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// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
// See License.txt for license information.
import FileInfoPreview from './file_info_preview.jsx';
import loadingGif from 'images/load.gif';
import React from 'react';
import PDFJS from 'pdfjs-dist';
import {FormattedMessage} from 'react-intl';
const MAX_PDF_PAGES = 5;
export default class PDFPreview extends React.Component {
constructor(props) {
super(props);
this.updateStateFromProps = this.updateStateFromProps.bind(this);
this.onDocumentLoad = this.onDocumentLoad.bind(this);
this.onPageLoad = this.onPageLoad.bind(this);
this.renderPDFPage = this.renderPDFPage.bind(this);
this.pdfPagesRendered = {};
this.state = {
pdf: null,
pdfPages: {},
pdfPagesLoaded: {},
numPages: 0,
loading: true,
success: false
};
}
componentDidMount() {
this.updateStateFromProps(this.props);
}
componentWillReceiveProps(nextProps) {
if (this.props.fileUrl !== nextProps.fileUrl) {
this.updateStateFromProps(nextProps);
this.pdfPagesRendered = {};
}
}
componentDidUpdate() {
if (this.state.success) {
for (let i = 0; i < this.state.numPages; i++) {
this.renderPDFPage(i);
}
}
}
renderPDFPage(pageIndex) {
if (this.pdfPagesRendered[pageIndex] || !this.state.pdfPagesLoaded[pageIndex]) {
return;
}
const canvas = this.refs['pdfCanvas' + pageIndex];
const context = canvas.getContext('2d');
const viewport = this.state.pdfPages[pageIndex].getViewport(1);
canvas.height = viewport.height;
canvas.width = viewport.width;
const renderContext = {
canvasContext: context,
viewport
};
this.state.pdfPages[pageIndex].render(renderContext);
this.pdfPagesRendered[pageIndex] = true;
}
updateStateFromProps(props) {
this.setState({
pdf: null,
pdfPages: {},
pdfPagesLoaded: {},
numPages: 0,
loading: true,
success: false
});
PDFJS.getDocument(window.mm_config.SiteURL + props.fileUrl).then(this.onDocumentLoad);
}
onDocumentLoad(pdf) {
const numPages = pdf.numPages <= MAX_PDF_PAGES ? pdf.numPages : MAX_PDF_PAGES;
this.setState({pdf, numPages});
for (let i = 1; i <= pdf.numPages; i++) {
pdf.getPage(i).then(this.onPageLoad);
}
}
onPageLoad(page) {
const pdfPages = Object.assign({}, this.state.pdfPages);
pdfPages[page.pageIndex] = page;
const pdfPagesLoaded = Object.assign({}, this.state.pdfPagesLoaded);
pdfPagesLoaded[page.pageIndex] = true;
this.setState({pdfPages, pdfPagesLoaded});
if (page.pageIndex === 0) {
this.setState({success: true, loading: false});
}
}
static supports(fileInfo) {
return fileInfo.extension === 'pdf';
}
render() {
if (this.state.loading) {
return (
<div className='view-image__loading'>
<img
className='loader-image'
src={loadingGif}
/>
</div>
);
}
if (!this.state.success) {
return (
<FileInfoPreview
fileInfo={this.props.fileInfo}
fileUrl={this.props.fileUrl}
/>
);
}
const pdfCanvases = [];
for (let i = 0; i < this.state.numPages; i++) {
pdfCanvases.push(
<canvas
ref={'pdfCanvas' + i}
key={'previewpdfcanvas' + i}
/>
);
if (i < this.state.numPages - 1 && this.state.numPages > 1) {
pdfCanvases.push(
<div className='pdf-preview-spacer'/>
);
}
}
if (this.state.pdf.numPages > MAX_PDF_PAGES) {
pdfCanvases.push(
<a
href={this.props.fileUrl}
className='pdf-max-pages'
>
<FormattedMessage
id='pdf_preview.max_pages'
defaultMessage='Download to read more pages'
/>
</a>
);
}
return (
<div className='post-code'>
{pdfCanvases}
</div>
);
}
}
PDFPreview.propTypes = {
fileInfo: React.PropTypes.object.isRequired,
fileUrl: React.PropTypes.string.isRequired
};
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