refactor printer details and add delete button

lib/pages/printer_details/printer_details_page.dart

@@ -8,6 +8,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:http/http.dart' as http;
 
+import '/util.dart';
 import '/widgets/cool_card.dart';
 import 'toner_indicator.dart';
 
@@ -38,7 +39,10 @@ class _PrinterDetailsPageState extends State<PrinterDetailsPage> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      appBar: AppBar(title: Text('Details zum Drucker ${widget.printer.hostname}')),
+      appBar: AppBar(
+        title: Text('Details zum Drucker ${widget.printer.hostname}'),
+        actions: [IconButton(onPressed: _onDelete, icon: Icon(Icons.delete_forever_rounded))],
+      ),
       body: Center(
         child: ConstrainedBox(
           constraints: BoxConstraints(maxWidth: 1024.0),
@@ -113,19 +117,7 @@ class _PrinterDetailsPageState extends State<PrinterDetailsPage> {
                             width: 256.0,
                             child: TextFormField(
                               autovalidateMode: AutovalidateMode.onUserInteraction,
-                              validator: (input) {
-                                final parts = input.split('.');
-
-                                if (parts.length != 4) {
-                                  return 'Eine IP muss im Format aaa.bbb.ccc.ddd vorliegen';
-                                }
-
-                                if (parts.map((e) => int.tryParse(e)).contains(null)) {
-                                  return 'Eine IP muss aus natürlichen Zahlen bestehen';
-                                }
-
-                                return null;
-                              },
+                              validator: validateIp,
                               textAlign: TextAlign.end,
                               initialValue: _printer.ip ?? '',
                               decoration: InputDecoration(border: InputBorder.none),
@@ -208,71 +200,6 @@ class _PrinterDetailsPageState extends State<PrinterDetailsPage> {
                             ),
                           ),
                         ),
-                        /* CheckboxListTile(
-                          title: Text('Toner überwachen'),
-                          value: _printer.watchToner,
-                          onChanged: (bool input) {
-                            setState(() {
-                              _dirty = true;
-                              _printer.watchToner = input;
-                            });
-                            _onSaveWatchers();
-                          },
-                        ),
-                        CheckboxListTile(
-                          title: Text('Papierfach 1 überwachen'),
-                          value: _printer.watchTray1,
-                          onChanged: (bool input) {
-                            setState(() {
-                              _dirty = true;
-                              _printer.watchTray1 = input;
-                            });
-                            _onSaveWatchers();
-                          },
-                        ),
-                        CheckboxListTile(
-                          title: Text('Papierfach 2 überwachen'),
-                          value: _printer.watchTray2,
-                          onChanged: (bool input) {
-                            setState(() {
-                              _dirty = true;
-                              _printer.watchTray2 = input;
-                            });
-                            _onSaveWatchers();
-                          },
-                        ),
-                        CheckboxListTile(
-                          title: Text('Papierfach 3 überwachen'),
-                          value: _printer.watchTray3,
-                          onChanged: (bool input) {
-                            setState(() {
-                              _dirty = true;
-                              _printer.watchTray3 = input;
-                            });
-                            _onSaveWatchers();
-                          },
-                        ),
-                        ListTile(
-                          title: Text('Überwachungsintervall'),
-                          trailing: SizedBox(
-                            width: 256.0,
-                            child: TextFormField(
-                              validator: (input) =>
-                                  int.tryParse(input) == null ? 'Nur Zahlen erlaubt' : null,
-                              autovalidateMode: AutovalidateMode.onUserInteraction,
-                              textAlign: TextAlign.end,
-                              initialValue: _printer.watchInterval.toString() ?? '',
-                              decoration:
-                                  InputDecoration(border: InputBorder.none, suffixText: 'Sekunden'),
-                              onChanged: (String input) => setState(() {
-                                _dirty = true;
-                                _printer.watchInterval =
-                                    int.tryParse(input) ?? _printer.watchInterval;
-                              }),
-                              onFieldSubmitted: (_) => _onSaveWatcherInterval(),
-                            ),
-                          ),
-                        ), */
                       ],
                     ),
                     CoolCard(
@@ -356,19 +283,19 @@ class _PrinterDetailsPageState extends State<PrinterDetailsPage> {
                               ListTile(
                                   title: Text('Papierfach 1'),
                                   trailing: Text(
-                                    _printer.status.tray1.toString(),
+                                    (_printer.status.tray1 ?? 0).toString(),
                                     style: Theme.of(context).textTheme.subtitle1,
                                   )),
                               ListTile(
                                   title: Text('Papierfach 2'),
                                   trailing: Text(
-                                    _printer.status.tray2.toString(),
+                                    (_printer.status.tray2 ?? 0).toString(),
                                     style: Theme.of(context).textTheme.subtitle1,
                                   )),
                               ListTile(
                                   title: Text('Papierfach 3'),
                                   trailing: Text(
-                                    _printer.status.tray3.toString(),
+                                    (_printer.status.tray3 ?? 0).toString(),
                                     style: Theme.of(context).textTheme.subtitle1,
                                   )),
                               ListTile(
@@ -388,9 +315,10 @@ class _PrinterDetailsPageState extends State<PrinterDetailsPage> {
                                     color: Colors.pink,
                                   )),
                               ListTile(
-                                  title: Text('Gelb'),
-                                  trailing: TonerIndicator(
-                                      value: _printer.status.tonerY, color: Colors.yellow)),
+                                title: Text('Gelb'),
+                                trailing: TonerIndicator(
+                                    value: _printer.status.tonerY, color: Colors.yellow),
+                              ),
                               ListTile(
                                   title: Text('Schwarz'),
                                   trailing: TonerIndicator(
@@ -450,9 +378,14 @@ class _PrinterDetailsPageState extends State<PrinterDetailsPage> {
     printersBloc = BlocProvider.of<PrintersBloc>(context);
     printQueueBloc = PrintQueueBloc(http.Client());
 
