nullable enable TopLevel

Terminal.Gui/Application/Application.Overlapped.cs

@@ -1,4 +1,6 @@
 #nullable enable
+using System.Reflection;
+
 namespace Terminal.Gui;
 
 /// <summary>
@@ -6,6 +8,17 @@ namespace Terminal.Gui;
 /// </summary>
 public static class ApplicationOverlapped
 {
+
+    /// <summary>
+    ///     Gets or sets if <paramref name="top"/> is in overlapped mode within a Toplevel container.
+    /// </summary>
+    /// <param name="top"></param>
+    /// <returns></returns>
+    public static bool IsOverlapped (Toplevel? top)
+    {
+        return ApplicationOverlapped.OverlappedTop is { } && ApplicationOverlapped.OverlappedTop != top && !top!.Modal;
+    }
+
     /// <summary>
     ///     Gets the list of the Overlapped children which are not modal <see cref="Toplevel"/> from the
     ///     <see cref="OverlappedTop"/>.
@@ -99,7 +112,7 @@ public static class ApplicationOverlapped
     }
 
     /// <summary>
-    ///     Move to the next Overlapped child from the <see cref="OverlappedTop"/> and set it as the <see cref="Top"/> if
+    ///     Move to the next Overlapped child from the <see cref="OverlappedTop"/> and set it as the <see cref="Application.Top"/> if
     ///     it is not already.
     /// </summary>
     /// <param name="top"></param>
@@ -262,7 +275,7 @@ public static class ApplicationOverlapped
     }
 
     /// <summary>
-    ///     Given <paramref name="view"/>, returns the first Superview up the chain that is <see cref="Top"/>.
+    ///     Given <paramref name="view"/>, returns the first Superview up the chain that is <see cref="Application.Top"/>.
     /// </summary>
     internal static View? FindTopFromView (View? view)
     {
@@ -284,7 +297,7 @@ public static class ApplicationOverlapped
     }
 
     /// <summary>
-    ///     If the <see cref="Current"/> is not the <paramref name="top"/> then <paramref name="top"/> is moved to the top of
+    ///     If the <see cref="Application.Current"/> is not the <paramref name="top"/> then <paramref name="top"/> is moved to the top of
     ///     the Toplevel stack and made Current.
     /// </summary>
     /// <param name="top"></param>
@@ -361,7 +374,7 @@ public static class ApplicationOverlapped
         {
             lock (Application.TopLevels)
             {
-                Application.TopLevels.MoveTo (top, 0, new ToplevelEqualityComparer ());
+                Application.TopLevels.MoveTo (top!, 0, new ToplevelEqualityComparer ());
                 Application.Current = top;
             }
         }

Terminal.Gui/Application/Application.Run.cs

@@ -579,7 +579,7 @@ public static partial class Application // Run (Begin, Run, End, Stop)
             {
                 ApplicationOverlapped.OverlappedTop?.OnDeactivate (state.Toplevel);
                 state.Toplevel = Current;
-                ApplicationOverlapped.OverlappedTop?.OnActivate (state.Toplevel);
+                ApplicationOverlapped.OverlappedTop?.OnActivate (state.Toplevel!);
                 Top!.SetSubViewNeedsDisplay ();
                 Refresh ();
             }

Terminal.Gui/View/Layout/ViewLayout.cs

@@ -404,7 +404,7 @@ public partial class View
         int targetY,
         out int nx,
         out int ny,
-        out StatusBar statusBar
+        out StatusBar? statusBar
     )
     {
         int maxDimension;

Terminal.Gui/Views/Toplevel.cs

@@ -1,3 +1,4 @@
+#nullable enable
 namespace Terminal.Gui;
 
 /// <summary>
@@ -60,7 +61,7 @@ public partial class Toplevel : View
     /// </summary>
     public bool Modal { get; set; }
 
