Single Page pdf is not viewing

[manojeeva]

From Local and also from URL single page pdf is not view.
The view is empty.
Test Case.
Simply put single page pdf URL in the widget.
Sample URL
https://en.unesco.org/inclusivepolicylab/sites/default/files/dummy-pdf_2.pdf

[lohanidamodar]

Hi, @manojeeva thanks for reporting. I will test and let you know.

[JoeCiou]

It may be caused because of this.

[manojeeva]

Is it possible to merge it?
Any idea when it will be available here?
Right now I'm updating count to 2 if it is 1.
I can see two same page.

[jags-aaron]

I changed some validations, and the issue seems to be fixed this

[irvincastellanos]

I changed some validations, and the issue seems to be fixed this

Awesome man, I have the same problem and this change solves it! 🙌🏽

[ararage]

I changed some validations, and the issue seems to be fixed this

This solves the problem :D

[dinhthienkhai]

I changed some validations, and the issue seems to be fixed this

Hi All,
I got same issue, just view pdf file with more 2 pages. I want to ask that what is "changed some validations"?

[jags-aaron]

@dinhthienkhai

If you are using MacOS

just open a terminal and copy this:

1.- cd /Users/$USER/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-1.2.1+2/lib/src/viewer.dart
2.- open ./
3.- open the file viewer.dart

NOTES:
Change (advance_pdf_viewer-1.2.1+2) with your version

dependencies:
  advance_pdf_viewer: ^1.2.1+2

Then replace the file viewer.dart content with this:
https://github.com/lohanidamodar/pdf_viewer/blob/49b58134fc22e0464e7f7f66b82439527988c26c/lib/src/viewer.dart

Because you are modifying the local library file this could be overwritten.
you will need to do the same every time you update your pubspect.yaml until the fix is in a new version of the library

hope it helps :)

[devmgs]

I created a custom class

import 'package:flutter/material.dart';
import 'package:advance_pdf_viewer/advance_pdf_viewer.dart';
import 'package:numberpicker/numberpicker.dart';

/// enum to describe indicator position
enum IndicatorPosition { topLeft, topRight, bottomLeft, bottomRight }

/// PDFViewer, a inbuild pdf viewer, you can create your own too.
/// [document] an instance of `PDFDocument`, document to be loaded
/// [indicatorText] color of indicator text
/// [indicatorBackground] color of indicator background
/// [pickerButtonColor] the picker button background color
/// [pickerIconColor] the picker button icon color
/// [indicatorPosition] position of the indicator position defined by `IndicatorPosition` enum
/// [showIndicator] show,hide indicator
/// [showPicker] show hide picker
/// [showNavigation] show hide navigation bar
/// [toolTip] tooltip, instance of `PDFViewerTooltip`
/// [enableSwipeNavigation] enable,disable swipe navigation
/// [scrollDirection] scroll direction horizontal or vertical
/// [lazyLoad] lazy load pages or load all at once
/// [controller] page controller to control page viewer
/// [zoomSteps] zoom steps for pdf page
/// [minScale] minimum zoom scale for pdf page
/// [maxScale] maximum zoom scale for pdf page
/// [panLimit] pan limit for pdf page
/// [onPageChanged] function called when page changes
///
class MyPDFViewer extends StatefulWidget {
  final PDFDocument document;
  final Color indicatorText;
  final Color indicatorBackground;
  final Color pickerButtonColor;
  final Color pickerIconColor;
  final IndicatorPosition indicatorPosition;
  final bool showIndicator;
  final bool showPicker;
  final bool showNavigation;
  final PDFViewerTooltip tooltip;
  final bool enableSwipeNavigation;
  final Axis scrollDirection;
  final bool lazyLoad;
  final PageController controller;
  final int zoomSteps;
  final double minScale;
  final double maxScale;
  final double panLimit;
  final ValueChanged<int> onPageChanged;

  final Widget Function(
      BuildContext,
      int pageNumber,
      int totalPages,
      void Function({int page}) jumpToPage,
      void Function({int page}) animateToPage,
      ) navigationBuilder;
  final Widget progressIndicator;

