ime.h

// SPDX-License-Identifier: GPL-2.0-only
/* Based on labwc (https://github.com/labwc/labwc) */

#include <assert.h>
#include <wlr/types/wlr_input_method_v2.h>
#include <wlr/types/wlr_text_input_v3.h>

#define DWL_SET_MAX_SIZE 16

#define znew(expr) ((__typeof__(expr) *)xzalloc(sizeof(expr)))

#define SAME_CLIENT(wlr_obj1, wlr_obj2)                                        \
  (wl_resource_get_client((wlr_obj1)->resource) ==                             \
   wl_resource_get_client((wlr_obj2)->resource))

struct dwl_set {
  uint32_t values[DWL_SET_MAX_SIZE];
  int size;
};

static void die_if_null(void *ptr) {
  if (!ptr) {
    perror("Failed to allocate memory");
    exit(EXIT_FAILURE);
  }
}

void *xzalloc(size_t size) {
  if (!size) {
    return NULL;
  }
  void *ptr = calloc(1, size);
  die_if_null(ptr);
  return ptr;
}

/*
 * The relay structure manages the relationship between text-inputs and
 * input-method on a given seat. Multiple text-inputs may be bound to a relay,
 * but at most one will be "active" (communicating with input-method) at a time.
 * At most one input-method may be bound to the seat. When an input-method and
 * an active text-input is present, the relay passes messages between them.
 */
struct input_method_relay {
  struct wl_list text_inputs; /* struct text_input.link */
  struct wlr_input_method_v2 *input_method;
  struct wlr_surface *focused_surface;

  struct dwl_set forwarded_pressed_keys;
  struct wlr_keyboard_modifiers forwarded_modifiers;

  /*
   * Text-input which is enabled by the client and communicating with
   * input-method.
   * This must be NULL if input-method is not present.
   * Its client must be the same as that of focused_surface.
   */
  struct text_input *active_text_input;

  struct wl_list popups; /* input_method_popup.link */
  struct wlr_scene_tree *popup_tree;

  struct wl_listener new_text_input;
  struct wl_listener new_input_method;

  struct wl_listener input_method_commit;
  struct wl_listener input_method_grab_keyboard;
  struct wl_listener input_method_destroy;
  struct wl_listener input_method_new_popup_surface;

  struct wl_listener keyboard_grab_destroy;
  struct wl_listener focused_surface_destroy;
};

struct input_method_popup {
  struct wlr_input_popup_surface_v2 *popup_surface;
  struct wlr_scene_tree *tree;
  struct wlr_scene_tree *scene_surface;
  struct input_method_relay *relay;
  struct wl_list link; /* input_method_relay.popups */

  struct wl_listener destroy;
  struct wl_listener commit;
};

struct text_input {
  struct input_method_relay *relay;
  struct wlr_text_input_v3 *input;
  struct wl_list link;

  struct wl_listener enable;
  struct wl_listener commit;
  struct wl_listener disable;
  struct wl_listener destroy;
};

struct wlr_input_method_manager_v2 *input_method_manager;
struct wlr_text_input_manager_v3 *text_input_manager;
struct input_method_relay *input_method_relay;

/*
 * Forward key event to keyboard grab of the seat from the keyboard
 * if the keyboard grab exists.
 * Returns true if the key event was forwarded.
 */
bool input_method_keyboard_grab_forward_key(
    KeyboardGroup *keyboard, struct wlr_keyboard_key_event *event);

/*
 * Forward modifier state to keyboard grab of the seat from the keyboard
 * if the keyboard grab exists.
 * Returns true if the modifier state was forwarded.
 */
bool input_method_keyboard_grab_forward_modifiers(KeyboardGroup *keyboard);

struct input_method_relay *input_method_relay_create(void);

void input_method_relay_finish(struct input_method_relay *relay);

/* Updates currently focused surface. Surface must belong to the same seat. */
void input_method_relay_set_focus(struct input_method_relay *relay,
                                  struct wlr_surface *surface);

bool dwl_set_contains(struct dwl_set *set, uint32_t value) {
  for (int i = 0; i < set->size; ++i) {
    if (set->values[i] == value) {
      return true;
    }
  }
  return false;
}

void dwl_set_add(struct dwl_set *set, uint32_t value) {
  if (dwl_set_contains(set, value)) {
    return;
  }
  if (set->size >= DWL_SET_MAX_SIZE) {
    wlr_log(WLR_ERROR, "dwl_set size exceeded");
    return;
  }
  set->values[set->size++] = value;
}

void dwl_set_remove(struct dwl_set *set, uint32_t value) {
  for (int i = 0; i < set->size; ++i) {
    if (set->values[i] == value) {
      --set->size;
      set->values[i] = set->values[set->size];
      return;
    }
  }
}

