deskflow/src/lib/platform/EiScreen.cpp

/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2022 Red Hat, Inc.
 * Copyright (C) 2024 Symless Ltd.
 *
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 *
 * This package is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "platform/EiScreen.h"

#include "arch/Arch.h"
#include "arch/XArch.h"
#include "base/IEventQueue.h"
#include "base/Log.h"
#include "base/Stopwatch.h"
#include "base/TMethodEventJob.h"
#include "platform/EiEventQueueBuffer.h"
#include "platform/EiKeyState.h"
#include "synergy/Clipboard.h"
#include "synergy/KeyMap.h"
#include "synergy/XScreen.h"

#if WINAPI_LIBPORTAL
#include "platform/PortalInputCapture.h"
#include "platform/PortalRemoteDesktop.h"
#endif

#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <unistd.h>
#include <vector>

struct ScrollRemainder {
  double x, y; // scroll remainder in pixels
};

namespace synergy {

EiScreen::EiScreen(bool is_primary, IEventQueue *events, bool use_portal)
    : PlatformScreen(events),
      is_primary_(is_primary),
      events_(events),
      w_(1),
      h_(1),
      is_on_screen_(is_primary) {
  init_ei();
  key_state_ = new EiKeyState(this, events);
  // install event handlers
  events_->adoptHandler(
      Event::kSystem, events_->getSystemTarget(),
      new TMethodEventJob<EiScreen>(this, &EiScreen::handleSystemEvent));

  if (use_portal) {
    events_->adoptHandler(
        events_->forEi().connected(), getEventTarget(),
        new TMethodEventJob<EiScreen>(
            this, &EiScreen::handle_connected_to_eis_event));
    if (is_primary) {
#if HAVE_LIBPORTAL_INPUTCAPTURE
      portal_input_capture_ = new PortalInputCapture(this, events_);
#else
      throw std::invalid_argument("missing libportal input capture support");
#endif // HAVE_LIBPORTAL_INPUTCAPTURE
    } else {
#if WINAPI_LIBPORTAL
      events_->adoptHandler(
          events_->forEi().sessionClosed(), getEventTarget(),
          new TMethodEventJob<EiScreen>(
              this, &EiScreen::handle_portal_session_closed));
      portal_remote_desktop_ = new PortalRemoteDesktop(this, events_);
#else
      throw std::invalid_argument("missing libportal remote desktop support");
#endif // WINAPI_LIBPORTAL
    }
  } else {
    // Note: socket backend does not support reconnections
    auto rc = ei_setup_backend_socket(ei_, nullptr);
    if (rc != 0) {
      LOG_ERR("ei init error: %s", strerror(-rc));
      throw std::runtime_error("failed to init ei context");
    }
  }
}

EiScreen::~EiScreen() {
  events_->adoptBuffer(nullptr);
  events_->removeHandler(Event::kSystem, events_->getSystemTarget());

  cleanup_ei();

  delete key_state_;

#if WINAPI_LIBPORTAL
  delete portal_remote_desktop_;
#endif
#if HAVE_LIBPORTAL_INPUTCAPTURE
  delete portal_input_capture_;
#endif
}

void EiScreen::handle_ei_log_event(
    ei *ei, ei_log_priority priority, const char *message,
    ei_log_context *context) {
  switch (priority) {
  case EI_LOG_PRIORITY_DEBUG:
    LOG_DEBUG1("ei: %s", message);
    break;
  case EI_LOG_PRIORITY_INFO:
    LOG_INFO("ei: %s", message);
    break;
  case EI_LOG_PRIORITY_WARNING:
    LOG_WARN("ei: %s", message);
    break;
  case EI_LOG_PRIORITY_ERROR:
    LOG_ERR("ei: %s", message);
    break;
  default:
    LOG_PRINT("ei: %s", message);
    break;
  }
}

void EiScreen::init_ei() {
  if (is_primary_) {
    ei_ = ei_new_receiver(nullptr); // we receive from the display server
  } else {
    ei_ = ei_new_sender(nullptr); // we send to the display server
  }
  ei_set_user_data(ei_, this);
  ei_log_set_priority(ei_, EI_LOG_PRIORITY_DEBUG);
  ei_log_set_handler(ei_, cb_handle_ei_log_event);
  ei_configure_name(ei_, "synergy client");

