codifyiq_pdf_viewer 1.1.0

A PDF viewer widget with zoom controls, a page indicator, and optional text search, powered by pdfrx.

codifyiq_pdf_viewer

A reusable PDF viewer backed by pdfrx. Renders a document from a network URI, a local file path, or in-memory bytes via a single PdfSource parameter.

Demo

Select the image for a quick walkthrough:

Features

• Built-in search UI — a Material search bar, debounced input, match counter, and next/previous controls that wrap around at both ends.
• Consistent zoom bounds — the minScale / maxScale you pass are honored by pinch, +/− buttons, and Ctrl/Cmd + scroll-wheel alike.
• On-screen web zoom buttons and a page indicator overlay.
• A unified PdfSource (value-equal variants) in place of pdfrx's separate .uri / .file / .data constructors, so swapping documents at runtime diffs cleanly.
• On-demand streaming for network PDFs — opt in with preferRangeAccess to fetch only the byte ranges the viewport needs, so the first page of a large document renders without waiting for the whole file to download. Pair it with useProgressiveLoading (on by default) so later pages resolve before the download finishes instead of all at once.
• Download progress — a linear progress bar (determinate when the server sends a content length) is shown across the top of the viewer while a network PDF loads; opt out with showDownloadProgress: false or hook onDownloadProgress to drive your own UI.
• Open to a page — initialPageNumber opens the document to a specific page (deep links, resuming a reader), and networkTimeout bounds a stalled network load so it surfaces the error UI instead of spinning forever.

Installation

dependencies:
  codifyiq_pdf_viewer: ^1.1.0

Usage

import 'package:codifyiq_pdf_viewer/codifyiq_pdf_viewer.dart';

PdfViewerWidget(
  source: PdfSource.uri(Uri.parse('https://example.com/file.pdf')),
  enableSearch: true,
  onDocumentLoaded: (pageCount) => debugPrint('Loaded $pageCount pages'),
);

Load from a local file or in-memory bytes with the other PdfSource variants:

PdfViewerWidget(source: PdfSource.file('/path/to/file.pdf'));
PdfViewerWidget(source: PdfSource.bytes(myUint8List));

Authentication

For PDFs behind an authenticated endpoint, pass HTTP headers via PdfSource.uri:

PdfViewerWidget(
  source: PdfSource.uri(
    Uri.parse('https://api.example.com/documents/42.pdf'),
    headers: {'Authorization': 'Bearer $jwt'},
  ),
);

Streaming large PDFs

Set preferRangeAccess: true on PdfSource.uri to render the first page after a single small request instead of downloading the entire file first:

PdfViewerWidget(
  source: PdfSource.uri(
    Uri.parse('https://example.com/large-report.pdf'),
    preferRangeAccess: true,
  ),
);

The server must answer range requests with 206 Partial Content; if it doesn't, pdfrx falls back to a full download automatically, so enabling this is safe even when range support is unknown. It's a load-time choice applied when the document first opens, and it has no effect on web.

For a large, multi-page document you usually want range access and progressive loading (the latter is on by default) so later pages render before the whole file arrives:

PdfViewerWidget(
  source: PdfSource.uri(
    Uri.parse('https://example.com/large-report.pdf'),
    preferRangeAccess: true,
    useProgressiveLoading: true, // default; shown for clarity
  ),
);

Requires a linearized PDF. True page-by-page streaming only works when the document is linearized ("Fast Web View") — a layout that puts a hint table and the first page at the front of the file. A non-linearized PDF keeps its cross-reference table and object streams at the end, so pages past the first can't resolve until (essentially) the whole file has been fetched, even with preferRangeAccess: true. In that case you'll see the first page, then the rest appear together once the download completes. Linearize your PDFs at ingest/build time — e.g. qpdf --linearize in.pdf out.pdf — to get incremental page loading; it's a one-time step and doesn't change how they render otherwise.

Web note: PDFs loaded via PdfSource.uri require the server to send appropriate CORS headers. PdfSource.file is not supported on the web platform.

---

Part of the CodifyIQ component family · pub.dev/publishers/codifyiq.com