Monitor *output_from_wlr_output(struct wlr_output *wlr_output) {
  Monitor *m;
  wl_list_for_each(m, &mons, link) {
    if (m->wlr_output == wlr_output) {
      return m;
    }
  }
  return NULL;
}

Monitor *output_nearest_to(int lx, int ly) {
  double closest_x, closest_y;
  wlr_output_layout_closest_point(output_layout, NULL, lx, ly, &closest_x,
                                  &closest_y);

  return output_from_wlr_output(
      wlr_output_layout_output_at(output_layout, closest_x, closest_y));
}

bool output_is_usable(Monitor *m) {
  /* output_is_usable(NULL) is safe and returns false */
  return m && m->wlr_output->enabled;
}

static bool
is_keyboard_emulated_by_input_method(struct wlr_keyboard *keyboard,
                                     struct wlr_input_method_v2 *input_method) {
  if (!keyboard || !input_method) {
    return false;
  }

  struct wlr_virtual_keyboard_v1 *virtual_keyboard =
      wlr_input_device_get_virtual_keyboard(&keyboard->base);

  return virtual_keyboard && SAME_CLIENT(virtual_keyboard, input_method);
}

/*
 * Get keyboard grab of the seat from keyboard if we should forward events
 * to it.
 */
static struct wlr_input_method_keyboard_grab_v2 *
get_keyboard_grab(KeyboardGroup *keyboard) {
  struct wlr_input_method_v2 *input_method = input_method_relay->input_method;
  if (!input_method || !input_method->keyboard_grab) {
    return NULL;
  }

  // labwc not need this , but maomao need
  if (keyboard != kb_group)
    return NULL;

  /*
   * Input-methods often use virtual keyboard to send raw key signals
   * instead of sending encoded text via set_preedit_string and
   * commit_string. We should not forward those key events back to the
   * input-method so key events don't loop between the compositor and
   * the input-method.
   */
  if (is_keyboard_emulated_by_input_method(&keyboard->wlr_group->keyboard,
                                           input_method)) {
    return NULL;
  }

  return input_method->keyboard_grab;
}

bool input_method_keyboard_grab_forward_modifiers(KeyboardGroup *keyboard) {
  struct wlr_input_method_keyboard_grab_v2 *keyboard_grab =
      get_keyboard_grab(keyboard);

  struct wlr_keyboard_modifiers *forwarded_modifiers =
      &input_method_relay->forwarded_modifiers;
  struct wlr_keyboard_modifiers *modifiers =
      &keyboard->wlr_group->keyboard.modifiers;

  if (forwarded_modifiers->depressed == modifiers->depressed &&
      forwarded_modifiers->latched == modifiers->latched &&
      forwarded_modifiers->locked == modifiers->locked &&
      forwarded_modifiers->group == modifiers->group) {
    return false;
  }

  if (keyboard_grab) {
    *forwarded_modifiers = keyboard->wlr_group->keyboard.modifiers;
    wlr_input_method_keyboard_grab_v2_set_keyboard(
        keyboard_grab, &keyboard->wlr_group->keyboard);
    wlr_input_method_keyboard_grab_v2_send_modifiers(keyboard_grab, modifiers);
    return true;
  } else {
    return false;
  }
}

bool input_method_keyboard_grab_forward_key(
    KeyboardGroup *keyboard, struct wlr_keyboard_key_event *event) {
  /*
   * We should not forward key-release events without corresponding
   * key-press events forwarded
   */
  struct dwl_set *pressed_keys = &input_method_relay->forwarded_pressed_keys;
  if (event->state == WL_KEYBOARD_KEY_STATE_RELEASED &&
      !dwl_set_contains(pressed_keys, event->keycode)) {
    return false;
  }

  struct wlr_input_method_keyboard_grab_v2 *keyboard_grab =
      get_keyboard_grab(keyboard);
  if (keyboard_grab) {
    if (event->state == WL_KEYBOARD_KEY_STATE_PRESSED) {
      dwl_set_add(pressed_keys, event->keycode);
    } else {
      dwl_set_remove(pressed_keys, event->keycode);
    }
    wlr_input_method_keyboard_grab_v2_set_keyboard(
        keyboard_grab, &keyboard->wlr_group->keyboard);
    wlr_input_method_keyboard_grab_v2_send_key(keyboard_grab, event->time_msec,
                                               event->keycode, event->state);
    return true;
  } else {
    return false;
  }
}