  // install the platform event queue
  events_->adoptBuffer(nullptr);
  events_->adoptBuffer(new EiEventQueueBuffer(this, ei_, events_));
}

void EiScreen::cleanup_ei() {
  if (ei_pointer_) {
    free(ei_device_get_user_data(ei_pointer_));
    ei_device_set_user_data(ei_pointer_, nullptr);
    ei_pointer_ = ei_device_unref(ei_pointer_);
  }
  if (ei_keyboard_) {
    free(ei_device_get_user_data(ei_keyboard_));
    ei_device_set_user_data(ei_keyboard_, nullptr);
    ei_keyboard_ = ei_device_unref(ei_keyboard_);
  }
  if (ei_abs_) {
    free(ei_device_get_user_data(ei_abs_));
    ei_device_set_user_data(ei_abs_, nullptr);
    ei_abs_ = ei_device_unref(ei_abs_);
  }
  ei_seat_unref(ei_seat_);
  for (auto it = ei_devices_.begin(); it != ei_devices_.end(); it++) {
    free(ei_device_get_user_data(*it));
    ei_device_set_user_data(*it, nullptr);
    ei_device_unref(*it);
  }
  ei_devices_.clear();
  ei_ = ei_unref(ei_);
}

void *EiScreen::getEventTarget() const {
  return const_cast<void *>(static_cast<const void *>(this));
}

bool EiScreen::getClipboard(ClipboardID id, IClipboard *clipboard) const {
  return false;
}

void EiScreen::getShape(int32_t &x, int32_t &y, int32_t &w, int32_t &h) const {
  x = x_;
  y = y_;
  w = w_;
  h = h_;
}

void EiScreen::getCursorPos(int32_t &x, int32_t &y) const {
  x = cursor_x_;
  y = cursor_y_;
}

void EiScreen::reconfigure(uint32_t) {
  // do nothing
}

void EiScreen::warpCursor(int32_t x, int32_t y) {
  cursor_x_ = x;
  cursor_y_ = y;
}

std::uint32_t EiScreen::registerHotKey(KeyID key, KeyModifierMask mask) {
  static std::uint32_t next_id;
  std::uint32_t id = std::min(++next_id, 1u);

  // Bug: id rollover means duplicate hotkey ids. Oh well.

  auto set = hotkeys_.find(key);
  if (set == hotkeys_.end()) {
    hotkeys_.emplace(key, HotKeySet{key});
    set = hotkeys_.find(key);
  }
  set->second.add_item(HotKeyItem(mask, id));

  return id;
}

void EiScreen::unregisterHotKey(uint32_t id) {
  for (auto &set : hotkeys_) {
    if (set.second.remove_by_id(id)) {
      break;
    }
  }
}

void EiScreen::fakeInputBegin() {
  // FIXME -- not implemented
}

void EiScreen::fakeInputEnd() {
  // FIXME -- not implemented
}

std::int32_t EiScreen::getJumpZoneSize() const { return 1; }

bool EiScreen::isAnyMouseButtonDown(uint32_t &buttonID) const { return false; }

void EiScreen::getCursorCenter(int32_t &x, int32_t &y) const {
  x = x_ + w_ / 2;
  y = y_ + h_ / 2;
}

void EiScreen::fakeMouseButton(ButtonID button, bool press) {
  uint32_t code;

  if (!ei_pointer_)
    return;

  switch (button) {
  case kButtonLeft:
    code = 0x110; // BTN_LEFT
    break;
  case kButtonMiddle:
    code = 0x112; // BTN_MIDDLE
    break;
  case kButtonRight:
    code = 0x111; // BTN_RIGHT
    break;
  default:
    code = 0x110 + (button - 1);
    break;
  }

  ei_device_button_button(ei_pointer_, code, press);
  ei_device_frame(ei_pointer_, ei_now(ei_));
}

