SfPdfViewer throws error when used inside a nested Navigator

[LiangShaing]

Hi Syncfusion team,

I'm encountering an issue when wrapping SfPdfViewer.memory inside a nested Navigator. When I try to use built-in features like page navigation, I consistently receive the following error:

Failed assertion: line 5646 pos 12: '_history.isNotEmpty': is not true.

Here's a simplified version of the code:

Navigator( key: navigationPossKey, onGenerateInitialRoutes: (navigatorState, initialRoute) { return [ MaterialPageRoute( builder: (context) => Builder( builder: (context) { return SfPdfViewer.memory( _pdfBytes!, ); }, ), ) ]; }, )

I suspect the internal use of Navigator within the PDF viewer is conflicting with the custom navigation context created by the nested Navigator. This causes the internal history stack to behave unexpectedly or break altogether.

Would it be possible to improve support for nested navigators or expose some options to disable internal navigation behavior? Alternatively, is there a recommended approach for using SfPdfViewer inside a tab/page structure with a nested navigator?

Thanks in advance!

[immankumarsync]

Hi @LiangShaing,
We are unable to replicate the reported behavior using the code snippet below. Please find the sample and the video recording attached.

Details

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

import 'package:syncfusion_flutter_pdfviewer/pdfviewer.dart';

void main() {
  runApp(const MainApp());
}

class MainApp extends StatelessWidget {
  const MainApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(home: HomePage());
  }
}

class HomePage extends StatelessWidget {
  const HomePage({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: TextButton(
          onPressed: () async {
            final ByteData data = await rootBundle.load(
              'assets/flutter-succinctly.pdf',
            );
            if (context.mounted) {
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) {
                    return PDFViewerPage(pdfData: data.buffer.asUint8List());
                  },
                ),
              );
            }
          },
          child: const Text('Open PDF'),
        ),
      ),
    );
  }
}

class PDFViewerPage extends StatefulWidget {
  const PDFViewerPage({super.key, required this.pdfData});

  final Uint8List pdfData;

  @override
  State<PDFViewerPage> createState() => _PDFViewerPageState();
}

class _PDFViewerPageState extends State<PDFViewerPage> {
  final GlobalKey<NavigatorState> navigationPossKey =
      GlobalKey<NavigatorState>();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Navigator(
        key: navigationPossKey,
        onGenerateInitialRoutes: (navigatorState, initialRoute) {
          return [
            MaterialPageRoute(
              builder: (context) => Builder(
                builder: (context) {
                  return SfPdfViewer.memory(
                    widget.pdfData,
                    pageLayoutMode: PdfPageLayoutMode.single,
                  );
                },
              ),
            ),
          ];
        },
      ),
    );
  }
}

Please share the below details to replicate the issue at our end.

1. Simple sample or complete code snippet
2. Platform in which the issue ocurs
3. flutter doctor -v report

Sample.zip

[LiangShaing]

Steps to reproduce:

1. Click Button.
2. Enter a page number in the input field.
3. Observe that an error is displayed/triggered.

Thanks in advance!

[immankumarsync]

@LiangShaing, we are able to replicate the reported issue with the provided replication steps where an exception occurs when performing page navigation using the pagination dialog in Single Page Layout mode, specifically when the SfPdfViewer is used within a nested navigator. We are currently validating this issue and will provide further updates once the issue validation is complete.