Changed from Terminal.Gui all EventHandler to Action.

Designer/Program.cs

@@ -85,10 +85,10 @@ namespace Designer {
 					HotNormal = Attribute.Make(Color.Red, Color.BrightRed),
 				},
 			};
-			loginText.MouseEnter += LoginText_MouseEnter;
-			loginText.MouseLeave += LoginText_MouseLeave;
-			loginText.Enter += LoginText_Enter;
-			loginText.Leave += LoginText_Leave;
+			loginText.MouseEnter += (e) => Text_MouseEnter (e, loginText);
+			loginText.MouseLeave += (e) => Text_MouseLeave (e, loginText);
+			loginText.Enter += (e) => Text_Enter (e, loginText);
+			loginText.Leave += (e) => Text_Leave (e, loginText);
 
 			var passText = new TextField ("") {
 				Secret = true,
@@ -102,30 +102,34 @@ namespace Designer {
 				Y = Pos.Top (test),
 				Width = Dim.Width (loginText)
 			};
+			testText.MouseEnter += (e) => Text_MouseEnter (e, testText);
+			testText.MouseLeave += (e) => Text_MouseLeave (e, testText);
+			testText.Enter += (e) => Text_Enter (e, testText);
+			testText.Leave += (e) => Text_Leave (e, testText);
 
 			surface.Add (login, password, test, loginText, passText, testText);
 			Application.Top.Add (menu, surface);
 			Application.Run ();
 		}
 
-		private static void LoginText_Leave (object sender, EventArgs e)
+		private static void Text_Leave (View.FocusEventArgs e, TextField view)
 		{
-			((TextField)sender).Text = $"Leaving from: {sender}";
+			view.Text = $"Leaving from: {view}";
 		}
 
-		private static void LoginText_Enter (object sender, EventArgs e)
+		private static void Text_Enter (View.FocusEventArgs e, TextField view)
 		{
-			((TextField)sender).Text = $"Entering in: {sender}";
+			view.Text = $"Entering in: {view}";
 		}
 
-		private static void LoginText_MouseLeave (object sender, View.MouseEventEventArgs e)
+		private static void Text_MouseLeave (View.MouseEventEventArgs e, TextField view)
 		{
-			((TextField)sender).Text = $"Mouse leave at X: {e.MouseEvent.X}; Y: {e.MouseEvent.Y} HasFocus: {e.MouseEvent.View.HasFocus}";
+			view.Text = $"Mouse leave at X: {e.MouseEvent.X}; Y: {e.MouseEvent.Y} HasFocus: {e.MouseEvent.View.HasFocus}";
 		}
 
-		private static void LoginText_MouseEnter (object sender, View.MouseEventEventArgs e)
+		private static void Text_MouseEnter (View.MouseEventEventArgs e, TextField view)
 		{
-			((TextField)sender).Text = $"Mouse enter at X: {e.MouseEvent.X}; Y: {e.MouseEvent.Y} HasFocus: {e.MouseEvent.View.HasFocus}";
+			view.Text = $"Mouse enter at X: {e.MouseEvent.X}; Y: {e.MouseEvent.Y} HasFocus: {e.MouseEvent.View.HasFocus}";
 		}
 	}
 }

Example/demo.cs

@@ -90,7 +90,7 @@ static class Demo {
 			Width = Dim.Fill (),
 			Height = Dim.Fill ()
 		};
-		container.KeyUp += (sender, e) => {
+		container.KeyUp += (e) => {
 			if (e.KeyEvent.Key == Key.Esc)
 				container.Running = false;
 		};
@@ -335,17 +335,16 @@ static class Demo {
 			$"{mi.Title.ToString ()} selected. Is from submenu: {mi.GetMenuBarItem ()}", "Ok");
 	}
 
-	static void MenuKeysStyle_Toggled (object sender, bool e)
+	static void MenuKeysStyle_Toggled (bool e)
 	{
 		menu.UseKeysUpDownAsKeysLeftRight = menuKeysStyle.Checked;
 	}
 
-	static void MenuAutoMouseNav_Toggled (object sender, bool e)
+	static void MenuAutoMouseNav_Toggled (bool e)
 	{
 		menu.WantMousePositionReports = menuAutoMouseNav.Checked;
 	}
 
-
 	static void Copy ()
 	{
 		TextField textField = menu.LastFocused as TextField;
@@ -501,10 +500,9 @@ static class Demo {
 			listView.MoveDown ();
 		}
 