void EiScreen::fakeMouseMove(int32_t x, int32_t y) {
  // We get one motion event before enter() with the target position
  if (!is_on_screen_) {
    cursor_x_ = x;
    cursor_y_ = y;
    return;
  }

  if (!ei_abs_)
    return;

  ei_device_pointer_motion_absolute(ei_abs_, x, y);
  ei_device_frame(ei_abs_, ei_now(ei_));
}

void EiScreen::fakeMouseRelativeMove(int32_t dx, int32_t dy) const {
  if (!ei_pointer_)
    return;

  ei_device_pointer_motion(ei_pointer_, dx, dy);
  ei_device_frame(ei_pointer_, ei_now(ei_));
}

void EiScreen::fakeMouseWheel(int32_t xDelta, int32_t yDelta) const {
  if (!ei_pointer_)
    return;

  // libei and synergy seem to use opposite directions, so we have
  // to send EI the opposite of the value received if we want to remain
  // compatible with other platforms (including X11).
  ei_device_scroll_discrete(ei_pointer_, -xDelta, -yDelta);
  ei_device_frame(ei_pointer_, ei_now(ei_));
}

void EiScreen::fakeKey(uint32_t keycode, bool is_down) const {
  if (!ei_keyboard_)
    return;

  auto xkb_keycode = keycode + 8;
  key_state_->update_xkb_state(xkb_keycode, is_down);
  ei_device_keyboard_key(ei_keyboard_, keycode, is_down);
  ei_device_frame(ei_keyboard_, ei_now(ei_));
}

void EiScreen::enable() {
  // Nothing really to be done here
}

void EiScreen::disable() {
  // Nothing really to be done here, maybe cleanup in the future but ideally
  // that's handled elsewhere
}

void EiScreen::enter() {
  is_on_screen_ = true;
  if (!is_primary_) {
    ++sequence_number_;
    if (ei_pointer_) {
      ei_device_start_emulating(ei_pointer_, sequence_number_);
    }
    if (ei_keyboard_) {
      ei_device_start_emulating(ei_keyboard_, sequence_number_);
    }
    if (ei_abs_) {
      ei_device_start_emulating(ei_abs_, sequence_number_);
      fakeMouseMove(cursor_x_, cursor_y_);
    }
  }
#if HAVE_LIBPORTAL_INPUTCAPTURE
  else {
    LOG_DEBUG("releasing input capture at x=%i y=%i", cursor_x_, cursor_y_);
    portal_input_capture_->release(cursor_x_, cursor_y_);
  }
#endif
}

bool EiScreen::leave() {
  if (!is_primary_) {
    if (ei_pointer_) {
      ei_device_stop_emulating(ei_pointer_);
    }
    if (ei_keyboard_) {
      ei_device_stop_emulating(ei_keyboard_);
    }
    if (ei_abs_) {
      ei_device_stop_emulating(ei_abs_);
    }
  }

  is_on_screen_ = false;
  return true;
}

bool EiScreen::setClipboard(ClipboardID id, const IClipboard *clipboard) {
  return false;
}

void EiScreen::checkClipboards() {
  // do nothing, we're always up to date
}

void EiScreen::openScreensaver(bool notify) {
  // FIXME
}

void EiScreen::closeScreensaver() {
  // FIXME
}

void EiScreen::screensaver(bool activate) {
  // FIXME
}

void EiScreen::resetOptions() {
  // Should reset options to neutral, see setOptions().
  // We don't have ei-specific options, nothing to do here
}

void EiScreen::setOptions(const OptionsList &options) {
  // We don't have ei-specific options, nothing to do here
}

void EiScreen::setSequenceNumber(uint32_t seqNum) {
  // FIXME: what is this used for?
}

bool EiScreen::isPrimary() const { return is_primary_; }

void EiScreen::update_shape() {

  for (auto it = ei_devices_.begin(); it != ei_devices_.end(); it++) {
    auto idx = 0;
    struct ei_region *r;
    while ((r = ei_device_get_region(*it, idx++)) != nullptr) {
      x_ = std::min(ei_region_get_x(r), x_);
      y_ = std::min(ei_region_get_y(r), y_);
      w_ = std::max(ei_region_get_x(r) + ei_region_get_width(r), w_);
      h_ = std::max(ei_region_get_y(r) + ei_region_get_height(r), h_);
    }
  }

