refactor: move Task editing responsibility to its own view model

Author: Xiphereal

Desktop/Tasks/TaskEditing.xaml.cs

@@ -7,21 +7,21 @@ namespace Desktop.Tasks;
 
 public partial class TaskEditing : Window
 {
+    private readonly TaskEditingViewModel viewModel;
+
     public TaskEditing(Task original)
     {
         InitializeComponent();
 
-        this.original = original;
+        viewModel = new TaskEditingViewModel(original);
+
         Name.Text = original.Name;
         Description.Text = original.Description;
     }
 
-    private readonly Task original;
-
     private void SaveTask(object sender, RoutedEventArgs e)
     {
-        original.Name = Name.Text;
-        original.Description = Description.Text;
+        viewModel.Save.Execute((Name.Text, Description.Text));
 
         Close();
     }

Desktop/Tasks/TaskEditingViewModel.cs

@@ -0,0 +1,26 @@
+using System.Windows.Input;
+using CommunityToolkit.Mvvm.Input;
+using Desktop.Common;
+using Task = Desktop.Domain.Task;
+
+namespace Desktop.Tasks;
+
+public class TaskEditingViewModel : ViewModelBase
+{
+    private readonly Task taskBeingEdited;
+
+    public TaskEditingViewModel(Task taskBeingEdited)
+    {
+        this.taskBeingEdited = taskBeingEdited;
+
+        Save = new RelayCommand<(string, string)>(args =>
+        {
+            var (name, description) = args;
+
+            taskBeingEdited.Name = name;
+            taskBeingEdited.Description = description;
+        });
+    }
+
+    public ICommand Save { get; }
+}