gotopage

[scerio]

gotopage

[emreesen27]

First of all, I'm sorry for my bad English. I am looking for a method that allows the user to go directly to a specific page.

[emreesen27]

native_pdf_view
https://pub.dev/packages/native_pdf_view

[SergeShkurko]

you can attach PageController

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  int _actualPageNumber = 1;
  PDFDocument _document;
  
  PageController _pageController; // <---------

  @override
  void initState() {
    _pageController = PageController(
      initialPage: 0
    );
    super.initState();
  }

  @override
  void dispose() {
    _pageController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => MaterialApp(
        theme: ThemeData(primaryColor: Colors.white),
        home: Scaffold(
          appBar: AppBar(title: Text('PDFView example')),
          body: FutureBuilder<PDFDocument>(
            future: _getDocument(),
            builder: (_, snapshot) {
              if (snapshot.hasData) {
                return Stack(
                  children: <Widget>[
                    PDFView(
                      controller: _pageController, // <---- attach controller
                      document: snapshot.data,
                      onPageChanged: (page) {
                        setState(() {
                          _actualPageNumber = page;
                        });
                      },
                    ),
                    Align(
                      alignment: Alignment.center,
                      child: Text(
                        '$_actualPageNumber/${snapshot.data.pagesCount}',
                        style: TextStyle(fontSize: 34),
                      ),
                    )
                  ],
                );
              }

              if (snapshot.hasError) {
                return Center(
                  child: Text(
                    'PDF Rendering does not '
                    'support on the system of this version',
                  ),
                );
              }

              return Center(child: CircularProgressIndicator());
            },
          ),
        ),
      );

  Future<PDFDocument> _getDocument() async {
    if (_document != null) {
      return _document;
    }
    if (await hasSupport()) {
      return _document = await PDFDocument.openAsset('assets/sample.pdf');
    } else {
      throw Exception(
        'PDF Rendering does not '
        'support on the system of this version',
      );
    }
  }
}

after call for choose:

_pageController.jumpToPage(pageIndex);

or call for animated choose:

_pageController.animateToPage(
  pageIndex,
  curve: Curves.decelerate,
  duration: Duration(milliseconds: 250),
);

[SergeShkurko]

@emreesen27 What kind of plugin are you talking about?

[SergeShkurko]

plugin native_pdf_view ?

[deakjahn]

With the caveat, Serge, that you should never load anything into a FutureBuilder like this. Calling the loader function from inside the builder means that it will be called repeatedly for each frame rendered, reloading the PDF each and every time.

Instead, declare a Future variable, not a function:

Future<PDFDocument> document;

Populate it inside initState():

_document = PDFDocument.openAsset('assets/sample.pdf');

then refer to this variable in the builder:

FutureBuilder<PDFDocument>(
        future: _document,

See the official docs for details.

[SergeShkurko]

@deakjahn I know. This code is used a simple example only.