From 553cd6f66f1417318edac6a51ea34027e227548c Mon Sep 17 00:00:00 2001
From: tznind <tznind@dundee.ac.uk>
Date: Fri, 20 Jan 2023 19:30:36 +0000
Subject: [PATCH] Adds TabView.TabClicked event

---
 Terminal.Gui/Views/TabView.cs  | 63 +++++++++++++++++++++++++++++++++-
 UICatalog/Scenarios/Notepad.cs | 29 ++++++++++++++--
 2 files changed, 88 insertions(+), 4 deletions(-)

diff --git a/Terminal.Gui/Views/TabView.cs b/Terminal.Gui/Views/TabView.cs
index 1baf85993..1bac1da3c 100644
--- a/Terminal.Gui/Views/TabView.cs
+++ b/Terminal.Gui/Views/TabView.cs
@@ -53,6 +53,14 @@ namespace Terminal.Gui {
 		/// </summary>
 		public event EventHandler<TabChangedEventArgs> SelectedTabChanged;
 
+
+		/// <summary>
+		/// Event fired when a <see cref="TabView.Tab"/> is clicked.  Can be used to cancel navigation,
+		/// show context menu (e.g. on right click) etc.
+		/// </summary>
+		public event EventHandler<TabMouseEventArgs> TabClicked;
+
+
 		/// <summary>
 		/// The currently selected member of <see cref="Tabs"/> chosen by the user
 		/// </summary>
@@ -665,6 +673,22 @@ namespace Terminal.Gui {
 
 			public override bool MouseEvent (MouseEvent me)
 			{
+				var hit = ScreenToTab (me.X, me.Y);
+
+				bool isClick = me.Flags.HasFlag (MouseFlags.Button1Clicked) ||
+					me.Flags.HasFlag (MouseFlags.Button2Clicked) ||
+					me.Flags.HasFlag (MouseFlags.Button3Clicked);
+
+				if (hit != null && isClick) {
+					host.OnTabClicked (new TabMouseEventArgs (hit, me));
+
+					// user canceled click
+					if (me.Handled) {
+						return true;
+					}
+				}
+
+
 				if (!me.Flags.HasFlag (MouseFlags.Button1Clicked) &&
 				!me.Flags.HasFlag (MouseFlags.Button1DoubleClicked) &&
 				!me.Flags.HasFlag (MouseFlags.Button1TripleClicked))
@@ -689,7 +713,7 @@ namespace Terminal.Gui {
 						return true;
 					}
 
-					var hit = ScreenToTab (me.X, me.Y);
+
 					if (hit != null) {
 						host.SelectedTab = hit;
 						SetNeedsDisplay ();
@@ -738,6 +762,43 @@ namespace Terminal.Gui {
 			}
 		}
 
+		/// <summary>
+		/// Raises the <see cref="TabClicked"/> event.
+		/// </summary>
+		/// <param name="tabMouseEventArgs"></param>
+		protected virtual private void OnTabClicked (TabMouseEventArgs tabMouseEventArgs)
+		{
+			TabClicked?.Invoke (this, tabMouseEventArgs);
+		}
+
+		/// <summary>
+		/// Describes a mouse event over a specific <see cref="TabView.Tab"/> in a <see cref="TabView"/>.
+		/// </summary>
+		public class TabMouseEventArgs : EventArgs {
+
+			/// <summary>
+			/// Gets the <see cref="TabView.Tab"/> that the mouse was over when the <see cref="MouseEvent"/>
+			/// occurred.
+			/// </summary>
+			public Tab Tab { get; }
+
+			/// <summary>
+			/// Gets the actual mouse event.  Use <see cref="MouseEvent.Handled"/> to cancel this event
+			/// and perform custom behavior (e.g. show a context menu).
+			/// </summary>
+			public MouseEvent MouseEvent { get; }
+
+			/// <summary>
+			/// Creates a new instance of the <see cref="TabMouseEventArgs"/> class.
+			/// </summary>
+			/// <param name="tab"><see cref="TabView.Tab"/> that the mouse was over when the event occurred.</param>
+			/// <param name="mouseEvent">The mouse activity being reported</param>
+			public TabMouseEventArgs (Tab tab, MouseEvent mouseEvent)
+			{
+				Tab = tab;
+				MouseEvent = mouseEvent;
+			}
+		}
 
 		/// <summary>
 		/// A single tab in a <see cref="TabView"/>
diff --git a/UICatalog/Scenarios/Notepad.cs b/UICatalog/Scenarios/Notepad.cs
index a4fe1992e..5e2fde4d8 100644
--- a/UICatalog/Scenarios/Notepad.cs
+++ b/UICatalog/Scenarios/Notepad.cs
@@ -38,6 +38,8 @@ namespace UICatalog.Scenarios {
 				Height = Dim.Fill (1),
 			};
 
+			tabView.TabClicked += TabView_TabClicked;
+
 			tabView.Style.ShowBorder = true;
 			tabView.ApplyStyleChanges ();
 
@@ -63,6 +65,19 @@ namespace UICatalog.Scenarios {
 			New ();
 		}
 
+		private void TabView_TabClicked (object sender, TabView.TabMouseEventArgs e)
+		{
+			var contextMenu = new ContextMenu (e.MouseEvent.X + 1, e.MouseEvent.Y + 1,
+				new MenuBarItem (new MenuItem [] {
+					new MenuItem ($"Save", "", () => Save(e.Tab)),
+					new MenuItem ($"Close", "", () => Close(e.Tab)),
+				})
+			);
+
+			contextMenu.Show ();
+			e.MouseEvent.Handled = true;
+		}
+
 		private void New ()
 		{
 			Open ("", null, $"new {numbeOfNewTabs++}");
@@ -70,7 +85,11 @@ namespace UICatalog.Scenarios {
 
 		private void Close ()
 		{
-			var tab = tabView.SelectedTab as OpenedFile;
+			Close (tabView.SelectedTab);
+		}
+		private void Close (TabView.Tab tabToClose)
+		{
+			var tab = tabToClose as OpenedFile;
 
 			if (tab == null) {
 				return;
@@ -156,9 +175,13 @@ namespace UICatalog.Scenarios {
 			};
 		}
 
-		public void Save ()
+		public void Save()
 		{
-			var tab = tabView.SelectedTab as OpenedFile;
+			Save (tabView.SelectedTab);
+		}
+		public void Save (TabView.Tab tabToSave )
+		{
+			var tab = tabToSave as OpenedFile;
 
 			if (tab == null) {
 				return;