@ViewChild("anchor", { read: ElementRef }) public anchor: ElementRef;
@ViewChild("popup", { read: ElementRef }) public popup: ElementRef;

@HostListener("document:keydown", ["$event"])
public keydown(event: KeyboardEvent): void {
  if (event.code === "Escape") {
    this.closePopup();
  }
}

@HostListener("document:click", ["$event"])
public documentClick(event: KeyboardEvent): void {
  if (!this.contains(event.target)) {
    this. closePopup();
  }
}

private contains(target: EventTarget): boolean {
  return (
    this.anchor.nativeElement.contains(target) ||
    (this.popup ? this.popup.nativeElement.contains(target) : false)
  );
}