import { Component, OnInit, HostListener, Inject } from '@angular/core';
import { DOCUMENT } from '@angular/common';

@Component({
  selector: 'navbar',
  templateUrl: './navbar.component.html',
  styleUrls: ['./navbar.component.scss']
})
export class NavbarComponent implements OnInit {

  constructor(@Inject(DOCUMENT) document) {}

  ngOnInit() { }

  @HostListener('window:scroll', ['$event'])
  onWindowScroll(e) {
    if (window.pageYOffset > 50) {
      let element = document.getElementById('mainNav');
      element.classList.add('navbar-shrink');
    } else {
      let element = document.getElementById('mainNav');
        element.classList.remove('navbar-shrink');
    }
  }

}