more reactive UI work

Stars Assistant/Stars Assistant.csproj

@@ -27,6 +27,7 @@
     <PackageReference Include="Avalonia.Fonts.Inter" Version="11.0.10" />
     <!--Condition below is needed to remove Avalonia.Diagnostics package from build output in Release configuration.-->
     <PackageReference Condition="'$(Configuration)' == 'Debug'" Include="Avalonia.Diagnostics" Version="11.1.3" />
+    <PackageReference Include="ReactiveUI.SourceGenerators" Version="1.0.3" />
     <PackageReference Include="Splat" Version="15.1.1" />
     <PackageReference Include="System.Reactive" Version="6.0.1" />
   </ItemGroup>

Stars Assistant/ViewModels/MainWindowViewModel.cs

@@ -1,5 +1,8 @@
 using System.Collections.ObjectModel;
+using System.Reactive.Disposables;
+using System.Reactive.Linq;
 using ReactiveUI;
+using ReactiveUI.SourceGenerators;
 
 namespace StarsAssistant.ViewModels;
 
@@ -7,6 +10,24 @@ public partial class MainWindowViewModel : ViewModelBase, IActivatableViewModel
 {
     public ViewModelActivator Activator { get; } = new ViewModelActivator();
 
+    [ObservableAsProperty]
+    private string _welcomeMessage;
+
+    public MainWindowViewModel()
+    {
+        _welcomeMessage = "Lorem Ipsum";
+        _welcomeMessageHelper = Observable.Return("Dolor sit amet")
+            .ToProperty(this, x => x.WelcomeMessage);
+
+        this.WhenActivated((CompositeDisposable disposables) => 
+        {
+            // /* handle activation */
+            // Disposable
+            //     .Create(() => { /* handle deactivation */ })
+            //     .DisposeWith(disposables);
+        });
+    }        
+
     public ObservableCollection<PlanetViewModel> Planets { get; } = PlanetViewModel.LoadAll();
 
 }

Stars Assistant/Views/MainWindow.axaml

@@ -19,10 +19,10 @@
 
     <TabControl>
         <TabItem Header="Home">
-            Welcome to Stars Assistant!
+            <TextBlock x:Name="WelcomeText">Hi</TextBlock>
         </TabItem>
         <TabItem Header="DataGrid">
-            <DataGrid ItemsSource="{Binding Planets}"   
+            <DataGrid x:Name="PlanetsGrid"
                 AutoGenerateColumns="True" IsReadOnly="True" 
                 GridLinesVisibility="All"
                 FrozenColumnCount="1"

Stars Assistant/Views/MainWindow.axaml.cs

@@ -4,6 +4,8 @@ using System.Diagnostics;
 using System;
 using StarsAssistant.ViewModels;
 using Avalonia.Markup.Xaml;
+using ReactiveUI;
+using System.Reactive.Disposables;
 
 namespace StarsAssistant.Views;
 
@@ -11,6 +13,21 @@ public partial class MainWindow : ReactiveWindow<MainWindowViewModel>
 {
     public MainWindow()
     {
-        AvaloniaXamlLoader.Load(this);
+        this.WhenActivated(
+
+            disposables => {
+                this.OneWayBind(ViewModel,
+                        viewModel => viewModel.Planets,
+                        view => view.PlanetsGrid.ItemsSource)
+                    .DisposeWith(disposables);
+                this.OneWayBind(ViewModel, 
+                        vm => vm.WelcomeMessage, 
+                        v => v.WelcomeText.Text)
+                    .DisposeWith(disposables);
+            }
+        );
+        
+        InitializeComponent();
     }
+
 }