From df3e191a72dfd67dede5b029abb2a1d384bf4825 Mon Sep 17 00:00:00 2001
From: tznind <t.z.nind@dundee.ac.uk>
Date: Thu, 31 Dec 2020 13:38:15 +0000
Subject: [PATCH] Added CellActivated event which occurs on Enter or double
 click

---
 Terminal.Gui/Views/TableView.cs    | 69 ++++++++++++++++++++++++++++++
 UICatalog/Scenarios/TableEditor.cs | 16 +++----
 2 files changed, 77 insertions(+), 8 deletions(-)

diff --git a/Terminal.Gui/Views/TableView.cs b/Terminal.Gui/Views/TableView.cs
index d631b5d92..8b185bc93 100644
--- a/Terminal.Gui/Views/TableView.cs
+++ b/Terminal.Gui/Views/TableView.cs
@@ -224,6 +224,16 @@ namespace Terminal.Gui {
 		/// </summary>
 		public event Action<SelectedCellChangedEventArgs> SelectedCellChanged;
 
+		/// <summary>
+		/// This event is raised when a cell is activated e.g. by double clicking or pressing <see cref="CellActivationKey"/>
+		/// </summary>
+		public event Action<CellActivatedEventArgs> CellActivated;
+
+		/// <summary>
+		/// The key which when pressed should trigger <see cref="CellActivated"/> event.  Defaults to Enter.
+		/// </summary>
+		public Key CellActivationKey {get;set;} = Key.Enter;
+
 		/// <summary>
 		/// Initialzies a <see cref="TableView"/> class using <see cref="LayoutStyle.Computed"/> layout. 
 		/// </summary>
@@ -535,6 +545,12 @@ namespace Terminal.Gui {
 		/// <inheritdoc/>
 		public override bool ProcessKey (KeyEvent keyEvent)
 		{
+			if(keyEvent.Key == CellActivationKey && Table != null) {
+				OnCellActivated(new CellActivatedEventArgs(Table,SelectedColumn,SelectedRow));
+				return true;
+			}
+				
+
 			switch (keyEvent.Key) {
 			case Key.CursorLeft:
 				SelectedColumn--;
@@ -660,6 +676,14 @@ namespace Terminal.Gui {
 				}
 			}
 
+			// Double clicking a cell activates
+			if(me.Flags == MouseFlags.Button1DoubleClicked) {
+				var hit = ScreenToCell(me.OfX,me.OfY);
+				if(hit!= null) {
+					OnCellActivated(new CellActivatedEventArgs(Table,hit.Value.X,hit.Value.Y));
+				}
+			}
+
 			return false;
 		}
 
@@ -813,6 +837,15 @@ namespace Terminal.Gui {
 		{
 			SelectedCellChanged?.Invoke(args);
 		}
+		
+		/// <summary>
+		/// Invokes the <see cref="CellActivated"/> event
+		/// </summary>
+		/// <param name="args"></param>
+		protected virtual void OnCellActivated (CellActivatedEventArgs args)
+		{
+			CellActivated?.Invoke(args);
+		}
 
