swaybar: add StatusNotifierWatcher to tray

include/swaybar/tray/tray.h

@@ -12,12 +12,16 @@
 
 struct swaybar;
 struct swaybar_output;
+struct swaybar_watcher;
 
 struct swaybar_tray {
 	struct swaybar *bar;
 
 	int fd;
 	sd_bus *bus;
+
+	struct swaybar_watcher *watcher_xdg;
+	struct swaybar_watcher *watcher_kde;
 };
 
 struct swaybar_tray *create_tray(struct swaybar *bar);

include/swaybar/tray/watcher.h

@@ -0,0 +1,18 @@
+#ifndef _SWAYBAR_TRAY_WATCHER_H
+#define _SWAYBAR_TRAY_WATCHER_H
+
+#include "swaybar/tray/tray.h"
+#include "list.h"
+
+struct swaybar_watcher {
+	char *interface;
+	sd_bus *bus;
+	list_t *hosts;
+	list_t *items;
+	int version;
+};
+
+struct swaybar_watcher *create_watcher(char *protocol, sd_bus *bus);
+void destroy_watcher(struct swaybar_watcher *watcher);
+
+#endif

swaybar/meson.build

@@ -1,5 +1,6 @@
 tray_files = get_option('enable-tray') ? [
 	'tray/tray.c',
+	'tray/watcher.c'
 ] : []
 
 swaybar_deps = [

swaybar/tray/tray.c

@@ -4,6 +4,7 @@
 #include <string.h>
 #include "swaybar/bar.h"
 #include "swaybar/tray/tray.h"
+#include "swaybar/tray/watcher.h"
 #include "log.h"
 
 struct swaybar_tray *create_tray(struct swaybar *bar) {
@@ -23,6 +24,10 @@ struct swaybar_tray *create_tray(struct swaybar *bar) {
 	tray->bar = bar;
 	tray->bus = bus;
 	tray->fd = sd_bus_get_fd(tray->bus);
+
+	tray->watcher_xdg = create_watcher("freedesktop", tray->bus);
+	tray->watcher_kde = create_watcher("kde", tray->bus);
+
 	return tray;
 }
 
@@ -30,6 +35,8 @@ void destroy_tray(struct swaybar_tray *tray) {
 	if (!tray) {
 		return;
 	}
+	destroy_watcher(tray->watcher_xdg);
+	destroy_watcher(tray->watcher_kde);
 	sd_bus_flush_close_unref(tray->bus);
 	free(tray);
 }