/*
 * update_text_inputs_focused_surface() should be called beforehand to set
 * right text-inputs to choose from.
 */
static struct text_input *
get_active_text_input(struct input_method_relay *relay) {
  if (!relay->input_method) {
    return NULL;
  }
  struct text_input *text_input;
  wl_list_for_each(text_input, &relay->text_inputs, link) {
    if (text_input->input->focused_surface &&
        text_input->input->current_enabled) {
      return text_input;
    }
  }
  return NULL;
}

/*
 * Updates active text-input and activates/deactivates the input-method if the
 * value is changed.
 */
static void update_active_text_input(struct input_method_relay *relay) {
  struct text_input *active_text_input = get_active_text_input(relay);

  if (relay->input_method && relay->active_text_input != active_text_input) {
    if (active_text_input) {
      wlr_input_method_v2_send_activate(relay->input_method);
    } else {
      wlr_input_method_v2_send_deactivate(relay->input_method);
    }
    wlr_input_method_v2_send_done(relay->input_method);
  }

  relay->active_text_input = active_text_input;
}

/*
 * Updates focused surface of text-inputs and sends enter/leave events to
 * the text-inputs whose focused surface is changed.
 * When input-method is present, text-inputs whose client is the same as the
 * relay's focused surface also have that focused surface. Clients can then
 * send enable request on a text-input which has the focused surface to make
 * the text-input active and start communicating with input-method.
 */
static void
update_text_inputs_focused_surface(struct input_method_relay *relay) {
  struct text_input *text_input;
  wl_list_for_each(text_input, &relay->text_inputs, link) {
    struct wlr_text_input_v3 *input = text_input->input;

    struct wlr_surface *new_focused_surface;
    if (relay->input_method && relay->focused_surface &&
        SAME_CLIENT(input, relay->focused_surface)) {
      new_focused_surface = relay->focused_surface;
    } else {
      new_focused_surface = NULL;
    }

    if (input->focused_surface == new_focused_surface) {
      continue;
    }
    if (input->focused_surface) {
      wlr_text_input_v3_send_leave(input);
    }
    if (new_focused_surface) {
      wlr_text_input_v3_send_enter(input, new_focused_surface);
    }
  }
}

static void update_popup_position(struct input_method_popup *popup) {
  struct input_method_relay *relay = popup->relay;
  struct text_input *text_input = relay->active_text_input;

  if (!text_input || !relay->focused_surface ||
      !popup->popup_surface->surface->mapped) {
    return;
  }

  struct wlr_box cursor_rect;
  struct wlr_xdg_surface *xdg_surface =
      wlr_xdg_surface_try_from_wlr_surface(relay->focused_surface);
  struct wlr_layer_surface_v1 *layer_surface =
      wlr_layer_surface_v1_try_from_wlr_surface(relay->focused_surface);

  if ((text_input->input->current.features &
       WLR_TEXT_INPUT_V3_FEATURE_CURSOR_RECTANGLE) &&
      (xdg_surface || layer_surface)) {
    cursor_rect = text_input->input->current.cursor_rectangle;

    /*
     * wlr_surface->data is:
     * - for XDG surfaces: view->content_tree
     * - for layer surfaces: dwl_layer_surface->scene_layer_surface->tree
     * - for layer popups: dwl_layer_popup->scene_tree
     */
    struct wlr_scene_tree *tree = relay->focused_surface->data;
    int lx, ly;
    wlr_scene_node_coords(&tree->node, &lx, &ly);
    cursor_rect.x += lx;
    cursor_rect.y += ly;

    if (xdg_surface) {
      /* Take into account invisible xdg-shell CSD borders */
      cursor_rect.x -= xdg_surface->geometry.x;
      cursor_rect.y -= xdg_surface->geometry.y;
    }
  } else {
    cursor_rect = (struct wlr_box){0};
  }

  Monitor *output = output_nearest_to(cursor_rect.x, cursor_rect.y);
  if (!output_is_usable(output)) {
    wlr_log(WLR_ERROR, "Cannot position IME popup (unusable output)");
    return;
  }
  struct wlr_box output_box;
  wlr_output_layout_get_box(output_layout, output->wlr_output, &output_box);

