Fix TabView and unit tests.

Terminal.Gui/Views/TabView.cs

@@ -117,6 +117,7 @@ public class TabView : View
             {
                 if (_selectedTab.View is { })
                 {
+                    _selectedTab.View.CanFocusChanged -= ContentViewCanFocus;
                     // remove old content
                     _contentView.Remove (_selectedTab.View);
                 }
@@ -129,12 +130,13 @@ public class TabView : View
                 // add new content
                 if (_selectedTab.View is { })
                 {
+                    _selectedTab.View.CanFocusChanged += ContentViewCanFocus;
                     _contentView.Add (_selectedTab.View);
                     // _contentView.Id = $"_contentView for {_selectedTab.DisplayText}";
                 }
             }
 
-            _contentView.CanFocus = _contentView.Subviews.Count (v => v.CanFocus) > 0;
+            ContentViewCanFocus (null, null);
 
             EnsureSelectedTabIsVisible ();
 
@@ -151,6 +153,11 @@ public class TabView : View
         }
     }
 
+    private void ContentViewCanFocus (object sender, EventArgs eventArgs)
+    {
+        _contentView.CanFocus = _contentView.Subviews.Count (v => v.CanFocus) > 0;
+    }
+
     private TabStyle _style = new ();
 
     /// <summary>Render choices for how to display tabs.  After making changes, call <see cref="ApplyStyleChanges()"/>.</summary>
@@ -289,6 +296,19 @@ public class TabView : View
     /// <returns>The valid <see cref="TabScrollOffset"/> for the given value.</returns>
     public int EnsureValidScrollOffsets (int value) { return Math.Max (Math.Min (value, Tabs.Count - 1), 0); }
 
+    /// <inheritdoc />
+    protected override void OnHasFocusChanged (bool newHasFocus, View previousFocusedView, View focusedVew)
+    {
+        if (SelectedTab is { } && !_contentView.CanFocus && focusedVew == this)
+        {
+            SelectedTab?.SetFocus ();
+
+            return;
+        }
+
+        base.OnHasFocusChanged (newHasFocus, previousFocusedView, focusedVew);
+    }
+
     /// <inheritdoc/>
     protected override bool OnDrawingContent (Rectangle viewport)
     {
@@ -652,14 +672,20 @@ public class TabView : View
         {
             _host._tabLocations = _host.CalculateViewport (Viewport).ToArray ();
 
-            RenderTabLine ();
 
-            RenderUnderline ();
             Driver?.SetAttribute (HasFocus ? GetFocusColor () : GetNormalColor ());
 
             return true;
         }
 
+        /// <inheritdoc />
+        protected override bool OnDrawingSubviews (Rectangle viewport)
+        {
+            RenderTabLine ();
+
+            return true;
+        }
+
         protected override void OnDrawComplete ()
         {
             if (_host._tabLocations is null)
@@ -1190,10 +1216,10 @@ public class TabView : View
                 }
 
                 tab.LineCanvas.Merge (lc);
-                tab.DrawAdornments ();
-            }
+                tab.RenderLineCanvas ();
 
-            return;
+                RenderUnderline ();
+            }
         }
 
         private int GetUnderlineYPosition ()

UnitTests/Views/TabViewTests.cs

@@ -103,7 +103,7 @@ public class TabViewTests (ITestOutputHelper output)
         Application.Shutdown ();
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [AutoInitShutdown]
     public void MouseClick_ChangesTab ()
     {
@@ -188,7 +188,7 @@ public class TabViewTests (ITestOutputHelper output)
         top.Dispose ();
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [AutoInitShutdown]
     public void MouseClick_Right_Left_Arrows_ChangesTab ()
     {
@@ -274,7 +274,7 @@ public class TabViewTests (ITestOutputHelper output)
         top.Dispose ();
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [AutoInitShutdown]
     public void MouseClick_Right_Left_Arrows_ChangesTab_With_Border ()
     {
@@ -369,7 +369,7 @@ public class TabViewTests (ITestOutputHelper output)
         top.Dispose ();
     }
 
-    [Fact (Skip="#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [AutoInitShutdown]
     public void ProcessKey_Down_Up_Right_Left_Home_End_PageDown_PageUp ()
     {
@@ -429,7 +429,7 @@ public class TabViewTests (ITestOutputHelper output)
         Assert.Equal (tab2, tv.SelectedTab);
         Assert.Equal (btn, top.MostFocused);
 
