keymap: Support <D-...> (super/command key).

Adds support for:
  - api:vim_input("<D-a>")
  - ":nnoremap <C-D-S-...>" and permutations thereof

UIs must capture the modifier and send it as "<D-...>" to vim_input().

Note: Before this commit, any arbitrary ":nnoremap <{foo}-{bar}>"
mapping could already be invoked with feedkeys("\<{foo}-{bar}>"). This
commit supports "D-" as a modifier that can be combined with "C-", "A-",
"S-" in any order.

For non-GUI (terminal) support, user must:
  :set <D-a>={CSI sequence}
then send the {CSI sequence} from their terminal. But this does not work
yet (regression #2204).

Closes #2190

runtime/doc/intro.txt

@@ -452,7 +452,7 @@ notation	meaning		    equivalent	decimal value(s)	~
 <C-...>		control-key			*control* *ctrl* *<C-*
 <M-...>		alt-key or meta-key		*meta* *alt* *<M-*
 <A-...>		same as <M-...>			*<A-*
-<D-...>		command-key (Macintosh only)	*<D-*
+<D-...>		command-key or "super" key	*<D-*
 <t_xx>		key with "xx" entry in termcap
 -----------------------------------------------------------------------
 

src/nvim/edit.c

@@ -4947,15 +4947,10 @@ int get_literal(void)
   return cc;
 }
 
-/*
+/// Insert character, taking care of special keys and mod_mask
- * Insert character, taking care of special keys and mod_mask
+///
- */
+/// @param ctrlv `c` was typed after CTRL-V
-static void
+static void insert_special(int c, int allow_modmask, int ctrlv)
-insert_special (
-    int c,
-    int allow_modmask,
-    int ctrlv                  /* c was typed after CTRL-V */
-)
 {
   char_u  *p;
   int len;
@@ -4967,6 +4962,9 @@ insert_special (
    * Only use mod_mask for special keys, to avoid things like <S-Space>,
    * unless 'allow_modmask' is TRUE.
    */
+  if (mod_mask & MOD_MASK_CMD) {  // Command-key never produces a normal key.
+    allow_modmask = true;
+  }
   if (IS_SPECIAL(c) || (mod_mask && allow_modmask)) {
     p = get_special_key_name(c, mod_mask);
     len = (int)STRLEN(p);

src/nvim/keymap.c

@@ -1,8 +1,3 @@
-/*
- * functions that use lookup tables for various things, generally to do with
- * special key codes.
- */
-
 #include <assert.h>
 #include <inttypes.h>
 #include <limits.h>
@@ -39,7 +34,8 @@ static struct modmasktable {
   {MOD_MASK_MULTI_CLICK,      MOD_MASK_2CLICK,        (char_u)'2'},
   {MOD_MASK_MULTI_CLICK,      MOD_MASK_3CLICK,        (char_u)'3'},
   {MOD_MASK_MULTI_CLICK,      MOD_MASK_4CLICK,        (char_u)'4'},
-  /* 'A' must be the last one */
+  {MOD_MASK_CMD,              MOD_MASK_CMD,           (char_u)'D'},
+  // 'A' must be the last one
   {MOD_MASK_ALT,              MOD_MASK_ALT,           (char_u)'A'},
   {0, 0, NUL}
 };
@@ -658,10 +654,12 @@ static int extract_modifiers(int key, int *modp)
 {
   int modifiers = *modp;
 
+  if (!(modifiers & MOD_MASK_CMD)) {  // Command-key is special
     if ((modifiers & MOD_MASK_SHIFT) && ASCII_ISALPHA(key)) {
       key = TOUPPER_ASC(key);
       modifiers &= ~MOD_MASK_SHIFT;
     }
+  }
   if ((modifiers & MOD_MASK_CTRL)
       && ((key >= '?' && key <= '_') || ASCII_ISALPHA(key))) {
     key = Ctrl_chr(key);

src/nvim/keymap.h

@@ -112,11 +112,11 @@
 #define TO_SPECIAL(a, b)    ((a) == KS_SPECIAL ? K_SPECIAL : (a) == \
                              KS_ZERO ? K_ZERO : TERMCAP2KEY(a, b))
 
-/*
+// Codes for keys that do not have a termcap name.
- * Codes for keys that do not have a termcap name.
+//
- *
+// K_SPECIAL KS_EXTRA KE_xxx
- * K_SPECIAL KS_EXTRA KE_xxx
+//
- */
+// Entries must be in the range 0x02-0x7f (see comment at K_SPECIAL).
 enum key_extra {
   KE_NAME = 3           /* name of this terminal entry */
 