  /* Use xdg-positioner utilities to position popup */
  struct wlr_xdg_positioner_rules positioner_rules = {
      .anchor_rect = cursor_rect,
      .anchor = XDG_POSITIONER_ANCHOR_BOTTOM_LEFT,
      .gravity = XDG_POSITIONER_GRAVITY_BOTTOM_RIGHT,
      .size =
          {
              .width = popup->popup_surface->surface->current.width,
              .height = popup->popup_surface->surface->current.height,
          },
      .constraint_adjustment = XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_FLIP_Y |
                               XDG_POSITIONER_CONSTRAINT_ADJUSTMENT_SLIDE_X,
  };

  struct wlr_box popup_box;
  wlr_xdg_positioner_rules_get_geometry(&positioner_rules, &popup_box);
  wlr_xdg_positioner_rules_unconstrain_box(&positioner_rules, &output_box, &popup_box);

  wlr_scene_node_set_position(&popup->tree->node, popup_box.x, popup_box.y);
  /* Make sure IME popups are always on top, above layer-shell surfaces */
  wlr_scene_node_raise_to_top(&relay->popup_tree->node);

  wlr_input_popup_surface_v2_send_text_input_rectangle(
      popup->popup_surface, &(struct wlr_box){
                                .x = cursor_rect.x - popup_box.x,
                                .y = cursor_rect.y - popup_box.y,
                                .width = cursor_rect.width,
                                .height = cursor_rect.height,
                            });
}

static void update_popups_position(struct input_method_relay *relay) {
  struct input_method_popup *popup;
  wl_list_for_each(popup, &relay->popups, link) {
    update_popup_position(popup);
  }
}

static void handle_input_method_commit(struct wl_listener *listener,
                                       void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, input_method_commit);
  struct wlr_input_method_v2 *input_method = data;
  assert(relay->input_method == input_method);

  struct text_input *text_input = relay->active_text_input;
  if (!text_input) {
    return;
  }

  if (input_method->current.preedit.text) {
    wlr_text_input_v3_send_preedit_string(
        text_input->input, input_method->current.preedit.text,
        input_method->current.preedit.cursor_begin,
        input_method->current.preedit.cursor_end);
  }
  if (input_method->current.commit_text) {
    wlr_text_input_v3_send_commit_string(text_input->input,
                                         input_method->current.commit_text);
  }
  if (input_method->current.delete.before_length ||
      input_method->current.delete.after_length) {
    wlr_text_input_v3_send_delete_surrounding_text(
        text_input->input, input_method->current.delete.before_length,
        input_method->current.delete.after_length);
  }
  wlr_text_input_v3_send_done(text_input->input);
}

static void handle_keyboard_grab_destroy(struct wl_listener *listener,
                                         void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, keyboard_grab_destroy);
  struct wlr_input_method_keyboard_grab_v2 *keyboard_grab = data;
  wl_list_remove(&relay->keyboard_grab_destroy.link);

  if (keyboard_grab->keyboard) {
    /* Send modifier state to original client */
    wlr_seat_keyboard_notify_modifiers(keyboard_grab->input_method->seat,
                                       &keyboard_grab->keyboard->modifiers);
  }
}

static void handle_input_method_grab_keyboard(struct wl_listener *listener,
                                              void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, input_method_grab_keyboard);
  struct wlr_input_method_keyboard_grab_v2 *keyboard_grab = data;

  struct wlr_keyboard *active_keyboard = wlr_seat_get_keyboard(seat);

  if (!is_keyboard_emulated_by_input_method(active_keyboard,
                                            relay->input_method)) {
    /* Send modifier state to grab */
    wlr_input_method_keyboard_grab_v2_set_keyboard(keyboard_grab,
                                                   active_keyboard);
  }

  relay->forwarded_pressed_keys = (struct dwl_set){0};
  relay->forwarded_modifiers = (struct wlr_keyboard_modifiers){0};

  relay->keyboard_grab_destroy.notify = handle_keyboard_grab_destroy;
  wl_signal_add(&keyboard_grab->events.destroy, &relay->keyboard_grab_destroy);
}

