Merge pull request #525 from KDERazorback/master

Edge case handling and Quality-of-life improvements on Core, ListView and MenuBar

Terminal.Gui/Core.cs

@@ -350,6 +350,15 @@ namespace Terminal.Gui {
 		/// <value>The identifier.</value>
 		public ustring Id { get; set; } = "";
 
+		/// <summary>
+		/// Returns a value indicating if this View is currently on Top (Active)
+		/// </summary>
+		public bool IsCurrentTop {
+			get {
+				return Application.Current == this;
+			}
+		}
+
 		/// <summary>
 		/// Gets or sets a value indicating whether this <see cref="View"/> want mouse position reports.
 		/// </summary>
@@ -531,7 +540,7 @@ namespace Terminal.Gui {
 		/// <param name="region">The region that must be flagged for repaint.</param>
 		public void SetNeedsDisplay (Rect region)
 		{
-			if (NeedDisplay.IsEmpty)
+			if (NeedDisplay == null || NeedDisplay.IsEmpty)
 				NeedDisplay = region;
 			else {
 				var x = Math.Min (NeedDisplay.X, region.X);
@@ -1015,7 +1024,7 @@ namespace Terminal.Gui {
 
 			if (subviews != null) {
 				foreach (var view in subviews) {
-					if (!view.NeedDisplay.IsEmpty || view.childNeedsDisplay) {
+					if (view.NeedDisplay != null && (!view.NeedDisplay.IsEmpty || view.childNeedsDisplay)) {
 						if (view.Frame.IntersectsWith (clipRect) && view.Frame.IntersectsWith (region)) {
 
 							// FIXED: optimize this by computing the intersection of region and view.Bounds
@@ -1704,8 +1713,8 @@ namespace Terminal.Gui {
 		{
 			Application.CurrentView = this;
 
-			if (this == Application.Top || this == Application.Current) {
-				if (!NeedDisplay.IsEmpty) {
+			if (IsCurrentTop) {
+				if (NeedDisplay != null && !NeedDisplay.IsEmpty) {
 					Driver.SetAttribute (Colors.TopLevel.Normal);
 					Clear (region);
 					Driver.SetAttribute (Colors.Base.Normal);
@@ -1887,7 +1896,7 @@ namespace Terminal.Gui {
 		{
 			Application.CurrentView = this;
 
-			if (!NeedDisplay.IsEmpty) {
+			if (NeedDisplay != null && !NeedDisplay.IsEmpty) {
 				DrawFrameWindow ();
 			}
 			contentView.Redraw (contentView.Bounds);
@@ -2487,7 +2496,7 @@ namespace Terminal.Gui {
 					Iteration?.Invoke (null, EventArgs.Empty);
 				} else if (wait == false)
 					return;
-				if (!state.Toplevel.NeedDisplay.IsEmpty || state.Toplevel.childNeedsDisplay) {
+				if (state.Toplevel.NeedDisplay != null && (!state.Toplevel.NeedDisplay.IsEmpty || state.Toplevel.childNeedsDisplay)) {
 					state.Toplevel.Redraw (state.Toplevel.Bounds);
 					if (DebugDrawBounds)
 						DrawBounds (state.Toplevel);

Terminal.Gui/Views/ListView.cs

@@ -593,12 +593,16 @@ namespace Terminal.Gui {
 		{
 			container.Move (col, line);
 			var t = src [item];
-			if (t is ustring) {
-				RenderUstr (driver, (ustring)t, col, line, width);
-			} else if (t is string) {
-				RenderUstr (driver, (string)t, col, line, width);
-			} else
-				RenderUstr (driver, t.ToString (), col, line, width);
+			if (t == null) {
+				RenderUstr (driver, ustring.Make(""), col, line, width);
+			} else {
+				if (t is ustring) {
+					RenderUstr (driver, (ustring)t, col, line, width);
+				} else if (t is string) {
+					RenderUstr (driver, (string)t, col, line, width);
+				} else
+					RenderUstr (driver, t.ToString (), col, line, width);
+			}
 		}
 
