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comparison Applications/StoneWebViewer/WebApplication/pdf-viewer.js @ 1652:fa9e6bf84958

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integrating pdf.js into Stone Web viewer
author Sebastien Jodogne <s.jodogne@gmail.com>
date Mon, 16 Nov 2020 20:47:53 +0100
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children 66e5fcdf5597
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1651:00674f3695f2 1652:fa9e6bf84958
1 /**
2 * Stone of Orthanc
3 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
4 * Department, University Hospital of Liege, Belgium
5 * Copyright (C) 2017-2020 Osimis S.A., Belgium
6 *
7 * This program is free software: you can redistribute it and/or
8 * modify it under the terms of the GNU Affero General Public License
9 * as published by the Free Software Foundation, either version 3 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Affero General Public License for more details.
16 *
17 * You should have received a copy of the GNU Affero General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 **/
20
21
22
23
24 // Loaded via <script> tag, create shortcut to access PDF.js exports.
25 var pdfjsLib = window['pdfjs-dist/build/pdf'];
26
27 // The workerSrc property shall be specified.
28 pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://cdn.jsdelivr.net/npm/pdfjs-dist@2.5.207/build/pdf.worker.min.js';
29
30
31
32 var ZOOM_FACTOR = 1.3;
33 var FIT_MARGIN = 10;
34
35 Vue.component('pdf-viewer', {
36 props: [ 'prefix', 'pdf' ], // "pdf" must correspond to a "Uint8Array"
37 template: '#pdf-viewer',
38 data: function() {
39 return {
40 container: null,
41 canvas: null,
42 ctx: null,
43
44 scale: 1,
45 countPages: 0,
46 currentPage: 0,
47 pdfDoc: null,
48 isRendering: false,
49 pageNumPending: null
50 }
51 },
52 watch: {
53 pdf: function(newVal, oldVal) {
54 this.LoadPdf();
55 }
56 },
57 mounted: function() {
58 this.container = document.getElementById(this.prefix + '-container');
59 this.canvas = document.getElementById(this.prefix + '-canvas');
60 this.ctx = this.canvas.getContext('2d');
61
62 if (this.container === null ||
63 this.canvas === null ||
64 this.ctx === null) {
65 alert('Bad viewer configuration');
66 }
67
68 var that = this;
69 this.container.addEventListener('wheel', function(event) {
70 that.MouseWheel(event);
71 });
72 },
73 methods: {
74 NextPage: function() {
75 if (this.pdfDoc !== null &&
76 this.currentPage < this.pdfDoc.numPages) {
77 this.QueueRenderPage(this.currentPage + 1);
78 }
79 },
80 PreviousPage: function() {
81 if (this.pdfDoc !== null &&
82 this.currentPage > 1) {
83 this.QueueRenderPage(this.currentPage - 1);
84 }
85 },
86 FitWidth: function() {
87 if (this.pdfDoc !== null) {
88 var that = this;
89 this.pdfDoc.getPage(this.currentPage).then(function(page) {
90 // https://github.com/mozilla/pdf.js/issues/5628
91 // https://stackoverflow.com/a/21064102/881731
92 // https://stackoverflow.com/a/60008044/881731
93 var scrollbarWidth = window.innerWidth - document.body.clientWidth + FIT_MARGIN;
94 that.scale = (that.container.offsetWidth - scrollbarWidth) / page.getViewport({ scale: 1.0 }).width;
95 that.QueueRenderPage(that.currentPage);
96 });
97 }
98 },
99 FitHeight: function() {
100 if (this.pdfDoc !== null) {
101 var that = this;
102 this.pdfDoc.getPage(this.currentPage).then(function(page) {
103 // The computation below assumes that "line-height: 0px" CSS
104 // on the parent element of the canvas.
105
106 // https://github.com/mozilla/pdf.js/issues/5628
107 var scrollbarHeight = window.innerHeight - document.body.clientHeight + FIT_MARGIN;
108 that.scale = (that.container.offsetHeight - scrollbarHeight) / page.getViewport({ scale: 1.0 }).height;
109 //that.scale = that.container.clientHeight / page.getViewport({ scale: 1.0 }).height;
110 that.QueueRenderPage(that.currentPage);
111 });
112 }
113 },
114 ZoomIn: function() {
115 this.scale *= ZOOM_FACTOR;
116 this.QueueRenderPage(this.currentPage);
117 },
118 ZoomOut: function() {
119 this.scale /= ZOOM_FACTOR;
120 this.QueueRenderPage(this.currentPage);
121 },
122 LoadPdf: function(pdf) {
123 var that = this;
124 pdfjsLib.getDocument(new Uint8Array(this.pdf)).promise.then(function(pdfDoc_) {
125 that.pdfDoc = pdfDoc_;
126 that.currentPage = 0;
127 that.countPages = pdfDoc_.numPages;
128 that.scale = 1;
129 that.isRendering = false;
130 that.pageNumPending = null;
131
132 // Initial/first page rendering
133 that.RenderPage(1);
134 });
135 },
136 RenderPage: function(pageNum) {
137 var that = this;
138
139 if (this.pdfDoc !== null &&
140 pageNum >= 1 &&
141 pageNum <= this.countPages) {
142 this.isRendering = true;
143 this.pdfDoc.getPage(pageNum).then(function(page) {
144 var viewport = page.getViewport({scale: that.scale});
145
146 that.canvas.height = viewport.height;
147 that.canvas.width = viewport.width;
148
149 // Horizontal centering of the canvas. This requires CSS
150 // "position: relative" on the canvas element.
151 if (that.canvas.width < that.container.clientWidth) {
152 that.canvas.style.left = Math.floor((that.container.clientWidth - viewport.width) / 2) + 'px';
153 } else {
154 that.canvas.style.left = '0px';
155 }
156
157 // Render PDF page into canvas context
158 var renderContext = {
159 canvasContext: that.ctx,
160 viewport: viewport
161 };
162
163 var renderTask = page.render(renderContext);
164
165 // Wait for rendering to finish
166 renderTask.promise.then(function() {
167 that.isRendering = false;
168 that.currentPage = pageNum;
169 if (that.pageNumPending !== null) {
170 // New page rendering is pending
171 that.currentPage = that.pageNumPending;
172 that.pageNumPending = null;
173 that.RenderPage();
174 }
175 });
176 });
177 }
178 },
179 QueueRenderPage: function(pageNum) {
180 if (this.isRendering) {
181 this.pageNumPending = pageNum;
182 } else {
183 this.RenderPage(pageNum);
184 }
185 },
186 MouseWheel: function(event) {
187 if (event.ctrlKey) {
188 if (event.deltaY < 0) {
189 this.ZoomIn();
190 } else if (event.deltaY > 0) {
191 this.ZoomOut();
192 }
193
194 event.preventDefault();
195 }
196 }
197 }
198 });