FreeRDP/uwac/libuwac/uwac-input.c

/*
 * Copyright © 2014-2015 David FORT <contact@hardening-consulting.com>
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */
#include "uwac-priv.h"
#include "uwac-utils.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <time.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/timerfd.h>
#include <sys/epoll.h>


static void keyboard_repeat_func(UwacTask *task, uint32_t events)
{
	UwacSeat *input = container_of(task, UwacSeat, repeat_task);
	UwacWindow *window = input->keyboard_focus;
	uint64_t exp;

	if (read(input->repeat_timer_fd, &exp, sizeof exp) != sizeof exp)
		/* If we change the timer between the fd becoming
		 * readable and getting here, there'll be nothing to
		 * read and we get EAGAIN. */
		return;

	if (window) {
		UwacKeyEvent *key;

		key = (UwacKeyEvent *)UwacDisplayNewEvent(input->display, UWAC_EVENT_KEY);
		if (!key)
			return;

		key->window = window;
		key->sym = input->repeat_sym;
		key->pressed = true;
	}

}

static void keyboard_handle_keymap(void *data, struct wl_keyboard *keyboard,
		       uint32_t format, int fd, uint32_t size)
{
	UwacSeat *input = data;
	struct xkb_keymap *keymap;
	struct xkb_state *state;
	char *map_str;

	if (!data) {
		close(fd);
		return;
	}

	if (format != WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1) {
		close(fd);
		return;
	}

	map_str = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
	if (map_str == MAP_FAILED) {
		close(fd);
		return;
	}

	keymap = xkb_keymap_new_from_string(input->xkb_context, map_str, XKB_KEYMAP_FORMAT_TEXT_V1, 0);
	munmap(map_str, size);
	close(fd);

	if (!keymap) {
		assert(uwacErrorHandler(input->display, UWAC_ERROR_INTERNAL, "failed to compile keymap\n"));
		return;
	}

	state = xkb_state_new(keymap);
	if (!state) {
		assert(uwacErrorHandler(input->display, UWAC_ERROR_NOMEMORY, "failed to create XKB state\n"));
		xkb_keymap_unref(keymap);
		return;
	}

	xkb_keymap_unref(input->xkb.keymap);
	xkb_state_unref(input->xkb.state);
	input->xkb.keymap = keymap;
	input->xkb.state = state;

	input->xkb.control_mask = 1 << xkb_keymap_mod_get_index(input->xkb.keymap, "Control");
	input->xkb.alt_mask = 1 << xkb_keymap_mod_get_index(input->xkb.keymap, "Mod1");
	input->xkb.shift_mask =	1 << xkb_keymap_mod_get_index(input->xkb.keymap, "Shift");
}

static void keyboard_handle_key(void *data, struct wl_keyboard *keyboard,
		    uint32_t serial, uint32_t time, uint32_t key,
		    uint32_t state_w);

static void keyboard_handle_enter(void *data, struct wl_keyboard *keyboard, uint32_t serial,
		struct wl_surface *surface, struct wl_array *keys)
{
	uint32_t *key, *pressedKey;
	UwacSeat *input = (UwacSeat *)data;
	int i, found;
	UwacKeyboardEnterLeaveEvent *event;

	event = (UwacKeyboardEnterLeaveEvent *)UwacDisplayNewEvent(input->display, UWAC_EVENT_KEYBOARD_ENTER);
	if (!event)
		return;

	event->window = input->keyboard_focus = (UwacWindow *)wl_surface_get_user_data(surface);

	/* look for keys that have been released */
	found = false;
	for (pressedKey = input->pressed_keys.data, i = 0; i < input->pressed_keys.size; i += sizeof(uint32_t)) {
		wl_array_for_each(key, keys) {
			if (*key == *pressedKey) {
				found = true;
				break;
			}
		}

		if (!found) {
			keyboard_handle_key(data, keyboard, serial, 0, *pressedKey, WL_KEYBOARD_KEY_STATE_RELEASED);
		} else {
			pressedKey++;
		}
	}

