindowIfNeeded()
   endif
-  call s:InvokeCompletion()
+
+  if g:ycm_auto_trigger
+    call s:InvokeCompletion()
+  endif
 endfunction
 
 

python/ycm/completers/completer.py

@@ -18,6 +18,7 @@
 # along with YouCompleteMe.  If not, see <http://www.gnu.org/licenses/>.
 
 import abc
+from collections import defaultdict
 from ycm.utils import ToUtf8IfNeeded, ForceSemanticCompletion, RunningInsideVim
 
 if RunningInsideVim():
@@ -100,8 +101,9 @@ class Completer( object ):
   def __init__( self, user_options ):
     self.user_options = user_options
     self.min_num_chars = user_options[ 'min_num_of_chars_for_completion' ]
-    self.triggers_for_filetype = TriggersForFiletype(
-      user_options[ 'semantic_triggers' ] )
+    self.triggers_for_filetype = (
+        TriggersForFiletype( user_options[ 'semantic_triggers' ] )
+        if user_options[ 'auto_trigger' ] else defaultdict( set ) )
     self.completions_future = None
     self._completions_cache = None
 

python/ycm/server/default_settings.json

@@ -1,5 +1,6 @@
 {
   "filepath_completion_use_working_dir": 0,
+  "auto_trigger": 1,
   "min_num_of_chars_for_completion": 2,
   "min_num_identifier_candidate_chars": 0,
   "semantic_triggers": {},

python/ycm/server/tests/get_completions_test.py

@@ -26,7 +26,7 @@ from .test_utils import ( Setup, BuildRequest, PathToTestFile,
 from webtest import TestApp
 from nose.tools import eq_, with_setup
 from hamcrest import ( assert_that, has_item, has_items, has_entry,
-                       contains_inanyorder )
+                       contains_inanyorder, empty )
 from ..responses import BuildCompletionData, UnknownExtraConf
 from .. import handlers
 import bottle
@@ -127,6 +127,36 @@ int main()
                                    CompletionEntryMatcher( 'x' ),
                                    CompletionEntryMatcher( 'y' ) ) )
 
+@with_setup( Setup )
+def GetCompletions_ClangCompleter_NoCompletionsWhenAutoTriggerOff_test():
+  ChangeSpecificOptions( { 'auto_trigger': False } )
+  app = TestApp( handlers.app )
+  contents = """
+struct Foo {
+  int x;
+  int y;
+  char c;
+};
+
+int main()
+{
+  Foo foo;
+  foo.
+}
+"""
+
+  # 0-based line and column!
+  completion_data = BuildRequest( filepath = '/foo.cpp',
+                                  filetype = 'cpp',
+                                  contents = contents,
+                                  line_num = 10,
+                                  column_num = 6,
+                                  start_column = 6,
+                                  compilation_flags = ['-x', 'c++'] )
+
+  results = app.post_json( '/completions', completion_data ).json
+  assert_that( results, empty() )
+
 
 @with_setup( Setup )
 def GetCompletions_ClangCompleter_UnknownExtraConfException_test():