-
-		container.KeyDown += (o, e) => KeyDownPressUp (e.KeyEvent, "Down");
-		container.KeyPress += (o, e) => KeyDownPressUp (e.KeyEvent, "Press");
-		container.KeyUp += (o, e) => KeyDownPressUp (e.KeyEvent, "Up");
+		container.KeyDown += (e) => KeyDownPressUp (e.KeyEvent, "Down");
+		container.KeyPress += (e) => KeyDownPressUp (e.KeyEvent, "Press");
+		container.KeyUp += (e) => KeyDownPressUp (e.KeyEvent, "Up");
 		Application.Run (container);
 	}
 	#endregion
@@ -638,7 +636,7 @@ static class Demo {
 		var bottom2 = new Label ("This should go on the bottom of another top-level!");
 		top.Add (bottom2);
 
-		top.LayoutComplete += (sender, e) => {
+		top.LayoutComplete += (e) => {
 			bottom.X = win.X;
 			bottom.Y = Pos.Bottom (win) - Pos.Top (win) - margin;
 			bottom2.X = Pos.Left (win);
@@ -648,14 +646,13 @@ static class Demo {
 
 		win.KeyPress += Win_KeyPress;
 
-
 		top.Add (win);
 		//top.Add (menu);
 		top.Add (menu, statusBar);
 		Application.Run ();
 	}
 
-	private static void Win_KeyPress (object sender, View.KeyEventEventArgs e)
+	private static void Win_KeyPress (View.KeyEventEventArgs e)
 	{
 		if (e.KeyEvent.Key == Key.ControlT) {
 			if (menu.IsMenuOpen)

Terminal.Gui/Core/Application.cs

@@ -92,7 +92,7 @@ namespace Terminal.Gui {
 		/// <remarks>
 		///   See also <see cref="Timeout"/>
 		/// </remarks>
-		public static event EventHandler Iteration;
+		public static event Action Iteration;
 
 		/// <summary>
 		/// Returns a rectangle that is centered in the screen for the provided size.
@@ -416,7 +416,7 @@ namespace Terminal.Gui {
 		/// This event is fired once when the application is first loaded. The dimensions of the
 		/// terminal are provided.
 		/// </summary>
-		public static event EventHandler<ResizedEventArgs> Loaded;
+		public static event Action<ResizedEventArgs> Loaded;
 
 		/// <summary>
 		/// Building block API: Prepares the provided <see cref="Toplevel"/>  for execution.
@@ -452,7 +452,7 @@ namespace Terminal.Gui {
 			if (toplevel.LayoutStyle == LayoutStyle.Computed)
 				toplevel.SetRelativeLayout (new Rect (0, 0, Driver.Cols, Driver.Rows));
 			toplevel.LayoutSubviews ();
-			Loaded?.Invoke (null, new ResizedEventArgs () { Rows = Driver.Rows, Cols = Driver.Cols });
+			Loaded?.Invoke (new ResizedEventArgs () { Rows = Driver.Rows, Cols = Driver.Cols });
 			toplevel.WillPresent ();
 			Redraw (toplevel);
 			toplevel.PositionCursor ();
@@ -572,7 +572,7 @@ namespace Terminal.Gui {
 					firstIteration = false;
 
 					MainLoop.MainIteration ();
-					Iteration?.Invoke (null, EventArgs.Empty);
+					Iteration?.Invoke ();
 				} else if (wait == false)
 					return;
 				if (state.Toplevel.NeedDisplay != null && (!state.Toplevel.NeedDisplay.IsEmpty || state.Toplevel.childNeedsDisplay)) {
@@ -678,12 +678,12 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// Invoked when the terminal was resized. The new size of the terminal is provided.
 		/// </summary>
-		public static event EventHandler<ResizedEventArgs> Resized;
+		public static event Action<ResizedEventArgs> Resized;
 
 		static void TerminalResized ()
 		{
 			var full = new Rect (0, 0, Driver.Cols, Driver.Rows);
-			Resized?.Invoke (null, new ResizedEventArgs () { Cols = full.Width, Rows = full.Height });
+			Resized?.Invoke (new ResizedEventArgs () { Cols = full.Width, Rows = full.Height });
 			Driver.Clip = full;
 			foreach (var t in toplevels) {
 				t.PositionToplevels ();

Terminal.Gui/Core/Toplevel.cs

@@ -53,14 +53,14 @@ namespace Terminal.Gui {
 		/// Subscribe to this event to perform tasks when the <see cref="Toplevel"/> has been laid out and focus has been set.
 		/// changes. A Ready event handler is a good place to finalize initialization after calling `<see cref="Application.Run()"/>(topLevel)`. 
 		/// </summary>
-		public event EventHandler Ready;
+		public event Action Ready;
 
