libinput-fun.c

// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <unistd.h>
#include <libudev.h>
#include <libinput.h>
#include <errno.h>
#include <termios.h>


static volatile sig_atomic_t doquit;

static void quit(int sig)
{
	(void)sig;
	doquit = 1;
}

static int open_restricted(const char *path, int flags, void *user_data)
{
	int fd = open(path, flags);

	return fd < 0 ? -errno : fd;
}

static void close_restricted(int fd, void *user_data)
{
	close(fd);
}

const static struct libinput_interface interface = {
	.open_restricted = open_restricted,
	.close_restricted = close_restricted,
};

void handle_event(struct libinput *li, struct libinput_event *event)
{
	switch (libinput_event_get_type(event)) {
		case LIBINPUT_EVENT_KEYBOARD_KEY: {
			struct libinput_event_keyboard *kbdevent;
			int keycode;

			kbdevent = libinput_event_get_keyboard_event(event);
			keycode = libinput_event_keyboard_get_key(kbdevent);
			if (libinput_event_keyboard_get_key_state(kbdevent) == LIBINPUT_KEY_STATE_PRESSED)
				printf("\33[2K\rGot keyboard event, keycode = %d!\n", keycode);
		}
		break;
		case LIBINPUT_EVENT_POINTER_MOTION: {
			struct libinput_event_pointer *ptrevent;
			ptrevent = libinput_event_get_pointer_event(event);
			double x = libinput_event_pointer_get_dx(ptrevent);
			double y = libinput_event_pointer_get_dy(ptrevent);
			printf("\33[2K\rX = %f, Y = %f relative", x, y);
			fflush(stdout);
		}
		break;
		case LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE: {
			struct libinput_event_pointer *ptrevent;
			ptrevent = libinput_event_get_pointer_event(event);
			double x = libinput_event_pointer_get_absolute_x_transformed(ptrevent, INT16_MAX);
			double y = libinput_event_pointer_get_absolute_y_transformed(ptrevent, INT16_MAX);
			printf("\33[2K\rX = %f, Y = %f absolute", x, y);
			fflush(stdout);
		}
		break;
	}
}

int main(void)
{
	struct libinput *li;
	struct libinput_event *event;
	struct udev *udev;
	int ret;

	// Disable local echo
	struct termios old, new;

	tcgetattr(STDIN_FILENO, &old);          // get current settings
	new = old;                              // create a backup
	new.c_lflag &= ~(ICANON | ECHO);        // disable line buffering and feedback
	tcsetattr(STDIN_FILENO, TCSANOW, &new); // set our new config

	udev = udev_new();

	li = libinput_udev_create_context(&interface, NULL, udev);
	if (!li) {
		printf("Error: cannot create libinput context!\n");
		return 1;
	}
	if (libinput_udev_assign_seat(li, "seat0") == -1) {
		printf("Error: cannot assign seat!\n");
		return 1;
	}
	if (libinput_dispatch(li) < 0) {
		printf("Error: cannot dispatch!\n");
		return 1;
	}

	struct pollfd fds[1];
	
	fds[0].fd = libinput_get_fd(li);
	fds[0].events = POLLIN;

	while (!doquit)	{
		ret = poll(fds, 1, 10000);

		if (ret > 0 && fds[0].revents & POLLIN) {
			libinput_dispatch(li);
			while ((event = libinput_get_event(li)) != NULL) {

				handle_event(li, event);

				libinput_event_destroy(event);
				//libinput_dispatch(li);
			}
		} else {
			printf("\33[2K\rtimeout");
			fflush(stdout);
		}
	}
	libinput_unref(li);

	udev_unref(udev);
	tcsetattr(STDIN_FILENO, TCSANOW, &old);
	return 0;
}