Created a service to display message boxes (view models that want to report errors are usually in a shitty situation - now for simple applications view models can send and error message that will either be displayed or used by a unit test to check the view model is actually failing as expected)

git-svn-id: file:///srv/devel/repo-conversion/nuwi@46 d2e56fa2-650e-0410-a79f-9358c0239efd

Nuclex.Windows.Forms (net-4.0).csproj

@@ -57,6 +57,17 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Source\AutoBinding\ConventionBinder.cs" />
     <Compile Include="Source\AutoBinding\IAutoBinder.cs" />
+    <Compile Include="Source\Messages\IMessageService.cs" />
+    <Compile Include="Source\Messages\MessageEventArgs.cs" />
+    <Compile Include="Source\Messages\MessageEventArgs.Test.cs">
+      <DependentUpon>MessageEventArgs.cs</DependentUpon>
+    </Compile>
+    <Compile Include="Source\Messages\MessageServiceHelper.cs" />
+    <Compile Include="Source\Messages\MessageText.cs" />
+    <Compile Include="Source\Messages\MessageText.Test.cs">
+      <DependentUpon>MessageText.cs</DependentUpon>
+    </Compile>
+    <Compile Include="Source\Messages\StandardMessageBoxManager.cs" />
     <Compile Include="Source\NullActiveWindowTracker.cs" />
     <Compile Include="Source\ViewModels\DialogViewModel.cs" />
     <Compile Include="Source\ViewModels\DialogViewModel.Test.cs">

Source/Messages/IMessageService.cs

@@ -0,0 +1,55 @@
+#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.Windows.Forms;
+
+namespace Nuclex.Windows.Forms.Messages {
+
+  /// <summary>Performs simple user interaction</summary>
+  /// <remarks>
+  ///   Methods provided by this service can be covered using plain old message boxes
+  ///   and do not require special dialogs or calls to the task dialog API.
+  /// </remarks>
+  public interface IMessageService {
+
+    /// <summary>Triggered when a message is about to be displayed to the user</summary>
+    event EventHandler<MessageEventArgs> MessageDisplaying;
+
+    /// <summary>Triggered when the user has acknowledged the current message</summary>
+    event EventHandler MessageAcknowledged;
+
+    /// <summary>Asks the user a question that can be answered via several buttons</summary>
+    /// <param name="image">Image that will be shown on the message box</param>
+    /// <param name="text">Text that will be shown to the user</param>
+    /// <param name="buttons">Buttons available for the user to click on</param>
+    /// <returns>The button the user has clicked on</returns>
+    DialogResult ShowQuestion(
+      MessageBoxIcon image, MessageText text, MessageBoxButtons buttons
+    );
+
+    /// <summary>Displays a notification to the user</summary>
+    /// <param name="image">Image that will be shown on the message bx</param>
+    /// <param name="text">Text that will be shown to the user</param>
+    void ShowNotification(MessageBoxIcon image, MessageText text);
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Messages

Source/Messages/MessageEventArgs.Test.cs

@@ -0,0 +1,49 @@
+#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.Windows.Forms;
+
+using NUnit.Framework;
+
+namespace Nuclex.Windows.Forms.Messages {
+
+  /// <summary>Unit tests for the message box event argument container</summary>
+  [TestFixture]
+  internal class MessageEventArgsTest {
+
+    /// <summary>Verifies that the image associated with the message gets stored</summary>
+    [Test]
+    public void ImageIsStored() {
+      var arguments = new MessageEventArgs(MessageBoxIcon.Exclamation, null);
+      Assert.AreEqual(MessageBoxIcon.Exclamation, arguments.Image);
+    }
+
+    /// <summary>Verifies that the text associated with the message gets stored</summary>
+    [Test]
+    public void TextIsStored() {
+      var text = new MessageText();
+      var arguments = new MessageEventArgs(MessageBoxIcon.None, text);
+      Assert.AreSame(text, arguments.Text);
+    }
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Messages