 		/// <summary>
 		/// Calculates which columns should be rendered given the <paramref name="bounds"/> in which to display and the <see cref="ColumnOffset"/>
@@ -1004,4 +1037,40 @@ namespace Terminal.Gui {
 			NewRow = newRow;
 		}
 	}
+
+	/// <summary>
+	/// Defines the event arguments for <see cref="TableView.CellActivated"/> event
+	/// </summary>
+	public class CellActivatedEventArgs : EventArgs
+	{
+		/// <summary>
+		/// The current table to which the new indexes refer.  May be null e.g. if selection change is the result of clearing the table from the view
+		/// </summary>
+		/// <value></value>
+		public DataTable Table {get;}
+
+
+		/// <summary>
+		/// The column index of the <see cref="Table"/> cell that is being activated
+		/// </summary>
+		/// <value></value>
+		public int Col {get;}
+		
+		/// <summary>
+		/// The row index of the <see cref="Table"/> cell that is being activated
+		/// </summary>
+		/// <value></value>
+		public int Row {get;}
+
+		/// <summary>
+		/// Creates a new instance of arguments describing a cell being activated in <see cref="TableView"/>
+		/// </summary>
+		/// <param name="t"></param>
+		public CellActivatedEventArgs(DataTable t, int col, int row)
+		{
+			Table = t;
+			Col = col;
+			Row = row;
+		}
+	}
 }
diff --git a/UICatalog/Scenarios/TableEditor.cs b/UICatalog/Scenarios/TableEditor.cs
index 863dc774b..a07212030 100644
--- a/UICatalog/Scenarios/TableEditor.cs
+++ b/UICatalog/Scenarios/TableEditor.cs
@@ -62,9 +62,8 @@ namespace UICatalog.Scenarios {
 			var statusBar = new StatusBar (new StatusItem [] {
 				//new StatusItem(Key.Enter, "~ENTER~ ApplyEdits", () => { _hexView.ApplyEdits(); }),
 				new StatusItem(Key.F2, "~F2~ OpenExample", () => OpenExample(true)),
-				new StatusItem(Key.F3, "~F3~ EditCell", () => EditCurrentCell()),
-				new StatusItem(Key.F4, "~F4~ CloseExample", () => CloseExample()),
-				new StatusItem(Key.F5, "~F5~ OpenSimple", () => OpenSimple(true)),
+				new StatusItem(Key.F3, "~F3~ CloseExample", () => CloseExample()),
+				new StatusItem(Key.F4, "~F4~ OpenSimple", () => OpenSimple(true)),
 				new StatusItem(Key.CtrlMask | Key.Q, "~^Q~ Quit", () => Quit()),
 			});
 			Top.Add (statusBar);
@@ -83,6 +82,7 @@ namespace UICatalog.Scenarios {
 			Win.Add(selectedCellLabel);
 
 			tableView.SelectedCellChanged += (e)=>{selectedCellLabel.Text = $"{tableView.SelectedRow},{tableView.SelectedColumn}";};
+			tableView.CellActivated += EditCurrentCell;
 		}
 
 		private void ClearColumnStyles ()
@@ -214,12 +214,12 @@ namespace UICatalog.Scenarios {
 			tableView.Table = BuildSimpleDataTable(big ? 30 : 5, big ? 1000 : 5);
 		}
 
-		private void EditCurrentCell ()
+		private void EditCurrentCell (CellActivatedEventArgs e)
 		{
-			if(tableView.Table == null)
+			if(e.Table == null)
 				return;
 
-			var oldValue = tableView.Table.Rows[tableView.SelectedRow][tableView.SelectedColumn].ToString();
+			var oldValue = e.Table.Rows[e.Row][e.Col].ToString();
 			bool okPressed = false;
 
 			var ok = new Button ("Ok", is_default: true);
@@ -231,7 +231,7 @@ namespace UICatalog.Scenarios {
 			var lbl = new Label() {
 				X = 0,
 				Y = 1,
-				Text = tableView.Table.Columns[tableView.SelectedColumn].ColumnName
+				Text = e.Table.Columns[e.Col].ColumnName
 			};
 
 			var tf = new TextField()
@@ -250,7 +250,7 @@ namespace UICatalog.Scenarios {
 			if(okPressed) {
 
 				try {
-					tableView.Table.Rows[tableView.SelectedRow][tableView.SelectedColumn] = string.IsNullOrWhiteSpace(tf.Text.ToString()) ? DBNull.Value : (object)tf.Text;
+					e.Table.Rows[e.Row][e.Col] = string.IsNullOrWhiteSpace(tf.Text.ToString()) ? DBNull.Value : (object)tf.Text;
 				}
 				catch(Exception ex) {
 					MessageBox.ErrorQuery(60,20,"Failed to set text", ex.Message,"Ok");