  LOG_NOTE("logical output size: %dx%d@%d.%d", w_, h_, x_, y_);
  cursor_x_ = x_ + w_ / 2;
  cursor_y_ = y_ + h_ / 2;

  sendEvent(events_->forIScreen().shapeChanged(), nullptr);
}

void EiScreen::add_device(struct ei_device *device) {
  LOG_DEBUG("adding device %s", ei_device_get_name(device));

  // Noteworthy: EI in principle supports multiple devices with multiple
  // capabilities, so there may be more than one logical pointer (or even
  // multiple seats). Supporting this is ... tricky so for now we go the easy
  // route: one device for each capability. Note this may be the same device
  // if the first device comes with multiple capabilities.

  if (!ei_pointer_ && ei_device_has_capability(device, EI_DEVICE_CAP_POINTER) &&
      ei_device_has_capability(device, EI_DEVICE_CAP_BUTTON) &&
      ei_device_has_capability(device, EI_DEVICE_CAP_SCROLL)) {
    ei_pointer_ = ei_device_ref(device);
  }

  if (!ei_keyboard_ &&
      ei_device_has_capability(device, EI_DEVICE_CAP_KEYBOARD)) {
    ei_keyboard_ = ei_device_ref(device);

    struct ei_keymap *keymap = ei_device_keyboard_get_keymap(device);
    if (keymap && ei_keymap_get_type(keymap) == EI_KEYMAP_TYPE_XKB) {
      int fd = ei_keymap_get_fd(keymap);
      size_t len = ei_keymap_get_size(keymap);
      key_state_->init(fd, len);
    } else {
      // We rely on the EIS implementation to give us a keymap, otherwise we
      // really have no idea what a keycode means (other than it's linux/input.h
      // code) Where the EIS implementation does not tell us, we just default to
      // whatever libxkbcommon thinks is default. At least this way we can
      // influence with env vars what we get
      LOG_WARN(
          "keyboard device %s does not have a keymap, we are guessing",
          ei_device_get_name(device));
      key_state_->init_default_keymap();
    }
    key_state_->updateKeyMap();
  }

  if (!ei_abs_ &&
      ei_device_has_capability(device, EI_DEVICE_CAP_POINTER_ABSOLUTE) &&
      ei_device_has_capability(device, EI_DEVICE_CAP_BUTTON) &&
      ei_device_has_capability(device, EI_DEVICE_CAP_SCROLL)) {
    ei_abs_ = ei_device_ref(device);
  }

  ei_devices_.emplace_back(ei_device_ref(device));

  update_shape();
}

void EiScreen::remove_device(struct ei_device *device) {
  LOG_DEBUG("removing device %s", ei_device_get_name(device));

  if (device == ei_pointer_)
    ei_pointer_ = ei_device_unref(ei_pointer_);
  if (device == ei_keyboard_)
    ei_keyboard_ = ei_device_unref(ei_keyboard_);
  if (device == ei_abs_)
    ei_abs_ = ei_device_unref(ei_abs_);

  for (auto it = ei_devices_.begin(); it != ei_devices_.end(); it++) {
    if (*it == device) {
      ei_devices_.erase(it);
      ei_device_unref(device);
      break;
    }
  }

  update_shape();
}

void EiScreen::sendEvent(Event::Type type, void *data) {
  events_->addEvent(Event(type, getEventTarget(), data));
}

