doneit-web/src/app/services/app-process-status.service.ts

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class AppProcessStatusService {

  status: 'resume' | 'pause' = 'resume'

  constructor() { 
    this.events()
  }

  private events() {
    document.addEventListener('pause', () => {
      // 
      this.status = 'pause'
    });

    document.addEventListener('resume', () => {
      // 
      this.status = 'resume'
    });
  }
}