diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 93504a4..f9fa9d1 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3993,6 +3993,26 @@
 	Can be overruled by using "\c" or "\C" in the pattern, see
 	|/ignorecase|.
 
+						*'imactivatefunc'* *'imaf'*
+'imactivatefunc' 'imaf'	string (default "")
+			global
+			{not in Vi}
+			{only available when compiled with |+xim| and
+			|+GUI_GTK|}
+	This option specifies a function that will be called to
+	activate/inactivate Input Method.
+
+	Example: >
+		function ImActivateFunc(active)
+		  if a:active
+		    ... do something
+		  else
+		    ... do something
+		  endif
+		  " return value is not used
+		endfunction
+		set imactivatefunc=ImActivateFunc
+<
 						*'imactivatekey'* *'imak'*
 'imactivatekey' 'imak'	string (default "")
 			global
@@ -4089,6 +4109,24 @@
 	The value 0 may not work correctly with Athena and Motif with some XIM
 	methods.  Use 'imdisable' to disable XIM then.
 
+						*'imstatusfunc'* *'imsf'*
+'imstatusfunc' 'imsf'	string (default "")
+			global
+			{not in Vi}
+			{only available when compiled with |+xim| and
+			|+GUI_GTK|}
+	This option specifies a function that is called to obtain the status
+	of Input Method.  It must return a positive number when IME is active.
+
+	Example: >
+		function ImStatusFunc()
+		  let is_active = ...do something
+		  return is_active ? 1 : 0
+		endfunction
+		set imstatusfunc=ImStatusFunc
+<
+	NOTE: This function is invoked very often.  Keep it fast.
+
 						*'include'* *'inc'*
 'include' 'inc'		string	(default "^\s*#\s*include")
 			global or local to buffer |global-local|
diff --git a/src/fileio.c b/src/fileio.c
index 6c8cba1..b6f4016 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -9572,6 +9572,12 @@
 # endif
 }
 
+    int
+is_autocmd_blocked()
+{
+    return autocmd_blocked != 0;
+}
+
 /*
  * Find next autocommand pattern that matches.
  */
diff --git a/src/mbyte.c b/src/mbyte.c
index 2059da4..61d83cf 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -4447,7 +4447,7 @@
 {
     int was_active;
 
-    was_active = !!im_is_active;
+    was_active = !!im_get_status();
     im_is_active = (active && !p_imdisable);
 
     if (im_is_active != was_active)
@@ -5071,44 +5071,25 @@
 {
     if (xic != NULL)
     {
-	/*
-	 * The third-party imhangul module (and maybe others too) ignores
-	 * gtk_im_context_reset() or at least doesn't reset the active state.
-	 * Thus sending imactivatekey would turn it off if it was on before,
-	 * which is clearly not what we want.  Fortunately we can work around
-	 * that for imhangul by sending GDK_Escape, but I don't know if it
-	 * works with all IM modules that support an activation key :/
-	 *
-	 * An alternative approach would be to destroy the IM context and
-	 * recreate it.  But that means loading/unloading the IM module on
-	 * every mode switch, which causes a quite noticeable delay even on
-	 * my rather fast box...
-	 * *
-	 * Moreover, there are some XIM which cannot respond to
-	 * im_synthesize_keypress(). we hope that they reset by
-	 * xim_shutdown().
-	 */
-	if (im_activatekey_keyval != GDK_VoidSymbol && im_is_active)
-	    im_synthesize_keypress(GDK_Escape, 0U);
-
 	gtk_im_context_reset(xic);
 
-	/*
-	 * HACK for Ami: This sequence of function calls makes Ami handle
-	 * the IM reset graciously, without breaking loads of other stuff.
-	 * It seems to force English mode as well, which is exactly what we
-	 * want because it makes the Ami status display work reliably.
-	 */
-	gtk_im_context_set_use_preedit(xic, FALSE);
-
 	if (p_imdisable)
 	    im_shutdown();
 	else
 	{
-	    gtk_im_context_set_use_preedit(xic, TRUE);
 	    xim_set_focus(gui.in_focus);
 