Source/Messages/MessageEventArgs.cs

@@ -0,0 +1,54 @@
+#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.Windows.Forms;
+
+namespace Nuclex.Windows.Forms.Messages {
+
+  /// <summary>Provides a displayed message and its severity to event subscribers</summary>
+  public class MessageEventArgs : EventArgs {
+
+    /// <summary>Initializes a new message box event argument container</summary>
+    /// <param name="image">Image the message box will be displaying</param>
+    /// <param name="text">Text that will be displayed in the message box</param>
+    public MessageEventArgs(MessageBoxIcon image, MessageText text) {
+      this.image = image;
+      this.text = text;
+    }
+
+    /// <summary>Image that indicates the severity of the message being displayed</summary>
+    public MessageBoxIcon Image {
+      get { return this.image; }
+    }
+
+    /// <summary>Text that is being displayed in the message box</summary>
+    public MessageText Text {
+      get { return this.text; }
+    }
+
+    /// <summary>Image that indicates the severity of the message being displayed</summary>
+    private MessageBoxIcon image;
+    /// <summary>Text that is being displayed in the message box</summary>
+    private MessageText text;
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Messages

Source/Messages/MessageServiceHelper.cs

@@ -0,0 +1,108 @@
+#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.Windows.Forms;
+
+namespace Nuclex.Windows.Forms.Messages {
+
+  /// <summary>Contains helper methods for the message service</summary>
+  public static class MessageServiceHelper {
+
+    /// <summary>Asks the user a question that can be answered with yes or no</summary>
+    /// <param name="messageService">
+    ///   Message service that will be used to display the question
+    /// </param>
+    /// <param name="text">Text that will be shown on the message box</param>
+    /// <returns>The button the user has clicked on</returns>
+    public static DialogResult AskYesNo(
+      this IMessageService messageService, MessageText text
+    ) {
+      return messageService.ShowQuestion(
+        MessageBoxIcon.Question, text, MessageBoxButtons.YesNo
+      );
+    }
+
+    /// <summary>Asks the user a question that can be answered with ok or cancel</summary>
+    /// <param name="messageService">
+    ///   Message service that will be used to display the question
+    /// </param>
+    /// <param name="text">Text that will be shown on the message box</param>
+    /// <returns>The button the user has clicked on</returns>
+    public static DialogResult AskOkCancel(
+      this IMessageService messageService, MessageText text
+    ) {
+      return messageService.ShowQuestion(
+        MessageBoxIcon.Question, text, MessageBoxButtons.OKCancel
+      );
+    }
+
+    /// <summary>
+    ///   Asks the user a question that can be answered with yes, no or cancel
+    /// </summary>
+    /// <param name="messageService">
+    ///   Message service that will be used to display the question
+    /// </param>
+    /// <param name="text">Text that will be shown on the message box</param>
+    /// <returns>The button the user has clicked on</returns>
+    public static DialogResult AskYesNoCancel(
+      this IMessageService messageService, MessageText text
+    ) {
+      return messageService.ShowQuestion(
+        MessageBoxIcon.Question, text, MessageBoxButtons.YesNoCancel
+      );
+    }
+
+    /// <summary>Displays an informative message</summary>
+    /// <param name="messageService">
+    ///   Message service that will be used to display the warning
+    /// </param>
+    /// <param name="text">Text to be displayed on the warning message</param>
+    public static void Inform(
+      this IMessageService messageService, MessageText text
+    ) {
+      messageService.ShowNotification(MessageBoxIcon.Information, text);
+    }
+
+    /// <summary>Displays a warning</summary>
+    /// <param name="messageService">
+    ///   Message service that will be used to display the warning
+    /// </param>
+    /// <param name="text">Text to be displayed on the warning message</param>
+    public static void Warn(
+      this IMessageService messageService, MessageText text
+    ) {
+      messageService.ShowNotification(MessageBoxIcon.Warning, text);
+    }
+
+    /// <summary>Reports an error</summary>
+    /// <param name="messageService">
+    ///   Message service that will be used to display the warning
+    /// </param>
+    /// <param name="text">Text to be displayed on the warning message</param>
+    public static void ReportError(
+      this IMessageService messageService, MessageText text
+    ) {
+      messageService.ShowNotification(MessageBoxIcon.Error, text);
+    }
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Messages