 		/// <summary>

Terminal.Gui/Views/Menu.cs

@@ -162,6 +162,9 @@ namespace Terminal.Gui {
 		/// <param name="children">The items in the current menu.</param>
 		public MenuBarItem (ustring title, MenuItem [] children)
 		{
+			if (children == null)
+				throw new ArgumentNullException (nameof (children), "The parameter cannot be null. Use an empty array instead.");
+
 			SetTitle (title ?? "");
 			Children = children;
 		}
@@ -320,7 +323,7 @@ namespace Terminal.Gui {
 
 		public override void PositionCursor ()
 		{
-			if (host == null || !host.isMenuClosed)
+			if (host == null || host.IsMenuOpen)
 				if (barItems.IsTopLevel) {
 					host.PositionCursor ();
 				} else
@@ -403,11 +406,11 @@ namespace Terminal.Gui {
 					var item = barItems.Children [current];
 					if (item == null || !item.IsEnabled ()) disabled = true;
 					if (host.UseKeysUpDownAsKeysLeftRight && barItems.Children [current]?.SubMenu != null &&
-						!disabled && !host.isMenuClosed) {
+						!disabled && host.IsMenuOpen) {
 						CheckSubMenu ();
 						break;
 					}
-					if (host.isMenuClosed)
+					if (!host.IsMenuOpen)
 						host.OpenMenu (host.selected);
 				} while (barItems.Children [current] == null || disabled);
 				SetNeedsDisplay ();
@@ -563,7 +566,7 @@ namespace Terminal.Gui {
 			selectedSub = -1;
 			ColorScheme = Colors.Menu;
 			WantMousePositionReports = true;
-			isMenuClosed = true;
+			IsMenuOpen = false;
 		}
 
 		bool openedByAltKey;
@@ -584,14 +587,14 @@ namespace Terminal.Gui {
 		{
 			if (keyEvent.IsAlt) {
 				// User pressed Alt - this may be a precursor to a menu accelerator (e.g. Alt-F)
-				if (!keyEvent.IsCtrl && openedByAltKey && isMenuClosed && openMenu == null && ((uint)keyEvent.Key & (uint)Key.CharMask) == 0) {
+				if (!keyEvent.IsCtrl && openedByAltKey && !IsMenuOpen && openMenu == null && ((uint)keyEvent.Key & (uint)Key.CharMask) == 0) {
 					// There's no open menu, the first menu item should be highlight.
 					// The right way to do this is to SetFocus(MenuBar), but for some reason
 					// that faults.
 
 					//Activate (0);
 					//StartMenu ();
-					isMenuClosed = false;
+					IsMenuOpen = true;
 					selected = 0;
 					CanFocus = true;
 					lastFocused = SuperView.MostFocused;
@@ -606,7 +609,7 @@ namespace Terminal.Gui {
 					if (openMenu != null)
 						CloseAllMenus ();
 					openedByAltKey = false;
-					isMenuClosed = true;
+					IsMenuOpen = false;
 					selected = -1;
 					CanFocus = false;
 					if (lastFocused != null)
@@ -658,13 +661,13 @@ namespace Terminal.Gui {
 			for (int i = 0; i < Menus.Length; i++) {
 				if (i == selected) {
 					pos++;
-					if (!isMenuClosed)
+					if (IsMenuOpen)
 						Move (pos + 1, 0);
 					else
 						Move (pos + 1, 0);
 					return;
 				} else {
-					if (!isMenuClosed)
+					if (IsMenuOpen)
 						pos += 1 + Menus [i].TitleLength + 2;
 					else
 						pos += 2 + Menus [i].TitleLength + 1;
@@ -695,12 +698,11 @@ namespace Terminal.Gui {
 		View previousFocused;
 		internal bool isMenuOpening;
 		internal bool isMenuClosing;
-		internal bool isMenuClosed;
 
 		/// <summary>
-		/// True of the menu is open; otherwise false.
+		/// True if the menu is open; otherwise false.
 		/// </summary>
-		public bool MenuOpen { get; set; }
+		public bool IsMenuOpen { get; protected set; }
 
 		View lastFocused;
 
@@ -748,12 +750,13 @@ namespace Terminal.Gui {
 				break;
 			}
 			isMenuOpening = false;
-			isMenuClosed = false;
-			MenuOpen = true;
+			IsMenuOpen = true;
 		}
 
