import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams } from 'ionic-angular';
import { QRScanner, QRScannerStatus } from '@ionic-native/qr-scanner';

@IonicPage()
@Component({
  selector: 'page-qrcode',
  templateUrl: 'qrcode.html',
})
export class QrcodePage {

  constructor(
  public navCtrl: NavController,
  public navParams: NavParams,
  private qrScanner: QRScanner){}

  ionViewDidLoad() {
      console.log('ionViewDidLoad QrcodePage');
  }

  this.qrScanner.prepare()
  .then((status: QRScannerStatus) => {
  if (status.authorized) {
   // camera permission was granted


   // start scanning
   let scanSub = this.qrScanner.scan().subscribe((text: string) => {
     console.log('Scanned something', text);

     this.qrScanner.hide(); // hide camera preview
     scanSub.unsubscribe(); // stop scanning
   });

   // show camera preview
   this.qrScanner.show();

   // wait for user to scan something, then the observable callback will be called

 } else if (status.denied) {
   // camera permission was permanently denied
   // you must use QRScanner.openSettings() method to guide the user to the settings page
   // then they can grant the permission from there
 } else {
   // permission was denied, but not permanently. You can ask for permission again at a later time.
 }
})
.catch((e: any) => console.log('Error is', e));
}