UNICODE_MODE_VIM: switch from i_CTRL-V u to i_CTRL-V U

docs/features/unicode.md

@@ -207,7 +207,7 @@ Not currently implemented. If you're a BSD user and want to contribute support f
 
 **Mode Name:** `UNICODE_MODE_VIM`
 
-Vim supports input of unicode characters up to `U+FFFF`. To insert a unicode character, press `ctrl+v u` in insert mode. For more informaton, see `:h utf-8-typing`.
+Vim supports input of all the unicode characters. For more information check `:h i_CTRL-V_digit`. In Vim unicode mode, keyboard sends `ctrl+v`, `shift+u`, and then digits of the unicode point.
 
 :::::
 
@@ -225,8 +225,8 @@ Vim supports input of unicode characters up to `U+FFFF`. To insert a unicode cha
 |`QK_UNICODE_MODE_WINDOWS`   |`UC_WIN` |Switch to Windows input                                         |
 |`QK_UNICODE_MODE_BSD`       |`UC_BSD` |Switch to BSD input (not implemented)                           |
 |`QK_UNICODE_MODE_WINCOMPOSE`|`UC_WINC`|Switch to Windows input using WinCompose                        |
-|`QK_UNICODE_MODE_EMACS`     |`UC_EMAC`|Switch to emacs input (`C-x-8 RET`)                                   |
+|`QK_UNICODE_MODE_EMACS`     |`UC_EMAC`|Switch to Emacs input (`C-x-8 RET`)                                   |
-|`QK_UNICODE_MODE_VIM`       |`UC_VIM`|Switch to vim input (`CTRL-V u`)                                   |
+|`QK_UNICODE_MODE_VIM`       |`UC_VIM`|Switch to Vim input (`CTRL-V U`)                                   |
 
 ## API {#api}
 
@@ -294,7 +294,7 @@ Begin the Unicode input sequence. The exact behavior depends on the currently se
  - **WinCompose**: Tap `UNICODE_KEY_WINC`, then U
  - **HexNumpad**: Hold Left Alt, then tap Numpad +
  - **Emacs**: Tap Ctrl+X, then 8, then Enter
- - **Vim**: Tap Ctrl+V, then u
+ - **Vim**: Tap Ctrl+V, then Shift+U
 
 This function is weakly defined, and can be overridden in user code.
 

docs/keycodes.md

@@ -903,4 +903,4 @@ See also: [Unicode Support](features/unicode)
 |`QK_UNICODE_MODE_BSD`       |`UC_BSD` |Switch to BSD input (not implemented)                           |
 |`QK_UNICODE_MODE_WINCOMPOSE`|`UC_WINC`|Switch to Windows input using WinCompose                        |
 |`QK_UNICODE_MODE_EMACS`     |`UC_EMAC`|Switch to Emacs input (`C-x-8 RET`)                             |
-|`QK_UNICODE_MODE_VIM`       |`UC_VIM` |Switch to Vim input (`i_CTRL-V u`)                              |
+|`QK_UNICODE_MODE_VIM`       |`UC_VIM` |Switch to Vim input (`i_CTRL-V U`)                              |

quantum/unicode/unicode.c

@@ -258,7 +258,7 @@ __attribute__((weak)) void unicode_input_start(void) {
             break;
         case UNICODE_MODE_VIM:
             tap_code16(LCTL(KC_V));
-            tap_code16(KC_U);
+            tap_code16(LSFT(KC_U));
             break;
     }
 
@@ -289,7 +289,7 @@ __attribute__((weak)) void unicode_input_finish(void) {
             tap_code16(KC_ENTER);
             break;
         case UNICODE_MODE_VIM:
-            // It finishes by itself when 4 hex digits received
+            // It finishes by itself when enough hex digits received
             break;
     }
 
@@ -350,6 +350,16 @@ void register_hex(uint16_t hex) {
 }
 
 void register_hex32(uint32_t hex) {
+    // In vim, `i_CTRL-V U` waits for exactly 8 digits, so we send them all
+    // @see `:h i_CTRL-V_digit`
+    if (unicode_config.input_mode == UNICODE_MODE_VIM) {
+        for (int i = 7; i >= 0; i--) {
+            uint8_t digit = ((hex >> (i * 4)) & 0xF);
+            send_nibble(digit);
+        }
+        return;
+    }
+
     bool first_digit        = true;
     bool needs_leading_zero = (unicode_config.input_mode == UNICODE_MODE_WINCOMPOSE);
     for (int i = 7; i >= 0; i--) {