swaybar/tray/watcher.c

@@ -0,0 +1,212 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "list.h"
+#include "log.h"
+#include "swaybar/tray/watcher.h"
+
+static const char *obj_path = "/StatusNotifierWatcher";
+
+static bool using_standard_protocol(struct swaybar_watcher *watcher) {
+	return watcher->interface[strlen("org.")] == 'f'; // freedesktop
+}
+
+static int cmp_id(const void *item, const void *cmp_to) {
+	return strcmp(item, cmp_to);
+}
+
+static int cmp_service(const void *item, const void *cmp_to) {
+	return strncmp(item, cmp_to, strlen(cmp_to));
+}
+
+static int handle_lost_service(sd_bus_message *msg,
+		void *data, sd_bus_error *error) {
+	char *service, *old_owner, *new_owner;
+	int ret = sd_bus_message_read(msg, "sss", &service, &old_owner, &new_owner);
+	if (ret < 0) {
+		wlr_log(WLR_ERROR, "Failed to parse owner change message: %s", strerror(-ret));
+		return ret;
+	}
+
+	if (!*new_owner) {
+		struct swaybar_watcher *watcher = data;
+		int idx = list_seq_find(watcher->items,
+				using_standard_protocol(watcher) ? cmp_id : cmp_service, service);
+		if (idx != -1) {
+			char *id = watcher->items->items[idx];
+			wlr_log(WLR_DEBUG, "Unregistering Status Notifier Item '%s'", id);
+			list_del(watcher->items, idx);
+			sd_bus_emit_signal(watcher->bus, obj_path, watcher->interface,
+					"StatusNotifierItemUnregistered", "s", id);
+			free(id);
+		}
+
+		idx = list_seq_find(watcher->hosts, cmp_id, service);
+		if (idx != -1) {
+			wlr_log(WLR_DEBUG, "Unregistering Status Notifier Host '%s'", service);
+			free(watcher->hosts->items[idx]);
+			list_del(watcher->hosts, idx);
+		}
+	}
+
+	return 0;
+}
+
+static int register_sni(sd_bus_message *msg, void *data, sd_bus_error *error) {
+	char *service_or_path, *id;
+	int ret = sd_bus_message_read(msg, "s", &service_or_path);
+	if (ret < 0) {
+		wlr_log(WLR_ERROR, "Failed to parse register SNI message: %s", strerror(-ret));
+		return ret;
+	}
+
+	struct swaybar_watcher *watcher = data;
+	if (using_standard_protocol(watcher)) {
+		id = strdup(service_or_path);
+	} else {
+		const char *service, *path;
+		if (service_or_path[0] == '/') {
+			service = sd_bus_message_get_sender(msg);
+			path = service_or_path;
+		} else {
+			service = service_or_path;
+			path = "/StatusNotifierItem";
+		}
+		size_t id_len = snprintf(NULL, 0, "%s%s", service, path) + 1;
+		id = malloc(id_len);
+		snprintf(id, id_len, "%s%s", service, path);
+	}
+
+	if (list_seq_find(watcher->items, cmp_id, id) == -1) {
+		wlr_log(WLR_DEBUG, "Registering Status Notifier Item '%s'", id);
+		list_add(watcher->items, id);
+		sd_bus_emit_signal(watcher->bus, obj_path, watcher->interface,
+				"StatusNotifierItemRegistered", "s", id);
+	} else {
+		wlr_log(WLR_DEBUG, "Status Notifier Item '%s' already registered", id);
+		free(id);
+	}
+
+	return sd_bus_reply_method_return(msg, "");
+}
+
+static int register_host(sd_bus_message *msg, void *data, sd_bus_error *error) {
+	char *service;
+	int ret = sd_bus_message_read(msg, "s", &service);
+	if (ret < 0) {
+		wlr_log(WLR_ERROR, "Failed to parse register host message: %s", strerror(-ret));
+		return ret;
+	}
+
+	struct swaybar_watcher *watcher = data;
+	if (list_seq_find(watcher->hosts, cmp_id, service) == -1) {
+		wlr_log(WLR_DEBUG, "Registering Status Notifier Host '%s'", service);
+		list_add(watcher->hosts, strdup(service));
+		sd_bus_emit_signal(watcher->bus, obj_path, watcher->interface,
+				"StatusNotifierHostRegistered", "s", service);
+	} else {
+		wlr_log(WLR_DEBUG, "Status Notifier Host '%s' already registered", service);
+	}
+
+	return sd_bus_reply_method_return(msg, "");
+}
+
+static int get_registered_snis(sd_bus *bus, const char *obj_path,
+		const char *interface, const char *property, sd_bus_message *reply,
+		void *data, sd_bus_error *error) {
+	struct swaybar_watcher *watcher = data;
+	list_add(watcher->items, NULL); // strv expects NULL-terminated string array
+	int ret = sd_bus_message_append_strv(reply, (char **)watcher->items->items);
+	list_del(watcher->items, watcher->items->length - 1);
+	return ret;
+}
+
+static int is_host_registered(sd_bus *bus, const char *obj_path,
+		const char *interface, const char *property, sd_bus_message *reply,
+		void *data, sd_bus_error *error) {
+	struct swaybar_watcher *watcher = data;
+	int val = watcher->hosts->length > 0; // dbus expects int rather than bool
+	return sd_bus_message_append_basic(reply, 'b', &val);
+}
+
+static const sd_bus_vtable watcher_vtable[] = {
+	SD_BUS_VTABLE_START(0),
+	SD_BUS_METHOD("RegisterStatusNotifierItem", "s", "", register_sni,
+			SD_BUS_VTABLE_UNPRIVILEGED),
+	SD_BUS_METHOD("RegisterStatusNotifierHost", "s", "", register_host,
+			SD_BUS_VTABLE_UNPRIVILEGED),
+	SD_BUS_PROPERTY("RegisteredStatusNotifierItems", "as", get_registered_snis,
+			0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
+	SD_BUS_PROPERTY("IsStatusNotifierHostRegistered", "b", is_host_registered,
+			0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
+	SD_BUS_PROPERTY("ProtocolVersion", "i", NULL,
+			offsetof(struct swaybar_watcher, version),
+			SD_BUS_VTABLE_PROPERTY_CONST),
+	SD_BUS_SIGNAL("StatusNotifierItemRegistered", "s", 0),
+	SD_BUS_SIGNAL("StatusNotifierItemUnregistered", "s", 0),
+	SD_BUS_SIGNAL("StatusNotifierHostRegistered", NULL, 0),
+	SD_BUS_VTABLE_END
+};
+
+struct swaybar_watcher *create_watcher(char *protocol, sd_bus *bus) {
+	struct swaybar_watcher *watcher =
+		calloc(1, sizeof(struct swaybar_watcher));
+	if (!watcher) {
+		return NULL;
+	}
+
+	size_t len = snprintf(NULL, 0, "org.%s.StatusNotifierWatcher", protocol) + 1;
+	watcher->interface = malloc(len);
+	snprintf(watcher->interface, len, "org.%s.StatusNotifierWatcher", protocol);
+
+	sd_bus_slot *signal_slot = NULL, *vtable_slot = NULL;
+	int ret = sd_bus_add_object_vtable(bus, &vtable_slot, obj_path,
+			watcher->interface, watcher_vtable, watcher);
+	if (ret < 0) {
+		wlr_log(WLR_ERROR, "Failed to add object vtable: %s", strerror(-ret));
+		goto error;
+	}
+
+	ret = sd_bus_match_signal(bus, &signal_slot, "org.freedesktop.DBus",
+			"/org/freedesktop/DBus", "org.freedesktop.DBus",
+			"NameOwnerChanged", handle_lost_service, watcher);
+	if (ret < 0) {
+		wlr_log(WLR_ERROR, "Failed to subscribe to unregistering events: %s",
+				strerror(-ret));
+		goto error;
+	}
+
+	ret = sd_bus_request_name(bus, watcher->interface, 0);
+	if (ret < 0) {
+		wlr_log(WLR_ERROR, "Failed to acquire service name: %s", strerror(-ret));
+		goto error;
+	}
+
+	sd_bus_slot_set_floating(signal_slot, 0);
+	sd_bus_slot_set_floating(vtable_slot, 0);
+
+	watcher->bus = bus;
+	watcher->hosts = create_list();
+	watcher->items = create_list();
+	watcher->version = 0;
+	wlr_log(WLR_DEBUG, "Registered %s", watcher->interface);
+	return watcher;
+error:
+	sd_bus_slot_unref(signal_slot);
+	sd_bus_slot_unref(vtable_slot);
+	destroy_watcher(watcher);
+	return NULL;
+}
+
+void destroy_watcher(struct swaybar_watcher *watcher) {
+	if (!watcher) {
+		return;
+	}
+	list_free_items_and_destroy(watcher->hosts);
+	list_free_items_and_destroy(watcher->items);
+	free(watcher->interface);
+	free(watcher);
+}