Fix unit test because OnLeave is now invoked on toplevel removing, preventing two views having focus.

UnitTests/TopLevels/ToplevelTests.cs

@@ -1009,7 +1009,7 @@ namespace Terminal.Gui.TopLevelTests {
 			Application.End (rs);
 
 			Assert.True (isEnter);
-			Assert.False (isLeave);
+			Assert.True (isLeave);  // Leave event is now also invoked on Application.End allowing preform same output action
 		}
 
 		[Fact, AutoInitShutdown]

UnitTests/Views/ViewTests.cs

@@ -1915,11 +1915,25 @@ Y
 			Assert.True (view1.CanFocus);
 			Assert.True (view1.HasFocus);
 			Assert.True (view2.CanFocus);
+			Assert.False (view2.HasFocus); // Only one of the most focused toplevels view can have focus
+
+			Assert.True (Application.Top.ProcessKey (new KeyEvent (Key.Tab, new KeyModifiers ())));
+			Assert.True (view1.CanFocus);
+			Assert.False (view1.HasFocus); // Only one of the most focused toplevels view can have focus
+			Assert.True (view2.CanFocus);
 			Assert.True (view2.HasFocus);
 
+			Assert.True (Application.Top.ProcessKey (new KeyEvent (Key.Tab, new KeyModifiers ())));
+			Assert.True (view1.CanFocus);
+			Assert.True (view1.HasFocus);
+			Assert.True (view2.CanFocus);
+			Assert.False (view2.HasFocus); // Only one of the most focused toplevels view can have focus
+
 			view1.CanFocus = false;
 			Assert.False (view1.CanFocus);
 			Assert.False (view1.HasFocus);
+			Assert.True (view2.CanFocus);
+			Assert.True (view2.HasFocus);
 			Assert.Equal (win2, Application.Current.Focused);
 			Assert.Equal (view2, Application.Current.MostFocused);
 		}
@@ -1941,11 +1955,26 @@ Y
 			Assert.True (view1.CanFocus);
 			Assert.True (view1.HasFocus);
 			Assert.True (view2.CanFocus);
+			Assert.False (view2.HasFocus); // Only one of the most focused toplevels view can have focus
+
+			Assert.True (Application.Top.ProcessKey (new KeyEvent (Key.Tab | Key.CtrlMask, new KeyModifiers ())));
+			Assert.True (Application.Top.ProcessKey (new KeyEvent (Key.Tab | Key.CtrlMask, new KeyModifiers ())));
+			Assert.True (view1.CanFocus);
+			Assert.False (view1.HasFocus); // Only one of the most focused toplevels view can have focus
+			Assert.True (view2.CanFocus);
 			Assert.True (view2.HasFocus);
 
+			Assert.True (Application.Top.ProcessKey (new KeyEvent (Key.Tab | Key.CtrlMask, new KeyModifiers ())));
+			Assert.True (view1.CanFocus);
+			Assert.True (view1.HasFocus);
+			Assert.True (view2.CanFocus);
+			Assert.False (view2.HasFocus); // Only one of the most focused toplevels view can have focus
+
 			view1.CanFocus = false;
 			Assert.False (view1.CanFocus);
 			Assert.False (view1.HasFocus);
+			Assert.True (view2.CanFocus);
+			Assert.False (view2.HasFocus);
 			Assert.Equal (win1, Application.Current.Focused);
 			Assert.Equal (view12, Application.Current.MostFocused);
 		}
@@ -1966,13 +1995,27 @@ Y
 			Assert.True (view1.CanFocus);
 			Assert.True (view1.HasFocus);
 			Assert.True (view2.CanFocus);
+			Assert.False (view2.HasFocus); // Only one of the most focused toplevels view can have focus
+
+			Assert.True (Application.Top.ProcessKey (new KeyEvent (Key.Tab | Key.CtrlMask, new KeyModifiers ())));
+			Assert.True (view1.CanFocus);
+			Assert.False (view1.HasFocus); // Only one of the most focused toplevels view can have focus
+			Assert.True (view2.CanFocus);
 			Assert.True (view2.HasFocus);
 
+			Assert.True (Application.Top.ProcessKey (new KeyEvent (Key.Tab | Key.CtrlMask, new KeyModifiers ())));
+			Assert.True (view1.CanFocus);
+			Assert.True (view1.HasFocus);
+			Assert.True (view2.CanFocus);
+			Assert.False (view2.HasFocus); // Only one of the most focused toplevels view can have focus
+
 			win1.CanFocus = false;
 			Assert.False (view1.CanFocus);
 			Assert.False (view1.HasFocus);
 			Assert.False (win1.CanFocus);
 			Assert.False (win1.HasFocus);
+			Assert.True (view2.CanFocus);
+			Assert.True (view2.HasFocus);
 			Assert.Equal (win2, Application.Current.Focused);
 			Assert.Equal (view2, Application.Current.MostFocused);
 		}