feat: implement JumpTo command in ApplicationViewModel and update navigation handling. (#803)

demo/Ursa.Demo/ViewModels/ApplicationViewModel.cs

@@ -0,0 +1,14 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using CommunityToolkit.Mvvm.Messaging;
+
+namespace Ursa.Demo.ViewModels;
+
+public partial class ApplicationViewModel : ObservableObject
+{
+    [RelayCommand]
+    private void JumpTo(string header)
+    {
+        WeakReferenceMessenger.Default.Send(header, "JumpTo");
+    }
+}

demo/Ursa.Demo/ViewModels/MainViewViewModel.cs

@@ -16,17 +16,12 @@ public partial class MainViewViewModel : ViewModelBase
     public WindowNotificationManager? NotificationManager { get; set; }
     public MenuViewModel Menus { get; set; } = new MenuViewModel();
 
-    private object? _content;
-
-    public object? Content
-    {
-        get => _content;
-        set => SetProperty(ref _content, value);
-    }
+    [ObservableProperty] private object? _content;
 
     public MainViewViewModel()
     {
-        WeakReferenceMessenger.Default.Register<MainViewViewModel, string>(this, OnNavigation);
+        WeakReferenceMessenger.Default.Register<MainViewViewModel, string, string>(this, "JumpTo", OnNavigation);
+        OnNavigation(this, MenuKeys.MenuKeyIntroduction);
     }
 
 

demo/Ursa.Demo/ViewModels/MenuItemViewModel.cs

@@ -32,6 +32,6 @@ public class MenuItemViewModel: ViewModelBase
     private void OnActivate()
     {
         if (IsSeparator || Key is null) return;
-        WeakReferenceMessenger.Default.Send(Key);
+        WeakReferenceMessenger.Default.Send(Key, "JumpTo");
     }
 }