	/* handle keys that are now pressed */
	wl_array_for_each(key, keys) {
		keyboard_handle_key(data, keyboard, serial, 0, *key, WL_KEYBOARD_KEY_STATE_PRESSED);
	}
}

static void keyboard_handle_leave(void *data, struct wl_keyboard *keyboard, uint32_t serial,
		struct wl_surface *surface)
{
	struct itimerspec its;
	UwacSeat *input;
	UwacPointerEnterLeaveEvent *event;

	input = (UwacSeat *)data;

	its.it_interval.tv_sec = 0;
	its.it_interval.tv_nsec = 0;
	its.it_value.tv_sec = 0;
	its.it_value.tv_nsec = 0;
	timerfd_settime(input->repeat_timer_fd, 0, &its, NULL);

	event = (UwacPointerEnterLeaveEvent *)UwacDisplayNewEvent(input->display, UWAC_EVENT_POINTER_LEAVE);
	if (!event)
		return;

	event->window = input->keyboard_focus;
}

static int update_key_pressed(UwacSeat *seat, uint32_t key) {
	uint32_t *keyPtr;

	/* check if the key is not already pressed */
	wl_array_for_each(keyPtr, &seat->pressed_keys) {
		if (*keyPtr == key)
			return 1;
	}

	keyPtr = wl_array_add(&seat->pressed_keys, sizeof(uint32_t));
	if (!keyPtr)
		return -1;

	*keyPtr = key;
	return 0;
}

static int update_key_released(UwacSeat *seat, uint32_t key) {
	uint32_t *keyPtr;
	int i, toMove;
	bool found = false;

	for (i = 0, keyPtr = seat->pressed_keys.data; i < seat->pressed_keys.size; i++, keyPtr++) {
		if (*keyPtr == key) {
			found = true;
			break;
		}
	}

	if (found) {
		toMove = seat->pressed_keys.size - ((i + 1) * sizeof(uint32_t));
		if (toMove)
			memmove(keyPtr, keyPtr+1, toMove);

		seat->pressed_keys.size -= sizeof(uint32_t);
	}
	return 1;

}

static void keyboard_handle_key(void *data, struct wl_keyboard *keyboard,
		    uint32_t serial, uint32_t time, uint32_t key,
		    uint32_t state_w)
{
	UwacSeat *input = (UwacSeat *)data;
	UwacWindow *window = input->keyboard_focus;
	UwacKeyEvent *keyEvent;

	uint32_t code, num_syms;
	enum wl_keyboard_key_state state = state_w;
	const xkb_keysym_t *syms;
	xkb_keysym_t sym;
	struct itimerspec its;

	if (state_w == WL_KEYBOARD_KEY_STATE_PRESSED)
		update_key_pressed(input, key);
	else
		update_key_released(input, key);

	input->display->serial = serial;
	code = key + 8;
	if (!window || !input->xkb.state)
		return;

	/* We only use input grabs for pointer events for now, so just
	 * ignore key presses if a grab is active.  We expand the key
	 * event delivery mechanism to route events to widgets to
	 * properly handle key grabs.  In the meantime, this prevents
	 * key event delivery while a grab is active. */
	/*if (input->grab && input->grab_button == 0)
		return;*/

	num_syms = xkb_state_key_get_syms(input->xkb.state, code, &syms);

	sym = XKB_KEY_NoSymbol;
	if (num_syms == 1)
		sym = syms[0];

	if (state == WL_KEYBOARD_KEY_STATE_RELEASED && key == input->repeat_key) {
		its.it_interval.tv_sec = 0;
		its.it_interval.tv_nsec = 0;
		its.it_value.tv_sec = 0;
		its.it_value.tv_nsec = 0;
		timerfd_settime(input->repeat_timer_fd, 0, &its, NULL);
	} else if (state == WL_KEYBOARD_KEY_STATE_PRESSED && xkb_keymap_key_repeats(input->xkb.keymap, code)) {
		input->repeat_sym = sym;
		input->repeat_key = key;
		input->repeat_time = time;
		its.it_interval.tv_sec = input->repeat_rate_sec;
		its.it_interval.tv_nsec = input->repeat_rate_nsec;
		its.it_value.tv_sec = input->repeat_delay_sec;
		its.it_value.tv_nsec = input->repeat_delay_nsec;
		timerfd_settime(input->repeat_timer_fd, 0, &its, NULL);
	}

	keyEvent = (UwacKeyEvent *)UwacDisplayNewEvent(input->display, UWAC_EVENT_KEY);
	if (!keyEvent)
		return;

	keyEvent->window = window;
	keyEvent->sym =  sym;
	keyEvent->raw_key = key;
	keyEvent->pressed = (state == WL_KEYBOARD_KEY_STATE_PRESSED);
}

static void keyboard_handle_modifiers(void *data, struct wl_keyboard *keyboard, uint32_t serial,
		uint32_t mods_depressed, uint32_t mods_latched, uint32_t mods_locked, uint32_t group)
{
	UwacSeat *input = data;
	xkb_mod_mask_t mask;