ButtonID EiScreen::map_button_from_evdev(ei_event *event) const {
  uint32_t button = ei_event_button_get_button(event);

  switch (button) {
  case 0x110:
    return kButtonLeft;
  case 0x111:
    return kButtonRight;
  case 0x112:
    return kButtonMiddle;
  case 0x113:
    return kButtonExtra0;
  case 0x114:
    return kButtonExtra1;
  default:
    return kButtonNone;
  }

  return kButtonNone;
}

bool EiScreen::on_hotkey(KeyID keyid, bool is_pressed, KeyModifierMask mask) {
  auto it = hotkeys_.find(keyid);

  if (it == hotkeys_.end()) {
    return false;
  }

  // Note: our mask (see on_key_event) only contains some modifiers
  // but we don't put a limitation on modifiers in the hotkeys. So some
  // key combinations may not work correctly, more effort is needed here.
  auto id = it->second.find_by_mask(mask);
  if (id != 0) {
    Event::Type type = is_pressed ? events_->forIPrimaryScreen().hotKeyDown()
                                  : events_->forIPrimaryScreen().hotKeyUp();
    sendEvent(type, HotKeyInfo::alloc(id));
    return true;
  }

  return false;
}

void EiScreen::on_key_event(ei_event *event) {
  uint32_t keycode = ei_event_keyboard_get_key(event);
  uint32_t keyval = keycode + 8;
  bool pressed = ei_event_keyboard_get_key_is_press(event);
  KeyID keyid = key_state_->map_key_from_keyval(keyval);
  KeyButton keybutton = static_cast<KeyButton>(keyval);

  key_state_->update_xkb_state(keyval, pressed);
  KeyModifierMask mask = key_state_->pollActiveModifiers();

  LOG_DEBUG1(
      "event: key %s keycode=%d keyid=%d mask=0x%x",
      pressed ? "press" : "release", keycode, keyid, mask);

  if (is_primary_ && on_hotkey(keyid, pressed, mask)) {
    return;
  }

  if (keyid != kKeyNone) {
    key_state_->sendKeyEvent(
        getEventTarget(), pressed, false, keyid, mask, 1, keybutton);
  }
}

void EiScreen::on_button_event(ei_event *event) {
  assert(is_primary_);

  ButtonID button = map_button_from_evdev(event);
  bool pressed = ei_event_button_get_is_press(event);
  KeyModifierMask mask = key_state_->pollActiveModifiers();

  LOG_DEBUG1(
      "event: button %s button=%d mask=0x%x", pressed ? "press" : "release",
      button, mask);

  if (button == kButtonNone) {
    LOG_DEBUG("event: button not recognized");
    return;
  }

  auto eventType = pressed ? events_->forIPrimaryScreen().buttonDown()
                           : events_->forIPrimaryScreen().buttonUp();

  sendEvent(eventType, ButtonInfo::alloc(button, mask));
}

void EiScreen::on_pointer_scroll_event(ei_event *event) {
  // Ratio of 10 pixels == one wheel click because that's what mutter/gtk
  // use (for historical reasons).
  const int PIXELS_PER_WHEEL_CLICK = 10;
  // Our logical wheel clicks are multiples 120, so we
  // convert between the two and keep the remainders because
  // we will very likely get subpixel scroll events.
  // This means a single pixel is 120/PIXEL_TO_WHEEL_RATIO in wheel values.
  const int PIXEL_TO_WHEEL_RATIO = 120 / PIXELS_PER_WHEEL_CLICK;

  assert(is_primary_);

  double dx = ei_event_scroll_get_dx(event);
  double dy = ei_event_scroll_get_dy(event);
  struct ei_device *device = ei_event_get_device(event);

  LOG_DEBUG1("event: scroll (%.2f, %.2f)", dx, dy);

  struct ScrollRemainder *remainder =
      static_cast<struct ScrollRemainder *>(ei_device_get_user_data(device));
  if (!remainder) {
    remainder = new ScrollRemainder();
    ei_device_set_user_data(device, remainder);
  }

  dx += remainder->x;
  dy += remainder->y;

  double x, y;
  double rx = modf(dx, &x);
  double ry = modf(dy, &y);

  assert(!std::isnan(x) && !std::isinf(x));
  assert(!std::isnan(y) && !std::isinf(y));

  // libei and synergy seem to use opposite directions, so we have
  // to send the opposite of the value reported by EI if we want to
  // remain compatible with other platforms (including X11).
  if (x != 0 || y != 0)
    sendEvent(
        events_->forIPrimaryScreen().wheel(),
        WheelInfo::alloc(
            (int32_t)-x * PIXEL_TO_WHEEL_RATIO,
            (int32_t)-y * PIXEL_TO_WHEEL_RATIO));

  remainder->x = rx;
  remainder->y = ry;
}

void EiScreen::on_pointer_scroll_discrete_event(ei_event *event) {
  // both libei and synergy use multiples of 120 to represent
  // one scroll wheel click event so we can just forward things
  // as-is.

