Windows - Enable preview events

src/Plugin.Maui.KeyListener/KeyPressedEventArgs.cs

@@ -3,7 +3,8 @@
 public sealed class KeyPressedEventArgs : EventArgs
 {
     public KeyboardModifiers Modifiers { get; internal set; }
-    public KeyboardKeys Keys { get; internal set; }
+    public KeyboardKeys Key { get; internal set; }
 
     public char KeyChar { get; internal set; }
+	public bool Handled { get; set; }
 }

src/Plugin.Maui.KeyListener/KeyboardBehavior.Windows.cs

@@ -1,85 +1,108 @@
 #if WINDOWS
 using Microsoft.UI.Xaml;
-using Microsoft.UI.Xaml.Input;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace Plugin.Maui.KeyListener;
 
 public partial class KeyboardBehavior : PlatformBehavior<VisualElement>
 {
-	protected override void OnAttachedTo(VisualElement bindable, FrameworkElement platformView)
+	public KeyboardBehavior()
 	{
-		base.OnAttachedTo(bindable, platformView);
+		// We prefer preview events on Windows
+		UsePreviewEvents = true;
+	}
 
-		var window = bindable.Window.Handler.PlatformView as Microsoft.UI.Xaml.Window;
+	// See: https://github.com/CommunityToolkit/Maui/issues/1912
+	private List<Guid> _boundIds = [Guid.Empty];
 
-		window.Content.KeyDown += OnKeyDown;
-		window.Content.KeyUp += OnKeyUp;
-		window.Content.PreviewKeyDown += OnPreviewKeyDown;
-		window.Content.PreviewKeyUp += OnPreviewKeyUp;
+	protected override void OnAttachedTo(VisualElement bindable, FrameworkElement platformView)
+	{
+		// Handle case where element is bound multiple times, we only allow a single binding for this behavior
+		if (_boundIds.Contains(bindable?.Id ?? Guid.Empty)) { return; }
+		_boundIds.Add(bindable.Id);
 
-		//platformView.KeyDown += OnKeyDown;
-		//platformView.KeyUp += OnKeyUp;
-		//platformView.PreviewKeyDown += OnPreviewKeyDown;
-		//platformView.PreviewKeyUp += OnPreviewKeyUp;
+		if (UsePreviewEvents)
+		{
+			platformView.PreviewKeyDown += OnPreviewKeyDown;
+			platformView.PreviewKeyUp += OnPreviewKeyUp;
+		}
+		else
+		{
+			platformView.KeyDown += OnKeyDown;
+			platformView.KeyUp += OnKeyUp;
+		}
+
+		base.OnAttachedTo(bindable, platformView);
 	}
 
 	protected override void OnDetachedFrom(VisualElement bindable, FrameworkElement platformView)
 	{
-		base.OnDetachedFrom(bindable, platformView);
-
-		var window = bindable.Window.Handler.PlatformView as Microsoft.UI.Xaml.Window;
+		if ((bindable?.Id ?? Guid.Empty) != Guid.Empty && _boundIds.Contains(bindable.Id)) { _boundIds.Remove(bindable.Id); }
 
-		window.Content.KeyDown -= OnKeyDown;
-		window.Content.KeyUp -= OnKeyUp;
-		window.Content.PreviewKeyDown -= OnPreviewKeyDown;
-		window.Content.PreviewKeyUp -= OnPreviewKeyUp;
+		if (UsePreviewEvents)
+		{
+			platformView.PreviewKeyDown -= OnPreviewKeyDown;
+			platformView.PreviewKeyUp -= OnPreviewKeyUp;
+		}
+		else
+		{
+			platformView.KeyDown -= OnKeyDown;
+			platformView.KeyUp -= OnKeyUp;
+		}
 