 		/// <summary>
 		/// Called from <see cref="Application.RunLoop"/> after the <see cref="Toplevel"/> has entered it's first iteration of the loop. 
 		/// </summary>
 		internal virtual void OnReady ()
 		{
-			Ready?.Invoke (this, EventArgs.Empty);
+			Ready?.Invoke ();
 		}
 
 		/// <summary>

Terminal.Gui/Core/View.cs

@@ -124,27 +124,27 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// Event fired when the view gets focus.
 		/// </summary>
-		public event EventHandler<FocusEventArgs> Enter;
+		public event Action<FocusEventArgs> Enter;
 
 		/// <summary>
 		/// Event fired when the view looses focus.
 		/// </summary>
-		public event EventHandler<FocusEventArgs> Leave;
+		public event Action<FocusEventArgs> Leave;
 
 		/// <summary>
 		/// Event fired when the view receives the mouse event for the first time.
 		/// </summary>
-		public event EventHandler<MouseEventEventArgs> MouseEnter;
+		public event Action<MouseEventEventArgs> MouseEnter;
 
 		/// <summary>
 		/// Event fired when the view receives a mouse event for the last time.
 		/// </summary>
-		public event EventHandler<MouseEventEventArgs> MouseLeave;
+		public event Action<MouseEventEventArgs> MouseLeave;
 
 		/// <summary>
 		/// Event fired when a mouse event is generated.
 		/// </summary>
-		public event EventHandler<MouseEventEventArgs> MouseClick;
+		public event Action<MouseEventEventArgs> MouseClick;
 
 		internal Direction FocusDirection {
 			get => SuperView?.FocusDirection ?? focusDirection;
@@ -840,7 +840,7 @@ namespace Terminal.Gui {
 		public override bool OnEnter ()
 		{
 			FocusEventArgs args = new FocusEventArgs ();
-			Enter?.Invoke (this, args);
+			Enter?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (base.OnEnter ())
@@ -853,7 +853,7 @@ namespace Terminal.Gui {
 		public override bool OnLeave ()
 		{
 			FocusEventArgs args = new FocusEventArgs ();
-			Leave?.Invoke (this, args);
+			Leave?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (base.OnLeave ())
@@ -988,7 +988,7 @@ namespace Terminal.Gui {
 		/// Rect provides the view-relative rectangle describing the currently visible viewport into the <see cref="View"/>.
 		/// </para>
 		/// </remarks>
-		public event EventHandler<Rect> DrawContent;
+		public event Action<Rect> DrawContent;
 
 		/// <summary>
 		/// Enables overrides to draw infinitely scrolled content and/or a background behind added controls. 
@@ -999,7 +999,7 @@ namespace Terminal.Gui {
 		/// </remarks>
 		public virtual void OnDrawContent (Rect viewport)
 		{
-			DrawContent?.Invoke (this, viewport);
+			DrawContent?.Invoke (viewport);
 		}
 
 		/// <summary>
@@ -1058,14 +1058,14 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// Invoked when a character key is pressed and occurs after the key up event.
 		/// </summary>
-		public event EventHandler<KeyEventEventArgs> KeyPress;
+		public event Action<KeyEventEventArgs> KeyPress;
 
 		/// <inheritdoc/>
 		public override bool ProcessKey (KeyEvent keyEvent)
 		{
 
 			KeyEventEventArgs args = new KeyEventEventArgs (keyEvent);
-			KeyPress?.Invoke (this, args);
+			KeyPress?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (Focused?.ProcessKey (keyEvent) == true)
@@ -1078,7 +1078,7 @@ namespace Terminal.Gui {
 		public override bool ProcessHotKey (KeyEvent keyEvent)
 		{
 			KeyEventEventArgs args = new KeyEventEventArgs (keyEvent);
-			KeyPress?.Invoke (this, args);
+			KeyPress?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (subviews == null || subviews.Count == 0)
@@ -1093,7 +1093,7 @@ namespace Terminal.Gui {
 		public override bool ProcessColdKey (KeyEvent keyEvent)
 		{
 			KeyEventEventArgs args = new KeyEventEventArgs (keyEvent);
-			KeyPress?.Invoke (this, args);
+			KeyPress?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (subviews == null || subviews.Count == 0)
@@ -1107,13 +1107,13 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// Invoked when a key is pressed
 		/// </summary>
-		public event EventHandler<KeyEventEventArgs> KeyDown;
+		public event Action<KeyEventEventArgs> KeyDown;
 