-    private void Toplevel_MouseClick (object sender, MouseEventEventArgs e) { e.Handled = InvokeCommand (Command.HotKey) == true; }
+    private void Toplevel_MouseClick (object? sender, MouseEventEventArgs e) { e.Handled = InvokeCommand (Command.HotKey) == true; }
 
     #endregion
 
@@ -68,11 +69,11 @@ public partial class Toplevel : View
 
     // TODO: Deprecate - Any view can host a menubar in v2
     /// <summary>Gets or sets the menu for this Toplevel.</summary>
-    public virtual MenuBar MenuBar { get; set; }
+    public MenuBar? MenuBar { get; set; }
 
     // TODO: Deprecate - Any view can host a statusbar in v2
     /// <summary>Gets or sets the status bar for this Toplevel.</summary>
-    public virtual StatusBar StatusBar { get; set; }
+    public StatusBar? StatusBar { get; set; }
 
     /// <inheritdoc/>
     public override View Add (View view)
@@ -141,22 +142,22 @@ public partial class Toplevel : View
     ///     Invoked when the last child of the Toplevel <see cref="RunState"/> is closed from by
     ///     <see cref="Application.End(RunState)"/>.
     /// </summary>
-    public event EventHandler AllChildClosed;
+    public event EventHandler? AllChildClosed;
 
     // TODO: Overlapped - Rename to *Subviews* - Move to View?
     /// <summary>
     ///     Invoked when a child of the Toplevel <see cref="RunState"/> is closed by
     ///     <see cref="Application.End(RunState)"/>.
     /// </summary>
-    public event EventHandler<ToplevelEventArgs> ChildClosed;
+    public event EventHandler<ToplevelEventArgs>? ChildClosed;
 
     // TODO: Overlapped - Rename to *Subviews* - Move to View?
     /// <summary>Invoked when a child Toplevel's <see cref="RunState"/> has been loaded.</summary>
-    public event EventHandler<ToplevelEventArgs> ChildLoaded;
+    public event EventHandler<ToplevelEventArgs>? ChildLoaded;
 
     // TODO: Overlapped - Rename to *Subviews* - Move to View?
     /// <summary>Invoked when a cjhild Toplevel's <see cref="RunState"/> has been unloaded.</summary>
-    public event EventHandler<ToplevelEventArgs> ChildUnloaded;
+    public event EventHandler<ToplevelEventArgs>? ChildUnloaded;
 
     #endregion
 
@@ -176,26 +177,26 @@ public partial class Toplevel : View
 
     // TODO: IRunnable: Re-implement as an event on IRunnable; IRunnable.Activating/Activate
     /// <summary>Invoked when the Toplevel <see cref="RunState"/> becomes the <see cref="Application.Current"/> Toplevel.</summary>
-    public event EventHandler<ToplevelEventArgs> Activate;
+    public event EventHandler<ToplevelEventArgs>? Activate;
 
     // TODO: IRunnable: Re-implement as an event on IRunnable; IRunnable.Deactivating/Deactivate?
     /// <summary>Invoked when the Toplevel<see cref="RunState"/> ceases to be the <see cref="Application.Current"/> Toplevel.</summary>
-    public event EventHandler<ToplevelEventArgs> Deactivate;
+    public event EventHandler<ToplevelEventArgs>? Deactivate;
 
     /// <summary>Invoked when the Toplevel's <see cref="RunState"/> is closed by <see cref="Application.End(RunState)"/>.</summary>
-    public event EventHandler<ToplevelEventArgs> Closed;
+    public event EventHandler<ToplevelEventArgs>? Closed;
 
     /// <summary>
     ///     Invoked when the Toplevel's <see cref="RunState"/> is being closed by
     ///     <see cref="Application.RequestStop(Toplevel)"/>.
     /// </summary>
-    public event EventHandler<ToplevelClosingEventArgs> Closing;
+    public event EventHandler<ToplevelClosingEventArgs>? Closing;
 
