Create & implement transient seat protocol

include/wlr/types/wlr_transient_seat_v1.h

@@ -0,0 +1,63 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
+#ifndef WLR_TYPES_WLR_TRANSIENT_SEAT_V1_H
+#define WLR_TYPES_WLR_TRANSIENT_SEAT_V1_H
+
+#include <wayland-server-core.h>
+
+struct wlr_seat;
+
+struct wlr_transient_seat_v1 {
+	struct wl_resource *resource;
+	struct wlr_seat *seat;
+
+        // private state
+	struct wl_listener seat_destroy;
+};
+
+struct wlr_transient_seat_manager_v1 {
+	struct wl_global *global;
+	struct wl_listener display_destroy;
+
+	struct {
+		/**
+		 * Upon receiving this signal, call
+		 * wlr_transient_seat_v1_ready() to pass a newly created seat
+		 * to the manager, or
+		 * wlr_transient_seat_v1_deny() to deny the request to create
+		 * a seat.
+		 */
+		struct wl_signal create_seat; // struct wlr_transient_seat_v1
+	} events;
+};
+
+struct wlr_transient_seat_manager_v1 *wlr_transient_seat_manager_v1_create(
+		struct wl_display *display);
+
+/**
+ * To be called when the create_seat event is received.
+ *
+ * This signals that the seat was successfully added and is ready.
+ *
+ * When the transient seat is destroyed by the client, the wlr_seat will be
+ * destroyed. The wlr_seat may also be destroyed from elsewhere, in which case
+ * the transient seat will become inert.
+ */
+void wlr_transient_seat_v1_ready(struct wlr_transient_seat_v1 *seat,
+		struct wlr_seat *wlr_seat);
+
+/**
+ * To be called when the create_seat event is received.
+ *
+ * This signals that the compositor has denied the user's request to create a
+ * transient seat.
+ */
+void wlr_transient_seat_v1_deny(struct wlr_transient_seat_v1 *seat);
+
+#endif /* WLR_TYPES_WLR_TRANSIENT_SEAT_V1_H */