-        // Add a focusable subview to Selected Tab
+        // Add a focusable subview to Selected Tab View which is a Label with CanFocus as false
         var btnSubView = new View ()
         {
             Id = "btnSubView",
@@ -438,9 +438,17 @@ public class TabViewTests (ITestOutputHelper output)
         };
         tv.SelectedTab.View.Add (btnSubView);
 
+        Assert.False (tv.SelectedTab.View.CanFocus);
+
         // Press cursor up. Should focus the subview in the selected tab.
         Application.RaiseKeyDownEvent (Key.CursorUp);
         Assert.Equal (tab2, tv.SelectedTab);
+        Assert.NotEqual (btnSubView, top.MostFocused);
+        Assert.Equal (tab2, top.MostFocused);
+
+        tv.SelectedTab.View.CanFocus = true;
+        Application.RaiseKeyDownEvent (Key.CursorDown);
+        Assert.Equal (tab2, tv.SelectedTab);
         Assert.Equal (btnSubView, top.MostFocused);
 
         Application.RaiseKeyDownEvent (Key.CursorUp);
@@ -451,24 +459,18 @@ public class TabViewTests (ITestOutputHelper output)
         Application.RaiseKeyDownEvent (Key.CursorDown);
         Assert.Equal (btn, top.MostFocused);
 
-        // Press the cursor down key again will focus next view in the toplevel, whic is the TabView
+        // Press the cursor down key again will focus next view in the toplevel, which is the TabView
         Application.RaiseKeyDownEvent (Key.CursorDown);
         Assert.Equal (tab2, tv.SelectedTab);
         Assert.Equal (tv, top.Focused);
-        Assert.Equal (tab1, tv.MostFocused);
+        // Due to the RestoreFocus method prioritize the _previouslyFocused, so btnSubView will be focused again
+        Assert.Equal (btnSubView, tv.MostFocused);
 
-        // Press the cursor down key to focus the selected tab view hosting again
-        Application.RaiseKeyDownEvent (Key.CursorDown);
-        Assert.Equal (tab2, tv.SelectedTab);
-        Assert.Equal (btnSubView, top.MostFocused);
-
-        // Press the cursor up key to focus the selected tab
+        // Press the cursor up key to focus the selected tab which it's the only way to do that
         Application.RaiseKeyDownEvent (Key.CursorUp);
-        Application.Refresh ();
-
-        // Is the selected tab focused
         Assert.Equal (tab2, tv.SelectedTab);
         Assert.Equal (tv, top.Focused);
+        Assert.Equal (tab2, top.Focused.MostFocused);
         Assert.Equal (tv.MostFocused, top.Focused.MostFocused);
 
         // Press the cursor left key to select the previous tab
@@ -479,6 +481,7 @@ public class TabViewTests (ITestOutputHelper output)
         Assert.Equal (tab1, tv.SelectedTab);
         Assert.Equal (tv, top.Focused);
         Assert.Equal (tv.MostFocused, top.Focused.MostFocused);
+        Assert.Equal (tab1, top.Focused.MostFocused);
 
         // Press the end key to select the last tab
         Application.RaiseKeyDownEvent (Key.End);
@@ -595,7 +598,7 @@ public class TabViewTests (ITestOutputHelper output)
         Application.Shutdown ();
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_False_TabsOnBottom_False_TestTabView_Width3 ()
     {
@@ -643,7 +646,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_False_TabsOnBottom_False_TestThinTabView_WithLongNames ()
     {
@@ -735,7 +738,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_False_TabsOnBottom_True_TestTabView_Width3 ()
     {
@@ -783,7 +786,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_False_TabsOnBottom_True_TestThinTabView_WithLongNames ()
     {
@@ -875,7 +878,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_True_TabsOnBottom_False_TestTabView_Width3 ()
     {
@@ -919,7 +922,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_True_TabsOnBottom_False_TestThinTabView_WithLongNames ()
     {
@@ -1009,7 +1012,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_True_TabsOnBottom_False_With_Unicode ()
     {
@@ -1050,7 +1053,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_True_TabsOnBottom_True_TestTabView_Width3 ()
     {
@@ -1098,7 +1101,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_True_TabsOnBottom_True_TestThinTabView_WithLongNames ()
     {
@@ -1174,7 +1177,7 @@ public class TabViewTests (ITestOutputHelper output)
                                                      );
     }
 
-    [Fact (Skip = "#3789 Broke. The right way to fix is to refactor TabView to separate Layout and Draw")]
+    [Fact]
     [SetupFakeDriver]
     public void ShowTopLine_True_TabsOnBottom_True_With_Unicode ()
     {