-	    if (im_activatekey_keyval != GDK_VoidSymbol)
+	    if (p_imaf[0] != NUL)
+	    {
+		char_u *argv[1];
+
+		if (im_is_active)
+		    argv[0] = (char_u *)"1";
+		else
+		    argv[0] = (char_u *)"0";
+		(void)call_func_retnr(p_imaf, 1, argv, FALSE);
+	    }
+	    else if (im_activatekey_keyval != GDK_VoidSymbol)
 	    {
 		if (im_is_active)
 		{
@@ -5268,6 +5249,20 @@
     int
 im_get_status(void)
 {
+    if (p_imsf[0] != NUL)
+    {
+	int is_active;
+
+	/* FIXME: Don't execute user function in unsafe situation. */
+	if (exiting || is_autocmd_blocked())
+	    return FALSE;
+	/* FIXME: :py print 'xxx' is shown duplicate result.
+	 * Use silent to avoid it. */
+	++msg_silent;
+	is_active = call_func_retnr(p_imsf, 0, NULL, FALSE);
+	--msg_silent;
+	return (is_active > 0);
+    }
     return im_is_active;
 }
 
diff --git a/src/option.c b/src/option.c
index f691f50..0932bb8 100644
--- a/src/option.c
+++ b/src/option.c
@@ -1425,6 +1425,15 @@
     {"ignorecase",  "ic",   P_BOOL|P_VI_DEF,
 			    (char_u *)&p_ic, PV_NONE,
 			    {(char_u *)FALSE, (char_u *)0L} SCRIPTID_INIT},
+    {"imactivatefunc","imaf",P_STRING|P_VI_DEF|P_SECURE,
+# if defined(FEAT_EVAL) && defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
+			    (char_u *)&p_imaf, PV_NONE,
+			    {(char_u *)"", (char_u *)NULL}
+# else
+			    (char_u *)NULL, PV_NONE,
+			    {(char_u *)NULL, (char_u *)0L}
+# endif
+			    SCRIPTID_INIT},
     {"imactivatekey","imak",P_STRING|P_VI_DEF,
 #if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
 			    (char_u *)&p_imak, PV_NONE,
@@ -1467,6 +1476,15 @@
 			    {(char_u *)B_IMODE_NONE, (char_u *)0L}
 #endif
 			    SCRIPTID_INIT},
+    {"imstatusfunc","imse",P_STRING|P_VI_DEF|P_SECURE,
+# if defined(FEAT_EVAL) && defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
+			    (char_u *)&p_imsf, PV_NONE,
+			    {(char_u *)"", (char_u *)NULL}
+# else
+			    (char_u *)NULL, PV_NONE,
+			    {(char_u *)NULL, (char_u *)0L}
+# endif
+			    SCRIPTID_INIT},
     {"include",	    "inc",  P_STRING|P_ALLOCED|P_VI_DEF,
 #ifdef FEAT_FIND_ID
 			    (char_u *)&p_inc, PV_INC,
diff --git a/src/option.h b/src/option.h
index b11316f..167b562 100644
--- a/src/option.h
+++ b/src/option.h
@@ -558,6 +558,8 @@
 EXTERN int	p_ic;		/* 'ignorecase' */
 #if defined(FEAT_XIM) && defined(FEAT_GUI_GTK)
 EXTERN char_u	*p_imak;	/* 'imactivatekey' */
+EXTERN char_u	*p_imaf;	/* 'imactivatefunc' */
+EXTERN char_u	*p_imsf;	/* 'imstatusfunc' */
 #endif
 #ifdef USE_IM_CONTROL
 EXTERN int	p_imcmdline;	/* 'imcmdline' */
diff --git a/src/proto/fileio.pro b/src/proto/fileio.pro
index 61eb712..b24b958 100644
--- a/src/proto/fileio.pro
+++ b/src/proto/fileio.pro
@@ -49,6 +49,7 @@
 int has_insertcharpre __ARGS((void));
 void block_autocmds __ARGS((void));
 void unblock_autocmds __ARGS((void));
+int is_autocmd_blocked __ARGS((void));
 char_u *getnextac __ARGS((int c, void *cookie, int indent));
 int has_autocmd __ARGS((event_T event, char_u *sfname, buf_T *buf));
 char_u *get_augroup_name __ARGS((expand_T *xp, int idx));
diff --git a/src/version.c b/src/version.c
index 025b856..3a48c0f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -729,6 +729,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1248,
+/**/
     1247,
 /**/
     1246,