  assert(is_primary_);

  std::int32_t dx = ei_event_scroll_get_discrete_dx(event);
  std::int32_t dy = ei_event_scroll_get_discrete_dy(event);

  LOG_DEBUG1("event: scroll discrete (%d, %d)", dx, dy);

  // libei and synergy seem to use opposite directions, so we have
  // to send the opposite of the value reported by EI if we want to
  // remain compatible with other platforms (including X11).
  sendEvent(events_->forIPrimaryScreen().wheel(), WheelInfo::alloc(-dx, -dy));
}

void EiScreen::on_motion_event(ei_event *event) {
  assert(is_primary_);

  double dx = ei_event_pointer_get_dx(event);
  double dy = ei_event_pointer_get_dy(event);

  if (is_on_screen_) {
    LOG_DEBUG("event: motion on primary x=%i y=%i)", cursor_x_, cursor_y_);
    sendEvent(
        events_->forIPrimaryScreen().motionOnPrimary(),
        MotionInfo::alloc(cursor_x_, cursor_y_));

#if HAVE_LIBPORTAL_INPUTCAPTURE
    if (portal_input_capture_->is_active()) {
      portal_input_capture_->release();
    }
#endif
  } else {
    buffer_dx += dx;
    buffer_dy += dy;
    auto pixel_dx = static_cast<std::int32_t>(buffer_dx);
    auto pixel_dy = static_cast<std::int32_t>(buffer_dy);
    if (pixel_dx || pixel_dy) {
      LOG_DEBUG1("event: motion on secondary x=%d y=%d", pixel_dx, pixel_dy);
      sendEvent(
          events_->forIPrimaryScreen().motionOnSecondary(),
          MotionInfo::alloc(pixel_dx, pixel_dy));
      buffer_dx -= pixel_dx;
      buffer_dy -= pixel_dy;
    }
  }
}

void EiScreen::on_abs_motion_event(ei_event *event) { assert(is_primary_); }

void EiScreen::handle_connected_to_eis_event(const Event &event, void *) {
  int fd = static_cast<EiConnectInfo *>(event.getData())->m_fd;
  LOG_DEBUG("eis connection established, fd=%d", fd);

  auto rc = ei_setup_backend_fd(ei_, fd);
  if (rc != 0) {
    LOG_NOTE("failed to set up ei: %s", strerror(-rc));
  }
}

void EiScreen::handle_portal_session_closed(const Event &event, void *) {
  // Portal may or may EI_EVENT_DISCONNECT us before sending the DBus Closed
  // signal Let's clean up either way.
  cleanup_ei();
  init_ei();
}

void EiScreen::handleSystemEvent(const Event &sysevent, void *) {
  std::lock_guard<std::mutex> lock(mutex_);
  bool disconnected = false;

  // Only one ei_dispatch per system event, see the comment in
  // EiEventQueueBuffer::addEvent
  ei_dispatch(ei_);
  struct ei_event *event;

  while ((event = ei_get_event(ei_)) != nullptr) {
    auto type = ei_event_get_type(event);
    auto seat = ei_event_get_seat(event);
    auto device = ei_event_get_device(event);

