Daniele
71e1a26b08
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On iOS the file viewer showed only the first page of a PDF, with no way to scroll to the rest — the document had to be downloaded and opened in another app. The cause was not ours: WebKit refuses to mount its PDF viewer inside an <iframe>/<object>/<embed> and paints a static first-page thumbnail instead. That hits Safari on iOS and every WKWebView, so the native shell too. The full viewer only exists for a top-level navigation. The desktop browsers do mount a viewer, but each mounts its own — Chrome's toolbar, Safari's page-index sidebar — so the same document also looked different on every machine. Both are answered by drawing the pages ourselves. New <pdf-view> (web/components/shared/pdf-view.js) renders a continuous scroll of canvas pages on the vendored pdf.js, with a zoom control and a page counter, and replaces the iframe for both native .pdf files and server-compiled LaTeX. Three properties are load-bearing: - pdf.js is imported lazily (~450 KB + a 1.2 MB worker), so a session that never opens a PDF never pays for it. - Canvases are created and destroyed as pages scroll. iOS caps the total canvas backing store a page may hold and silently blanks canvases past it, so an eager render would come out empty on exactly the platform this was written for. Off-screen pages keep only a correctly-sized box, which is also what keeps the scrollbar honest. - The text layer (selection, in-page find) is best-effort: it is transparent DOM over the pixels, so its failures are swallowed rather than surfaced. Vendored from pdfjs-dist 6.2.108: pdf.min.mjs, pdf.worker.min.mjs, the standard-font data (needed by PDFs that reference Helvetica/Times without embedding them) and the .textLayer block of pdf_viewer.css. CJK cmaps are deliberately left out. pdf.js 6 needs Safari/iOS 17.4+. Verified in headless Chromium against both a synthetic 12-page PDF using non-embedded Helvetica and a real 14-page paper with embedded fonts and figures: all pages present, last page renders after scrolling, page 1 released off-screen, text layer populated, zoom re-renders at the new scale, no JS errors.
28 lines
1.5 KiB
Plaintext
28 lines
1.5 KiB
Plaintext
// Copyright 2014 PDFium Authors. All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following disclaimer
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// in the documentation and/or other materials provided with the
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// distribution.
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// * Neither the name of Google Inc. nor the names of its
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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