@@ -436,11 +436,12 @@ enum key_extra {
 /* 0x01 cannot be used, because the modifier must be 0x02 or higher */
 #define MOD_MASK_SHIFT      0x02
 #define MOD_MASK_CTRL       0x04
-#define MOD_MASK_ALT        0x08        /* aka META */
+#define MOD_MASK_ALT        0x08        // aka META
-#define MOD_MASK_META       0x10        /* META when it's different from ALT */
+#define MOD_MASK_META       0x10        // META when it's different from ALT
-#define MOD_MASK_2CLICK     0x20        /* use MOD_MASK_MULTI_CLICK */
+#define MOD_MASK_2CLICK     0x20        // use MOD_MASK_MULTI_CLICK
-#define MOD_MASK_3CLICK     0x40        /* use MOD_MASK_MULTI_CLICK */
+#define MOD_MASK_3CLICK     0x40        // use MOD_MASK_MULTI_CLICK
-#define MOD_MASK_4CLICK     0x60        /* use MOD_MASK_MULTI_CLICK */
+#define MOD_MASK_4CLICK     0x60        // use MOD_MASK_MULTI_CLICK
+#define MOD_MASK_CMD        0x80        // "super" key (OSX/Mac: command-key)
 
 #define MOD_MASK_MULTI_CLICK    (MOD_MASK_2CLICK|MOD_MASK_3CLICK| \
                                  MOD_MASK_4CLICK)
@@ -451,14 +452,13 @@ enum key_extra {
  */
 #define MAX_KEY_NAME_LEN    25
 
-/* Maximum length of a special key event as tokens.  This includes modifiers.
+// Maximum length of a special key event as tokens.  This includes modifiers.
- * The longest event is something like <M-C-S-T-4-LeftDrag> which would be the
+// The longest event is something like <M-C-S-T-4-LeftDrag> which would be the
- * following string of tokens:
+// following string of tokens:
- *
+//
- * <K_SPECIAL> <KS_MODIFIER> bitmask <K_SPECIAL> <KS_EXTRA> <KT_LEFTDRAG>.
+// <K_SPECIAL> <KS_MODIFIER> bitmask <K_SPECIAL> <KS_EXTRA> <KE_LEFTDRAG>.
- *
+//
- * This is a total of 6 tokens, and is currently the longest one possible.
+// This is a total of 6 tokens, and is currently the longest one possible.
- */
 #define MAX_KEY_CODE_LEN    6
 
 

test/functional/api/vim_spec.lua

@@ -144,15 +144,23 @@ describe('vim_* functions', function()
 
   describe('replace_termcodes', function()
     it('escapes K_SPECIAL as K_SPECIAL KS_SPECIAL KE_FILLER', function()
-      eq(helpers.nvim('replace_termcodes', '\128', true, true, true), '\128\254X')
+      eq('\128\254X', helpers.nvim('replace_termcodes', '\128', true, true, true))
     end)
 
-    it('leaves non K_SPECIAL string unchanged', function()
+    it('leaves non-K_SPECIAL string unchanged', function()
-      eq(helpers.nvim('replace_termcodes', 'abc', true, true, true), 'abc')
+      eq('abc', helpers.nvim('replace_termcodes', 'abc', true, true, true))
     end)
 
     it('converts <expressions>', function()
-      eq(helpers.nvim('replace_termcodes', '<Leader>', true, true, true), '\\')
+      eq('\\', helpers.nvim('replace_termcodes', '<Leader>', true, true, true))
+    end)
+
+    it('converts <LeftMouse> to K_SPECIAL KS_EXTRA KE_LEFTMOUSE', function()
+      -- K_SPECIAL KS_EXTRA KE_LEFTMOUSE
+      -- 0x80      0xfd     0x2c
+      -- 128       253      44
+      eq('\128\253\44', helpers.nvim('replace_termcodes',
+                                     '<LeftMouse>', true, true, true))
     end)
   end)
 

test/functional/ui/input_spec.lua

@@ -25,6 +25,9 @@ describe('mappings', function()
     add_mapping('<s-up>', '<s-up>')
     add_mapping('<c-s-up>', '<c-s-up>')
     add_mapping('<c-s-a-up>', '<c-s-a-up>')
+    add_mapping('<c-s-a-d-up>', '<c-s-a-d-up>')
+    add_mapping('<c-d-a>', '<c-d-a>')
+    add_mapping('<d-1>', '<d-1>')
   end)
 
   it('ok', function()
@@ -37,6 +40,12 @@ describe('mappings', function()
     check_mapping('<s-a-c-up>', '<c-s-a-up>')
     check_mapping('<a-c-s-up>', '<c-s-a-up>')
     check_mapping('<a-s-c-up>', '<c-s-a-up>')
+    check_mapping('<c-s-a-d-up>', '<c-s-a-d-up>')
+    check_mapping('<s-a-d-c-up>', '<c-s-a-d-up>')
+    check_mapping('<d-s-a-c-up>', '<c-s-a-d-up>')
+    check_mapping('<c-d-a>', '<c-d-a>')
+    check_mapping('<d-c-a>', '<c-d-a>')
+    check_mapping('<d-1>', '<d-1>')
   end)
 end)