    switch (type) {
    case EI_EVENT_CONNECT:
      LOG_DEBUG("connected to eis");
      break;
    case EI_EVENT_SEAT_ADDED:
      if (!ei_seat_) {
        ei_seat_ = ei_seat_ref(seat);
        ei_seat_bind_capabilities(
            ei_seat_, EI_DEVICE_CAP_POINTER, EI_DEVICE_CAP_POINTER_ABSOLUTE,
            EI_DEVICE_CAP_KEYBOARD, EI_DEVICE_CAP_BUTTON, EI_DEVICE_CAP_SCROLL,
            nullptr);
        LOG_DEBUG("ei: using seat %s", ei_seat_get_name(ei_seat_));
        // we don't care about touch
      }
      break;
    case EI_EVENT_DEVICE_ADDED:
      if (seat == ei_seat_) {
        add_device(device);
      } else {
        LOG_INFO("seat %s is ignored", ei_seat_get_name(ei_seat_));
      }
      break;
    case EI_EVENT_DEVICE_REMOVED:
      remove_device(device);
      break;
    case EI_EVENT_SEAT_REMOVED:
      if (seat == ei_seat_) {
        ei_seat_ = ei_seat_unref(ei_seat_);
      }
      break;
    case EI_EVENT_DISCONNECT:
      // We're using libei which emulates the various seat/device remove events
      // so by the time we get here our EiScreen should be in a neutral state.
      //
      // We don't do anything here, we let the portal's Session.Closed signal
      // handle the rest.
      LOG_WARN("disconnected from eis");
      disconnected = true;
      break;
    case EI_EVENT_DEVICE_PAUSED:
      LOG_DEBUG("device %s is paused", ei_device_get_name(device));
      break;
    case EI_EVENT_DEVICE_RESUMED:
      LOG_DEBUG("device %s is resumed", ei_device_get_name(device));
      if (!is_primary_ && is_on_screen_) {
        ei_device_start_emulating(device, ++sequence_number_);
      }
      break;
    case EI_EVENT_KEYBOARD_MODIFIERS:
      // FIXME
      break;

    // events below are for a receiver context (barriers)
    case EI_EVENT_FRAME:
      break;
    case EI_EVENT_DEVICE_START_EMULATING:
      LOG_DEBUG("device %s started emulating", ei_device_get_name(device));
      break;
    case EI_EVENT_DEVICE_STOP_EMULATING:
      LOG_DEBUG("device %s stopped emulating", ei_device_get_name(device));
      break;
    case EI_EVENT_KEYBOARD_KEY:
      on_key_event(event);
      break;
    case EI_EVENT_BUTTON_BUTTON:
      on_button_event(event);
      break;
    case EI_EVENT_POINTER_MOTION:
      on_motion_event(event);
      break;
    case EI_EVENT_POINTER_MOTION_ABSOLUTE:
      on_abs_motion_event(event);
      break;
    case EI_EVENT_TOUCH_UP:
      break;
    case EI_EVENT_TOUCH_MOTION:
      break;
    case EI_EVENT_TOUCH_DOWN:
      break;
    case EI_EVENT_SCROLL_DELTA:
      on_pointer_scroll_event(event);
      break;
    case EI_EVENT_SCROLL_DISCRETE:
      on_pointer_scroll_discrete_event(event);
      break;
    case EI_EVENT_SCROLL_STOP:
    case EI_EVENT_SCROLL_CANCEL:
      break;
    }
    ei_event_unref(event);
  }

  if (disconnected)
    ei_ = ei_unref(ei_);
}

void EiScreen::updateButtons() {
  // libei relies on the EIS implementation to keep our button count correct,
  // so there's not much we need to/can do here.
}

IKeyState *EiScreen::getKeyState() const { return key_state_; }

String EiScreen::getSecureInputApp() const {
  throw std::runtime_error("get security input app not implemented");
}

EiScreen::HotKeyItem::HotKeyItem(std::uint32_t mask, std::uint32_t id)
    : mask_(mask),
      id_(id) {}

EiScreen::HotKeySet::HotKeySet(KeyID key) : id_(key) {}

bool EiScreen::HotKeySet::remove_by_id(std::uint32_t id) {
  for (auto it = set_.begin(); it != set_.end(); ++it) {
    if (it->id_ == id) {
      set_.erase(it);
      return true;
    }
  }
  return false;
}

void EiScreen::HotKeySet::add_item(HotKeyItem item) { set_.push_back(item); }

std::uint32_t EiScreen::HotKeySet::find_by_mask(std::uint32_t mask) const {
  for (const auto &item : set_) {
    if (item.mask_ == mask) {
      return item.id_;
    }
  }
  return 0;
}

} // namespace synergy