Add foundation

Toolkit.Foundation/ObservableViewModel.cs

@@ -0,0 +1,72 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace Toolkit.Foundation;
+
+public  partial class ObservableViewModel : 
+    ObservableObject,
+    IObservableViewModel,
+    IInitializer,
+    IActivated,
+    IDeactivating,
+    IDeactivated,
+    IDeactivatable
+{
+    [ObservableProperty]
+    private bool isInitialized;
+
+    public ObservableViewModel(IServiceProvider serviceProvider,
+        IServiceFactory serviceFactory,
+        IPublisher publisher,
+        ISubscriber subscriber,
+        IDisposer disposer)
+    {
+        ServiceProvider = serviceProvider;
+        ServiceFactory = serviceFactory;
+        Publisher = publisher;
+        Disposer = disposer;
+
+        subscriber.Add(this);
+    }
+
+    public event EventHandler? DeactivateHandler;
+
+    public IDisposer Disposer { get; }
+
+    public IPublisher Publisher { get; }
+
+    public IServiceFactory ServiceFactory { get; }
+
+    public IServiceProvider ServiceProvider { get; }
+
+    public virtual Task Activated() =>
+        Task.CompletedTask;
+
+    public Task Deactivate()
+    {
+        DeactivateHandler?.Invoke(this, new EventArgs());
+        return Task.CompletedTask;
+    }
+
+    public virtual Task Deactivated() =>
+        Task.CompletedTask;
+
+    public virtual Task Deactivating() =>
+        Task.CompletedTask;
+
+    public void Dispose()
+    {
+        GC.SuppressFinalize(this);
+        Disposer.Dispose(this);
+    }
+
+    public Task Initialize()
+    {
+        if (IsInitialized)
+        {
+            return Task.CompletedTask;
+        }
+
+        IsInitialized = true;
+        return Task.CompletedTask;
+    }
+}