     /// <summary>
     ///     Invoked when the <see cref="Toplevel"/> <see cref="RunState"/> has begun to be loaded. A Loaded event handler
     ///     is a good place to finalize initialization before calling <see cref="Application.RunLoop(RunState)"/>.
     /// </summary>
-    public event EventHandler Loaded;
+    public event EventHandler? Loaded;
 
     /// <summary>
     ///     Called from <see cref="Application.Begin(Toplevel)"/> before the <see cref="Toplevel"/> redraws for the first
@@ -209,8 +210,9 @@ public partial class Toplevel : View
     {
         IsLoaded = true;
 
-        foreach (Toplevel tl in Subviews.Where (v => v is Toplevel))
+        foreach (var view in Subviews.Where (v => v is Toplevel))
         {
+            var tl = (Toplevel)view;
             tl.OnLoaded ();
         }
 
@@ -225,7 +227,7 @@ public partial class Toplevel : View
     ///         <see cref="Application.Run(Toplevel, Func{Exception, bool})"/> on this <see cref="Toplevel"/>.
     ///     </para>
     /// </summary>
-    public event EventHandler Ready;
+    public event EventHandler? Ready;
 
     /// <summary>
     ///     Stops and closes this <see cref="Toplevel"/>. If this Toplevel is the top-most Toplevel,
@@ -288,7 +290,7 @@ public partial class Toplevel : View
     ///     Invoked when the Toplevel <see cref="RunState"/> has been unloaded. A Unloaded event handler is a good place
     ///     to dispose objects after calling <see cref="Application.End(RunState)"/>.
     /// </summary>
-    public event EventHandler Unloaded;
+    public event EventHandler? Unloaded;
 
     internal virtual void OnActivate (Toplevel deactivated) { Activate?.Invoke (this, new (deactivated)); }
 
@@ -331,8 +333,9 @@ public partial class Toplevel : View
     /// </summary>
     internal virtual void OnReady ()
     {
-        foreach (Toplevel tl in Subviews.Where (v => v is Toplevel))
+        foreach (var view in Subviews.Where (v => v is Toplevel))
         {
+            var tl = (Toplevel)view;
             tl.OnReady ();
         }
 
@@ -342,8 +345,9 @@ public partial class Toplevel : View
     /// <summary>Called from <see cref="Application.End(RunState)"/> before the <see cref="Toplevel"/> is disposed.</summary>
     internal virtual void OnUnloaded ()
     {
-        foreach (Toplevel tl in Subviews.Where (v => v is Toplevel))
+        foreach (var view in Subviews.Where (v => v is Toplevel))
         {
+            var tl = (Toplevel)view;
             tl.OnUnloaded ();
         }
 
@@ -411,7 +415,7 @@ public partial class Toplevel : View
 
     /// <inheritdoc/>
     public override bool OnLeave (View view) { return MostFocused?.OnLeave (view) ?? base.OnLeave (view); }
-    
+
     #endregion
 
     #region Size / Position Management
@@ -458,15 +462,20 @@ public partial class Toplevel : View
     ///     implementation of specific positions for inherited <see cref="Toplevel"/> views.
     /// </summary>
     /// <param name="top">The Toplevel to adjust.</param>
-    public virtual void PositionToplevel (Toplevel top)
+    public virtual void PositionToplevel (Toplevel? top)
     {
-        View superView = GetLocationEnsuringFullVisibility (
+        if (top is null)
+        {
+            return;
+        }
+
+        View? superView = GetLocationEnsuringFullVisibility (
                                                             top,
                                                             top.Frame.X,
                                                             top.Frame.Y,
                                                             out int nx,
                                                             out int ny,
-                                                            out StatusBar sb
+                                                            out StatusBar? sb
                                                            );
 
         if (superView is null)
@@ -482,25 +491,25 @@ public partial class Toplevel : View
             maxWidth -= superView.GetAdornmentsThickness ().Left + superView.GetAdornmentsThickness ().Right;
         }
 
