Cleaned and added a base class for view models with background processing tha uses the new ThreadedAction class to do its background processing; added a view binding interface for WinForms that emulates the WPF design

git-svn-id: file:///srv/devel/repo-conversion/nuwi@41 d2e56fa2-650e-0410-a79f-9358c0239efd

Source/Views/IView.cs

@@ -0,0 +1,37 @@
+#region CPL License
+/*
+Nuclex Framework
+Copyright (C) 2002-2019 Nuclex Development Labs
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the IBM Common Public License as
+published by the IBM Corporation; either version 1.0 of the
+License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+IBM Common Public License for more details.
+
+You should have received a copy of the IBM Common Public
+License along with this library
+*/
+#endregion
+
+using System;
+
+namespace Nuclex.Windows.Forms.Views {
+
+  /// <summary>View with support for data binding</summary>
+  public interface IView {
+
+    /// <summary>Provides the data binding target for the view</summary>
+    /// <remarks>
+    ///   This property is identical to the same-named one in WPF, it provides
+    ///   the view model to which the view should bind its controls.
+    /// </remarks>
+    object DataContext { get; set; }
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Views

Source/Views/ViewControl.cs

@@ -0,0 +1,87 @@
+#region CPL License
+/*
+Nuclex Framework
+Copyright (C) 2002-2019 Nuclex Development Labs
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the IBM Common Public License as
+published by the IBM Corporation; either version 1.0 of the
+License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+IBM Common Public License for more details.
+
+You should have received a copy of the IBM Common Public
+License along with this library
+*/
+#endregion
+
+using System;
+using System.ComponentModel;
+using System.Windows.Forms;
+
+using Nuclex.Support;
+
+namespace Nuclex.Windows.Forms.Views {
+
+  /// <summary>
+  ///   Base class for MVVM user controls that act as views connected to a view model
+  /// </summary>
+  public class ViewControl : UserControl, IView {
+
+    /// <summary>Initializes a new view control</summary>
+    public ViewControl() {
+      this.onViewModelPropertyChangedDelegate = OnViewModelPropertyChanged;
+    }
+
+		/// <summary>Called when the control's data context is changed</summary>
+		/// <param name="sender">Control whose data context was changed</param>
+		/// <param name="oldDataContext">Data context that was previously used</param>
+		/// <param name="newDataContext">Data context that will be used from now on</param>
+		protected virtual void OnDataContextChanged(
+      object sender, object oldDataContext, object newDataContext
+    ) {
+      var oldViewModel = oldDataContext as INotifyPropertyChanged;
+      if(oldViewModel != null) {
+        oldViewModel.PropertyChanged -= this.onViewModelPropertyChangedDelegate;
+      }
+
+      var newViewModel = newDataContext as INotifyPropertyChanged;
+      if(newViewModel != null) {
+        newViewModel.PropertyChanged += this.onViewModelPropertyChangedDelegate;
+        InvalidateAllViewModelProperties();
+      }
+    }
+
+    /// <summary>Refreshes all properties from the view model</summary>
+    protected void InvalidateAllViewModelProperties() {
+      OnViewModelPropertyChanged(this.dataContext, PropertyChangedEventArgsHelper.Wildcard);
+    }
+
+    /// <summary>Called when a property of the view model is changed</summary>
+    /// <param name="sender">View model in which a property was changed</param>
+    /// <param name="arguments">Contains the name of the property that has changed</param>
+    protected virtual void OnViewModelPropertyChanged(
+      object sender, PropertyChangedEventArgs arguments
+    ) { }
+
+    /// <summary>Provides the data binding target for the view</summary>
+    public object DataContext {
+      get { return this.dataContext; }
+      set {
+        if(value != this.dataContext) {
+          this.dataContext = value;
+        }
+      }
+    }
+
+    /// <summary>Active data binding target, can be null</summary>
+    private object dataContext;
+    /// <summary>Delegate for the OnViewModelPropertyChanged() method</summary>
+    private PropertyChangedEventHandler onViewModelPropertyChangedDelegate;
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Views

Source/Views/ViewForm.cs

@@ -0,0 +1,87 @@
+#region CPL License
+/*
+Nuclex Framework
+Copyright (C) 2002-2019 Nuclex Development Labs
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the IBM Common Public License as
+published by the IBM Corporation; either version 1.0 of the
+License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+IBM Common Public License for more details.
+
+You should have received a copy of the IBM Common Public
+License along with this library
+*/
+#endregion
+
+using System;
+using System.ComponentModel;
+using System.Windows.Forms;
+
+using Nuclex.Support;
+
+namespace Nuclex.Windows.Forms.Views {
+
+  /// <summary>
+  ///   Base class for MVVM windows that act as views connected to a view model
+  /// </summary>
+  public class ViewForm : Form, IView {
+
+    /// <summary>Initializes a new view control</summary>
+    public ViewForm() {
+      this.onViewModelPropertyChangedDelegate = OnViewModelPropertyChanged;
+    }
+
+		/// <summary>Called when the window's data context is changed</summary>
+		/// <param name="sender">Window whose data context was changed</param>
+		/// <param name="oldDataContext">Data context that was previously used</param>
+		/// <param name="newDataContext">Data context that will be used from now on</param>
+		protected virtual void OnDataContextChanged(
+      object sender, object oldDataContext, object newDataContext
+    ) {
+      var oldViewModel = oldDataContext as INotifyPropertyChanged;
+      if(oldViewModel != null) {
+        oldViewModel.PropertyChanged -= this.onViewModelPropertyChangedDelegate;
+      }
+
+      var newViewModel = newDataContext as INotifyPropertyChanged;
+      if(newViewModel != null) {
+        newViewModel.PropertyChanged += this.onViewModelPropertyChangedDelegate;
+        InvalidateAllViewModelProperties();
+      }
+    }
+
+    /// <summary>Refreshes all properties from the view model</summary>
+    protected void InvalidateAllViewModelProperties() {
+      OnViewModelPropertyChanged(this.dataContext, PropertyChangedEventArgsHelper.Wildcard);
+    }
+
+    /// <summary>Called when a property of the view model is changed</summary>
+    /// <param name="sender">View model in which a property was changed</param>
+    /// <param name="arguments">Contains the name of the property that has changed</param>
+    protected virtual void OnViewModelPropertyChanged(
+      object sender, PropertyChangedEventArgs arguments
+    ) { }
+
+    /// <summary>Provides the data binding target for the view</summary>
+    public object DataContext {
+      get { return this.dataContext; }
+      set {
+        if(value != this.dataContext) {
+          this.dataContext = value;
+        }
+      }
+    }
+
+    /// <summary>Active data binding target, can be null</summary>
+    private object dataContext;
+    /// <summary>Delegate for the OnViewModelPropertyChanged() method</summary>
+    private PropertyChangedEventHandler onViewModelPropertyChangedDelegate;
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Views