Implement Tray Icons

This commit implements the StatusNotifierItem protocol, and enables
swaybar to show tray icons. It also uses `xembedsniproxy` in order to
communicate with xembed applications.
The tray is completely optional, and can be disabled on compile time
with the `enable-tray` option. Or on runtime with the bar config option
`tray_output none`.

Overview of changes:
In swaybar very little is changed outside the tray subfolder except
that all events are now polled in `event_loop.c`, this creates no
functional difference.

Six bar configuration options were added, these are detailed in
sway-bar(5)

The tray subfolder is where all protocol implementation takes place and
is organised as follows:

tray/sni_watcher.c:
	This file contains the StatusNotifierWatcher. It keeps track of
	items and hosts and reports when they come or go.
tray/tray.c
	This file contains the StatusNotifierHost. It keeps track of
	sway's version of the items and represents the tray itself.
tray/sni.c
	This file contains the StatusNotifierItem struct and all
	communication with individual items.
tray/icon.c
	This file implements the icon theme protocol. It allows for
	finding icons by name, rather than by pixmap.
tray/dbus.c
	This file allows for asynchronous DBus communication.

See #986 #343

1 files changed, 279 insertions, 0 deletions

diff --git a/swaybar/tray/tray.c b/swaybar/tray/tray.c
new file mode 100644
index 00000000..9a709fe4
--- /dev/null
+++ b/swaybar/tray/tray.c
@@ -0,0 +1,279 @@
+#define _XOPEN_SOURCE 500
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dbus/dbus.h>
+#include "swaybar/bar.h"
+#include "swaybar/tray/tray.h"
+#include "swaybar/tray/dbus.h"
+#include "swaybar/tray/sni.h"
+#include "swaybar/bar.h"
+#include "list.h"
+#include "log.h"
+
+struct tray *tray;
+
+static void register_host(char *name) {
+	DBusMessage *message;
+
+	message = dbus_message_new_method_call(
+			"org.freedesktop.StatusNotifierWatcher",
+			"/StatusNotifierWatcher",
+			"org.freedesktop.StatusNotifierWatcher",
+			"RegisterStatusNotifierHost");
+	if (!message) {
+		sway_log(L_ERROR, "Cannot allocate dbus method call");
+		return;
+	}
+
+	dbus_message_append_args(message,
+			DBUS_TYPE_STRING, &name,
+			DBUS_TYPE_INVALID);
+
+	dbus_connection_send(conn, message, NULL);
+
+	dbus_message_unref(message);
+}
+
+static void get_items_reply(DBusPendingCall *pending, void *_data) {
+	DBusMessage *reply = dbus_pending_call_steal_reply(pending);
+
+	if (!reply) {
+		sway_log(L_ERROR, "Got no items reply from sni watcher");
+		goto bail;
+	}
+
+	int message_type = dbus_message_get_type(reply);
+
+	if (message_type == DBUS_MESSAGE_TYPE_ERROR) {
+		char *msg;
+
+		dbus_message_get_args(reply, NULL,
+				DBUS_TYPE_STRING, &msg,
+				DBUS_TYPE_INVALID);
+
+		sway_log(L_ERROR, "Message is error: %s", msg);
+		goto bail;
+	}
+
+	DBusMessageIter iter;
+	DBusMessageIter variant;
+	DBusMessageIter array;
+
+	dbus_message_iter_init(reply, &iter);
+	if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT) {
+		sway_log(L_ERROR, "Replyed with wrong type, not v(as)");
+		goto bail;
+	}
+	dbus_message_iter_recurse(&iter, &variant);
+	if (dbus_message_iter_get_arg_type(&variant) != DBUS_TYPE_ARRAY ||
+			dbus_message_iter_get_element_type(&variant) != DBUS_TYPE_STRING) {
+		sway_log(L_ERROR, "Replyed with wrong type, not v(as)");
+		goto bail;
+	}
+
+	// Clear list
+	list_foreach(tray->items, (void (*)(void *))sni_free);
+	list_free(tray->items);
+	tray->items = create_list();
+
+	// O(n) function, could be faster dynamically reading values
+	int len = dbus_message_iter_get_element_count(&variant);
+
+	dbus_message_iter_recurse(&variant, &array);
+	for (int i = 0; i < len; i++) {
+		const char *name;
+		dbus_message_iter_get_basic(&array, &name);
+
+		struct StatusNotifierItem *item = sni_create(name);
+
+		sway_log(L_DEBUG, "Item registered with host: %s", name);
+		list_add(tray->items, item);
+		dirty = true;
+	}
+
+bail:
+	dbus_message_unref(reply);
+	return;
+}
+static void get_items() {
+	DBusPendingCall *pending;
+	DBusMessage *message = dbus_message_new_method_call(
+			"org.freedesktop.StatusNotifierWatcher",
+			"/StatusNotifierWatcher",
+			"org.freedesktop.DBus.Properties",
+			"Get");
+
+	const char *iface = "org.freedesktop.StatusNotifierWatcher";
+	const char *prop = "RegisteredStatusNotifierItems";
+	dbus_message_append_args(message,
+			DBUS_TYPE_STRING, &iface,
+			DBUS_TYPE_STRING, &prop,
+			DBUS_TYPE_INVALID);
+
+	bool status =
+		dbus_connection_send_with_reply(conn, message, &pending, -1);
+	dbus_message_unref(message);
