virtual-keyboard: add wlr_input_device_get_virtual_keyboard

include/wlr/types/wlr_virtual_keyboard_v1.h

@@ -26,8 +26,8 @@ struct wlr_virtual_keyboard_manager_v1 {
 };
 
 struct wlr_virtual_keyboard_v1 {
-	struct wl_resource *resource;
 	struct wlr_input_device input_device;
+	struct wl_resource *resource;
 	struct wlr_seat *seat;
 	bool has_keymap;
 
@@ -41,4 +41,7 @@ struct wlr_virtual_keyboard_v1 {
 struct wlr_virtual_keyboard_manager_v1* wlr_virtual_keyboard_manager_v1_create(
 	struct wl_display *display);
 
+struct wlr_virtual_keyboard_v1 *wlr_input_device_get_virtual_keyboard(
+	struct wlr_input_device *wlr_dev);
+
 #endif

types/wlr_virtual_keyboard_v1.c

@@ -40,6 +40,14 @@ static struct wlr_virtual_keyboard_v1 *virtual_keyboard_from_resource(
 	return wl_resource_get_user_data(resource);
 }
 
+struct wlr_virtual_keyboard_v1 *wlr_input_device_get_virtual_keyboard(
+		struct wlr_input_device *wlr_dev) {
+	if (wlr_dev->impl != &input_device_impl) {
+		return NULL;
+	}
+	return (struct wlr_virtual_keyboard_v1 *)wlr_dev;
+}
+
 static void virtual_keyboard_keymap(struct wl_client *client,
 		struct wl_resource *resource, uint32_t format, int32_t fd,
 		uint32_t size) {