made tasks dismissible

lib/pages/task_overview_page.dart

@@ -5,6 +5,7 @@ import '../model/extensions/controller_context.dart';
 import '../model/task.dart';
 import '../service/controllers/task_controller.dart';
 import '../service/tools.dart';
+import '../widgets/task_dismissible.dart';
 import 'task_edit_page.dart';
 
 class TaskOverviewPage extends StatefulWidget {
@@ -37,24 +38,28 @@ class _TaskOverviewPageState extends State<TaskOverviewPage> {
   Widget itemBuilder(BuildContext context, int index) {
     final task = tasks.elementAt(index);
 
-    return ListTile(
+    return TaskDismissible(
       key: Key(task.id),
-      title: Text(task.title),
+      onDismissedRight: () =>
-      subtitle: task.description.isNotEmpty ? Text(task.description) : null,
+          context.controller<TaskController>().deleteTask(task),
-      trailing: Checkbox(
+      child: ListTile(
-        value: task.isCompleted,
+        title: Text(task.title),
-        onChanged: (isCompleted) => context
+        subtitle: task.description.isNotEmpty ? Text(task.description) : null,
-            .controller<TaskController>()
+        trailing: Checkbox(
-            .saveTask(task.copyWith(isCompleted: isCompleted)),
+          value: task.isCompleted,
+          onChanged: (isCompleted) => context
+              .controller<TaskController>()
+              .saveTask(task.copyWith(isCompleted: isCompleted)),
+        ),
+        onTap: () async {
+          final result = await onTaskTapped(task);
+          if (result != null && context.mounted) {
+            context.controller<TaskController>().saveTask(
+              result.toTask(id: task.id),
+            );
+          }
+        },
       ),
-      onTap: () async {
-        final result = await onTaskTapped(task);
-        if (result != null && context.mounted) {
-          context.controller<TaskController>().saveTask(
-            result.toTask(id: task.id),
-          );
-        }
-      },
     );
   }
 

lib/widgets/task_dismissible.dart

@@ -0,0 +1,41 @@
+import 'package:flutter/material.dart';
+
+class TaskDismissible extends StatelessWidget {
+  const TaskDismissible({
+    required super.key,
+    this.onDismissedRight,
+    required this.child,
+  });
+
+  final VoidCallback? onDismissedRight;
+  final Widget child;
+
+  @override
+  Widget build(BuildContext context) {
+    return Dismissible(
+      key: key!,
+      direction: DismissDirection.startToEnd,
+      background: Container(
+        color: Theme.of(context).colorScheme.error,
+        child: Align(
+          alignment: AlignmentGeometry.centerLeft,
+          child: Padding(
+            padding: const EdgeInsets.symmetric(horizontal: 12),
+            child: Icon(
+              Icons.delete,
+              color: Theme.of(context).colorScheme.onError,
+            ),
+          ),
+        ),
+      ),
+      onDismissed: onDismissed,
+      child: child,
+    );
+  }
+
+  void onDismissed(DismissDirection direction) {
+    if (direction == DismissDirection.startToEnd && onDismissedRight != null) {
+      onDismissedRight!();
+    }
+  }
+}