added a new global variable g:XkbSwitchIminsertToggleKey (see docs)

this is related to #54

README.md

@@ -260,21 +260,23 @@ and map g:XkbSwitchKeymapNames to keymap names instead of values of
 b:keymap_name. For example
 
 ```vim
-    let g:XkbSwitchKeymapNames = {'ru' : 'russian-jcukenwin',
-                \ 'uk' : 'ukrainian-jcuken'}
+let g:XkbSwitchKeymapNames =
+            \ {'ru' : 'russian-jcukenwin', 'uk' : 'ukrainian-jcuken'}
+
 ```
 
 Now keymap will automatically switch to the last keyboard layout when you
 leave Insert mode.
 
-To reset commands *r* and *f* to the usual Normal mode keyboard layout simply
-switch to it in Insert mode or enter command
+To toggle keymap layout in Normal mode for using in commands *r* and *f*, you
+may need to set a dedicated key:
 
 ```vim
-:setlocal iminsert=0
+let g:XkbSwitchIminsertToggleKey = '<C-^>'
 ```
 
-To reset search lines press *Ctrl-^*.
+Notice that toggling keymap layout when typing a pattern for a search command
+can be done with the builtin key *Ctrl-^*.
 
 There is only one problem not solved so far: the system keyboard layout
 indicator when in Normal mode and search lines will show the usual Normal mode

doc/xkbswitch.txt

@@ -231,18 +231,19 @@ define a new variable
 and map g:XkbSwitchKeymapNames to keymap names instead of values of
 b:keymap_name. For example
 >
-    let g:XkbSwitchKeymapNames = {'ru' : 'russian-jcukenwin',
-                \ 'uk' : 'ukrainian-jcuken'}
+    let g:XkbSwitchKeymapNames =
+                \ {'ru' : 'russian-jcukenwin', 'uk' : 'ukrainian-jcuken'}
 <
 Now keymap will automatically switch to the last keyboard layout when you
 leave Insert mode.
 
-To reset commands |r| and |f| to the usual Normal mode keyboard layout simply
-switch to it in Insert mode or enter command
+To toggle keymap layout in Normal mode for using in commands |r| and |f|, you
+may need to set a dedicated key:
 >
-    :setlocal iminsert=0
+    let g:XkbSwitchIminsertToggleKey = '<C-^>'
 <
-To reset search lines press |c_Ctrl-^|.
+Notice that toggling keymap layout when typing a pattern for a search command
+can be done with the builtin key |c_Ctrl-^|.
 
 There is only one problem not solved so far: the system keyboard layout
 indicator when in Normal mode and search lines will show the usual Normal mode

plugin/xkbswitch.vim

@@ -132,6 +132,10 @@ if !exists('g:XkbSwitchDynamicKeymap')
     let g:XkbSwitchDynamicKeymap = 0
 endif
 
+if !exists('g:XkbSwitchIminsertToggleKey')
+    let g:XkbSwitchIminsertToggleKey = ''
+endif
+
 if !exists('g:XkbSwitchSkipFt')
     let g:XkbSwitchSkipFt = ['tagbar', 'gundo', 'nerdtree', 'fuf']
 endif
@@ -353,6 +357,16 @@ fun! <SID>xkb_mappings_load()
                         \ " :call <SID>xkb_switch(1, 1)<CR>".cmd
         endfor
     endif
+    if !empty(g:XkbSwitchIminsertToggleKey)
+        exe "nnoremap <buffer> <silent> ".g:XkbSwitchIminsertToggleKey.
+                    \ " :if !empty(&keymap) <Bar> if &iminsert == 0 <Bar>".
+                    \ "setlocal iminsert=1 <Bar>".
+                    \ "echo 'set keymap' &keymap <Bar>".
+                    \ "elseif &iminsert == 1 <Bar>".
+                    \ "setlocal iminsert=0 <Bar>".
+                    \ "echo 'unset keymap' &keymap <Bar>".
+                    \ "endif <Bar> endif<CR>"
+    endif
     let b:xkb_mappings_loaded = 1
 endfun