multi_engine_pdf_viewer 0.2.0

An engine-independent PDF viewer for Android and iOS with PDFKit, PDF.js, EmbedPDF and native PDFium, search, outlines, links, and named actions.

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

0.2.0

• Add an automatically registered iOS PDFKit engine, adapted from feature/pdf_native_ios, behind the existing controller/session contract.
• Keep PDF.js as the package default on iOS and Android; host applications own the PDFKit platform default and disable flags.
• Log unsupported mobile engine selections and fall back to PDF.js before creating the adapter, retaining page/layout/callbacks and emitting a diagnostic.
• Support native vertical/grid rendering, pinch/double-tap zoom, page callbacks, internal/named links, outline destinations and cancellable progressive search.
• Forward only allowlisted external links to the host, redact native errors, and fall back once to pdfrx for PDFKit plugin/transport failures.
• Add native-session/facade regression tests, generated-fixture iOS integration coverage and an opt-in real-HID simulator harness.
• Show per-page PDF.js loading indicators and remove the startup overlay once page layout is ready.
• Keep the JavaScript compatibility guard as an upper bound without requiring unused logical-assignment syntax.

0.1.8

• Keep the same anchored page geometry throughout EmbedPDF pinch, touch end and cancellation instead of transforming the full document and relaying it out on release.
• Defer zoom raster work until the gesture settles; replace canvases atomically, release old backing stores and reuse pixel-capped resolutions.
• Reserve raster-cache headroom for replacements and recheck the budget when overlapping worker results arrive, without evicting visible pages.
• Cover pinch geometry, stale render results, large-document limits, overlapping navigation and real-browser pinch thresholds while preserving fatal fallback.

0.1.7

• Coalesce identical PDFium form-action callbacks from a single EmbedPDF click so PDFs that repeat NextPage or PrevPage navigate once instead of failing with ambiguous-widget-action. Conflicting actions remain rejected.
• Verify forward and backward navigation with a real PDF in the iOS simulator. Unit tests and new physical Android/iOS smoke checks were explicitly deferred by the maintainer for this release.

0.1.6

• Remove the four-page touch-scroll limiter from all PDF.js tiers, preserving native dragging and momentum without changing pinch zoom, grid layout or navigation anchors.
• Remove the unused shared scroll limiter and cover forward and backward scrolling during dragging, after touch end and after touch cancellation in legacy, compatibility and current tiers.

0.1.5

• Remove the four-page touch-scroll limiter from EmbedPDF so native dragging and momentum no longer snap back at the gesture boundary. PDF.js behavior is unchanged.
• Cover forward and backward touch scrolling during dragging, after touch end, and after touch cancellation while preserving pinch zoom and navigation anchors.

0.1.4

• Fall back once from fatal EmbedPDF failures to native pdfrx while retaining the last page and layout. PDF.js remains the default engine.
• Raise the EmbedPDF document limit to 200 MiB and send larger documents directly to native progressive loading; other resource quotas remain terminal.
• Ignore targetless overlapping PDFium links, prefer explicit native link annotations over detected URLs, and preserve coordinate-bearing native destinations.
• Clear native link caches on document changes and discard asynchronous taps after document or layout replacement.
• Cover overlapping link selection with a real PDFium-WASM regression test and align fallback documentation.

0.1.3

• Polyfill ReadableStream async iteration in the PDF.js host page. WebKit lacks it, so PDF.js text extraction failed and in-document search found nothing on iOS.

0.1.2

• Keep unresolved outline destinations null in PDF.js and EmbedPDF instead of copying a preceding or parent target. A heading still uses the first descendant that has a real destination.
• Resolve PDF.js named destinations one name at a time, so an incomplete bulk name tree does not drop a real target, and accept indirect page references.
• Treat a pdfrx outline destination whose page number is below 1 as unresolved. PDFium reports that case as page 0.
• Limit single-column touch scrolling to four pages of momentum in the PDF.js and EmbedPDF viewers.
• Pause the EmbedPDF heartbeat while another route covers the viewer, and restore it when that route is current again.
• Include the failure in PdfViewerDiagnostic.toString.

0.1.1

• Ship the PDF.js pdf.min.mjs and pdf.worker.min.mjs files for the legacy, compat, and current tiers. Version 0.1.0 omitted them.

0.1.0

Initial release.

• Engine-independent PDF viewer for Android and iOS behind a single controller.
• Three interchangeable rendering engines: PDF.js (WebView), EmbedPDF (offline PDFium-WASM) and pdfrx/PDFium (native).
• Vertical fit-width and grid layouts, pinch and double-tap zoom.
• Text search with result navigation and counters.
• Engine-neutral outline bookmarks, internal links and named-action handling.
• Allowlisted external links forwarded to the host application.
• Runnable Android and iOS example application.