 		/// <param name="keyEvent">Contains the details about the key that produced the event.</param>
 		public override bool OnKeyDown (KeyEvent keyEvent)
 		{
 			KeyEventEventArgs args = new KeyEventEventArgs (keyEvent);
-			KeyDown?.Invoke (this, args);
+			KeyDown?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (subviews == null || subviews.Count == 0)
@@ -1128,13 +1128,13 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// Invoked when a key is released
 		/// </summary>
-		public event EventHandler<KeyEventEventArgs> KeyUp;
+		public event Action<KeyEventEventArgs> KeyUp;
 
 		/// <param name="keyEvent">Contains the details about the key that produced the event.</param>
 		public override bool OnKeyUp (KeyEvent keyEvent)
 		{
 			KeyEventEventArgs args = new KeyEventEventArgs (keyEvent);
-			KeyUp?.Invoke (this, args);
+			KeyUp?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (subviews == null || subviews.Count == 0)
@@ -1386,14 +1386,14 @@ namespace Terminal.Gui {
 		/// <remarks>
 		/// Subscribe to this event to perform tasks when the <see cref="View"/> has been resized or the layout has otherwise changed.
 		/// </remarks>
-		public event EventHandler<LayoutEventArgs> LayoutComplete;
+		public event Action<LayoutEventArgs> LayoutComplete;
 
 		/// <summary>
 		/// Raises the <see cref="LayoutComplete"/> event. Called from  <see cref="LayoutSubviews"/> after all sub-views have been laid out.
 		/// </summary>
 		internal virtual void OnLayoutComplete (LayoutEventArgs args)
 		{
-			LayoutComplete?.Invoke (this, args);
+			LayoutComplete?.Invoke (args);
 		}
 
 		/// <summary>
@@ -1483,7 +1483,7 @@ namespace Terminal.Gui {
 		public override bool OnMouseEnter (MouseEvent mouseEvent)
 		{
 			MouseEventEventArgs args = new MouseEventEventArgs (mouseEvent);
-			MouseEnter?.Invoke (this, args);
+			MouseEnter?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (base.OnMouseEnter (mouseEvent))
@@ -1496,7 +1496,7 @@ namespace Terminal.Gui {
 		public override bool OnMouseLeave (MouseEvent mouseEvent)
 		{
 			MouseEventEventArgs args = new MouseEventEventArgs (mouseEvent);
-			MouseLeave?.Invoke (this, args);
+			MouseLeave?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (base.OnMouseLeave (mouseEvent))
@@ -1514,7 +1514,7 @@ namespace Terminal.Gui {
 		public virtual bool OnMouseEvent (MouseEvent mouseEvent)
 		{
 			MouseEventEventArgs args = new MouseEventEventArgs (mouseEvent);
-			MouseClick?.Invoke (this, args);
+			MouseClick?.Invoke (args);
 			if (args.Handled)
 				return true;
 			if (MouseEvent (mouseEvent))

Terminal.Gui/Views/Checkbox.cs

@@ -25,14 +25,14 @@ namespace Terminal.Gui {
 		///   raised when the <see cref="CheckBox"/> is activated either with
 		///   the mouse or the keyboard. The passed <c>bool</c> contains the previous state. 
 		/// </remarks>
-		public event EventHandler<bool> Toggled;
+		public event Action<bool> Toggled;
 
 		/// <summary>
 		/// Called when the <see cref="Checked"/> property changes. Invokes the <see cref="Toggled"/> event.
 		/// </summary>
 		public virtual void OnToggled (bool previousChecked)
 		{
-			Toggled?.Invoke (this, previousChecked);
+			Toggled?.Invoke (previousChecked);
 		}
 
 		/// <summary>

Terminal.Gui/Views/ComboBox.cs

@@ -22,7 +22,7 @@ namespace Terminal.Gui {
 		///   Client code can hook up to this event, it is
 		///   raised when the selection has been confirmed.
 		/// </remarks>
-		public event EventHandler<ustring> Changed;
+		public event Action<ustring> Changed;
 
 		IList<string> listsource;
 		IList<string> searchset;

Terminal.Gui/Views/DateField.cs

@@ -80,7 +80,7 @@ namespace Terminal.Gui {
 			Changed += DateField_Changed;
 		}
 
-		void DateField_Changed (object sender, ustring e)
+		void DateField_Changed (ustring e)
 		{
 			try {
 				if (!DateTime.TryParseExact (GetDate (Text).ToString (), GetInvarianteFormat (), CultureInfo.CurrentCulture, DateTimeStyles.None, out DateTime result))

Terminal.Gui/Views/ListView.cs

@@ -307,12 +307,12 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// This event is raised when the selected item in the <see cref="ListView"/> has changed.
 		/// </summary>
-		public event EventHandler<ListViewItemEventArgs> SelectedChanged;
+		public event Action<ListViewItemEventArgs> SelectedChanged;
 