+
+	if (!(pending || status)) {
+		sway_log(L_ERROR, "Could not get items");
+		return;
+	}
+
+	dbus_pending_call_set_notify(pending, get_items_reply, NULL, NULL);
+}
+
+static DBusHandlerResult signal_handler(DBusConnection *connection,
+		DBusMessage *message, void *_data) {
+	if (dbus_message_is_signal(message, "org.freedesktop.StatusNotifierWatcher",
+				"StatusNotifierItemRegistered")) {
+		const char *name;
+		if (!dbus_message_get_args(message, NULL,
+				DBUS_TYPE_STRING, &name,
+				DBUS_TYPE_INVALID)) {
+			sway_log(L_ERROR, "Error getting StatusNotifierItemRegistered args");
+			return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+		}
+
+		if (list_seq_find(tray->items, sni_str_cmp, name) == -1) {
+			struct StatusNotifierItem *item = sni_create(name);
+
+			list_add(tray->items, item);
+			dirty = true;
+		}
+
+		return DBUS_HANDLER_RESULT_HANDLED;
+	} else if (dbus_message_is_signal(message, "org.freedesktop.StatusNotifierWatcher",
+				"StatusNotifierItemUnregistered")) {
+		const char *name;
+		if (!dbus_message_get_args(message, NULL,
+				DBUS_TYPE_STRING, &name,
+				DBUS_TYPE_INVALID)) {
+			sway_log(L_ERROR, "Error getting StatusNotifierItemUnregistered args");
+			return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+		}
+
+		int index;
+		if ((index = list_seq_find(tray->items, sni_str_cmp, name)) != -1) {
+			sni_free(tray->items->items[index]);
+			list_del(tray->items, index);
+			dirty = true;
+		} else {
+			// If it's not in our list, then our list is incorrect.
+			// Fetch all items again
+			sway_log(L_INFO, "Host item list incorrect, refreshing");
+			get_items();
+		}
+
+		return DBUS_HANDLER_RESULT_HANDLED;
+	} else if (dbus_message_is_signal(message, "org.freedesktop.StatusNotifierItem",
+				"NewIcon") || dbus_message_is_signal(message,
+				"org.kde.StatusNotifierItem", "NewIcon")) {
+		const char *name;
+		int index;
+		struct StatusNotifierItem *item;
+
+		name = dbus_message_get_sender(message);
+		if ((index = list_seq_find(tray->items, sni_uniq_cmp, name)) != -1) {
+			item = tray->items->items[index];
+			get_icon(item);
+		}
+
+		return DBUS_HANDLER_RESULT_HANDLED;
+	}
+	return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+int init_tray() {
+	tray = (struct tray *)malloc(sizeof(tray));
+
+	tray->items = create_list();
+
+	DBusError error;
+	dbus_error_init(&error);
+	char *name = NULL;
+	if (!conn) {
+		sway_log(L_ERROR, "Connection is null, cannot init SNI host");
+		goto err;
+	}
+	name = calloc(sizeof(char), 256);
+
+	if (!name) {
+		sway_log(L_ERROR, "Cannot allocate name");
+		goto err;
+	}
+
+	pid_t pid = getpid();
+	if (snprintf(name, 256, "org.freedesktop.StatusNotifierHost-%d", pid)
+			>= 256) {
+		sway_log(L_ERROR, "Cannot get host name because string is too short."
+				"This should not happen");
+		goto err;
+	}
+
+	// We want to be the sole owner of this name
+	if (dbus_bus_request_name(conn, name, DBUS_NAME_FLAG_DO_NOT_QUEUE,
+			&error) != DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER) {
+		sway_log(L_ERROR, "Cannot get host name and start the tray");
+		goto err;
+	}
+	if (dbus_error_is_set(&error)) {
+		sway_log(L_ERROR, "Dbus err getting host name: %s\n", error.message);
+		goto err;
+	}
+	sway_log(L_DEBUG, "Got host name");
+
+	register_host(name);
+
+	get_items();
+
+	// Perhaps use addmatch helper functions like wlc does?
+	dbus_bus_add_match(conn,
+			"type='signal',\
+			sender='org.freedesktop.StatusNotifierWatcher',\
+			member='StatusNotifierItemRegistered'",
+			&error);
+	if (dbus_error_is_set(&error)) {
+		sway_log(L_ERROR, "dbus_err: %s", error.message);
+		goto err;
+	}
+	dbus_bus_add_match(conn,
+			"type='signal',\
+			sender='org.freedesktop.StatusNotifierWatcher',\
+			member='StatusNotifierItemUnregistered'",
+			&error);
+	if (dbus_error_is_set(&error)) {
+		sway_log(L_ERROR, "dbus_err: %s", error.message);
+		return -1;
+	}
+
+	// SNI matches
+	dbus_bus_add_match(conn,
+			"type='signal',\
+			interface='org.freedesktop.StatusNotifierItem',\
+			member='NewIcon'",
+			&error);
+	if (dbus_error_is_set(&error)) {
+		sway_log(L_ERROR, "dbus_err %s", error.message);
+		goto err;
+	}
+	dbus_bus_add_match(conn,
+			"type='signal',\
+			interface='org.kde.StatusNotifierItem',\
+			member='NewIcon'",
+			&error);
+	if (dbus_error_is_set(&error)) {
+		sway_log(L_ERROR, "dbus_err %s", error.message);
+		goto err;
+	}
+
+	dbus_connection_add_filter(conn, signal_handler, NULL, NULL);
+
+	free(name);
+	return 0;
+
+err:
+	// TODO better handle errors
+	free(name);
+	return -1;
+}