-		// Starts the menu from a hotkey
-		void StartMenu ()
+		/// <summary>
+		/// Opens the current Menu programatically.
+		/// </summary>
+		public void OpenMenu ()
 		{
 			if (openMenu != null)
 				return;
@@ -778,6 +781,13 @@ namespace Terminal.Gui {
 			SetNeedsDisplay ();
 		}
 
+		/// <summary>
+		/// Closes the current Menu programatically, if open.
+		/// </summary>
+		public void CloseMenu()
+		{
+			CloseMenu (false, false);
+		}
 		internal void CloseMenu (bool reopen = false, bool isSubMenu = false)
 		{
 			isMenuClosing = true;
@@ -799,12 +809,12 @@ namespace Terminal.Gui {
 					if (!reopen)
 						selected = -1;
 					LastFocused.SuperView?.SetFocus (LastFocused);
+					IsMenuOpen = false;
 				} else {
 					SuperView.SetFocus (this);
-					isMenuClosed = true;
+					IsMenuOpen = false;
 					PositionCursor ();
 				}
-				isMenuClosed = true;
 				break;
 
 			case true:
@@ -816,7 +826,7 @@ namespace Terminal.Gui {
 				break;
 			}
 			isMenuClosing = false;
-			MenuOpen = false;
+			IsMenuOpen = false;
 		}
 
 		void RemoveSubMenu (int index)
@@ -879,7 +889,7 @@ namespace Terminal.Gui {
 				if (LastFocused != null && LastFocused != this)
 					selected = -1;
 			}
-			isMenuClosed = true;
+			IsMenuOpen = false;
 			openedByHotKey = false;
 			openedByAltKey = false;
 		}
@@ -993,8 +1003,8 @@ namespace Terminal.Gui {
 		public override bool ProcessHotKey (KeyEvent kb)
 		{
 			if (kb.Key == Key.F9) {
-				if (isMenuClosed)
-					StartMenu ();
+				if (!IsMenuOpen)
+					OpenMenu ();
 				else
 					CloseAllMenus ();
 				return true;
@@ -1085,7 +1095,7 @@ namespace Terminal.Gui {
 				for (int i = 0; i < Menus.Length; i++) {
 					if (cx > pos && me.X < pos + 1 + Menus [i].TitleLength) {
 						if (selected == i && (me.Flags == MouseFlags.Button1Pressed || me.Flags == MouseFlags.Button1DoubleClicked) &&
-											!isMenuClosed) {
+											IsMenuOpen) {
 							Application.UngrabMouse ();
 							if (Menus [i].IsTopLevel) {
 								var menu = new Menu (this, i, 0, Menus [i]);
@@ -1094,7 +1104,7 @@ namespace Terminal.Gui {
 								CloseMenu ();
 							}
 						} else if ((me.Flags == MouseFlags.Button1Pressed || me.Flags == MouseFlags.Button1DoubleClicked) &&
-							isMenuClosed) {
+							!IsMenuOpen) {
 							if (Menus [i].IsTopLevel) {
 								var menu = new Menu (this, i, 0, Menus [i]);
 								menu.Run (Menus [i].Action);
@@ -1102,12 +1112,12 @@ namespace Terminal.Gui {
 								Activate (i);
 							}
 						} else if (selected != i && selected > -1 && me.Flags == MouseFlags.ReportMousePosition) {
-							if (!isMenuClosed) {
+							if (IsMenuOpen) {
 								CloseMenu ();
 								Activate (i);
 							}
 						} else {
-							if (!isMenuClosed)
+							if (IsMenuOpen)
 								Activate (i);
 						}
 						return true;
@@ -1139,7 +1149,7 @@ namespace Terminal.Gui {
 					handled = false;
 					return false;
 				}
-			} else if (isMenuClosed && (me.Flags == MouseFlags.Button1Pressed || me.Flags == MouseFlags.Button1DoubleClicked ||
+			} else if (!IsMenuOpen && (me.Flags == MouseFlags.Button1Pressed || me.Flags == MouseFlags.Button1DoubleClicked ||
 				me.Flags.HasFlag (MouseFlags.Button1Pressed | MouseFlags.ReportMousePosition))) {
 				Application.GrabMouse (current);
 			} else {