 		/// <summary>
 		/// This event is raised when the user Double Clicks on an item or presses ENTER to open the selected item.
 		/// </summary>
-		public event EventHandler<ListViewItemEventArgs> OpenSelectedItem;
+		public event Action<ListViewItemEventArgs> OpenSelectedItem;
 
 		///<inheritdoc/>
 		public override bool ProcessKey (KeyEvent kb)
@@ -469,7 +469,7 @@ namespace Terminal.Gui {
 		{
 			if (selected != lastSelectedItem) {
 				var value = source.ToList () [selected];
-				SelectedChanged?.Invoke (this, new ListViewItemEventArgs (selected, value));
+				SelectedChanged?.Invoke (new ListViewItemEventArgs (selected, value));
 				lastSelectedItem = selected;
 				return true;
 			}
@@ -484,7 +484,7 @@ namespace Terminal.Gui {
 		public virtual bool OnOpenSelectedItem ()
 		{
 			var value = source.ToList () [selected];
-			OpenSelectedItem?.Invoke (this, new ListViewItemEventArgs (selected, value));
+			OpenSelectedItem?.Invoke (new ListViewItemEventArgs (selected, value));
 
 			return true;
 		}

Terminal.Gui/Views/Menu.cs

@@ -691,14 +691,14 @@ namespace Terminal.Gui {
 		}
 
 		/// <summary>
-		/// Raised as a menu is opened.
+		/// Raised as a menu is opening.
 		/// </summary>
-		public event EventHandler OnOpenMenu;
+		public event Action MenuOpening;
 
 		/// <summary>
 		/// Raised when a menu is closing.
 		/// </summary>
-		public event EventHandler OnCloseMenu;
+		public event Action MenuClosing;
 
 		internal Menu openMenu;
 		Menu openCurrentMenu;
@@ -712,6 +712,22 @@ namespace Terminal.Gui {
 		/// </summary>
 		public bool IsMenuOpen { get; protected set; }
 
+		/// <summary>
+		/// Virtual method that will invoke the <see cref="MenuOpening"/>
+		/// </summary>
+		public virtual void OnMenuOpening ()
+		{
+			MenuOpening?.Invoke ();
+		}
+
+		/// <summary>
+		/// Virtual method that will invoke the <see cref="MenuClosing"/>
+		/// </summary>
+		public virtual void OnMenuClosing ()
+		{
+			MenuClosing?.Invoke ();
+		}
+
 		View lastFocused;
 
 		/// <summary>
@@ -722,7 +738,7 @@ namespace Terminal.Gui {
 		internal void OpenMenu (int index, int sIndex = -1, MenuBarItem subMenu = null)
 		{
 			isMenuOpening = true;
-			OnOpenMenu?.Invoke (this, null);
+			OnMenuOpening ();
 			int pos = 0;
 			switch (subMenu) {
 			case null:
@@ -800,7 +816,7 @@ namespace Terminal.Gui {
 		internal void CloseMenu (bool reopen = false, bool isSubMenu = false)
 		{
 			isMenuClosing = true;
-			OnCloseMenu?.Invoke (this, null);
+			OnMenuClosing ();
 			switch (isSubMenu) {
 			case false:
 				if (openMenu != null)

Terminal.Gui/Views/ScrollView.cs

@@ -389,12 +389,12 @@ namespace Terminal.Gui {
 			SetNeedsLayout ();
 		}
 
-		void View_MouseLeave (object sender, MouseEventEventArgs e)
+		void View_MouseLeave (MouseEventEventArgs e)
 		{
 			Application.UngrabMouse ();
 		}
 
-		void View_MouseEnter (object sender, MouseEventEventArgs e)
+		void View_MouseEnter (MouseEventEventArgs e)
 		{
 			Application.GrabMouse (this);
 		}

Terminal.Gui/Views/StatusBar.cs

@@ -125,7 +125,7 @@ namespace Terminal.Gui {
 			Width = Dim.Fill ();
 			Height = 1;
 
-			LayoutComplete += (sender, e) => {
+			LayoutComplete += (e) => {
 				X = 0;
 				Height = 1;
 #if SNAP_TO_TOP

Terminal.Gui/Views/TextField.cs

@@ -41,7 +41,7 @@ namespace Terminal.Gui {
 		/// <remarks>
 		///   The passed <see cref="EventArgs"/> is a <see cref="ustring"/> containing the old value. 
 		/// </remarks>
-		public event EventHandler<ustring> Changed;
+		public event Action<ustring> Changed;
 