	/* If we're not using a keymap, then we don't handle PC-style modifiers */
	if (!input->xkb.keymap)
		return;

	xkb_state_update_mask(input->xkb.state, mods_depressed, mods_latched, mods_locked, 0, 0, group);
	mask = xkb_state_serialize_mods(input->xkb.state, XKB_STATE_MODS_DEPRESSED | XKB_STATE_MODS_LATCHED);
	input->modifiers = 0;
	if (mask & input->xkb.control_mask)
		input->modifiers |= UWAC_MOD_CONTROL_MASK;
	if (mask & input->xkb.alt_mask)
		input->modifiers |= UWAC_MOD_ALT_MASK;
	if (mask & input->xkb.shift_mask)
		input->modifiers |= UWAC_MOD_SHIFT_MASK;
}

static void set_repeat_info(UwacSeat *input, int32_t rate, int32_t delay)
{
	input->repeat_rate_sec = input->repeat_rate_nsec = 0;
	input->repeat_delay_sec = input->repeat_delay_nsec = 0;

	/* a rate of zero disables any repeating, regardless of the delay's
	 * value */
	if (rate == 0)
		return;

	if (rate == 1)
		input->repeat_rate_sec = 1;
	else
		input->repeat_rate_nsec = 1000000000 / rate;

	input->repeat_delay_sec = delay / 1000;
	delay -= (input->repeat_delay_sec * 1000);
	input->repeat_delay_nsec = delay * 1000 * 1000;
}


static void keyboard_handle_repeat_info(void *data, struct wl_keyboard *keyboard,
			    int32_t rate, int32_t delay)
{
	UwacSeat *input = data;

	set_repeat_info(input, rate, delay);
}

static const struct wl_keyboard_listener keyboard_listener = {
	keyboard_handle_keymap,
	keyboard_handle_enter,
	keyboard_handle_leave,
	keyboard_handle_key,
	keyboard_handle_modifiers,
	keyboard_handle_repeat_info
};

static bool touch_send_start_frame(UwacSeat *seat) {
	UwacTouchFrameBegin *ev;

	ev = (UwacTouchFrameBegin *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_TOUCH_FRAME_BEGIN);
	if (!ev)
		return false;

	seat->touch_frame_started = true;
	return true;
}

static void touch_handle_down(void *data, struct wl_touch *wl_touch,
		  uint32_t serial, uint32_t time, struct wl_surface *surface,
		  int32_t id, wl_fixed_t x_w, wl_fixed_t y_w)
{
	UwacSeat *seat = data;
	UwacTouchDown *tdata;

	seat->display->serial = serial;
	if (!seat->touch_frame_started && !touch_send_start_frame(seat))
		return;

	tdata = (UwacTouchDown *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_TOUCH_DOWN);
	if (!tdata)
		return;

	tdata->seat = seat;
	tdata->id = id;
	tdata->x = x_w;
	tdata->y = y_w;

#if 0
	struct widget *widget;
	float sx = wl_fixed_to_double(x);
	float sy = wl_fixed_to_double(y);


	input->touch_focus = wl_surface_get_user_data(surface);
	if (!input->touch_focus) {
		DBG("Failed to find to touch focus for surface %p\n", surface);
		return;
	}

	if (surface != input->touch_focus->main_surface->surface) {
		DBG("Ignoring input event from subsurface %p\n", surface);
		input->touch_focus = NULL;
		return;
	}

	if (input->grab)
		widget = input->grab;
	else
		widget = window_find_widget(input->touch_focus,
					    wl_fixed_to_double(x),
					    wl_fixed_to_double(y));
	if (widget) {
		struct touch_point *tp = xmalloc(sizeof *tp);
		if (tp) {
			tp->id = id;
			tp->widget = widget;
			tp->x = sx;
			tp->y = sy;
			wl_list_insert(&input->touch_point_list, &tp->link);

			if (widget->touch_down_handler)
				(*widget->touch_down_handler)(widget, input,
							      serial, time, id,
							      sx, sy,
							      widget->user_data);
		}
	}
#endif
}

static void touch_handle_up(void *data, struct wl_touch *wl_touch,
		uint32_t serial, uint32_t time, int32_t id)
{
	UwacSeat *seat = data;
	UwacTouchUp *tdata;

	if (!seat->touch_frame_started && !touch_send_start_frame(seat))
		return;

	tdata = (UwacTouchUp *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_TOUCH_UP);
	if (!tdata)
		return;

	tdata->seat = seat;
	tdata->id = id;


