Setup Test UI and Added Prototype DataGrid

Stars Assistant/ViewModels/MainWindowViewModel.cs

@@ -1,8 +1,13 @@
-namespace net.nehmer.sa.ViewModels;
+using System.Collections.ObjectModel;
 
-public class MainWindowViewModel : ViewModelBase
+namespace net.nehmer.sa.ViewModels;
+
+public partial class MainWindowViewModel : ViewModelBase
 {
 #pragma warning disable CA1822 // Mark members as static
     public string Greeting => "Welcome to Stars Assistant!";
 #pragma warning restore CA1822 // Mark members as static
+
+    public ObservableCollection<PlanetViewModel> Planets { get; } = PlanetViewModel.LoadAll();
+
 }

Stars Assistant/ViewModels/PlanetViewModel.cs

@@ -0,0 +1,26 @@
+using System.Collections.ObjectModel;
+using net.nehmer.sa.Model;
+
+namespace net.nehmer.sa.ViewModels;
+
+public partial class PlanetViewModel(Planet planet) : ViewModelBase
+{
+    public static ObservableCollection<PlanetViewModel> LoadAll() {
+        var context = new StarsDatabase("stars.sqlite");
+        var result = new ObservableCollection<PlanetViewModel>();
+        foreach (Planet planet in context.Planets.ToList())
+        {
+            var vm = new PlanetViewModel(planet);
+            result.Add(vm);
+        }
+        return result;
+    }
+
+    private readonly Planet planet = planet;
+
+    public string Name => planet.Name;
+
+    public string Owner => planet.Owner ?? String.Empty;
+
+    public int Value => planet.Value ?? 0;
+}

Stars Assistant/ViewModels/ViewModelBase.cs

@@ -1,7 +1,7 @@
-using ReactiveUI;
+using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace net.nehmer.sa.ViewModels;
 
-public class ViewModelBase : ReactiveObject
+public class ViewModelBase : ObservableObject
 {
 }