 		/// <summary>
 		/// Initializes a new instance of the <see cref="TextField"/> class using <see cref="LayoutStyle.Computed"/> positioning.
@@ -145,7 +145,7 @@ namespace Terminal.Gui {
 					historyText.Add (ustring.Make (text));
 					idxhistoryText++;
 				}
-				Changed?.Invoke (this, oldText);
+				Changed?.Invoke (oldText);
 
 				if (point > text.Count)
 					point = Math.Max (DisplaySize (text, 0) - 1, 0);

Terminal.Gui/Views/TextView.cs

@@ -285,7 +285,7 @@ namespace Terminal.Gui {
 		/// <summary>
 		/// Raised when the <see cref="Text"/> of the <see cref="TextView"/> changes.
 		/// </summary>
-		public event EventHandler TextChanged;
+		public event Action TextChanged;
 
 #if false
 		/// <summary>
@@ -295,7 +295,7 @@ namespace Terminal.Gui {
 		///   Client code can hook up to this event, it is
 		///   raised when the text in the entry changes.
 		/// </remarks>
-		public event EventHandler Changed;
+		public event Action Changed;
 #endif
 		/// <summary>
 		///   Initalizes a <see cref="TextView"/> on the specified area, with absolute position and size.
@@ -334,7 +334,7 @@ namespace Terminal.Gui {
 			set {
 				ResetPosition ();
 				model.LoadString (value);
-				TextChanged?.Invoke(this, new EventArgs());
+				TextChanged?.Invoke ();
 				SetNeedsDisplay ();
 			}
 		}

Terminal.Gui/Views/TimeField.cs

@@ -80,7 +80,7 @@ namespace Terminal.Gui {
 			Changed += TimeField_Changed;
 		}
 
-		void TimeField_Changed (object sender, ustring e)
+		void TimeField_Changed (ustring e)
 		{
 			try {
 				if (!TimeSpan.TryParseExact (Text.ToString ().Trim (), Format.Trim (), CultureInfo.CurrentCulture, TimeSpanStyles.None, out TimeSpan result))

UICatalog/Scenarios/AllViewsTester.cs

@@ -91,10 +91,10 @@ namespace UICatalog {
 				AllowsMarking = false,
 				ColorScheme = Colors.TopLevel,
 			};
-			_classListView.OpenSelectedItem += (o, a) => {
+			_classListView.OpenSelectedItem += (a) => {
 				Top.SetFocus (_settingsPane);
 			};
-			_classListView.SelectedChanged += (sender, args) => {
+			_classListView.SelectedChanged += (args) => {
 				ClearClass (_curView);
 				_curView = CreateClass (_viewClasses.Values.ToArray () [_classListView.SelectedItem]);
 			};
@@ -109,7 +109,7 @@ namespace UICatalog {
 				ColorScheme = Colors.TopLevel,
 			};
 			_computedCheckBox = new CheckBox ("Computed Layout", true) { X = 0, Y = 0 };
-			_computedCheckBox.Toggled += (sender, previousState) => {
+			_computedCheckBox.Toggled += (previousState) => {
 				if (_curView != null) {
 					_curView.LayoutStyle = previousState ? LayoutStyle.Absolute : LayoutStyle.Computed;
 					_hostPane.LayoutSubviews ();
@@ -134,7 +134,7 @@ namespace UICatalog {
 				SelectionChanged = (selected) => DimPosChanged (_curView),
 			};
 			_xText = new TextField ($"{_xVal}") { X = Pos.Right (label) + 1, Y = 0, Width = 4 };
-			_xText.Changed += (sender, args) => {
+			_xText.Changed += (args) => {
 				try {
 					_xVal = int.Parse (_xText.Text.ToString ());
 					DimPosChanged (_curView);
@@ -150,7 +150,7 @@ namespace UICatalog {
 			label = new Label ("y:") { X = Pos.Right (_xRadioGroup) + 1, Y = 0 };
 			_locationFrame.Add (label);
 			_yText = new TextField ($"{_yVal}") { X = Pos.Right (label) + 1, Y = 0, Width = 4 };
-			_yText.Changed += (sender, args) => {
+			_yText.Changed += (args) => {
 				try {
 					_yVal = int.Parse (_yText.Text.ToString ());
 					DimPosChanged (_curView);
@@ -182,7 +182,7 @@ namespace UICatalog {
 				SelectionChanged = (selected) => DimPosChanged (_curView)
 			};
 			_wText = new TextField ($"{_wVal}") { X = Pos.Right (label) + 1, Y = 0, Width = 4 };
-			_wText.Changed += (sender, args) => {
+			_wText.Changed += (args) => {
 				try {
 					_wVal = int.Parse (_wText.Text.ToString ());
 					DimPosChanged (_curView);
@@ -197,7 +197,7 @@ namespace UICatalog {
 			label = new Label ("height:") { X = Pos.Right (_wRadioGroup) + 1, Y = 0 };
 			_sizeFrame.Add (label);
 			_hText = new TextField ($"{_hVal}") { X = Pos.Right (label) + 1, Y = 0, Width = 4 };
-			_hText.Changed += (sender, args) => {
+			_hText.Changed += (args) => {
 				try {
 					_hVal = int.Parse (_hText.Text.ToString ());
 					DimPosChanged (_curView);

