Add macOS left Alt to Command mapping option

docs/configuration.md

@@ -614,6 +614,30 @@ editing the `conf` file in a text editor. Use the examples as reference.
     </tr>
 </table>
 
+### key_leftalt_to_key_cmd
+
+<table>
+    <tr>
+        <td>Description</td>
+        <td colspan="2">
+            On macOS, map the Left Alt key from Moonlight to the left Command key. This can be useful when the client cannot send the Windows key directly.
+            @caution{Applies to macOS only.}
+        </td>
+    </tr>
+    <tr>
+        <td>Default</td>
+        <td colspan="2">@code{}
+            disabled
+            @endcode</td>
+    </tr>
+    <tr>
+        <td>Example</td>
+        <td colspan="2">@code{}
+            key_leftalt_to_key_cmd = enabled
+            @endcode</td>
+    </tr>
+</table>
+
 ### mouse
 
 <table>

src/config.cpp

@@ -580,6 +580,7 @@ namespace config {
     true,  // mouse enabled
     true,  // controller enabled
     true,  // always send scancodes
+    false,  // map left alt to command on macOS
     true,  // high resolution scrolling
     true,  // native pen/touch support
   };
@@ -1279,6 +1280,8 @@ namespace config {
       input.keybindings.emplace(0xA5, 0x5B);
     }
 
+    bool_f(vars, "key_leftalt_to_key_cmd", input.key_leftalt_to_key_cmd);
+
     to = std::numeric_limits<int>::min();
     int_f(vars, "back_button_timeout", to);
 

src/config.h

@@ -212,6 +212,7 @@ namespace config {
     bool controller;
 
     bool always_send_scancodes;
+    bool key_leftalt_to_key_cmd;
 
     bool high_resolution_scrolling;
     bool native_pen_touch;

src/platform/macos/input.cpp

@@ -14,6 +14,7 @@
 #include <mach/mach.h>
 
 // local includes
+#include "src/config.h"
 #include "src/display_device.h"
 #include "src/input.h"
 #include "src/logging.h"
@@ -229,6 +230,10 @@ const KeyCodeMap kKeyCodesMap[] = {
   // clang-format on
 
   int keysym(int keycode) {
+    if (config::input.key_leftalt_to_key_cmd && keycode == 0xA4 /* VKEY_LMENU */) {
+      return kVK_Command;
+    }
+
     KeyCodeMap key_map {};
 
     key_map.win_keycode = keycode;

src_assets/common/assets/web/config.html

@@ -209,6 +209,7 @@ <h1 class="my-4">{{ $t('config.configuration') }}</h1>
               "key_repeat_frequency": 24.9,
               "always_send_scancodes": "enabled",
               "key_rightalt_to_key_win": "disabled",
+              "key_leftalt_to_key_cmd": "disabled",
               "mouse": "enabled",
               "high_resolution_scrolling": "enabled",
               "native_pen_touch": "enabled",

src_assets/common/assets/web/configs/tabs/Inputs.vue

@@ -155,6 +155,15 @@ const config = ref(props.config)
               default="false"
     ></Checkbox>
 
+    <!-- Mapping Key AltLeft to Key Command -->
+    <Checkbox v-if="config.keyboard === 'enabled' && platform === 'macos'"
+              class="mb-3"
+              id="key_leftalt_to_key_cmd"
+              locale-prefix="config"
+              v-model="config.key_leftalt_to_key_cmd"
+              default="false"
+    ></Checkbox>
+
     <!-- Enable Mouse Input -->
     <hr>
     <Checkbox class="mb-3"

src_assets/common/assets/web/public/assets/locale/en.json

@@ -252,6 +252,8 @@
     "key_repeat_frequency_desc": "How often keys repeat every second. This configurable option supports decimals.",
     "key_rightalt_to_key_win": "Map Right Alt key to Windows key",
     "key_rightalt_to_key_win_desc": "It may be possible that you cannot send the Windows Key from Moonlight directly. In those cases it may be useful to make Sunshine think the Right Alt key is the Windows key",
+    "key_leftalt_to_key_cmd": "Map Left Alt key to Command key",
+    "key_leftalt_to_key_cmd_desc": "On macOS, map the Left Alt key from Moonlight to the left Command key. This can be useful when the client cannot send the Windows key directly.",
     "keybindings": "Keybindings",
     "keyboard": "Enable Keyboard Input",
     "keyboard_desc": "Allows guests to control the host system with the keyboard",

src_assets/common/assets/web/public/assets/locale/en_GB.json

@@ -249,6 +249,8 @@
     "key_repeat_frequency_desc": "How often keys repeat every second. This configurable option supports decimals.",
     "key_rightalt_to_key_win": "Map Right Alt key to Windows key",
     "key_rightalt_to_key_win_desc": "It may be possible that you cannot send the Windows Key from Moonlight directly. In those cases it may be useful to make Sunshine think the Right Alt key is the Windows key",
+    "key_leftalt_to_key_cmd": "Map Left Alt key to Command key",
+    "key_leftalt_to_key_cmd_desc": "On macOS, map the Left Alt key from Moonlight to the left Command key. This can be useful when the client cannot send the Windows key directly.",
     "keybindings": "Keybindings",
     "keyboard": "Enable Keyboard Input",
     "keyboard_desc": "Allows guests to control the host system with the keyboard",

src_assets/common/assets/web/public/assets/locale/en_US.json

@@ -249,6 +249,8 @@
     "key_repeat_frequency_desc": "How often keys repeat every second. This configurable option supports decimals.",
     "key_rightalt_to_key_win": "Map Right Alt key to Windows key",
     "key_rightalt_to_key_win_desc": "It may be possible that you cannot send the Windows Key from Moonlight directly. In those cases it may be useful to make Sunshine think the Right Alt key is the Windows key",
+    "key_leftalt_to_key_cmd": "Map Left Alt key to Command key",
+    "key_leftalt_to_key_cmd_desc": "On macOS, map the Left Alt key from Moonlight to the left Command key. This can be useful when the client cannot send the Windows key directly.",
     "keybindings": "Keybindings",
     "keyboard": "Enable Keyboard Input",
     "keyboard_desc": "Allows guests to control the host system with the keyboard",