main.dart

import 'dart:async';
import 'dart:io' show Platform;

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:pdftron_flutter/pdftron_flutter.dart';
// If you are using local files, add the permission_handler
// dependency to pubspec.yaml and uncomment the line below.
// import 'package:permission_handler/permission_handler.dart';

//set this value to view document via Widget
var enableWidget = true;

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Viewer(),
    );
  }
}

class Viewer extends StatefulWidget {
  @override
  _ViewerState createState() => _ViewerState();
}

class _ViewerState extends State<Viewer> {
  String _version = 'Unknown';
  String _document =
      "https://pdftron.s3.amazonaws.com/downloads/pl/PDFTRON_mobile_about.pdf";
  bool _showViewer = true;

  @override
  void initState() {
    super.initState();
    initPlatformState();
    if (!enableWidget) {
      showViewer();
    }

    // If you are using local files:
    // * Remove the above line `showViewer();`.
    // * Change the _document field to your local filepath.
    // * Uncomment the section below, including launchWithPermission().
    // if (Platform.isIOS) {
    // showViewer(); // Permission not required for iOS.
    // } else {
    // launchWithPermission(); // Permission required for Android.
    // }
  }

  // Uncomment this if you are using local files:
  // Future<void> launchWithPermission() async {
  //  PermissionStatus permission = await Permission.storage.request();
  //  if (permission.isGranted) {
  //    showViewer();
  //  }
  // }

  // Platform messages are asynchronous, so initialize in an async method.
  Future<void> initPlatformState() async {
    String version;
    // Platform messages may fail, so use a try/catch PlatformException.
    try {
      // Initializes the PDFTron SDK, it must be called before you can use
      // any functionality.
      PdftronFlutter.initialize("your_pdftron_license_key");

      version = await PdftronFlutter.version;
    } on PlatformException {
      version = 'Failed to get platform version.';
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, you want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      _version = version;
    });
  }

  void showViewer() async {
    // Opening without a config file will have all functionality enabled.
    // await PdftronFlutter.openDocument(_document);

    var config = Config();
    // How to disable functionality:
    //      config.disabledElements = [Buttons.shareButton, Buttons.searchButton];
    //      config.disabledTools = [Tools.annotationCreateLine, Tools.annotationCreateRectangle];
    // Other viewer configurations:
    //      config.multiTabEnabled = true;
    //      config.customHeaders = {'headerName': 'headerValue'};

    // An event listener for document loading
    var documentLoadedCancel = startDocumentLoadedListener((filePath) {
      print("document loaded: $filePath");
    });

    await PdftronFlutter.openDocument(_document, config: config);

    try {
      // The imported command is in XFDF format and tells whether to add,
      // modify or delete annotations in the current document.
      PdftronFlutter.importAnnotationCommand(
          "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
              "    <xfdf xmlns=\"http://ns.adobe.com/xfdf/\" xml:space=\"preserve\">\n" +
              "      <add>\n" +
              "        <square style=\"solid\" width=\"5\" color=\"#E44234\" opacity=\"1\" creationdate=\"D:20200619203211Z\" flags=\"print\" date=\"D:20200619203211Z\" name=\"c684da06-12d2-4ccd-9361-0a1bf2e089e3\" page=\"1\" rect=\"113.312,277.056,235.43,350.173\" title=\"\" />\n" +
              "      </add>\n" +
              "      <modify />\n" +
              "      <delete />\n" +
              "      <pdf-info import-version=\"3\" version=\"2\" xmlns=\"http://www.pdftron.com/pdfinfo\" />\n" +
              "    </xfdf>");
    } on PlatformException catch (e) {
      print("Failed to importAnnotationCommand '${e.message}'.");
    }

    try {
      PdftronFlutter.importBookmarkJson('{"0":"Page 1"}');
    } on PlatformException catch (e) {
      print("Failed to importBookmarkJson '${e.message}'.");
    }

    // An event listener for when local annotation changes are committed
    // to the document. xfdfCommand is the XFDF Command of the annotation
    // that was last changed.
    var annotCancel = startExportAnnotationCommandListener((xfdfCommand) {
      // Local annotation changed.
      // Upload XFDF command to server here.
      String command = xfdfCommand;
      // Dart limits how many characters are printed onto the console.
      // The code below ensures that all of the XFDF command is printed.
      if (command.length > 1024) {
        print("flutter xfdfCommand:\n");
        int start = 0;
        int end = 1023;
        while (end < command.length) {
          print(command.substring(start, end) + "\n");
          start += 1024;
          end += 1024;
        }
        print(command.substring(start));
      } else {
        print(command);
      }
    });

    // An event listener for when local bookmark changes are committed to
    // the document. bookmarkJson is the JSON string containing all the
    // bookmarks that exist when the change was made.
    var bookmarkCancel = startExportBookmarkListener((bookmarkJson) {
      print("flutter bookmark: $bookmarkJson");
    });

    var path = await PdftronFlutter.saveDocument();
    print("flutter save: $path");

    // To cancel event:
    // annotCancel();
    // bookmarkCancel();
    // documentLoadedCancel();
  }

  @override
  Widget build(BuildContext context) {
    Widget documentChild = Container();

    if (enableWidget) {
      // If using Android Widget, uncomment one of the following:
      // If using Flutter v2.3.0-17.0.pre or earlier.
      // SystemChrome.setEnabledSystemUIOverlays(SystemUiOverlay.values);
      // If using later Flutter versions.
      SystemChrome.setEnabledSystemUIMode(
        SystemUiMode.edgeToEdge,
      );
      documentChild = _showViewer
          ? SafeArea(
              child: DocumentView(
              onCreated: _onDocumentViewCreated,
            ))
          : Container();
    }

    return Scaffold(
      body: Container(
        width: double.infinity,
        height: double.infinity,
        child: documentChild,
      ),
    );
  }

  // This function is used to control the DocumentView widget after it
  // has been created. The widget will not work without a void
  // Function(DocumentViewController controller) being passed to it.
  void _onDocumentViewCreated(DocumentViewController controller) async {
    Config config = new Config();

    var leadingNavCancel = startLeadingNavButtonPressedListener(() {
      // Uncomment this to quit viewer when leading navigation button is pressed:
      // this.setState(() {
      //   _showViewer = !_showViewer;
      // });

      // Show a dialog when leading navigation button is pressed.
      PdftronFlutter.showMyToast();
    });

    await controller.openDocument(_document, config: config);
  }

  Future<void> _showMyDialog() async {
    print('hello');
    return showDialog<void>(
      context: context,
      barrierDismissible: false, // User must tap button!
      builder: (BuildContext context) {
        return AlertDialog(
          title: Text('AlertDialog'),
          content: SingleChildScrollView(
            child: Text('Leading navigation button has been pressed.'),
          ),
          actions: <Widget>[
            TextButton(
              child: Text('OK'),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }
}