#if 0
	struct touch_point *tp, *tmp;

	if (!input->touch_focus) {
		DBG("No touch focus found for touch up event!\n");
		return;
	}

	wl_list_for_each_safe(tp, tmp, &input->touch_point_list, link) {
		if (tp->id != id)
			continue;

		if (tp->widget->touch_up_handler)
			(*tp->widget->touch_up_handler)(tp->widget, input, serial,
							time, id,
							tp->widget->user_data);

		wl_list_remove(&tp->link);
		free(tp);

		return;
	}
#endif
}

static void touch_handle_motion(void *data, struct wl_touch *wl_touch,
		    uint32_t time, int32_t id, wl_fixed_t x_w, wl_fixed_t y_w)
{
	UwacSeat *seat = data;
	UwacTouchMotion *tdata;

	if (!seat->touch_frame_started && !touch_send_start_frame(seat))
		return;

	tdata = (UwacTouchMotion *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_TOUCH_MOTION);
	if (!tdata)
		return;

	tdata->seat = seat;
	tdata->id = id;
	tdata->x = x_w;
	tdata->y = y_w;

#if 0
	struct touch_point *tp;
	float sx = wl_fixed_to_double(x);
	float sy = wl_fixed_to_double(y);

	DBG("touch_handle_motion: %i %i\n", id, wl_list_length(&seat->touch_point_list));

	if (!seat->touch_focus) {
		DBG("No touch focus found for touch motion event!\n");
		return;
	}

	wl_list_for_each(tp, &seat->touch_point_list, link) {
		if (tp->id != id)
			continue;

		tp->x = sx;
		tp->y = sy;
		if (tp->widget->touch_motion_handler)
			(*tp->widget->touch_motion_handler)(tp->widget, seat, time,
							    id, sx, sy,
							    tp->widget->user_data);
		return;
	}
#endif
}

static void touch_handle_frame(void *data, struct wl_touch *wl_touch)
{
	UwacSeat *seat = data;
	UwacTouchFrameEnd *ev;

	ev = (UwacTouchFrameEnd *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_TOUCH_FRAME_END);
	if (!ev)
		return;

	ev->seat = seat;
	seat->touch_frame_started = false;
}

static void touch_handle_cancel(void *data, struct wl_touch *wl_touch)
{
	UwacSeat *seat = data;
	UwacTouchCancel *ev;

	ev = (UwacTouchCancel *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_TOUCH_CANCEL);
	if (!ev)
		return;

	ev->seat = seat;
	seat->touch_frame_started = false;

#if 0
	struct touch_point *tp, *tmp;

	DBG("touch_handle_cancel\n");

	if (!input->touch_focus) {
		DBG("No touch focus found for touch cancel event!\n");
		return;
	}

	wl_list_for_each_safe(tp, tmp, &input->touch_point_list, link) {
		if (tp->widget->touch_cancel_handler)
			(*tp->widget->touch_cancel_handler)(tp->widget, input,
							    tp->widget->user_data);

		wl_list_remove(&tp->link);
		free(tp);
	}
#endif
}

static const struct wl_touch_listener touch_listener = {
	touch_handle_down,
	touch_handle_up,
	touch_handle_motion,
	touch_handle_frame,
	touch_handle_cancel,
};


static void pointer_handle_enter(void *data, struct wl_pointer *pointer, uint32_t serial,
		struct wl_surface *surface, wl_fixed_t sx_w, wl_fixed_t sy_w)
{
	UwacSeat *input = data;
	UwacWindow *window;
	UwacPointerEnterLeaveEvent *event;

	float sx = wl_fixed_to_double(sx_w);
	float sy = wl_fixed_to_double(sy_w);

	if (!surface) {
		/* enter event for a window we've just destroyed */
		return;
	}

	input->display->serial = serial;
	window = wl_surface_get_user_data(surface);
	if (window)
		window->pointer_enter_serial = serial;
	input->pointer_focus = window;
	input->sx = sx;
	input->sy = sy;

	event = (UwacPointerEnterLeaveEvent *)UwacDisplayNewEvent(input->display, UWAC_EVENT_POINTER_ENTER);
	if (!event)
		return;

	event->seat = input;
	event->window = window;
	event->x = sx;
	event->y = sy;
}

static void pointer_handle_leave(void *data, struct wl_pointer *pointer, uint32_t serial,
		struct wl_surface *surface)
{
	UwacPointerEnterLeaveEvent *event;
	UwacWindow *window;
	UwacSeat *input = data;

	input->display->serial = serial;

	event = (UwacPointerEnterLeaveEvent *)UwacDisplayNewEvent(input->display, UWAC_EVENT_POINTER_LEAVE);
	if (!event)
		return;

	window = wl_surface_get_user_data(surface);

	event->seat = input;
	event->window = window;

