mpv pluging to inhibit screensaver while playing a video using freedesktop dbus api

mpv-freedesktop-screensaver-plugin.c

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <gio/gio.h>

#include <mpv/client.h>

/**
 * mpv pluging to inhibit screensaver while playing a video on GNOME Desktop
 * or any other not implementing Wayland "idle-inihibit" protocole
 * 
 * compile and install it with:
 *     gcc -o ~/.config/mpv/scripts/mpv-freedesktop-screensaver-plugin.so mpv-freedesktop-screensaver-plugin.c `pkg-config --cflags --libs glib-2.0 mpv`   -pthread -shared -fPIC
 *
 **/

guint32 inhibit(GDBusProxy *proxy) {
	GVariant *result;
	GError *error = NULL;
	result = g_dbus_proxy_call_sync(proxy,
					"Inhibit",
					g_variant_new ("(ss)", "mpv", "playing video"),
					G_DBUS_CALL_FLAGS_NONE,
					-1,
					NULL,
					&error);

	if (error != NULL) {
		printf("Cannot inhibit screensaver: %s\n", error->message);
		g_error_free (error);
		return 0;
	} else {
		guint32 cookie;
		g_variant_get(result, "(u)", &cookie);
		g_variant_unref(result);
		printf("Screensaver inhibited with cookie: %ld\n", cookie);
		return cookie;
	}
}

guint32 uninhibit(GDBusProxy *proxy, guint32 cookie) {
	GVariant *result;
	GError *error = NULL;
	result = g_dbus_proxy_call_sync(proxy,
					"UnInhibit",
					g_variant_new("(u)", cookie),
					G_DBUS_CALL_FLAGS_NONE,
					-1,
					NULL,
					&error);

	if (error != NULL) {
		printf("Cannot uninhibit screensaver: %s\n", error->message);
		g_error_free (error);
		return cookie;
	} else {
		g_variant_unref(result);
		printf("Screensaver uninhibited\n");
		return 0;
	}

}

int mpv_open_cplugin(mpv_handle *handle)
{
  printf("Hello world from C plugin '%s'!\n", mpv_client_name(handle));

	GDBusProxy *proxy;
	GDBusConnection *conn;
	GError *error = NULL;
  guint32 cookie = 0;

	conn = g_bus_get_sync(G_BUS_TYPE_SESSION, NULL, &error);
	if (error != NULL) {
		printf("Cannot get dbus sesstion bus: %s\n", error->message);
		g_error_free (error);
		return 1;
	}

	proxy = g_dbus_proxy_new_sync(conn,
				      G_DBUS_PROXY_FLAGS_NONE,
				      NULL,				/* GDBusInterfaceInfo */
				      "org.freedesktop.ScreenSaver",		/* name */
				      "/org/freedesktop/ScreenSaver",	/* object path */
				      "org.freedesktop.ScreenSaver",	/* interface */
				      NULL,				/* GCancellable */
				      &error);
	if (error != NULL) {
		printf("Cannot create proxy for org.freedesktop.ScreenSaver: %s\n", error->message);
		g_error_free (error);
		g_object_unref(conn);
		return 1;
	}

	mpv_observe_property(handle, 0, "pause", MPV_FORMAT_FLAG);

	while (1) {
		mpv_event *event = mpv_wait_event(handle, 0);
		if (event->event_id == MPV_EVENT_NONE) {
			continue;
		}

		printf("event: %s\n", mpv_event_name(event->event_id));

		if (event->event_id == MPV_EVENT_PROPERTY_CHANGE) {
			mpv_event_property *prop = (mpv_event_property *)event->data;
			if (strcmp(prop->name, "pause") == 0 && (prop->format == MPV_FORMAT_FLAG)) {
				int pause = *(int *)prop->data;
				printf("pause: %d\n", pause);
				if (pause == 0 && !cookie) cookie = inhibit(proxy); 
				if (pause == 1 && cookie) cookie = uninhibit(proxy, cookie); 
			}
		}

		if (!cookie && (event->event_id == MPV_EVENT_PLAYBACK_RESTART)) {
			cookie = inhibit(proxy);
		}

		if (cookie && (event->event_id == MPV_EVENT_END_FILE ||
			             event->event_id == MPV_EVENT_IDLE )) {
			cookie = uninhibit(proxy, cookie);
		}

		if (event->event_id == MPV_EVENT_SHUTDOWN) {
			break;
		}
	}

	g_object_unref(proxy);
	g_object_unref(conn);

	return 0;
}