refactored list items into seperate class

lib/box_checker.dart

@@ -15,14 +15,16 @@ class BoxChecker extends StatelessWidget {
   Widget build(BuildContext context) {
     return MaterialApp(
       title: 'Flutter Demo',
+      // starting with dark theme but changing the primary colors manually
       theme: ThemeData.from(colorScheme: const ColorScheme.dark()).copyWith(
         canvasColor: Colors.blueGrey[900],
-        cardColor: Colors.grey[800],
         scaffoldBackgroundColor: Colors.black12,
         shadowColor: Colors.black38,
         toggleableActiveColor: Colors.blue,
         colorScheme: ColorScheme.fromSwatch(
           primarySwatch: Colors.blue,
+          cardColor: Colors.grey[800],
+          backgroundColor: Colors.black12,
         ),
       ),
       themeMode: ThemeMode.dark,

lib/check_list.dart

@@ -1,3 +1,4 @@
+import 'package:boxchecker/check_list_item.dart';
 import 'package:flutter/material.dart';
 import 'data_util.dart' as data;
 import 'db_helper.dart';
@@ -11,7 +12,7 @@ class CheckList extends StatefulWidget {
 }
 
 class _CheckList extends State<CheckList> {
-  bool _editable = false;
+  late bool _editable;
   data.List? listData;
   List<data.Check> list = [];
 
@@ -29,6 +30,7 @@ class _CheckList extends State<CheckList> {
   void _loadListData() async {
     var rows = await DBHelper.dbHelper.getListData(widget.id);
     listData = (rows.isNotEmpty) ? data.List.fromMap(rows[0]) : null;
+    _editable = (listData != null && !listData!.isTemplate!);
   }
 
   void _addItem() async {
@@ -40,14 +42,6 @@ class _CheckList extends State<CheckList> {
     });
   }
 
-  void _removeItem(data.Check item) async {
-    DBHelper.dbHelper.deleteItem(item);
-  }
-
-  void _updateItem(data.Check item) async {
-    DBHelper.dbHelper.updateItem(item);
-  }
-
   void _toggleEditable() {
     setState(() {
       _editable = !_editable;
@@ -87,65 +81,25 @@ class _CheckList extends State<CheckList> {
           child: ListView.builder(
             itemCount: list.length,
             itemBuilder: (context, index) {
-              return Dismissible(
+              return CheckListItem(
-                key: Key(list[index].id.toString()),
                 confirmDismiss: (direction) async {
-                  var item = list[index];
+                  if (!_editable) return false;
+
                   if (direction == DismissDirection.endToStart) {
                     setState(() {
-                      _removeItem(item);
+                      DBHelper.dbHelper.deleteItem(list[index]);
                       list.removeAt(index);
                     });
                     return true;
                   }
-                  _updateItem(item);
+                  DBHelper.dbHelper.updateItem(list[index]);
                   setState(() {
-                    item.value = !item.value;
+                    list[index].value = !list[index].value;
                   });
                   return false;
                 },
-                background: Container(
+                item: list[index],
-                  color: Colors.blue,
+                locked: !_editable,
-                  child: Row(children: const [
-                    Padding(
-                      padding: EdgeInsets.all(10),
-                      child: Icon(Icons.check),
-                    ),
-                    Spacer(),
-                  ]),
-                ),
-                secondaryBackground: Container(
-                  color: Colors.red,
-                  child: Row(children: const [
-                    Spacer(),
-                    Padding(
-                        padding: EdgeInsets.all(10),
-                        child: Icon(Icons.delete_forever)),
-                  ]),
-                ),
-                child: CheckboxListTile(
-                  title: TextFormField(
-                    enabled: (listData != null &&
-                        (!listData!.isTemplate! || _editable)),
-                    decoration: const InputDecoration(border: InputBorder.none),
-                    initialValue: list[index].text,
-                    onChanged: (value) {
-                      list[index].text = value;
-                      _updateItem(list[index]);
-                    },
-                  ),
-                  controlAffinity: ListTileControlAffinity.leading,
-                  value: list[index].value,
-                  onChanged: (listData != null &&
-                          (!listData!.isTemplate! || _editable))
-                      ? ((value) {
-                          _updateItem(list[index]);
-                          setState(() {
-                            list[index].value = value!;
-                          });
-                        })
-                      : null,
-                ),
               );
             },
           ),

lib/check_list_item.dart

@@ -0,0 +1,96 @@
+import 'package:boxchecker/check_list.dart';
+import 'package:flutter/material.dart';
+import 'data_util.dart' as data;
+import 'db_helper.dart';
+
+typedef FutureCallback = Future<bool?> Function(DismissDirection);
+
+class CheckListItem extends StatefulWidget {
+  const CheckListItem(
+      {Key? key,
+      required this.item,
+      required this.confirmDismiss,
+      this.locked = false})
+      : super(key: key);
+  final data.Check item;
+  final FutureCallback confirmDismiss;
+  final bool locked;
+
+  @override
+  State<StatefulWidget> createState() => _CheckListItem();
+}
+
+class _CheckListItem extends State<CheckListItem> {
+  Widget dismissIconPadding(Widget icon) {
+    return Padding(
+      padding: const EdgeInsets.all(10),
+      child: icon,
+    );
+  }
+
+  Widget dismissBackground() {
+    return Container(
+        color: Colors.blue,
+        child: Row(children: const [
+          Padding(
+            padding: EdgeInsets.all(10),
+            child: Icon(Icons.check),
+          ),
+          Spacer(),
+        ]));
+  }
+
+  Widget dismissSecondaryBackground() {
+    return Container(
+      color: Colors.red,
+      child: Row(children: [
+        const Spacer(),
+        dismissIconPadding(const Icon(Icons.delete_forever)),
+      ]),
+    );
+  }
+
+  Widget dismissLockedBackground() {
+    return Container(
+        color: Colors.grey[900],
+        child: Row(
+          children: [
+            dismissIconPadding(const Icon(Icons.lock)),
+            const Spacer(),
+            dismissIconPadding(const Icon(Icons.lock)),
+          ],
+        ));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Dismissible(
+      key: Key(widget.item.id.toString()),
+      background:
+          !widget.locked ? dismissBackground() : dismissLockedBackground(),
+      secondaryBackground: !widget.locked ? dismissSecondaryBackground() : null,
+      confirmDismiss: widget.confirmDismiss,
+      child: CheckboxListTile(
+        title: TextFormField(
+          enabled: !widget.locked,
+          decoration: const InputDecoration(border: InputBorder.none),
+          initialValue: widget.item.text,
+          onChanged: (value) {
+            widget.item.text = value;
+            DBHelper.dbHelper.updateItem(widget.item);
+          },
+        ),
+        controlAffinity: ListTileControlAffinity.leading,
+        value: widget.item.value,
+        onChanged: !widget.locked
+            ? ((value) {
+                DBHelper.dbHelper.updateItem(widget.item);
+                setState(() {
+                  widget.item.value = value!;
+                });
+              })
+            : null,
+      ),
+    );
+  }
+}