UICatalog/Scenarios/Buttons.cs

@@ -149,7 +149,7 @@ namespace UICatalog {
 				ColorScheme = Colors.TopLevel
 			};
 
-			lvTextAlig.SelectedChanged += (o, e) => {
+			lvTextAlig.SelectedChanged += (e) => {
 				switch (e.Value) {
 				case "Left":
 					sizeBtn.TextAlignment = TextAlignment.Left;

UICatalog/Scenarios/CharacterMap.cs

@@ -81,7 +81,7 @@ namespace UICatalog {
 			ContentSize = new Size (CharMap.RowWidth, MaxCodePointVal / 16);
 			ShowVerticalScrollIndicator = true;
 			ShowHorizontalScrollIndicator = false;
-			LayoutComplete += (sender, args) => {
+			LayoutComplete += (args) => {
 				if (Bounds.Width <= RowWidth) {
 					ShowHorizontalScrollIndicator = true;
 				} else {
@@ -93,7 +93,7 @@ namespace UICatalog {
 		}
 
 #if true
-		private void CharMap_DrawContent (object sender, Rect viewport)
+		private void CharMap_DrawContent (Rect viewport)
 		{
 			for (int header = 0; header < 16; header++) {
 				Move (viewport.X + RowHeaderWidth + 1 + (header * 3), 0);

UICatalog/Scenarios/ComputedLayout.cs

@@ -57,7 +57,7 @@ namespace UICatalog {
 				ColorScheme = Colors.Error
 			};
 
-			Win.LayoutComplete += (sender, a) => {
+			Win.LayoutComplete += (a) => {
 				horizontalRuler.Text = rule.Repeat ((int)Math.Ceiling ((double)(horizontalRuler.Bounds.Width) / (double)rule.Length)) [0..(horizontalRuler.Bounds.Width)];
 				verticalRuler.Text = vrule.Repeat ((int)Math.Ceiling ((double)(verticalRuler.Bounds.Height * 2) / (double)rule.Length)) [0..(verticalRuler.Bounds.Height * 2)];
 			};

UICatalog/Scenarios/Keys.cs

@@ -92,7 +92,7 @@ namespace UICatalog {
 			};
 			Win.Add (labelKeypress);
 
-			Win.KeyPress += (sender, a) => labelKeypress.Text = a.KeyEvent.ToString ();
+			Win.KeyPress += (a) => labelKeypress.Text = a.KeyEvent.ToString ();
 
 			// Key stroke log:
 			var keyLogLabel = new Label ("Key stroke log:") {
@@ -163,9 +163,9 @@ namespace UICatalog {
 				Height = Dim.Fill (),
 			};
 
-			Win.KeyDown += (sender, a) => KeyDownPressUp (a.KeyEvent, "Down");
-			Win.KeyPress += (sender, a) => KeyDownPressUp (a.KeyEvent, "Press");
-			Win.KeyUp += (sender, a) => KeyDownPressUp (a.KeyEvent, "Up");
+			Win.KeyDown += (a) => KeyDownPressUp (a.KeyEvent, "Down");
+			Win.KeyPress += (a) => KeyDownPressUp (a.KeyEvent, "Press");
+			Win.KeyUp += (a) => KeyDownPressUp (a.KeyEvent, "Up");
 
 			void KeyDownPressUp (KeyEvent keyEvent, string updown)
 			{

UICatalog/Scenarios/Progress.cs

@@ -167,7 +167,7 @@ namespace UICatalog {
 				systemTimerDemo.PulseProgressBar.Fraction = 1F;
 			};
 			systemTimerDemo.Speed.Text = $"{_systemTimerTick}";
-			systemTimerDemo.Speed.Changed += (sender, a) => {
+			systemTimerDemo.Speed.Changed += (a) => {
 				uint result;
 				if (uint.TryParse (systemTimerDemo.Speed.Text.ToString(), out result)) {
 					_systemTimerTick = result;
@@ -210,7 +210,7 @@ namespace UICatalog {
 			};
 
 			mainLoopTimeoutDemo.Speed.Text = $"{_mainLooopTimeoutTick}";
-			mainLoopTimeoutDemo.Speed.Changed += (sender, a) => {
+			mainLoopTimeoutDemo.Speed.Changed += (a) => {
 				uint result;
 				if (uint.TryParse (mainLoopTimeoutDemo.Speed.Text.ToString (), out result)) {
 					_mainLooopTimeoutTick = result;

