92 lines
2.0 KiB
TypeScript
92 lines
2.0 KiB
TypeScript
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/// <reference lib="webworker" />
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import PDFDocument from 'pdfkit/lib/document'
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import SVGtoPDF from 'svg-to-pdfkit'
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type ImgType = 'svg' | 'png'
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type DataResultType = 'dataUrl' | 'text'
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const readData = (blob: Blob, type: DataResultType): Promise<string> => {
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return new Promise((resolve, reject) => {
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const reader = new FileReader()
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reader.onload = (): void => {
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const result = reader.result
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resolve(result as string)
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}
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reader.onerror = reject
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if (type === 'dataUrl') {
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reader.readAsDataURL(blob)
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} else {
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reader.readAsText(blob)
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}
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})
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}
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const fetchBlob = async (imgUrl: string): Promise<Blob> => {
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const r = await fetch(imgUrl, {
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cache: 'no-cache',
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})
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return r.blob()
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}
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const generatePDF = async (imgBlobs: Blob[], imgType: ImgType, width: number, height: number): Promise<ArrayBuffer> => {
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// @ts-ignore
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const pdf = new (PDFDocument as typeof import('pdfkit'))({
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// compress: true,
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size: [width, height],
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autoFirstPage: false,
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margin: 0,
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layout: 'portrait',
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})
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if (imgType === 'png') {
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const imgDataUrlList: string[] = await Promise.all(imgBlobs.map(b => readData(b, 'dataUrl')))
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imgDataUrlList.forEach((data) => {
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pdf.addPage()
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pdf.image(data, {
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width,
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height,
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})
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})
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} else { // imgType == "svg"
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const svgList = await Promise.all(imgBlobs.map(b => readData(b, 'text')))
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svgList.forEach((svg) => {
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pdf.addPage()
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SVGtoPDF(pdf, svg, 0, 0, {
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preserveAspectRatio: 'none',
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})
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})
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}
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// @ts-ignore
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const buf: Uint8Array = await pdf.getBuffer()
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return buf.buffer
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}
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export type PDFWorkerMessage = [string[], ImgType, number, number];
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onmessage = async (e): Promise<void> => {
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const [
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imgUrls,
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imgType,
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width,
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height,
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] = e.data as PDFWorkerMessage
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const imgBlobs = await Promise.all(imgUrls.map(url => fetchBlob(url)))
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const pdfBuf = await generatePDF(
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imgBlobs,
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imgType,
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width,
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height,
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)
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postMessage(pdfBuf, [pdfBuf])
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}
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