Class TargetMenuAim

src/cdk/menu/menu-aim.ts:111–259

 */
@Service({autoProvided: false})
export class TargetMenuAim implements MenuAim, OnDestroy {
  private readonly _ngZone = inject(NgZone);
  private readonly _renderer = inject(RendererFactory2).createRenderer(null, null);
  private _cleanupMousemove: (() => void) | undefined;

  /** The last NUM_POINTS mouse move events. */
  private readonly _points: Point[] = [];

  /** Reference to the root menu in which we are tracking mouse moves. */
  private _menu!: Menu;

  /** Reference to the root menu's mouse manager. */
  private _pointerTracker!: PointerFocusTracker<Toggler & FocusableElement>;

  /** The id associated with the current timeout call waiting to resolve. */
  private _timeoutId: number | null = null;

  /** Emits when this service is destroyed. */
  private readonly _destroyed: Subject<void> = new Subject();

  ngOnDestroy() {
    this._cleanupMousemove?.();
    this._destroyed.next();
    this._destroyed.complete();
  }

  /**
   * Set the Menu and its PointerFocusTracker.
   * @param menu The menu that this menu aim service controls.
   * @param pointerTracker The `PointerFocusTracker` for the given menu.
   */
  initialize(menu: Menu, pointerTracker: PointerFocusTracker<FocusableElement & Toggler>) {
    this._menu = menu;
    this._pointerTracker = pointerTracker;
    this._subscribeToMouseMoves();
  }

  /**
   * Calls the `doToggle` callback when it is deemed that the user is not moving towards
   * the submenu.
   * @param doToggle the function called when the user is not moving towards the submenu.
   */
  toggle(doToggle: () => void) {
    // If the menu is horizontal the sub-menus open below and there is no risk of premature
    // closing of any sub-menus therefore we automatically resolve the callback.
    if (this._menu.orientation === 'horizontal') {
      doToggle();
    }

    this._checkConfigured();

    const siblingItemIsWaiting = !!this._timeoutId;
    const hasPoints = this._points.length > 1;

    if (hasPoints && !siblingItemIsWaiting) {
      if (this._isMovingToSubmenu()) {
        this._startTimeout(doToggle);
      } else {