Source/Messages/MessageText.Test.cs

@@ -0,0 +1,51 @@
+#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.Windows;
+
+using NUnit.Framework;
+
+namespace Nuclex.Windows.Forms.Messages {
+
+  /// <summary>Unit tests for the message text container</summary>
+  [TestFixture]
+  internal class MessageTextTest {
+
+    /// <summary>Ensures that the message text class provides a copy constructor</summary>
+    [Test]
+    public void HasCopyConstructor() {
+      var text = new MessageText() {
+        Caption = "Caption",
+        Message = "Message",
+        Details = "Details",
+        ExpandedDetails = "ExpandedDetails"
+      };
+      var copy = new MessageText(text);
+
+      Assert.AreEqual(text.Caption, copy.Caption);
+      Assert.AreEqual(text.Message, copy.Message);
+      Assert.AreEqual(text.Details, copy.Details);
+      Assert.AreEqual(text.ExpandedDetails, copy.ExpandedDetails);
+    }
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Messages

Source/Messages/MessageText.cs

@@ -0,0 +1,55 @@
+#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.Messages {
+
+  /// <summary>Text that will be displayed in a message box</summary>
+  public class MessageText {
+
+    /// <summary>Initializs a new message text</summary>
+    public MessageText() { }
+
+    /// <summary>Initializes a new message text by copying another instance</summary>
+    /// <param name="other">Instance that will be copied</param>
+    public MessageText(MessageText other) {
+      Caption = other.Caption;
+      Message = other.Message;
+      Details = other.Details;
+      ExpandedDetails = other.ExpandedDetails;
+    }
+
+    /// <summary>The caption used when the is displayed in a message box</summary>
+    public string Caption { get; set; }
+    /// <summary>Main message being displayed to the user</summary>
+    public string Message { get; set; }
+    /// <summary>Message details shown below the main message</summary>
+    public string Details { get; set; }
+    /// <summary>
+    ///   Additional informations the user can display by expanding
+    ///   the message dialog. Can be null, in which case the message dialog
+    ///   will not be expandable.
+    /// </summary>
+    public string ExpandedDetails { get; set; }
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Messages

