UIAttach, UIDetach

runtime/doc/autocmd.txt

@@ -280,8 +280,8 @@ Name			triggered by ~
 
 	Startup and exit
 |VimEnter|		after doing all the startup stuff
-|GUIEnter|		after starting the GUI successfully
+|UIAttach|		after a new UI attaches
-|GUIFailed|		after starting the GUI failed
+|UIDetach|		after a UI detaches
 |TermResponse|		after the terminal response to t_RV is received
 |QuitPre|		when using `:quit`, before deciding whether to exit
 |ExitPre|		when using a command that may make Vim exit
@@ -805,19 +805,14 @@ FuncUndefined			When a user function is used but it isn't
 				NOTE: When writing Vim scripts a better
 				alternative is to use an autoloaded function.
 				See |autoload-functions|.
-							*GUIEnter*
+							{Nvim} *UIAttach*
-GUIEnter			After starting the GUI successfully, and after
+UIAttach			After a new UI connects to nvim and successfully
-				opening the window.  It is triggered before
+				calls |nvim_ui_attach|. Sets chan in |v:event| with
-				VimEnter when using gvim.  Can be used to
+				the channel id or 0 if using the internal UI.
-				position the window from a gvimrc file: >
+							{Nvim} *UIDetach*
-	:autocmd GUIEnter * winpos 100 50
+UIDetach			After a UI detaches from nvim. Sets chan in |v:event|
-<							*GUIFailed*
+				with the channel id or 0 if using the internal UI.
-GUIFailed			After starting the GUI failed.  Vim may
+							*InsertChange*
-				continue to run in the terminal, if possible
-				(only on Unix and alikes, when connecting the
-				X server fails).  You may want to quit Vim: >
-	:autocmd GUIFailed * qall
-<							*InsertChange*
 InsertChange			When typing <Insert> while in Insert or
 				Replace mode.  The |v:insertmode| variable
 				indicates the new mode.

runtime/doc/deprecated.txt

@@ -28,6 +28,8 @@ Environment Variables ~
 Events ~
 *EncodingChanged*	Never fired; 'encoding' is always "utf-8".
 *FileEncoding*		Never fired; equivalent to |EncodingChanged|.
+*GUIEnter*		Never fired; Use |UIAttach| instead.
+*GUIFailed*		Never fired.
 
 Keycodes ~
 *<MouseDown>*		Use <ScrollWheelUp> instead.

runtime/doc/vim_diff.txt

@@ -154,6 +154,8 @@ Events:
   |TermClose|
   |TermOpen|
   |TextYankPost|
+  |UIAttach|
+  |UIDetach|
   |VimResume|
   |VimSuspend|
 

src/nvim/api/ui.c

@@ -19,6 +19,8 @@
 #include "nvim/highlight.h"
 #include "nvim/screen.h"
 #include "nvim/window.h"
+#include "nvim/fileio.h"
+#include "nvim/eval.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "api/ui.c.generated.h"
@@ -169,6 +171,12 @@ void nvim_ui_attach(uint64_t channel_id, Integer width, Integer height,
 
   pmap_put(uint64_t)(connected_uis, channel_id, ui);
   ui_attach_impl(ui);
+
+  dict_T *dict = get_vim_var_dict(VV_EVENT);
+  tv_dict_add_nr(dict, S_LEN("chan"), (long)channel_id);
+  tv_dict_set_keys_readonly(dict);
+  apply_autocmds(EVENT_UIATTACH, NULL, NULL, false, curbuf);
+  tv_dict_clear(dict);
 }
 
 /// @deprecated
@@ -196,6 +204,12 @@ void nvim_ui_detach(uint64_t channel_id, Error *err)
     return;
   }
   remote_ui_disconnect(channel_id);
+
+  dict_T *dict = get_vim_var_dict(VV_EVENT);
+  tv_dict_add_nr(dict, S_LEN("chan"), (long)channel_id);
+  tv_dict_set_keys_readonly(dict);
+  apply_autocmds(EVENT_UIDETACH, NULL, NULL, false, curbuf);
+  tv_dict_clear(dict);
 }
 
