Class TreeItemGroup

src/aria/tree/tree-item-group.ts:47–86

  hostDirectives: [DeferredContent],
})
export class TreeItemGroup<V> implements OnInit, OnDestroy {
  /** A reference to the host element. */
  private readonly _elementRef = inject(ElementRef);

  /** A reference to the host element. */
  readonly element = this._elementRef.nativeElement as HTMLElement;

  /** The DeferredContent host directive. */
  private readonly _deferredContent = inject(DeferredContent);

  /** All groupable items that are descendants of the group. */
  private readonly _unorderedItems = signal(new Set<TreeItem<V>>());

  /** Child items within this group. */
  readonly _childPatterns = computed<TreeItemPattern<V>[]>(() =>
    [...this._unorderedItems()].sort(sortDirectives).map(c => c._pattern),
  );

  /** Tree item that owns the group. */
  readonly ownedBy = input.required<TreeItem<V>>();

  ngOnInit() {
    this._deferredContent.deferredContentAware.set(this.ownedBy());
    this.ownedBy()._register(this);
  }

  ngOnDestroy() {
    this.ownedBy()._unregister();
  }

  _register(child: TreeItem<V>) {
    this._unorderedItems().add(child);
    this._unorderedItems.set(new Set(this._unorderedItems()));
  }

  _unregister(child: TreeItem<V>) {
    this._unorderedItems().delete(child);
    this._unorderedItems.set(new Set(this._unorderedItems()));
  }
}