visualizzazione file dei servizi e copia nei file del cliente

lib/core/widgets/pdf_viewer_widget.dart

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+import 'package:flutter/material.dart';
+import 'package:pdfx/pdfx.dart';
+import 'package:internet_file/internet_file.dart'; // flutter pub add internet_file
+
+class PdfViewerWidget extends StatefulWidget {
+  final String url;
+
+  const PdfViewerWidget({super.key, required this.url});
+
+  @override
+  State<PdfViewerWidget> createState() => _PdfViewerWidgetState();
+}
+
+class _PdfViewerWidgetState extends State<PdfViewerWidget> {
+  late PdfControllerPinch _pdfController;
+  bool _isLoading = true;
+
+  @override
+  void initState() {
+    super.initState();
+    _initPdf();
+  }
+
+  Future<void> _initPdf() async {
+    // Scarica il file in memoria in modo fluido
+    final pdfData = await InternetFile.get(widget.url);
+    _pdfController = PdfControllerPinch(
+      document: PdfDocument.openData(pdfData),
+    );
+    if (mounted) setState(() => _isLoading = false);
+  }
+
+  @override
+  void dispose() {
+    _pdfController.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (_isLoading) {
+      return const Center(child: CircularProgressIndicator());
+    }
+    return Scaffold(
+      // Usiamo Scaffold dentro il Dialog per avere l'AppBar e poter chiudere
+      appBar: AppBar(
+        title: const Text("Visualizzatore PDF"),
+        leading: IconButton(
+          icon: const Icon(Icons.close),
+          onPressed: () => Navigator.pop(context),
+        ),
+      ),
+      body: PdfViewPinch(
+        controller: _pdfController,
+        // pdfx gestisce nativamente il pinch to zoom!
+      ),
+    );
+  }
+}