Improve key code to key name mapping. (#784)

Use the key detected by WebUI and our mapping only for from_settings call.
Replace the old Win + ~ with the correct value

src/common/settings_objects.h

@@ -132,9 +132,7 @@ namespace PowerToysSettings {
     }
     const web::json::value& get_json() const { return m_json; }
 
-    std::wstring get_key() {
-      return key_from_code(get_code());
-    }
+    std::wstring get_key() { return m_json[L"key"].as_string(); }
     UINT get_code() { return m_json[L"code"].as_integer(); }
     bool win_pressed() { return m_json[L"win"].as_bool(); }
     bool ctrl_pressed() { return m_json[L"ctrl"].as_bool(); }
@@ -151,23 +149,37 @@ namespace PowerToysSettings {
     }
   protected:
     static std::wstring key_from_code(UINT key_code) {
-      auto scan_code = MapVirtualKeyW(key_code, MAPVK_VK_TO_VSC);
       auto layout = GetKeyboardLayout(0);
-      std::array<BYTE, 256> key_states{}; // zero-initialize, no key pressed
+      auto scan_code = MapVirtualKeyExW(key_code, MAPVK_VK_TO_VSC_EX, layout);
+      // Determinate if vk is an extended key. Unfortunatly MAPVK_VK_TO_VSC_EX
+      // does not return correct values.
+      static std::vector<UINT> extended_keys = {
+        VK_APPS, VK_CANCEL, VK_SNAPSHOT, VK_DIVIDE, VK_NUMLOCK, VK_LWIN, VK_RWIN, VK_RMENU,
+        VK_RCONTROL, VK_RSHIFT, VK_RETURN, VK_INSERT, VK_DELETE, VK_PRIOR, VK_NEXT,
+        VK_HOME, VK_END, VK_UP, VK_DOWN, VK_LEFT, VK_RIGHT, 
+      };
+      if (find(begin(extended_keys), end(extended_keys), key_code) != end(extended_keys)) {
+        scan_code |= 0x100;
+      }
+      std::array<BYTE, 256> key_states{}; // Zero-initialize
       std::array<wchar_t, 256> output;
       auto output_bytes = ToUnicodeEx(key_code, scan_code, key_states.data(), output.data(), (int)output.size() - 1, 0, layout);
-      if (output_bytes == 0) {
-        return L"(unknown)";
-      } else {
-        if (output_bytes == -1) {
-          output_bytes = 1;
-        }
+      if (output_bytes <= 0) {
+        // If ToUnicodeEx fails (e.g. for F1-F12 keys) use GetKeyNameTextW
+        output_bytes = GetKeyNameTextW(scan_code << 16, output.data(), static_cast<int>(output.size()));
+      }
+      if (output_bytes > 0) {
         output[output_bytes] = 0;
+        if (output_bytes == 1 && output[0] >= 'a' && output[0] <= 'z') {
+          // Make Latin letters keys capital, as it looks better
+          output[0] = toupper(output[0]);
+        }
         return output.data();
       }
+      return L"(Key " + std::to_wstring(key_code) + L")";
     }
     HotkeyObject(web::json::value hotkey_json) : m_json(hotkey_json) {
-      if (m_json.has_number_field(L"code")) {
+      if (get_key() == L"~" && get_modifiers_repeat() == MOD_WIN) {
         m_json.as_object()[L"key"] = web::json::value::string(key_from_code(get_code()));
       }
     };

src/settings-web/src/components/HotkeySettingsControl.tsx

@@ -78,13 +78,7 @@ export class HotkeySettingsControl extends BaseSettingsControl {
               new_value.key = '~';
             }
             if (!new_value.key || new_value.key === 'Unidentified') {
-              switch (new_value.code) {
-                case 192:
-                  new_value.key = '~';
-                  break;
-                default:
-                  new_value.key = `(Key ${new_value.code})`;
-              }
+              new_value.key = `(Key ${new_value.code})`;
             }
             if (new_value.key.length === 1) {
               new_value.key = new_value.key.toLocaleUpperCase();