static void handle_input_method_destroy(struct wl_listener *listener,
                                        void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, input_method_destroy);
  assert(relay->input_method == data);
  wl_list_remove(&relay->input_method_commit.link);
  wl_list_remove(&relay->input_method_grab_keyboard.link);
  wl_list_remove(&relay->input_method_new_popup_surface.link);
  wl_list_remove(&relay->input_method_destroy.link);
  relay->input_method = NULL;

  update_text_inputs_focused_surface(relay);
  update_active_text_input(relay);
}

static void handle_popup_surface_destroy(struct wl_listener *listener,
                                         void *data) {
  struct input_method_popup *popup = wl_container_of(listener, popup, destroy);
  wlr_scene_node_destroy(&popup->tree->node);
  wl_list_remove(&popup->destroy.link);
  wl_list_remove(&popup->commit.link);
  wl_list_remove(&popup->link);
  free(popup);
}

static void handle_popup_surface_commit(struct wl_listener *listener,
                                        void *data) {
  struct input_method_popup *popup = wl_container_of(listener, popup, commit);
  update_popup_position(popup);
}

static void handle_input_method_new_popup_surface(struct wl_listener *listener,
                                                  void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, input_method_new_popup_surface);

  struct input_method_popup *popup = znew(*popup);
  popup->popup_surface = data;
  popup->relay = relay;

  popup->destroy.notify = handle_popup_surface_destroy;
  wl_signal_add(&popup->popup_surface->events.destroy, &popup->destroy);

  popup->commit.notify = handle_popup_surface_commit;
  wl_signal_add(&popup->popup_surface->surface->events.commit, &popup->commit);

  // popup->tree = wlr_scene_subsurface_tree_create(
  // 	relay->popup_tree, popup->popup_surface->surface);
  // node_descriptor_create(&popup->tree->node, dwl_NODE_DESC_IME_POPUP, NULL);

  popup->tree = wlr_scene_tree_create(layers[LyrIMPopup]);
  popup->scene_surface = wlr_scene_subsurface_tree_create(
      popup->tree, popup->popup_surface->surface);
  popup->scene_surface->node.data = popup;

  wl_list_insert(&relay->popups, &popup->link);

  update_popup_position(popup);
}

static void handle_new_input_method(struct wl_listener *listener, void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, new_input_method);
  struct wlr_input_method_v2 *input_method = data;
  if (seat != input_method->seat) {
    return;
  }

  if (relay->input_method) {
    wlr_log(WLR_INFO, "Attempted to connect second input method to a seat");
    wlr_input_method_v2_send_unavailable(input_method);
    return;
  }

  relay->input_method = input_method;

  relay->input_method_commit.notify = handle_input_method_commit;
  wl_signal_add(&relay->input_method->events.commit,
                &relay->input_method_commit);

  relay->input_method_grab_keyboard.notify = handle_input_method_grab_keyboard;
  wl_signal_add(&relay->input_method->events.grab_keyboard,
                &relay->input_method_grab_keyboard);

  relay->input_method_destroy.notify = handle_input_method_destroy;
  wl_signal_add(&relay->input_method->events.destroy,
                &relay->input_method_destroy);

  relay->input_method_new_popup_surface.notify =
      handle_input_method_new_popup_surface;
  wl_signal_add(&relay->input_method->events.new_popup_surface,
                &relay->input_method_new_popup_surface);

  update_text_inputs_focused_surface(relay);
  update_active_text_input(relay);
}

/* Conveys state from active text-input to input-method */
static void send_state_to_input_method(struct input_method_relay *relay) {
  assert(relay->active_text_input && relay->input_method);

  struct wlr_input_method_v2 *input_method = relay->input_method;
  struct wlr_text_input_v3 *input = relay->active_text_input->input;

  /* TODO: only send each of those if they were modified */
  if (input->active_features & WLR_TEXT_INPUT_V3_FEATURE_SURROUNDING_TEXT) {
    wlr_input_method_v2_send_surrounding_text(
        input_method, input->current.surrounding.text,
        input->current.surrounding.cursor, input->current.surrounding.anchor);
  }
  wlr_input_method_v2_send_text_change_cause(input_method,
                                             input->current.text_change_cause);
  if (input->active_features & WLR_TEXT_INPUT_V3_FEATURE_CONTENT_TYPE) {
    wlr_input_method_v2_send_content_type(input_method,
                                          input->current.content_type.hint,
                                          input->current.content_type.purpose);
  }
  wlr_input_method_v2_send_done(input_method);
}