 

src/nvim/auevents.lua

@@ -96,6 +96,8 @@ return {
     'TextChangedI',           -- text was modified in Insert mode(no popup)
     'TextChangedP',           -- text was modified in Insert mode(popup)
     'TextYankPost',           -- after a yank or delete was done (y, d, c)
+    'UIAttach',               -- after a UI attached
+    'UIDetach',               -- after a UI detaches
     'User',                   -- user defined autocommand
     'VimEnter',               -- after starting Vim
     'VimLeave',               -- before exiting Vim
@@ -123,5 +125,7 @@ return {
     TabNewEntered=true,
     TermClose=true,
     TermOpen=true,
+    UIAttach=true,
+    UIDetach=true,
   },
 }

src/nvim/channel.c

@@ -172,6 +172,7 @@ static Channel *channel_alloc(ChannelStreamType type)
   chan->refcount = 1;
   chan->exit_status = -1;
   chan->streamtype = type;
+  assert(chan->id <= VARNUMBER_MAX);
   pmap_put(uint64_t)(channels, chan->id, chan);
   return chan;
 }
@@ -190,6 +191,7 @@ void channel_create_event(Channel *chan, const char *ext_source)
     source = (const char *)IObuff;
   }
 
+  assert(chan->id <= VARNUMBER_MAX);
   Dictionary info = channel_info(chan->id);
   typval_T tv = TV_INITIAL_VALUE;
   // TODO(bfredl): do the conversion in one step. Also would be nice

src/nvim/ui_bridge.c

@@ -17,6 +17,8 @@
 #include "nvim/ui_bridge.h"
 #include "nvim/ugrid.h"
 #include "nvim/api/private/helpers.h"
+#include "nvim/fileio.h"
+#include "nvim/eval.h"
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "ui_bridge.c.generated.h"
@@ -86,6 +88,13 @@ UI *ui_bridge_attach(UI *ui, ui_main_fn ui_main, event_scheduler scheduler)
   uv_mutex_unlock(&rv->mutex);
 
   ui_attach_impl(&rv->bridge);
+
+  dict_T *dict = get_vim_var_dict(VV_EVENT);
+  tv_dict_add_nr(dict, S_LEN("chan"), 0);
+  tv_dict_set_keys_readonly(dict);
+  apply_autocmds(EVENT_UIATTACH, NULL, NULL, false, curbuf);
+  tv_dict_clear(dict);
+
   return &rv->bridge;
 }
 
@@ -107,6 +116,13 @@ static void ui_bridge_stop(UI *b)
   // Detach bridge first, so that "stop" is the last event the TUI loop
   // receives from the main thread. #8041
   ui_detach_impl(b);
+
+  dict_T *dict = get_vim_var_dict(VV_EVENT);
+  tv_dict_add_nr(dict, S_LEN("chan"), 0);
+  tv_dict_set_keys_readonly(dict);
+  apply_autocmds(EVENT_UIDETACH, NULL, NULL, false, curbuf);
+  tv_dict_clear(dict);
+
   UIBridgeData *bridge = (UIBridgeData *)b;
   bool stopped = bridge->stopped = false;
   UI_BRIDGE_CALL(b, stop, 1, b);

test/functional/api/ui_spec.lua

@@ -6,6 +6,7 @@ local eval = helpers.eval
 local meths = helpers.meths
 local request = helpers.request
 local pcall_err = helpers.pcall_err
+local command = helpers.command
 
 describe('nvim_ui_attach()', function()
   before_each(function()
@@ -34,4 +35,13 @@ describe('nvim_ui_attach()', function()
     eq('UI already attached to channel: 1',
       pcall_err(request, 'nvim_ui_attach', 40, 10, { rgb=false }))
   end)
+  it('autocmds UIAttach/Detach set v:event', function()
+    local screen = Screen.new()
+    command('autocmd UIAttach * :let g:ui_attach_v_event = deepcopy(v:event)')
+    command('autocmd UIDetach * :let g:ui_detach_v_event = deepcopy(v:event)')
+    screen:attach()
+    assert.same({chan=1}, eval('g:ui_attach_v_event'))
+    screen:detach()
+    assert.same({chan=1}, eval('g:ui_detach_v_event'))
+  end)
 end)