overleaf/services/web/frontend/js/features/pdf-preview/util/pdf-js-wrapper.js

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7.4 KiB
JavaScript
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import { captureException } from '../../../infrastructure/error-reporter'
import { generatePdfCachingTransportFactory } from './pdf-caching-transport'
import { debugConsole } from '@/utils/debugging'
const params = new URLSearchParams(window.location.search)
const disableFontFace = params.get('disable-font-face') === 'true'
const disableStream = process.env.NODE_ENV !== 'test'
const DEFAULT_RANGE_CHUNK_SIZE = 128 * 1024 // 128K chunks
export default class PDFJSWrapper {
constructor(container) {
this.container = container
}
async init() {
const {
PDFJS,
PDFJSViewer,
cMapUrl,
imageResourcesPath,
standardFontDataUrl,
} = await import('./pdf-js-versions').then(m => {
return m.default
})
this.PDFJS = PDFJS
this.genPdfCachingTransport = generatePdfCachingTransportFactory(PDFJS)
this.PDFJSViewer = PDFJSViewer
this.cMapUrl = cMapUrl
this.standardFontDataUrl = standardFontDataUrl
this.imageResourcesPath = imageResourcesPath
// create the event bus
const eventBus = new PDFJSViewer.EventBus()
// create the link service
const linkService = new PDFJSViewer.PDFLinkService({
eventBus,
externalLinkTarget: 2,
externalLinkRel: 'noopener',
})
// create the localization
// const l10n = new PDFJSViewer.GenericL10n('en-GB') // TODO: locale mapping?
// create the viewer
const viewer = new PDFJSViewer.PDFViewer({
container: this.container,
eventBus,
imageResourcesPath,
linkService,
// l10n, // commented out since it currently breaks `aria-label` rendering in pdf pages
enableScripting: false, // default is false, but set explicitly to be sure
enableXfa: false, // default is false (2021-10-12), but set explicitly to be sure
renderInteractiveForms: false,
maxCanvasPixels: 8192 * 8192, // default is 4096 * 4096, increased for better resolution at high zoom levels
annotationMode: PDFJS.AnnotationMode?.ENABLE, // enable annotations but not forms
annotationEditorMode: PDFJS.AnnotationEditorType?.DISABLE, // disable annotation editing
})
linkService.setViewer(viewer)
this.eventBus = eventBus
this.linkService = linkService
this.viewer = viewer
}
// load a document from a URL
loadDocument({ url, pdfFile, abortController, handleFetchError }) {
// cancel any previous loading task
if (this.loadDocumentTask) {
this.loadDocumentTask.destroy()
this.loadDocumentTask = undefined
}
return new Promise((resolve, reject) => {
const rangeTransport = this.genPdfCachingTransport({
url,
pdfFile,
abortController,
handleFetchError,
})
let rangeChunkSize = DEFAULT_RANGE_CHUNK_SIZE
if (rangeTransport && pdfFile.size < 2 * DEFAULT_RANGE_CHUNK_SIZE) {
// pdf.js disables the "bulk" download optimization when providing a
// custom range transport. Restore it by bumping the chunk size.
rangeChunkSize = pdfFile.size
}
this.loadDocumentTask = this.PDFJS.getDocument({
url,
cMapUrl: this.cMapUrl,
cMapPacked: true,
standardFontDataUrl: this.standardFontDataUrl,
disableFontFace,
rangeChunkSize,
disableAutoFetch: true,
disableStream,
isEvalSupported: false,
textLayerMode: 2, // PDFJSViewer.TextLayerMode.ENABLE,
range: rangeTransport,
})
this.loadDocumentTask.promise
.then(doc => {
if (!this.loadDocumentTask) {
return // ignoring the response since loading task has been aborted
}
const previousDoc = this.viewer.pdfDocument
this.viewer.setDocument(doc)
this.linkService.setDocument(doc)
resolve(doc)
if (previousDoc) {
previousDoc.cleanup().catch(debugConsole.error)
previousDoc.destroy()
}
})
.catch(error => {
if (this.loadDocumentTask) {
if (!error || error.name !== 'MissingPDFException') {
captureException(error, {
tags: { handler: 'pdf-preview' },
})
}
reject(error)
}
})
.finally(() => {
this.loadDocumentTask = undefined
})
})
}
// update the current scale value if the container size changes
updateOnResize() {
if (!this.isVisible()) {
return
}
// Use requestAnimationFrame to prevent errors like "ResizeObserver loop
// completed with undelivered notifications" that can occur if updating the
// viewer causes another repaint. The cost of this is that the viewer update
// lags one frame behind, but it's unlikely to matter.
// Further reading: https://github.com/WICG/resize-observer/issues/38
window.requestAnimationFrame(() => {
const currentScaleValue = this.viewer.currentScaleValue
if (
currentScaleValue === 'auto' ||
currentScaleValue === 'page-fit' ||
currentScaleValue === 'page-width'
) {
this.viewer.currentScaleValue = currentScaleValue
}
this.viewer.update()
})
}
// get the page and offset of a click event
clickPosition(event, pageElement, textLayer) {
const { viewport } = this.viewer.getPageView(textLayer.pageNumber - 1)
const pageCanvas = pageElement.querySelector('canvas')
if (!pageCanvas) {
return
}
const pageRect = pageCanvas.getBoundingClientRect()
const dx = event.clientX - pageRect.left
const dy = event.clientY - pageRect.top
const [left, top] = viewport.convertToPdfPoint(dx, dy)
return {
page: textLayer.pageNumber - 1,
offset: {
left,
top: viewport.viewBox[3] - top,
},
}
}
// get the current page, offset and page size
get currentPosition() {
const pageIndex = this.viewer.currentPageNumber - 1
const pageView = this.viewer.getPageView(pageIndex)
const pageRect = pageView.div.getBoundingClientRect()
const containerRect = this.container.getBoundingClientRect()
const dy = containerRect.top - pageRect.top
const dx = containerRect.left - pageRect.left
const [left, top] = pageView.viewport.convertToPdfPoint(dx, dy)
const [, , width, height] = pageView.viewport.viewBox
return {
page: pageIndex,
offset: { top, left },
pageSize: { height, width },
}
}
scrollToPosition(position, scale = null) {
const destArray = [
null,
{
name: 'XYZ', // 'XYZ' = scroll to the given coordinates
},
position.offset.left,
position.offset.top,
scale,
]
this.viewer.scrollPageIntoView({
pageNumber: position.page + 1,
destArray,
})
// scroll the page left and down by an extra few pixels to account for the pdf.js viewer page border
const pageIndex = this.viewer.currentPageNumber - 1
const pageView = this.viewer.getPageView(pageIndex)
const offset = parseFloat(getComputedStyle(pageView.div).borderWidth)
this.viewer.container.scrollBy({
top: -offset,
left: -offset,
})
}
isVisible() {
return this.viewer.container.offsetParent !== null
}
abortDocumentLoading() {
this.loadDocumentTask = undefined
}
destroy() {
if (this.loadDocumentTask) {
this.loadDocumentTask.destroy()
this.loadDocumentTask = undefined
}
if (this.viewer) {
this.viewer.destroy()
}
}
}