-        if ((superView != top || top?.SuperView is { } || (top != Application.Top && top.Modal) || (top?.SuperView is null && top.IsOverlapped))
-            && (top.Frame.X + top.Frame.Width > maxWidth || ny > top.Frame.Y))
+        if ((superView != top || top?.SuperView is { } || (top != Application.Top && top!.Modal) || (top?.SuperView is null && ApplicationOverlapped.IsOverlapped (top)))
+            && (top!.Frame.X + top.Frame.Width > maxWidth || ny > top.Frame.Y))
         {
-            if ((top.X is null || top.X is PosAbsolute) && top.Frame.X != nx)
+            if (top?.X is null or PosAbsolute && top?.Frame.X != nx)
             {
-                top.X = nx;
+                top!.X = nx;
                 layoutSubviews = true;
             }
 
-            if ((top.Y is null || top.Y is PosAbsolute) && top.Frame.Y != ny)
+            if (top?.Y is null or PosAbsolute && top?.Frame.Y != ny)
             {
-                top.Y = ny;
+                top!.Y = ny;
                 layoutSubviews = true;
             }
         }
 
         // TODO: v2 - This is a hack to get the StatusBar to be positioned correctly.
         if (sb != null
-            && !top.Subviews.Contains (sb)
+            && !top!.Subviews.Contains (sb)
             && ny + top.Frame.Height != superView.Frame.Height - (sb.Visible ? 1 : 0)
             && top.Height is DimFill
             && -top.Height.GetAnchor (0) < 1)
@@ -521,7 +530,7 @@ public partial class Toplevel : View
     }
 
     /// <summary>Invoked when the terminal has been resized. The new <see cref="Size"/> of the terminal is provided.</summary>
-    public event EventHandler<SizeChangedEventArgs> SizeChanging;
+    public event EventHandler<SizeChangedEventArgs>? SizeChanging;
 
     private bool OutsideTopFrame (Toplevel top)
     {
@@ -560,7 +569,7 @@ public class ToplevelEqualityComparer : IEqualityComparer<Toplevel>
     /// <param name="x">The first object of type <see cref="Toplevel"/> to compare.</param>
     /// <param name="y">The second object of type <see cref="Toplevel"/> to compare.</param>
     /// <returns><see langword="true"/> if the specified objects are equal; otherwise, <see langword="false"/>.</returns>
-    public bool Equals (Toplevel x, Toplevel y)
+    public bool Equals (Toplevel? x, Toplevel? y)
     {
         if (y is null && x is null)
         {
@@ -623,7 +632,7 @@ public sealed class ToplevelComparer : IComparer<Toplevel>
     ///     <paramref name="x"/> equals <paramref name="y"/> .Greater than zero <paramref name="x"/> is greater than
     ///     <paramref name="y"/>.
     /// </returns>
-    public int Compare (Toplevel x, Toplevel y)
+    public int Compare (Toplevel? x, Toplevel? y)
     {
         if (ReferenceEquals (x, y))
         {
@@ -640,6 +649,6 @@ public sealed class ToplevelComparer : IComparer<Toplevel>
             return 1;
         }
 
-        return string.Compare (x.Id, y.Id);
+        return string.CompareOrdinal (x.Id, y.Id);
     }
 }

Terminal.Gui/Views/ToplevelOverlapped.cs

@@ -2,9 +2,6 @@
 
 public partial class Toplevel
 {
-    /// <summary>Gets or sets if this Toplevel is in overlapped mode within a Toplevel container.</summary>
-    public bool IsOverlapped => ApplicationOverlapped.OverlappedTop is { } && ApplicationOverlapped.OverlappedTop != this && !Modal;
-
     /// <summary>Gets or sets if this Toplevel is a container for overlapped children.</summary>
     public bool IsOverlappedContainer { get; set; }
 }

UICatalog/UICatalog.cs

@@ -658,7 +658,7 @@ internal class UICatalogApp
 
             ColorScheme = Colors.ColorSchemes [_topLevelColorScheme];
 
