Method constructor

src/aria/menu/menu.ts:152–205

()

  readonly expansionDelay = input<number>(100); // Arbitrarily chosen.

  constructor() {
    this._pattern = new MenuPattern({
      ...this,
      parent: computed(() => this.parent()?._pattern),
      items: this._itemPatterns,
      multi: () => false,
      focusMode: () => 'roving',
      orientation: () => 'vertical',
      selectionMode: () => 'explicit',
      activeItem: signal(undefined),
      element: computed(() => this._elementRef.nativeElement),
      itemSelected: (value: V) => this.itemSelected.emit(value),
    });

    afterRenderEffect({
      write: () => {
        const parent = this.parent();
        if (parent instanceof MenuItem && parent.parent instanceof MenuBar) {
          this._deferredContentAware?.contentVisible.set(true);
        } else {
          this._deferredContentAware?.contentVisible.set(
            this._pattern.visible() || !!this.parent()?._pattern.hasBeenInteracted(),
          );
        }
      },
    });

    // Focuses an active menu item when the menu becomes visible. This is needed to
    // properly restore focus to the active item when returning to a menu, and to
    // focus the first item when navigating into a submenu with hover.
    afterRenderEffect({
      write: () => {
        if (this.visible()) {
          const activeItem = untracked(() => this._pattern.inputs.activeItem());
          this._pattern.listBehavior.goto(activeItem!);
        }
      },
    });

    afterRenderEffect({write: () => this._pattern.setDefaultStateEffect()});

    // Check for any violations after the DOM has been updated.
    if (typeof ngDevMode === 'undefined' || ngDevMode) {
      afterRenderEffect({
        read: () => {
          reportViolations(this._pattern.validate(), this.element);
        },
      });
    }

    afterNextRender(() => {
      this._collection.startObserving(this.element);
    });
  }

  ngOnDestroy() {
    this._collection.stopObserving();