#if 0
	input_remove_pointer_focus(input);
#endif
}

static void pointer_handle_motion(void *data, struct wl_pointer *pointer, uint32_t time,
		wl_fixed_t sx_w, wl_fixed_t sy_w)
{
	UwacPointerMotionEvent *motion_event;
	UwacSeat *input = data;
	UwacWindow *window = input->pointer_focus;

	float sx = wl_fixed_to_double(sx_w);
	float sy = wl_fixed_to_double(sy_w);

	if (!window)
		return;

	input->sx = sx;
	input->sy = sy;

	motion_event = (UwacPointerMotionEvent *)UwacDisplayNewEvent(input->display, UWAC_EVENT_POINTER_MOTION);
	if (!motion_event)
		return;

	motion_event->seat = input;
	motion_event->window = window;
	motion_event->x = wl_fixed_to_int(sx_w);
	motion_event->y = wl_fixed_to_int(sy_w);
}

static void pointer_handle_button(void *data, struct wl_pointer *pointer, uint32_t serial,
		      uint32_t time, uint32_t button, uint32_t state_w)
{
	UwacPointerButtonEvent *event;
	UwacSeat *seat = data;
	UwacWindow *window = seat->pointer_focus;

	seat->display->serial = serial;

	event = (UwacPointerButtonEvent *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_POINTER_BUTTONS);
	if (!event)
		return;

	event->seat = seat;
	event->window = window;
	event->x = seat->sx;
	event->y = seat->sy;
	event->button = button;
	event->state = (enum wl_pointer_button_state)state_w;
}

static void pointer_handle_axis(void *data, struct wl_pointer *pointer, uint32_t time,
		uint32_t axis, wl_fixed_t value)
{
	UwacPointerAxisEvent *event;
	UwacSeat *seat = data;
	UwacWindow *window = seat->pointer_focus;

	if (!window)
		return;

	event = (UwacPointerAxisEvent *)UwacDisplayNewEvent(seat->display, UWAC_EVENT_POINTER_AXIS);
	if (!event)
		return;

	event->seat = seat;
	event->window = window;
	event->x = seat->sx;
	event->y = seat->sy;
	event->axis = axis;
	event->value = value;
}

static const struct wl_pointer_listener pointer_listener = {
	pointer_handle_enter,
	pointer_handle_leave,
	pointer_handle_motion,
	pointer_handle_button,
	pointer_handle_axis,
};



static void seat_handle_capabilities(void *data, struct wl_seat *seat, enum wl_seat_capability caps)
{
	UwacSeat *input = data;

	if ((caps & WL_SEAT_CAPABILITY_POINTER) && !input->pointer) {
		input->pointer = wl_seat_get_pointer(seat);
		wl_pointer_set_user_data(input->pointer, input);
		wl_pointer_add_listener(input->pointer, &pointer_listener, input);
	} else if (!(caps & WL_SEAT_CAPABILITY_POINTER) && input->pointer) {
#ifdef WL_POINTER_RELEASE_SINCE_VERSION
		if (input->seat_version >= WL_POINTER_RELEASE_SINCE_VERSION)
			wl_pointer_release(input->pointer);
		else
#endif
			wl_pointer_destroy(input->pointer);
		input->pointer = NULL;
	}

	if ((caps & WL_SEAT_CAPABILITY_KEYBOARD) && !input->keyboard) {
		input->keyboard = wl_seat_get_keyboard(seat);
		wl_keyboard_set_user_data(input->keyboard, input);
		wl_keyboard_add_listener(input->keyboard, &keyboard_listener, input);
	} else if (!(caps & WL_SEAT_CAPABILITY_KEYBOARD) && input->keyboard) {
#ifdef WL_KEYBOARD_RELEASE_SINCE_VERSION
		if (input->seat_version >= WL_KEYBOARD_RELEASE_SINCE_VERSION)
			wl_keyboard_release(input->keyboard);
		else
#endif
			wl_keyboard_destroy(input->keyboard);
		input->keyboard = NULL;
	}

