Enable Barcode Scanning and Writing with React

1import React, { useRef, useEffect, useState } from 'react';
2import WebViewer from '@pdftron/webviewer';
3import Barcode from '../Barcode';
4import javascriptBarcodeReader from 'javascript-barcode-reader';
5import jsQR from "jsqr";
6import './webviewer.css';
7
8const WebViewerPDFTron = () => {
9  const viewer = useRef(null);
10  const [viewerInstance, setViewerInstance] = useState(null);
11
12  // if using a class, equivalent of componentDidMount
13  useEffect(() => {
14    WebViewer(
15      {
16        path: '/webviewer/lib',
17        initialDoc:
18          'https://pdftron.s3.amazonaws.com/downloads/pl/webviewer-demo.pdf',
19        fullAPI: true,
20        ui: 'legacy',
21        disabledElements: ['ribbons', 'cropToolGroupButton', 'snippingToolGroupButton']
22      },
23      viewer.current,
24    ).then(async (instance) => {
25      setViewerInstance(instance);
26      const {
27        documentViewer,
28        annotationManager,
29        Annotations,
30        Tools,
31        PDFNet,
32        getCanvasMultiplier,
33      } = instance.Core;
34      await PDFNet.initialize();
35
36      const createSnipTool = docViewer => {
37        const SnipTool = function() {
38          Tools.RectangleCreateTool.apply(this, arguments);
39          this.defaults.StrokeColor = new Annotations.Color('#ff0000');
40          this.defaults.StrokeThickness = 2;
41        };
42        SnipTool.prototype = new Tools.RectangleCreateTool();
43
44        return new SnipTool(docViewer);
45      };
46
47      const customSnipTool = createSnipTool(documentViewer);
48
49      instance.UI.setToolbarGroup('toolbarGroup-Edit');
50
51      // Register tool
52      instance.UI.registerTool({
53        toolName: 'SnipTool',
54        toolObject: customSnipTool,
55        // Icon made by https://www.flaticon.com/authors/smalllikeart from https://www.flaticon.com/
56        buttonImage: '../../../price.svg',
57        buttonName: 'snipToolButton',
58        tooltip: 'Snipping Tool',
59      });
60
61      // Add tool button in header
62      instance.UI.setHeaderItems((header) => {
63        header
64          .getHeader('toolbarGroup-Edit')
65          .get('cropToolGroupButton')
66          .insertAfter({
67            type: 'toolButton',
68            toolName: 'SnipTool',
69          })
70          .insertAfter({
71            type: 'actionButton',
72            img:
73              '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M0 0h24v24H0z" fill="none"/><path d="M17 3H5c-1.11 0-2 .9-2 2v14c0 1.1.89 2 2 2h14c1.1 0 2-.9 2-2V7l-4-4zm-5 16c-1.66 0-3-1.34-3-3s1.34-3 3-3 3 1.34 3 3-1.34 3-3 3zm3-10H5V5h10v4z"/></svg>',
74            onClick: async () => {
75              // flatten annotations
76              const annots = await annotationManager.exportAnnotations();
77              const fdf_doc = await PDFNet.FDFDoc.createFromXFDF(annots);
78              const doc = await documentViewer.getDocument().getPDFDoc();
79              await doc.fdfUpdate(fdf_doc);
80              await doc.flattenAnnotations();
81              annotationManager.deleteAnnotations(annotationManager.getAnnotationsList());
82              documentViewer.refreshAll();
83              documentViewer.updateView();
84              documentViewer.getDocument().refreshTextData();
85            },
86            title: 'Flatten Annotations',
87          });
88      });
89
90      customSnipTool.addEventListener('annotationAdded', annotation => {
91        const pageIndex = annotation.PageNumber;
92        // get the canvas for the page
93        const rootElement = document.getElementsByTagName('apryse-webviewer')[0].shadowRoot;
94        const canvasMultiplier = getCanvasMultiplier();
95        const pageContainer = rootElement.getElementById(
96          'pageContainer' + pageIndex,
97        );
98        const pageCanvas = pageContainer.querySelector('.canvas' + pageIndex);
99        const topOffset = parseFloat(pageContainer.style.top) || 0;
100        const leftOffset = parseFloat(pageContainer.style.left) || 0;
101
102        const zoom = documentViewer.getZoomLevel();
103        const x = annotation.X * zoom - leftOffset;
104        const y = annotation.Y * zoom - topOffset;
105        const width = annotation.Width * zoom * canvasMultiplier;
106        const height = annotation.Height * zoom * canvasMultiplier;
107
108        const copyCanvas = document.createElement('canvas');
109        copyCanvas.width = width;
110        copyCanvas.height = height;
111        const ctx = copyCanvas.getContext('2d');
112        // copy the image data from the page to a new canvas so we can get the data URL
113        ctx.drawImage(pageCanvas, x, y, width, height, 0, 0, width, height);
114        const imageData = ctx.getImageData(0, 0, width, height);
115        const code = jsQR(imageData.data, imageData.width, imageData.height);
116
117        if (code) {
118          alert(`QR Code: ${code.data}`);
119        } else {
120          javascriptBarcodeReader({
121            image: copyCanvas,
122            barcode: 'code-128',
123          }).then((result) => {
124            alert(`Barcode: ${result}`);
125          }).catch(console.log);
126        }
127
128        annotationManager.deleteAnnotation(annotation);
129      });
130    });
131  }, []);
132
133  return (
134    <div className="container">
135      <div className="webviewer" ref={viewer}></div>
136      <Barcode instance={viewerInstance} />
137    </div>
138  );
139};
140
141export default WebViewerPDFTron;
142