WPF NotifyIcon

--------------
ADD   Added ParentTaskbarIcon attached dependency property which is set for tooltips, popups, and custom balloons.
CHG   Made CloseBalloon public.
CHG   Changed sample, cleaned up commands pattern.


git-svn-id: https://svn.evolvesoftware.ch/repos/evolve.net/WPF/NotifyIcon@93 9f600761-6f11-4665-b6dc-0185e9171623

Source/Sample Project/Commands/CommandBase.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Windows.Input;
+using System.Windows.Markup;
+
+namespace Sample_Project.Commands
+{
+  /// <summary>
+  /// Basic implementation of the <see cref="ICommand"/>
+  /// interface, which is also accessible as a markup
+  /// extension.
+  /// </summary>
+  public abstract class CommandBase<T> : MarkupExtension, ICommand
+      where T : class, ICommand, new()
+  {
+    /// <summary>
+    /// A singleton instance.
+    /// </summary>
+    private static T command;
+
+    /// <summary>
+    /// Gets a shared command instance.
+    /// </summary>
+    public override object ProvideValue(IServiceProvider serviceProvider)
+    {
+      if (command == null) command = new T();
+      return command;
+    }
+
+    /// <summary>
+    /// Fires when changes occur that affect whether
+    /// or not the command should execute.
+    /// </summary>
+    public event EventHandler CanExecuteChanged
+    {
+      add { CommandManager.RequerySuggested += value; }
+      remove { CommandManager.RequerySuggested -= value; }
+    }
+
+    /// <summary>
+    /// Defines the method to be called when the command is invoked.
+    /// </summary>
+    /// <param name="parameter">Data used by the command.
+    /// If the command does not require data to be passed,
+    /// this object can be set to null.
+    /// </param>
+    public abstract void Execute(object parameter);
+
+    /// <summary>
+    /// Defines the method that determines whether the command
+    /// can execute in its current state.
+    /// </summary>
+    /// <returns>
+    /// This default implementation always returns true.
+    /// </returns>
+    /// <param name="parameter">Data used by the command.  
+    /// If the command does not require data to be passed,
+    /// this object can be set to null.
+    /// </param>
+    public virtual bool CanExecute(object parameter)
+    {
+      return true;
+    }
+  }
+}

Source/Sample Project/Commands/HideMainWindowCommand.cs

@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Windows;
+using System.Windows;
 using System.Windows.Input;
 
 namespace Sample_Project.Commands
@@ -10,30 +6,21 @@ namespace Sample_Project.Commands
   /// <summary>
   /// Hides the main window.
   /// </summary>
-  public class HideMainWindowCommand : ICommand
+  public class HideMainWindowCommand : CommandBase<HideMainWindowCommand>
   {
-    public event EventHandler CanExecuteChanged;
 
-    public void Execute(object parameter)
+    public override void Execute(object parameter)
     {
       Application.Current.MainWindow.Hide();
-      TaskbarIconCommands.RefreshCommands();
+      CommandManager.InvalidateRequerySuggested();
     }
 
 
-    public bool CanExecute(object parameter)
+    public override bool CanExecute(object parameter)
     {
       return Application.Current.MainWindow.IsVisible;
     }
 
 
-    /// <summary>
-    /// Raises the <see cref="CanExecuteChanged"/> event.
-    /// </summary>
-    internal void RaiseCanExcecuteChanged()
-    {
-      if (CanExecuteChanged != null) CanExecuteChanged(this, EventArgs.Empty);
-    }
-
   }
 }

Source/Sample Project/Commands/ShowMainWindowCommand.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
 using System.Windows;
 using System.Windows.Input;
 
@@ -10,29 +9,19 @@ namespace Sample_Project.Commands
   /// <summary>
   /// Shows the main window.
   /// </summary>
-  public class ShowMainWindowCommand : ICommand
+  public class ShowMainWindowCommand : CommandBase<ShowMainWindowCommand>
   {
-    public event EventHandler CanExecuteChanged;
-
-    public void Execute(object parameter)
+    public override void Execute(object parameter)
     {
       Application.Current.MainWindow.Show();
-      TaskbarIconCommands.RefreshCommands();
+      CommandManager.InvalidateRequerySuggested();
     }
 
 
-    public bool CanExecute(object parameter)
+    public override bool CanExecute(object parameter)
     {
       return Application.Current.MainWindow.IsVisible == false;
     }
 
-    /// <summary>
-    /// Raises the <see cref="CanExecuteChanged"/> event.
-    /// </summary>
-    internal void RaiseCanExcecuteChanged()
-    {
-      if (CanExecuteChanged != null) CanExecuteChanged(this, EventArgs.Empty);
-    }
-
   }
 }

Source/Sample Project/Commands/TaskbarIconCommands.cs

@@ -1,27 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Windows.Input;
-
-namespace Sample_Project.Commands
-{
-  public static class TaskbarIconCommands
-  {
-    public static HideMainWindowCommand HideMain { get; set; }
-    public static ShowMainWindowCommand ShowMain { get; set; }
-
-
-    static TaskbarIconCommands()
-    {
-      HideMain = new HideMainWindowCommand();
-      ShowMain  =new ShowMainWindowCommand();
-    }
-
-    public static void RefreshCommands()
-    {
-      HideMain.RaiseCanExcecuteChanged();
-      ShowMain.RaiseCanExcecuteChanged();
-    }
-  }
-}