	if ((caps & WL_SEAT_CAPABILITY_TOUCH) && !input->touch) {
		input->touch = wl_seat_get_touch(seat);
		wl_touch_set_user_data(input->touch, input);
		wl_touch_add_listener(input->touch, &touch_listener, input);
	} else if (!(caps & WL_SEAT_CAPABILITY_TOUCH) && input->touch) {
#ifdef WL_TOUCH_RELEASE_SINCE_VERSION
		if (input->seat_version >= WL_TOUCH_RELEASE_SINCE_VERSION)
			wl_touch_release(input->touch);
		else
#endif
			wl_touch_destroy(input->touch);
		input->touch = NULL;
	}
}

static void
seat_handle_name(void *data, struct wl_seat *seat, const char *name)
{
	UwacSeat *input = data;
	if (input->name)
		free(input->name);

	input->name = strdup(name);
	if (!input->name)
		assert(uwacErrorHandler(input->display, UWAC_ERROR_NOMEMORY, "unable to strdup seat's name\n"));
}

static const struct wl_seat_listener seat_listener = {
	seat_handle_capabilities,
	seat_handle_name,
};


UwacSeat *UwacSeatNew(UwacDisplay *d, uint32_t id, uint32_t version) {
	UwacSeat *ret;

	ret = zalloc(sizeof(UwacSeat));
	ret->display = d;
	ret->seat_id = id;
	ret->seat_version = version;

	wl_array_init(&ret->pressed_keys);
	ret->xkb_context = xkb_context_new(0);
	if (!ret->xkb_context) {
		fprintf(stderr, "%s: unable to allocate a xkb_context\n", __FUNCTION__);
		goto error_xkb_context;
	}

	ret->seat = wl_registry_bind(d->registry, id, &wl_seat_interface, version);
	wl_seat_add_listener(ret->seat, &seat_listener, ret);
	wl_seat_set_user_data(ret->seat, ret);

	ret->repeat_timer_fd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC | TFD_NONBLOCK);
	if (ret->repeat_timer_fd < 0) {
		fprintf(stderr, "%s: error creating repeat timer\n", __FUNCTION__);
		goto error_timer_fd;
	}
	ret->repeat_task.run = keyboard_repeat_func;
	if (UwacDisplayWatchFd(d, ret->repeat_timer_fd, EPOLLIN, &ret->repeat_task) < 0) {
		fprintf(stderr, "%s: error polling repeat timer\n", __FUNCTION__);
		goto error_watch_timerfd;
	}

	wl_list_insert(d->seats.prev, &ret->link);
	return ret;

error_watch_timerfd:
	close(ret->repeat_timer_fd);
error_timer_fd:
	wl_seat_destroy(ret->seat);
error_xkb_context:
	free(ret);
	return NULL;
}

void UwacSeatDestroy(UwacSeat *s) {
	if (s->seat) {
#ifdef WL_SEAT_RELEASE_SINCE_VERSION
		if (s->seat_version >= WL_SEAT_RELEASE_SINCE_VERSION)
			wl_seat_release(s->seat);
		else
#endif
			wl_seat_destroy(s->seat);
	}
	s->seat = NULL;

	free(s->name);
	wl_array_release(&s->pressed_keys);

	xkb_state_unref(s->xkb.state);
	xkb_context_unref(s->xkb_context);

	if (s->pointer) {
#ifdef WL_POINTER_RELEASE_SINCE_VERSION
		if (s->seat_version >= WL_POINTER_RELEASE_SINCE_VERSION)
			wl_pointer_release(s->pointer);
		else
#endif
			wl_pointer_destroy(s->pointer);
	}

	if (s->touch) {
#ifdef WL_TOUCH_RELEASE_SINCE_VERSION
		if (s->seat_version >= WL_TOUCH_RELEASE_SINCE_VERSION)
			wl_touch_release(s->touch);
		else
#endif
			wl_touch_destroy(s->touch);
	}

	if (s->keyboard) {
#ifdef WL_KEYBOARD_RELEASE_SINCE_VERSION
		if (s->seat_version >= WL_KEYBOARD_RELEASE_SINCE_VERSION)
			wl_keyboard_release(s->keyboard);
		else
#endif
			wl_keyboard_destroy(s->keyboard);
	}

	wl_list_remove(&s->link);
	free(s);
}

const char *UwacSeatGetName(const UwacSeat *seat) {
	return seat->name;
}