sis-flutter/lib/plugins/pdf_viewer.dart

import 'package:flutter/material.dart';
import 'package:flutter_pdfview/flutter_pdfview.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:open_file/open_file.dart';
import 'package:path_provider/path_provider.dart';
import 'dart:io';

class PdfViewerPage extends StatefulWidget {
  final String filePath;
  final String fileName;

  const PdfViewerPage(
      {Key? key, required this.filePath, required this.fileName})
      : super(key: key);

  @override
  _PdfViewerPageState createState() => _PdfViewerPageState();
}

class _PdfViewerPageState extends State<PdfViewerPage> {
  late PDFViewController _pdfViewController;
  int? pages;
  int? currentPage;
  bool isReady = false;
  String errorMessage = '';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Visualizador de PDF"),
        actions: [
          IconButton(
            icon: Icon(Icons.download),
            onPressed: _downloadPdf,
          ),
        ],
      ),
      body: Stack(
        children: <Widget>[
          PDFView(
            filePath: widget.filePath,
            enableSwipe: true,
            swipeHorizontal: true,
            autoSpacing: false,
            pageFling: false,
            onRender: (_pages) {
              setState(() {
                pages = _pages;
                isReady = true;
              });
            },
            onError: (error) {
              setState(() {
                errorMessage = error.toString();
              });
              print(error.toString());
            },
            onPageError: (page, error) {
              setState(() {
                errorMessage = '$page: ${error.toString()}';
              });
              print('$page: ${error.toString()}');
            },
            onViewCreated: (PDFViewController pdfViewController) {
              _pdfViewController = pdfViewController;
            },
            onPageChanged: (int? page, int? total) {
              print('page change: $page/$total');
              setState(() {
                currentPage = page;
              });
            },
          ),
          errorMessage.isEmpty
              ? !isReady
                  ? Center(
                      child: CircularProgressIndicator(),
                    )
                  : Container()
              : Center(
                  child: Text(errorMessage),
                )
        ],
      ),
    );
  }

  Future<void> _downloadPdf() async {
    try {
      if (await Permission.storage.request().isGranted) {
        final directory = await getExternalStorageDirectory();
        if (directory != null) {
          final filePath = '${directory.path}/${widget.fileName}';
          final file = File(filePath);

          await file.writeAsBytes(await File(widget.filePath).readAsBytes());

          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(content: Text('Archivo guardado en $filePath')),
          );

          OpenFile.open(filePath);
        }
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Permisos de almacenamiento denegados')),
        );
      }
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error al descargar el archivo: $e')),
      );
    }
  }
}