-    _printerListener = printersBloc.stream.listen((PrintersState state) {
+    _printerListener = printersBloc.stream.where((e) => e.isResult).listen((PrintersState state) {
+      final results = state.value.where((Printer e) => e.deviceId == widget.printer.deviceId);
+      if (results.isEmpty) {
+        ScaffoldMessenger.of(context).showSnackBar(
+            const SnackBar(content: Text('Der Drucker konnte nicht gefunden werden')));
+      }
       setState(() {
-        _printer = state.value.singleWhere((Printer e) => e.deviceId == widget.printer.deviceId);
+        _printer = results.first;
       });
     });
 
@@ -472,6 +405,32 @@ class _PrinterDetailsPageState extends State<PrinterDetailsPage> {
     printQueueBloc.onRefresh();
   }
 
+  Future<void> _onDelete() async {
+    final result = await showDialog<bool>(
+        context: context,
+        builder: (BuildContext context) => AlertDialog(
+              title: Text('Wirklich löschen?'),
+              content: Text(
+                  'Der Drucker ${_printer.deviceId} kann danach nicht wiederhergestellt werden.'),
+              actions: [
+                MaterialButton(
+                  onPressed: () => Navigator.of(context).pop(true),
+                  child: Text('Löschen'),
+                ),
+                ElevatedButton(
+                  onPressed: () => Navigator.of(context).pop(false),
+                  child: Text('Abbrechen'),
+                )
+              ],
+            ));
+
+    if (result == null) return;
+
+    printersBloc.onDeletePrinter(_printer.deviceId);
+
+    Navigator.of(context).pop();
+  }
+
   void _onEmptyQueue() {
     printQueueBloc.onCancelJobs();
   }

lib/util.dart

@@ -69,5 +69,19 @@ String validateEmail(String value) {
   return 'Bitte gebe eine richtige E-Mail Adresse ein';
 }
 
+String validateIp(String input) {
+  final parts = input.split('.');
+
+  if (parts.length != 4) {
+    return 'Eine IP muss im Format aaa.bbb.ccc.ddd vorliegen';
+  }
+
+  if (parts.map((e) => int.tryParse(e)).contains(null)) {
+    return 'Eine IP muss aus natürlichen Zahlen bestehen';
+  }
+
+  return null;
+}
+
 String validatePassword(String input) =>
     input.length > 5 ? null : 'Das Passwort muss aus mindestens 6 Zeichen bestehen';