static void handle_text_input_enable(struct wl_listener *listener, void *data) {
  struct text_input *text_input = wl_container_of(listener, text_input, enable);
  struct input_method_relay *relay = text_input->relay;

  update_active_text_input(relay);
  if (relay->active_text_input == text_input) {
    update_popups_position(relay);
    send_state_to_input_method(relay);
  }
}

static void handle_text_input_disable(struct wl_listener *listener,
                                      void *data) {
  struct text_input *text_input =
      wl_container_of(listener, text_input, disable);
  /*
   * When the focus is moved between surfaces from different clients and
   * then the old client sends "disable" event, the relay ignores it and
   * doesn't deactivate the input-method.
   */
  update_active_text_input(text_input->relay);
}

static void handle_text_input_commit(struct wl_listener *listener, void *data) {
  struct text_input *text_input = wl_container_of(listener, text_input, commit);
  struct input_method_relay *relay = text_input->relay;

  if (relay->active_text_input == text_input) {
    update_popups_position(relay);
    send_state_to_input_method(relay);
  }
}

static void handle_text_input_destroy(struct wl_listener *listener,
                                      void *data) {
  struct text_input *text_input =
      wl_container_of(listener, text_input, destroy);
  wl_list_remove(&text_input->enable.link);
  wl_list_remove(&text_input->disable.link);
  wl_list_remove(&text_input->commit.link);
  wl_list_remove(&text_input->destroy.link);
  wl_list_remove(&text_input->link);
  update_active_text_input(text_input->relay);
  free(text_input);
}

static void handle_new_text_input(struct wl_listener *listener, void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, new_text_input);
  struct wlr_text_input_v3 *wlr_text_input = data;
  if (seat != wlr_text_input->seat) {
    return;
  }

  struct text_input *text_input = znew(*text_input);
  text_input->input = wlr_text_input;
  text_input->relay = relay;
  wl_list_insert(&relay->text_inputs, &text_input->link);

  text_input->enable.notify = handle_text_input_enable;
  wl_signal_add(&text_input->input->events.enable, &text_input->enable);

  text_input->disable.notify = handle_text_input_disable;
  wl_signal_add(&text_input->input->events.disable, &text_input->disable);

  text_input->commit.notify = handle_text_input_commit;
  wl_signal_add(&text_input->input->events.commit, &text_input->commit);

  text_input->destroy.notify = handle_text_input_destroy;
  wl_signal_add(&text_input->input->events.destroy, &text_input->destroy);

  update_text_inputs_focused_surface(relay);
}

/*
 * Usually this function is not called because the client destroys the surface
 * role (like xdg_toplevel) first and input_method_relay_set_focus() is called
 * before wl_surface is destroyed.
 */
static void handle_focused_surface_destroy(struct wl_listener *listener,
                                           void *data) {
  struct input_method_relay *relay =
      wl_container_of(listener, relay, focused_surface_destroy);
  assert(relay->focused_surface == data);

  input_method_relay_set_focus(relay, NULL);
}

struct input_method_relay *input_method_relay_create() {
  struct input_method_relay *relay = znew(*relay);
  wl_list_init(&relay->text_inputs);
  wl_list_init(&relay->popups);
  relay->popup_tree = wlr_scene_tree_create(&scene->tree);

  relay->new_text_input.notify = handle_new_text_input;
  wl_signal_add(&text_input_manager->events.text_input, &relay->new_text_input);

  relay->new_input_method.notify = handle_new_input_method;
  wl_signal_add(&input_method_manager->events.input_method,
                &relay->new_input_method);

  relay->focused_surface_destroy.notify = handle_focused_surface_destroy;

  return relay;
}

void input_method_relay_finish(struct input_method_relay *relay) {
  wl_list_remove(&relay->new_text_input.link);
  wl_list_remove(&relay->new_input_method.link);
  free(relay);
}

void input_method_relay_set_focus(struct input_method_relay *relay,
                                  struct wlr_surface *surface) {
  if (relay->focused_surface == surface) {
    wlr_log(WLR_INFO, "The surface is already focused");
    return;
  }

  if (relay->focused_surface) {
    wl_list_remove(&relay->focused_surface_destroy.link);
  }
  relay->focused_surface = surface;
  if (surface) {
    wl_signal_add(&surface->events.destroy, &relay->focused_surface_destroy);
  }

  update_text_inputs_focused_surface(relay);
  update_active_text_input(relay);
}