  MyPDFViewer({
    Key key,
    @required this.document,
    this.scrollDirection,
    this.lazyLoad = true,
    this.indicatorText = Colors.white,
    this.indicatorBackground = Colors.black54,
    this.showIndicator = true,
    this.showPicker = true,
    this.showNavigation = true,
    this.enableSwipeNavigation = true,
    this.tooltip = const PDFViewerTooltip(),
    this.navigationBuilder,
    this.controller,
    this.indicatorPosition = IndicatorPosition.topRight,
    this.zoomSteps,
    this.minScale,
    this.maxScale,
    this.panLimit,
    this.progressIndicator,
    this.pickerButtonColor,
    this.pickerIconColor,
    this.onPageChanged,
  }) : super(key: key);

  _MyPDFViewerState createState() => _MyPDFViewerState();
}

class _MyPDFViewerState extends State<MyPDFViewer> {
  bool _isLoading = true;
  int _pageNumber;
  bool _swipeEnabled = true;
  List<PDFPage> _pages;
  PageController _pageController;
  final Duration animationDuration = Duration(milliseconds: 200);
  final Curve animationCurve = Curves.easeIn;

  @override
  void initState() {
    super.initState();
    //if(widget.document.count==1)
   // widget.document.count=widget.document.count+1;
    _pages = List(widget.document.count);
    _pageController = widget.controller ?? PageController();
    _pageNumber = _pageController.initialPage + 1;
    if (!widget.lazyLoad)
      widget.document.preloadPages(
        onZoomChanged: onZoomChanged,
        zoomSteps: widget.zoomSteps,
        minScale: widget.minScale,
        maxScale: widget.maxScale,
        panLimit: widget.panLimit,
      );
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _pageNumber = _pageController.initialPage + 1;
    _isLoading = true;
    _pages = List(widget.document.count);
    // _loadAllPages();
    _loadPage();
  }

  @override
  void didUpdateWidget(MyPDFViewer oldWidget) {
    super.didUpdateWidget(oldWidget);
  }

  onZoomChanged(double scale) {
    if (scale != 1.0) {
      setState(() {
        _swipeEnabled = false;
      });
    } else {
      setState(() {
        _swipeEnabled = true;
      });
    }
  }

  _loadPage() async {
    if (_pages[_pageNumber - 1] != null) return;
    setState(() {
      _isLoading = true;
    });
    final data = await widget.document.get(
      page: _pageNumber,
      onZoomChanged: onZoomChanged,
      zoomSteps: widget.zoomSteps,
      minScale: widget.minScale,
      maxScale: widget.maxScale,
      panLimit: widget.panLimit,
    );
    _pages[_pageNumber - 1] = data;
    if (mounted) {
      setState(() {
        _isLoading = false;
      });
    }
  }

  _animateToPage({int page}) {
    _pageController.animateToPage(page != null ? page : _pageNumber - 1,
        duration: animationDuration, curve: animationCurve);
  }

  _jumpToPage({int page}) {
    _pageController.jumpToPage(page != null ? page : _pageNumber - 1);
  }

  Widget _drawIndicator() {
    print("widget.document.count : "+widget.document.count.toString());
    Widget child = GestureDetector(
        onTap:
        widget.showPicker && widget.document.count >= 1 ? _pickPage : null,
        child: Container(
            padding:
            EdgeInsets.only(top: 4.0, left: 16.0, bottom: 4.0, right: 16.0),
            decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(4.0),
                color: widget.indicatorBackground),
            child: Text("$_pageNumber/${widget.document.count}",
                style: TextStyle(
                    color: widget.indicatorText,
                    fontSize: 16.0,
                    fontWeight: FontWeight.w400))));

    switch (widget.indicatorPosition) {
      case IndicatorPosition.topLeft:
        return Positioned(top: 20, left: 20, child: child);
      case IndicatorPosition.topRight:
        return Positioned(top: 20, right: 20, child: child);
      case IndicatorPosition.bottomLeft:
        return Positioned(bottom: 20, left: 20, child: child);
      case IndicatorPosition.bottomRight:
        return Positioned(bottom: 20, right: 20, child: child);
      default:
        return Positioned(top: 20, right: 20, child: child);
    }
  }

