xavierk
cedf4839bd
Rendering moves into a module Web Worker behind a latest-wins RenderClient with a watchdog and a handshake-based main-thread fallback. The preview shows the real PDF through pdf.js at 2x with zoom, page indicator, audit issues popover and a focus modal. A4/Letter and margin controls are frozen into each invoice at issue and can be saved as the default (migration M3). react-pdf and pdf.js are lazy-loaded; the main chunk shrinks from 1.8 MB to 0.5 MB. The HTML twin and its styles are removed.
51 lines
2.1 KiB
TypeScript
51 lines
2.1 KiB
TypeScript
import { getDocument, GlobalWorkerOptions, type PDFDocumentProxy, type PDFPageProxy, type RenderTask } from "pdfjs-dist";
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import { installStreamAsyncIterator } from "./streamPolyfill";
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GlobalWorkerOptions.workerSrc = new URL("pdfjs-dist/build/pdf.worker.min.mjs", import.meta.url).toString();
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installStreamAsyncIterator();
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export type { PDFDocumentProxy, PDFPageProxy };
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/**
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* Opens PDF bytes. The bytes are copied because pdf.js transfers the buffer to its worker, which
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* would detach the caller's array. Glyphs are drawn as paths (`disableFontFace`) so the preview looks
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* the same on WebKitGTK and WebView2. (pdf.js 6 dropped `isEvalSupported`; it no longer evaluates font code.)
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*/
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export function openPdf(bytes: Uint8Array): Promise<PDFDocumentProxy> {
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return getDocument({ data: bytes.slice(), disableFontFace: true }).promise;
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}
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/** Releases the document and its worker resources. */
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export function closePdf(doc: PDFDocumentProxy): Promise<void> {
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return doc.loadingTask.destroy();
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}
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const tasks = new WeakMap<object, RenderTask>();
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/** Cancels whatever render is running for `slot` (a canvas, or any object the caller keys on). */
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export function cancelPageRender(slot: object): void {
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tasks.get(slot)?.cancel();
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tasks.delete(slot);
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}
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/**
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* Draws `page` into `canvas` at `scale` device pixels per PDF point, sizing the backing store to
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* match. Starting a render for a slot cancels its previous one; a cancelled render rejects with
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* pdf.js's RenderingCancelledException (see isRenderCancelled).
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*/
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export async function renderPageToCanvas(page: PDFPageProxy, canvas: HTMLCanvasElement, scale: number, slot: object = canvas): Promise<void> {
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cancelPageRender(slot);
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const viewport = page.getViewport({ scale });
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canvas.width = Math.ceil(viewport.width);
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canvas.height = Math.ceil(viewport.height);
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const task = page.render({ canvas, viewport });
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tasks.set(slot, task);
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try {
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await task.promise;
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} finally {
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if (tasks.get(slot) === task) tasks.delete(slot);
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}
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}
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export const isRenderCancelled = (err: unknown): boolean => (err as { name?: string } | null)?.name === "RenderingCancelledException";
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