Add a function for getting the active modifiers

src/wine-host/editor.cpp

@@ -854,7 +854,22 @@ void Editor::run_timer_proc() {
     idle_timer_proc();
 }
 
-std::optional<POINT> Editor::get_current_pointer_position() const {
+std::optional<uint16_t> Editor::get_active_modifiers() const noexcept {
+    xcb_generic_error_t* error = nullptr;
+    const xcb_query_pointer_cookie_t query_pointer_cookie =
+        xcb_query_pointer(x11_connection.get(), wine_window);
+    const std::unique_ptr<xcb_query_pointer_reply_t> query_pointer_reply(
+        xcb_query_pointer_reply(x11_connection.get(), query_pointer_cookie,
+                                &error));
+    if (error) {
+        free(error);
+        return std::nullopt;
+    }
+
+    return query_pointer_reply->mask;
+}
+
+std::optional<POINT> Editor::get_current_pointer_position() const noexcept {
     xcb_generic_error_t* error = nullptr;
     const xcb_query_pointer_cookie_t query_pointer_cookie =
         xcb_query_pointer(x11_connection.get(), wine_window);

src/wine-host/editor.h

@@ -263,6 +263,14 @@ class Editor {
     const bool use_xembed;
 
    private:
+    /**
+     * Get the X11 event mask containing the current keyboard modifiers. Because
+     * we don't want to link with `xcb-xkb` and we also can't really use
+     * key/motion events for this, we'll do this by querying the pointer
+     * position instead. Will return a nullopt if that query fails.
+     */
+    std::optional<uint16_t> get_active_modifiers() const noexcept;
+
     /**
      * Get the current cursor position, in Win32 screen coordinates. This is
      * needed for our `LeaveNotify` handling because `GetCursorPos()` only
@@ -273,7 +281,7 @@ class Editor {
      *
      * If we cannot obtain the X11 cursor position, then this returns a nullopt.
      */
-    std::optional<POINT> get_current_pointer_position() const;
+    std::optional<POINT> get_current_pointer_position() const noexcept;
 
     /**
      * Returns `true` if the currently active window (as per