Adding point works

ViewModels/MainWindowViewModel.cs

@@ -1,6 +1,40 @@
-namespace GazpromApp.ViewModels;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace GazpromApp.ViewModels;
+using GazpromApp.Messages;
+using CommunityToolkit.Mvvm.Input;
+using CommunityToolkit.Mvvm.Messaging;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Threading.Tasks;
 
 public partial class MainWindowViewModel : ViewModelBase
 {
-    public string Greeting { get; } = "Welcome to Avalonia!";
+    public ObservableCollection<PointViewModel> Points { get; } = new ObservableCollection<PointViewModel>();
+
+    [RelayCommand]
+    private async Task AddPoint()
+    {
+        var point = await WeakReferenceMessenger.Default.Send(new NewPointMessage());
+        if (point != null)
+            Points.Add(point);
+        IsLineVisible = true;
+    }
+
+    [RelayCommand]
+    private void RemovePoint(PointViewModel point)
+    {
+        Points.Remove(point);
+        if (Points.Count == 0)
+            IsLineVisible = false;
+    }
+
+    [RelayCommand]
+    private void EditPoint(PointViewModel point)
+    {
+        Debug.WriteLine(point.Name);
+    }
+
+    [ObservableProperty]
+    private bool _isLineVisible;
 }