Source/Messages/StandardMessageBoxManager.cs

@@ -0,0 +1,162 @@
+#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.Windows.Forms;
+
+namespace Nuclex.Windows.Forms.Messages {
+
+  /// <summary>Uses task dialogs to display message boxes</summary>
+  public class StandardMessageBoxManager : IMessageService {
+
+    #region class MessageScope
+
+    /// <summary>Triggers the message displayed and acknowledged events</summary>
+    private class MessageScope : IDisposable {
+
+      /// <summary>
+      ///   Initializes a new message scope, triggering the message displayed event
+      /// </summary>
+      /// <param name="self">Message service the scope belongs to</param>
+      /// <param name="image">Image of the message being displayed</param>
+      /// <param name="text">Text contained in the message being displayed</param>
+      public MessageScope(
+        StandardMessageBoxManager self, MessageBoxIcon image, MessageText text
+      ) {
+        EventHandler<MessageEventArgs> messageDisplayed = self.MessageDisplaying;
+        if(messageDisplayed != null) {
+          messageDisplayed(this, new MessageEventArgs(image, text));
+        }
+
+        this.self = self;
+      }
+
+      /// <summary>Triggers the message acknowledged event</summary>
+      public void Dispose() {
+        EventHandler messageAcknowledged = self.MessageAcknowledged;
+        if(messageAcknowledged != null) {
+          messageAcknowledged(this, EventArgs.Empty);
+        }
+      }
+
+      /// <summary>Message service the scope belongs to</summary>
+      private StandardMessageBoxManager self;
+
+    }
+
+    #endregion // class MessageScope
+
+    /// <summary>Delegate for the standard message box show function</summary>
+    /// <param name="owner">Window that will modally display the message box</param>
+    /// <param name="text">Text that will be presented to the user</param>
+    /// <param name="caption">Contents of the message box' title bar</param>
+    /// <param name="buttons">Buttons available for the user to choose from</param>
+    /// <param name="icon">Icon that will be displayed next to the text</param>
+    /// <returns>The choice made by the user if multiple buttons were provided</returns>
+    private delegate DialogResult ShowMessageBoxDelegate(
+      IWin32Window owner,
+      string text,
+      string caption,
+      MessageBoxButtons buttons,
+      MessageBoxIcon icon
+    );
+
+    /// <summary>Triggered when a message is displayed to the user</summary>
+    public event EventHandler<MessageEventArgs> MessageDisplaying;
+
+    /// <summary>Triggered when the user has acknowledged the current message</summary>
+    public event EventHandler MessageAcknowledged;
+
+    /// <summary>Initializes a new task dialog message service</summary>
+    public StandardMessageBoxManager() : this(NullActiveWindowTracker.Default) { }
+
+    /// <summary>Initializes a new task dialog message service</summary>
+    /// <param name="tracker">
+    ///   Active window tracker used to obtain the parent window for message boxes
+    /// </param>
+    public StandardMessageBoxManager(IActiveWindowTracker tracker) {
+      this.tracker = tracker;
+      this.showMessageDelegate = new ShowMessageBoxDelegate(MessageBox.Show);
+    }
+
+    /// <summary>Asks the user a question that can be answered via several buttons</summary>
+    /// <param name="image">Image that will be shown on the message box</param>
+    /// <param name="text">Text that will be shown to the user</param>
+    /// <param name="buttons">Buttons available for the user to click on</param>
+    /// <returns>The button the user has clicked on</returns>
+    public DialogResult ShowQuestion(
+      MessageBoxIcon image, MessageText text, MessageBoxButtons buttons
+    ) {
+      using(var scope = new MessageScope(this, image, text)) {
+        return showMessageBoxInActiveUiThread(
+          text.Message,
+          text.Caption,
+          buttons,
+          image
+        );
+      }
+    }
+
+    /// <summary>Displays a notification to the user</summary>
+    /// <param name="image">Image that will be shown on the message bx</param>
+    /// <param name="text">Text that will be shown to the user</param>
+    public void ShowNotification(MessageBoxIcon image, MessageText text) {
+      using(var scope = new MessageScope(this, image, text)) {
+        showMessageBoxInActiveUiThread(
+          text.Message,
+          text.Caption,
+          MessageBoxButtons.OK,
+          image
+        );
+      }
+    }
+
+    /// <summary>Displays the message box in the active view's thread</summary>
+    /// <param name="message">Text that will be presented to the user</param>
+    /// <param name="caption">Contents of the message box' title bar</param>
+    /// <param name="buttons">Buttons available for the user to choose from</param>
+    /// <param name="image">Image that will be displayed next to the text</param>
+    /// <returns></returns>
+    private DialogResult showMessageBoxInActiveUiThread(
+      string message,
+      string caption,
+      MessageBoxButtons buttons,
+      MessageBoxIcon image
+    ) {
+      Form mainWindow = this.tracker.ActiveWindow;
+      if(mainWindow != null) {
+        return (DialogResult)mainWindow.Invoke(
+          this.showMessageDelegate,
+          (IWin32Window)mainWindow, message, caption, buttons, image
+        );
+      }
+
+      // No window tracker or unknown main window -- just show the message box
+      return MessageBox.Show(message, caption, buttons, image);
+    }
+
+    /// <summary>Provides the currently active top-level window</summary>
+    private IActiveWindowTracker tracker;
+    /// <summary>Delegate for the MessageBox.Show() method</summary>
+    private ShowMessageBoxDelegate showMessageDelegate;
+
+  }
+
+} // namespace Nuclex.Windows.Forms.Messages

Source/WindowManager.Test.cs

@@ -1,4 +1,24 @@
-using System;
+#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 NUnit.Framework;