  _pickPage() {
    showDialog<int>(
        context: context,
        builder: (BuildContext context) {
          return NumberPickerDialog.integer(
            title: Text(widget.tooltip.pick),
            minValue: 1,
            cancelWidget: Container(),
            maxValue: widget.document.count,
            initialIntegerValue: _pageNumber,
          );
        }).then((int value) {
      if (value != null) {
        _pageNumber = value;
        _jumpToPage();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: <Widget>[
          PageView.builder(
            physics:
            _swipeEnabled && widget.enableSwipeNavigation && !_isLoading
                ? null
                : NeverScrollableScrollPhysics(),
            onPageChanged: (page) {
              setState(() {
                _pageNumber = page + 1;
              });
              _loadPage();
              widget.onPageChanged?.call(page);
            },
            scrollDirection: widget.scrollDirection ?? Axis.horizontal,
            controller: _pageController,
            itemCount: _pages?.length ?? 0,
            itemBuilder: (context, index) => _pages[index] == null
                ? Center(
              child:
              widget.progressIndicator ?? CircularProgressIndicator(),
            )
                : _pages[index],
          ),
          (widget.showIndicator && !_isLoading)
              ? _drawIndicator()
              : Container(),
        ],
      ),
      floatingActionButton: widget.showPicker && widget.document.count >= 1
          ? FloatingActionButton(
        elevation: 4.0,
        tooltip: widget.tooltip.jump,
        child: Icon(
          Icons.view_carousel,
          color: widget.pickerIconColor ?? Colors.white,
        ),
        backgroundColor: widget.pickerButtonColor ?? Colors.blue,
        onPressed: () {
          _pickPage();
        },
      )
          : null,
      floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
      bottomNavigationBar: (widget.showNavigation && widget.document.count > 0)
          ? widget.navigationBuilder != null
          ? widget.navigationBuilder(
        context,
        _pageNumber,
        widget.document.count,
        _jumpToPage,
        _animateToPage,
      )
          : BottomAppBar(
        child: new Row(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Expanded(
              child: IconButton(
                icon: Icon(Icons.first_page),
                tooltip: widget.tooltip.first,
                onPressed: _pageNumber == 1 || _isLoading
                    ? null
                    : () {
                  _pageNumber = 1;
                  _jumpToPage();
                },
              ),
            ),
            Expanded(
              child: IconButton(
                icon: Icon(Icons.chevron_left),
                tooltip: widget.tooltip.previous,
                onPressed: _pageNumber == 1 || _isLoading
                    ? null
                    : () {
                  _pageNumber--;
                  if (1 > _pageNumber) {
                    _pageNumber = 1;
                  }
                  _animateToPage();
                },
              ),
            ),
            widget.showPicker
                ? Expanded(child: Text(''))
                : SizedBox(width: 1),
            Expanded(
              child: IconButton(
                icon: Icon(Icons.chevron_right),
                tooltip: widget.tooltip.next,
                onPressed:
                _pageNumber == widget.document.count || _isLoading
                    ? null
                    : () {
                  _pageNumber++;
                  if (widget.document.count < _pageNumber) {
                    _pageNumber = widget.document.count;
                  }
                  _animateToPage();
                },
              ),
            ),
            Expanded(
              child: IconButton(
                icon: Icon(Icons.last_page),
                tooltip: widget.tooltip.last,
                onPressed:
                _pageNumber == widget.document.count || _isLoading
                    ? null
                    : () {
                  _pageNumber = widget.document.count;
                  _jumpToPage();
                },
              ),
            ),
          ],
        ),
      )
          : Container(),
    );
  }
}

After this instead of using

MyPDFViewer(document: document,

          showIndicator: false,
          showPicker: false,

          )

using

MyPDFViewer(document: document,

          showIndicator: false,
          showPicker: false,

          )

This way not have to change anything until it is fixed even after pub get.

Also problem is corrected by
bottomNavigationBar: (widget.showNavigation && widget.document.count > 0)

[ruan65]

@lohanidamodar
Merge this pr
#13
please

[lohanidamodar]

Thank you everyone, I'll verify the changes and publish the updates ASAP