-		//platformView.KeyDown -= OnKeyDown;
-		//platformView.KeyUp -= OnKeyUp;
-		//platformView.PreviewKeyDown -= OnPreviewKeyDown;
-		//platformView.PreviewKeyUp -= OnPreviewKeyUp;
+		base.OnDetachedFrom(bindable, platformView);
 	}
 
-	void OnWindowKeyDown(object sender, Microsoft.UI.Xaml.Input.KeyRoutedEventArgs e)
+	void OnPreviewKeyDown(object sender, Microsoft.UI.Xaml.Input.KeyRoutedEventArgs e)
 	{
-		Console.WriteLine($"OnWindowKeyDown {e.Key}");
+		char keyChar = ((char)e.Key);
+		var eventArgs = new KeyPressedEventArgs
+		{
+			Key = e.Key.ToKeyboardKey(),
+			KeyChar = keyChar
+		};
+
+		this.RaiseKeyDown(eventArgs);
+
+		e.Handled = eventArgs.Handled;
 	}
 
 	void OnKeyDown(object sender, Microsoft.UI.Xaml.Input.KeyRoutedEventArgs e)
 	{
 		char keyChar = ((char)e.Key);
 		var eventArgs = new KeyPressedEventArgs
 		{
-			Keys = e.Key.ToKeyboardKeys(),
+			Key = e.Key.ToKeyboardKey(),
 			KeyChar = keyChar
 		};
 
 		this.RaiseKeyDown(eventArgs);
+
+		e.Handled = eventArgs.Handled;
 	}
+
 	void OnPreviewKeyUp(object sender, Microsoft.UI.Xaml.Input.KeyRoutedEventArgs e)
 	{
-		Console.WriteLine($"OnPreviewKeyUp {e.Key}");
-	}
+		char keyChar = ((char)e.Key);
+		var eventArgs = new KeyPressedEventArgs
+		{
+			Key = e.Key.ToKeyboardKey(),
+			KeyChar = keyChar
+		};
 
-	void OnPreviewKeyDown(object sender, Microsoft.UI.Xaml.Input.KeyRoutedEventArgs e)
-	{
-		Console.WriteLine($"OnPreviewKeyDown {e.Key}");
+		this.RaiseKeyUp(eventArgs);
+		e.Handled = eventArgs.Handled;
 	}
 
 	void OnKeyUp(object sender, Microsoft.UI.Xaml.Input.KeyRoutedEventArgs e)
 	{
 		char keyChar = ((char)e.Key);
 		var eventArgs = new KeyPressedEventArgs
 		{
-			Keys = e.Key.ToKeyboardKeys(),
+			Key = e.Key.ToKeyboardKey(),
 			KeyChar = keyChar
 		};
 		this.RaiseKeyUp(eventArgs);
+		e.Handled = eventArgs.Handled;
 	}
 }
 #endif

src/Plugin.Maui.KeyListener/KeyboardBehavior.cs

@@ -1,16 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Plugin.Maui.KeyListener
+namespace Plugin.Maui.KeyListener
 {
 	public partial class KeyboardBehavior : PlatformBehavior<VisualElement>
 	{
-		KeyboardBehaviorTriggers _triggers;
-
-		public KeyboardBehaviorTriggers Triggers => _triggers ??= new KeyboardBehaviorTriggers();
+		public bool UsePreviewEvents { get; set; }
 
 		public event EventHandler<KeyPressedEventArgs> KeyDown;
 		public event EventHandler<KeyPressedEventArgs> KeyUp;

src/Plugin.Maui.KeyListener/KeyboardBehavior.iOS.cs

@@ -1,10 +1,4 @@
 #if MACCATALYST || IOS
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using Foundation;
 using UIKit;
 
 namespace Plugin.Maui.KeyListener

src/Plugin.Maui.KeyListener/KeyboardFlags.cs

@@ -10,7 +10,6 @@ public enum KeyboardModifiers
     Alt = 16
 }
 
-[Flags]
 public enum KeyboardKeys
 {
     None,