UICatalog/Scenarios/Scrolling.cs

@@ -122,7 +122,7 @@ namespace UICatalog {
 			};
 			scrollView.Add (verticalRuler);
 
-			Win.LayoutComplete += (sender, a) => {
+			Win.LayoutComplete += (a) => {
 				horizontalRuler.Text = rule.Repeat ((int)Math.Ceiling ((double)(horizontalRuler.Bounds.Width) / (double)rule.Length)) [0..(horizontalRuler.Bounds.Width)] +
 				"\n" + "|         ".Repeat ((int)Math.Ceiling ((double)(horizontalRuler.Bounds.Width) / (double)rule.Length)) [0..(horizontalRuler.Bounds.Width)];
 				verticalRuler.Text = vrule.Repeat ((int)Math.Ceiling ((double)(verticalRuler.Bounds.Height * 2) / (double)rule.Length)) [0..(verticalRuler.Bounds.Height * 2)];
@@ -182,8 +182,8 @@ namespace UICatalog {
 				X = Pos.X(scrollView),
 				Y = Pos.Bottom(scrollView) + 1,
 			};
-			hCheckBox.Toggled += (sender, previousChecked) => {
-				scrollView.ShowHorizontalScrollIndicator = ((CheckBox)sender).Checked;
+			hCheckBox.Toggled += (previousChecked) => {
+				scrollView.ShowHorizontalScrollIndicator = hCheckBox.Checked;
 			};
 			Win.Add (hCheckBox);
 
@@ -191,8 +191,8 @@ namespace UICatalog {
 				X = Pos.Right (hCheckBox) + 3,
 				Y = Pos.Bottom (scrollView) + 1,
 			};
-			vCheckBox.Toggled += (sender, previousChecked) => {
-				scrollView.ShowVerticalScrollIndicator = ((CheckBox)sender).Checked;
+			vCheckBox.Toggled += (previousChecked) => {
+				scrollView.ShowVerticalScrollIndicator = vCheckBox.Checked;
 			};
 			Win.Add (vCheckBox);
 

UICatalog/UICatalog.cs

@@ -111,7 +111,7 @@ namespace UICatalog {
 			_top.Add (_rightPane);
 			_top.Add (_statusBar);
 
-			_top.Ready += (o, a) => {
+			_top.Ready += () => {
 				if (_runningScenario != null) {
 					_top.SetFocus (_rightPane);
 					_runningScenario = null;
@@ -192,7 +192,7 @@ namespace UICatalog {
 				AllowsMarking = false,
 				CanFocus = true,
 			};
-			_categoryListView.OpenSelectedItem += (o, a) => {
+			_categoryListView.OpenSelectedItem += (a) => {
 				_top.SetFocus (_rightPane);
 			};
 			_categoryListView.SelectedChanged += CategoryListView_SelectedChanged;
@@ -244,7 +244,7 @@ namespace UICatalog {
 			});
 		}
 
-		private static void _scenarioListView_OpenSelectedItem (object sender, EventArgs e)
+		private static void _scenarioListView_OpenSelectedItem (EventArgs e)
 		{
 			if (_runningScenario is null) {
 				var source = _scenarioListView.Source as ScenarioListDataSource;
@@ -306,7 +306,7 @@ namespace UICatalog {
 		/// to not be impacted. Same as for tabs.
 		/// </summary>
 		/// <param name="ke"></param>
-		private static void KeyDownHandler (object sender, View.KeyEventEventArgs a)
+		private static void KeyDownHandler (View.KeyEventEventArgs a)
 		{
 			if (a.KeyEvent.Key == Key.Tab || a.KeyEvent.Key == Key.BackTab) {
 				// BUGBUG: Work around Issue #434 by implementing our own TAB navigation
@@ -341,7 +341,7 @@ namespace UICatalog {
 			}
 		}
 
-		private static void CategoryListView_SelectedChanged (object sender, ListViewItemEventArgs e)
+		private static void CategoryListView_SelectedChanged (ListViewItemEventArgs e)
 		{
 			var item = _categories [_categoryListView.SelectedItem];
 			List<Type> newlist;