implemented item selection + button to print a list of issues/news etc(Button has no functionality yet).

lib/UserDefinedList.dart

@@ -3,14 +3,19 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 import 'package:firebase_storage/firebase_storage.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
+import 'package:printing/printing.dart';
 import 'DetailPage.dart';
 import 'package:intl/intl.dart';
+import 'package:pdf/widgets.dart' as pdfWidgets;
+import 'package:http/http.dart' as http;
 
 class UserDefinedItem extends StatelessWidget {
   final String title;
   final String datum;
   final String description;
   final String imageUrl;
+  final Function onLongPress;
+  final bool isSelected;
 
   const UserDefinedItem({
     Key? key,
@@ -18,12 +23,14 @@ class UserDefinedItem extends StatelessWidget {
     required this.description,
     required this.datum,
     required this.imageUrl,
+    required this.onLongPress,
+    required this.isSelected,
   }) : super(key: key);
 
+
   @override
   Widget build(BuildContext context) {
-    return Card(
+    return InkWell(
-      child: InkWell(
       onTap: () {
         // Open a new screen when the user taps on the list item
         Navigator.push(
@@ -38,8 +45,12 @@ class UserDefinedItem extends StatelessWidget {
           ),
         );
       },
+      onLongPress: onLongPress as void Function()?,
+      child: Card(
         child: Row(
           crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Stack(
               children: [
                 SizedBox(
                   width: 120,
@@ -56,6 +67,19 @@ class UserDefinedItem extends StatelessWidget {
                     errorWidget: (context, url, error) => const Icon(Icons.error),
                   ),
                 ),
+                if (isSelected)  // Wenn das Element ausgewählt ist, zeigen Sie die Checkbox an
+                  Positioned(
+                    top: 0,
+                    left: 0,
+                    child: Checkbox(
+                      value: isSelected,
+                      onChanged: (bool? value) {
+                        onLongPress();  // Wenn die Checkbox angeklickt wird, rufen Sie die onLongPress-Funktion auf
+                      },
+                    ),
+                  ),
+              ],
+            ),
             Flexible(
               flex: 1,
               child: Column(
@@ -104,6 +128,8 @@ class UserDefinedItem extends StatelessWidget {
   }
 }
 
+
+
 class GenericList extends StatefulWidget {
   final String collectionName;
   const GenericList({Key? key, required this.collectionName}) : super(key: key);
@@ -114,6 +140,7 @@ class GenericList extends StatefulWidget {
 
 class _GenericListState extends State<GenericList> {
   final FirebaseFirestore firestore = FirebaseFirestore.instance;
+  Map<String, bool> selectedItems = {};
 
   @override
   void initState() {
@@ -139,7 +166,9 @@ class _GenericListState extends State<GenericList> {
         await FirebaseStorage.instance.refFromURL(imageUrl).delete();
       }
       // Löschen Sie das Dokument von der Firestore-Kollektion
-      await firestore.collection(widget.collectionName).doc(documentId).delete();
+      await firestore.collection(widget.collectionName)
+          .doc(documentId)
+          .delete();
     } catch (e) {
       if (kDebugMode) {
         print('Error deleting document: $e');
@@ -149,9 +178,13 @@ class _GenericListState extends State<GenericList> {
 
   @override
   Widget build(BuildContext context) {
-    return StreamBuilder<QuerySnapshot>(
+    return Scaffold(
+      body: Stack(
+        children: [
+          StreamBuilder<QuerySnapshot>(
             stream: getDocumentStream(),
-      builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
+            builder: (BuildContext context,
+                AsyncSnapshot<QuerySnapshot> snapshot) {
               if (snapshot.hasError) {
                 return Text('Error: ${snapshot.error}');
               }
@@ -159,7 +192,8 @@ class _GenericListState extends State<GenericList> {
                 case ConnectionState.waiting:
                   return const Text('Loading...');
                 default:
-            final List<QueryDocumentSnapshot> documents = snapshot.data!.docs;
+                  final List<QueryDocumentSnapshot> documents = snapshot.data!
+                      .docs;
                   return ListView.builder(
                     itemCount: documents.length,
                     itemBuilder: (BuildContext context, int index) {
@@ -190,12 +224,93 @@ class _GenericListState extends State<GenericList> {
                           datum: formattedDate,
                           description: data['description'] ?? '',
                           imageUrl: data['imageUrl'] ?? '',
+                          isSelected: selectedItems.containsKey(documentId)
+                              ? selectedItems[documentId]!
+                              : false,
+                          onLongPress: () {
+                            // Aktualisieren Sie den ausgewählten Zustand des Elements
+                            setState(() {
+                              selectedItems[documentId] =
+                              !selectedItems.containsKey(documentId)
+                                  ? true
+                                  : !selectedItems[documentId]!;
+                            });
+                          },
                         ),
                       );
                     },
                   );
               }
             },
+          ),
+          if (selectedItems.containsValue(true))
+            Align(
+              alignment: Alignment.bottomLeft,
+              child: Padding(
+                padding: const EdgeInsets.all(16.0),
+                child: FloatingActionButton(
+                  onPressed: () {
+                    // Führen Sie hier die gewünschte Aktion aus
+                  },
+                  backgroundColor: Colors.red,
+                  child: const Icon(Icons.picture_as_pdf),
+                ),
+              ),
+            ),
+        ],
+      ),
     );
   }
+  /*
+  Future<pdfWidgets.ImageProvider> _loadNetworkImage(String url) async {
+    final response = await http.get(Uri.parse(url));
+
+    if (response.statusCode != 200) {
+      throw Exception('Failed to load network image.');
+    }
+
+    final Uint8List bytes = response.bodyBytes;
+    final imageProvider = pdfWidgets.MemoryImage(bytes);
+
+    return imageProvider;
+  }
+  Future<void> _printPdf() async {
+    final pdf = pdfWidgets.Document();
+
+    for (var docId in selectedItems.keys) {
+      final title = selectedItems[docId]!['title'];
+      final datum = selectedItems[docId]!['datum'];
+      final description = selectedItems[docId]!['description'];
+      final imageUrl = selectedItems[docId]!['imageUrl'];
+
+      final image = await _loadNetworkImage(imageUrl);
+
+      pdf.addPage(
+        pdfWidgets.MultiPage(
+          build: (context) => [
+            pdfWidgets.Center(
+              child: pdfWidgets.SizedBox(
+                width: double.infinity,
+                child: pdfWidgets.AspectRatio(
+                  aspectRatio: 1,
+                  child: pdfWidgets.Image(image),
+                ),
+              ),
+            ),
+            pdfWidgets.Text(
+                title,
+                style: pdfWidgets.TextStyle(
+                    fontSize: 20,
+                    fontWeight: pdfWidgets.FontWeight.bold
+                )
+            ),
+            pdfWidgets.Text(datum, style: const pdfWidgets.TextStyle(fontSize: 14, )),
+            pdfWidgets.Paragraph(text: description, style: const pdfWidgets.TextStyle(fontSize: 12)),
+          ],
+        ),
+      );
+    }
+
+    await Printing.sharePdf(bytes: await pdf.save(), filename: 'selectedItems.pdf');
+  }*/
 }

lib/home.dart

@@ -30,6 +30,7 @@ class _MyHomePageState extends State<MyHomePage> {
     });
   }
 
+
   @override
   Widget build(BuildContext context) {
     final List<Widget> widgetOptions = <Widget>[