backend/session: replace session_signal with events.active

This is more idiomatic wlroots API. The new name makes it clear that the
signal is emitted when wlr_session.active changes.

backend/drm/backend.c

@@ -85,7 +85,7 @@ bool wlr_backend_is_drm(struct wlr_backend *b) {
 static void session_signal(struct wl_listener *listener, void *data) {
 	struct wlr_drm_backend *drm =
 		wl_container_of(listener, drm, session_signal);
-	struct wlr_session *session = data;
+	struct wlr_session *session = drm->session;
 
 	if (session->active) {
 		wlr_log(WLR_INFO, "DRM fd resumed");
@@ -170,7 +170,7 @@ struct wlr_backend *wlr_drm_backend_create(struct wl_display *display,
 	}
 
 	drm->session_signal.notify = session_signal;
-	wl_signal_add(&session->session_signal, &drm->session_signal);
+	wl_signal_add(&session->events.active, &drm->session_signal);
 
 	if (!check_drm_features(drm)) {
 		goto error_event;

backend/libinput/backend.c

@@ -175,7 +175,7 @@ bool wlr_backend_is_libinput(struct wlr_backend *b) {
 static void session_signal(struct wl_listener *listener, void *data) {
 	struct wlr_libinput_backend *backend =
 		wl_container_of(listener, backend, session_signal);
-	struct wlr_session *session = data;
+	struct wlr_session *session = backend->session;
 
 	if (!backend->libinput_context) {
 		return;
@@ -219,7 +219,7 @@ struct wlr_backend *wlr_libinput_backend_create(struct wl_display *display,
 	backend->display = display;
 
 	backend->session_signal.notify = session_signal;
-	wl_signal_add(&session->session_signal, &backend->session_signal);
+	wl_signal_add(&session->events.active, &backend->session_signal);
 
 	backend->session_destroy.notify = handle_session_destroy;
 	wl_signal_add(&session->events.destroy, &backend->session_destroy);

backend/session/direct-freebsd.c

@@ -115,7 +115,7 @@ static int vt_handler(int signo, void *data) {
 
 	if (session->base.active) {
 		session->base.active = false;
-		wlr_signal_emit_safe(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.events.active, NULL);
 
 		wl_list_for_each(dev, &session->base.devices, link) {
 			if (ioctl(dev->fd, DRM_IOCTL_VERSION, &dv) == 0) {
@@ -134,7 +134,7 @@ static int vt_handler(int signo, void *data) {
 		}
 
 		session->base.active = true;
-		wlr_signal_emit_safe(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.events.active, NULL);
 	}
 
 	return 1;

backend/session/direct.c

@@ -126,7 +126,7 @@ static int vt_handler(int signo, void *data) {
 
 	if (session->base.active) {
 		session->base.active = false;
-		wlr_signal_emit_safe(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.events.active, NULL);
 
 		struct wlr_device *dev;
 		wl_list_for_each(dev, &session->base.devices, link) {
@@ -149,7 +149,7 @@ static int vt_handler(int signo, void *data) {
 		}
 
 		session->base.active = true;
-		wlr_signal_emit_safe(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.events.active, NULL);
 	}
 
 	return 1;

backend/session/libseat.c

@@ -35,13 +35,13 @@ struct libseat_session {
 static void handle_enable_seat(struct libseat *seat, void *data) {
 	struct libseat_session *session = data;
 	session->base.active = true;
-	wlr_signal_emit_safe(&session->base.session_signal, session);
+	wlr_signal_emit_safe(&session->base.events.active, NULL);
 }
 
 static void handle_disable_seat(struct libseat *seat, void *data) {
 	struct libseat_session *session = data;
 	session->base.active = false;
-	wlr_signal_emit_safe(&session->base.session_signal, session);
+	wlr_signal_emit_safe(&session->base.events.active, NULL);
 	libseat_disable_seat(session->seat);
 }
 

backend/session/logind.c

@@ -306,7 +306,7 @@ static int pause_device(sd_bus_message *msg, void *userdata,
 	if (major == DRM_MAJOR && strcmp(type, "gone") != 0) {
 		assert(session->has_drm);
 		session->base.active = false;
-		wlr_signal_emit_safe(&session->base.session_signal, session);
+		wlr_signal_emit_safe(&session->base.events.active, NULL);
 	}
 
 	if (strcmp(type, "pause") == 0) {
@@ -348,7 +348,7 @@ static int resume_device(sd_bus_message *msg, void *userdata,
 
 		if (!session->base.active) {
 			session->base.active = true;
-			wlr_signal_emit_safe(&session->base.session_signal, session);
+			wlr_signal_emit_safe(&session->base.events.active, NULL);
 		}
 	}
 
@@ -407,7 +407,7 @@ static int session_properties_changed(sd_bus_message *msg, void *userdata,
 
 			if (session->base.active != active) {
 				session->base.active = active;
-				wlr_signal_emit_safe(&session->base.session_signal, session);
+				wlr_signal_emit_safe(&session->base.events.active, NULL);
 			}
 			return 0;
 		} else {
@@ -447,7 +447,7 @@ static int session_properties_changed(sd_bus_message *msg, void *userdata,
 
 			if (session->base.active != active) {
 				session->base.active = active;
-				wlr_signal_emit_safe(&session->base.session_signal, session);
+				wlr_signal_emit_safe(&session->base.events.active, NULL);
 			}
 			return 0;
 		}

backend/session/session.c

@@ -101,7 +101,7 @@ static void handle_display_destroy(struct wl_listener *listener, void *data) {
 }
 
 void session_init(struct wlr_session *session) {
-	wl_signal_init(&session->session_signal);
+	wl_signal_init(&session->events.active);
 	wl_signal_init(&session->events.add_drm_card);
 	wl_signal_init(&session->events.destroy);
 	wl_list_init(&session->devices);

include/wlr/backend/session.h

@@ -24,7 +24,6 @@ struct wlr_session {
 	 * Signal for when the session becomes active/inactive.
 	 * It's called when we swap virtual terminal.
 	 */
-	struct wl_signal session_signal;
 	bool active;
 
 	/*
@@ -44,6 +43,7 @@ struct wlr_session {
 	struct wl_listener display_destroy;
 
 	struct {
+		struct wl_signal active;
 		struct wl_signal add_drm_card; // struct wlr_session_add_event
 		struct wl_signal destroy;
 	} events;