app.component.ts

import { AfterViewInit, ChangeDetectorRef, Component, ElementRef, ViewChild } from '@angular/core';

import { BehaviorSubject, Subject, delay, filter, switchMap, takeUntil, tap } from 'rxjs';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})
export class AppComponent implements AfterViewInit{
  @ViewChild(TopologyComponent) commandReceiver: TopologyComponent;
  @ViewChild(TopologyControlbarAssistantComponent) assistantCommandInvoker: TopologyControlbarAssistantComponent;
  
  commandStack: TopologyCommand[] = [];

  ngAfterViewInit() {
    this.setCommandStack(this.assistantCommandInvoker, this.commandStack);
    this.setMakeCommand(this.assistantCommandInvoker);
  }
  
  setCommandStack(invoker: TopologyCommandInvoker, commandStack: TopologyCommand[]) {
    invoker.setCommandStack(commandStack);
   }
 
   setMakeCommand(invoker: TopologyCommandInvoker) {
     invoker.setMakeCommand(this.makeCommand.bind(this));
   }

   private makeCommand(statusType: TopologyStatusType): TopologyCommand {
    return new TopologyCommand(this.commandReceiver, statusType);
  }
}