-            MenuBar.Menus [0].Children [0].Shortcut = (KeyCode)Application.QuitKey;
+            MenuBar!.Menus [0].Children [0].Shortcut = (KeyCode)Application.QuitKey;
 
             if (StatusBar is { })
             {
@@ -942,7 +942,7 @@ internal class UICatalogApp
                                              {
                                                  MiIsMenuBorderDisabled.Checked = (bool)!MiIsMenuBorderDisabled.Checked!;
 
-                                                 MenuBar.MenusBorderStyle = !(bool)MiIsMenuBorderDisabled.Checked
+                                                 MenuBar!.MenusBorderStyle = !(bool)MiIsMenuBorderDisabled.Checked
                                                                                 ? LineStyle.Single
                                                                                 : LineStyle.None;
                                              };
@@ -985,7 +985,7 @@ internal class UICatalogApp
             MiUseSubMenusSingleFrame.Action += () =>
                                                {
                                                    MiUseSubMenusSingleFrame.Checked = (bool)!MiUseSubMenusSingleFrame.Checked!;
-                                                   MenuBar.UseSubMenusSingleFrame = (bool)MiUseSubMenusSingleFrame.Checked;
+                                                   MenuBar!.UseSubMenusSingleFrame = (bool)MiUseSubMenusSingleFrame.Checked;
                                                };
             menuItems.Add (MiUseSubMenusSingleFrame);
 

UnitTests/Views/OverlappedTests.cs

@@ -231,11 +231,11 @@ public class OverlappedTests
 
         Application.Iteration += (s, a) =>
                                  {
-                                     Assert.False (overlapped.IsOverlapped);
-                                     Assert.True (c1.IsOverlapped);
-                                     Assert.True (c2.IsOverlapped);
-                                     Assert.True (c3.IsOverlapped);
-                                     Assert.False (d.IsOverlapped);
+                                     Assert.False (ApplicationOverlapped.IsOverlapped(overlapped));
+                                     Assert.True (ApplicationOverlapped.IsOverlapped(c1));
+                                     Assert.True (ApplicationOverlapped.IsOverlapped(c2));
+                                     Assert.True (ApplicationOverlapped.IsOverlapped(c3));
+                                     Assert.False (ApplicationOverlapped.IsOverlapped(d));
 
                                      overlapped.RequestStop ();
                                  };
@@ -1068,11 +1068,11 @@ public class OverlappedTests
         Assert.False (top.IsCurrentTop);
         Assert.Equal (win1, Application.Current);
         Assert.True (win1.IsCurrentTop);
-        Assert.True (win1.IsOverlapped);
+        Assert.True (ApplicationOverlapped.IsOverlapped(win1));
         Assert.Null (top.Focused);
         Assert.Null (top.MostFocused);
         Assert.Equal (tf1W1, win1.MostFocused);
-        Assert.True (win1.IsOverlapped);
+        Assert.True (ApplicationOverlapped.IsOverlapped(win1));
         Assert.Single (ApplicationOverlapped.OverlappedChildren!);
         Application.Begin (win2);
         Assert.Equal (new (0, 0, 40, 25), win2.Frame);
@@ -1080,7 +1080,7 @@ public class OverlappedTests
         Assert.False (top.IsCurrentTop);
         Assert.Equal (win2, Application.Current);
         Assert.True (win2.IsCurrentTop);
-        Assert.True (win2.IsOverlapped);
+        Assert.True (ApplicationOverlapped.IsOverlapped(win2));
         Assert.Null (top.Focused);
         Assert.Null (top.MostFocused);
         Assert.Equal (tf1W2, win2.MostFocused);

UnitTests/Views/ToplevelTests.cs

@@ -17,7 +17,7 @@ public partial class ToplevelTests (ITestOutputHelper output)
         Assert.Null (top.MenuBar);
         Assert.Null (top.StatusBar);
         Assert.False (top.IsOverlappedContainer);
-        Assert.False (top.IsOverlapped);
+        Assert.False (ApplicationOverlapped.IsOverlapped(top));
     }
 
     [Fact]