gui-cs · tig · Dec 15, 2025 · Dec 7, 2025 · Dec 9, 2025 · Dec 9, 2025
@@ -9,6 +9,7 @@
   "Themes": [
     {
       "Hot Dog Stand": {
+        "Glyphs.WideGlyphReplacement": "①",
         "Schemes": [
           {
             "Runnable": {
@@ -134,7 +135,7 @@
       }
     },
     {
-      "UI Catalog Theme": {
+      "UI Catalog": {
         "Window.DefaultShadow": "Transparent",
         "Button.DefaultShadow": "None",
         "CheckBox.DefaultHighlightStates": "In, Pressed, PressedOutside",

@@ -34,10 +34,6 @@ public override void Main ()
             AutoSelectAdornments = false,
             ShowViewIdentifier = true
         };
-        adornmentsEditor.ExpanderButton.Accepting += (sender, args) =>
-                                                             {
-                                                                 //adornmentsEditor.ExpanderButton.Collapsed = args.NewValue;
-                                                             };
         appWindow.Add (adornmentsEditor);
 
         ViewportSettingsEditor viewportSettingsEditor = new ()

@@ -26,6 +26,11 @@ public class Glyphs
     // IMPORTANT: Configuration Manager test SaveDefaults uses this class to generate the default config file
     // IMPORTANT: in ./UnitTests/bin/Debug/netX.0/config.json
 
+    /// <summary>Unicode replacement character; used by Drivers when rendering in cases where a wide glyph can't
+    /// be output because it would be clipped. Defaults to ' ' (Space).</summary>
+    [ConfigurationProperty (Scope = typeof (ThemeScope))]
+    public static Rune WideGlyphReplacement { get; set; } = (Rune)' ';
+
     /// <summary>File icon.  Defaults to ☰ (Trigram For Heaven)</summary>
     [ConfigurationProperty (Scope = typeof (ThemeScope))]
     public static Rune File { get; set; } = (Rune)'☰';

@@ -146,6 +146,9 @@ public void Dispose ()
 
     private readonly IOutput _output;
 
+    /// <inheritdoc />
+    public IOutputBuffer GetOutputBuffer () => OutputBuffer;
+
     public IOutput GetOutput () => _output;
 
     private readonly IInputProcessor _inputProcessor;

@@ -64,7 +64,13 @@ public interface IDriver : IDisposable
     IInputProcessor GetInputProcessor ();
 
     /// <summary>
-    ///     Gets the output handler responsible for writing to the terminal.
+    ///     Gets the <see cref="IOutputBuffer"/> containing the buffered screen contents.
+    /// </summary>
+    /// <returns></returns>
+    IOutputBuffer GetOutputBuffer ();
+
+    /// <summary>
+    ///     Gets the <see cref="IOutput"/> responsible for writing to the terminal.
     /// </summary>
     IOutput GetOutput ();
 

@@ -1,5 +1,4 @@
-
-namespace Terminal.Gui.Drivers;
+namespace Terminal.Gui.Drivers;
 
 /// <summary>
 ///     Represents the desired screen state for console rendering. This interface provides methods for building up
@@ -128,4 +127,15 @@ public interface IOutputBuffer
     ///     Changing this may have unexpected consequences.
     /// </summary>
     int Top { get; set; }
+
+    /// <summary>
+    ///     Sets the replacement character that will be used when a wide glyph (double-width character) cannot fit in the
+    ///     available space.
+    ///     If not set, the default will be <see cref="Glyphs.WideGlyphReplacement"/>.
+    /// </summary>
+    /// <param name="column1ReplacementChar">
+    ///     The character used when the first column of a wide character is invalid (for example, when it is overlapped by the
+    ///     trailing half of a previous wide character).
+    /// </param>
+    void SetWideGlyphReplacement (Rune column1ReplacementChar);
 }
@@ -65,6 +65,14 @@ public int Cols
     /// <summary>The topmost row in the terminal.</summary>
     public virtual int Top { get; set; } = 0;
 
+    private Rune _column1ReplacementChar = Glyphs.WideGlyphReplacement;
+
+    /// <inheritdoc />
+    public void SetWideGlyphReplacement (Rune column1ReplacementChar)
+    {
+        _column1ReplacementChar = column1ReplacementChar;
+    }
+
     /// <summary>
     ///     Indicates which lines have been modified and need to be redrawn.
     /// </summary>
@@ -205,7 +213,7 @@ private void InvalidateOverlappedWideGlyph (int col, int row)
     {
         if (col > 0 && Contents! [row, col - 1].Grapheme.GetColumns () > 1)
         {
-            Contents [row, col - 1].Grapheme = Rune.ReplacementChar.ToString ();
+            Contents [row, col - 1].Grapheme = _column1ReplacementChar.ToString ();
             Contents [row, col - 1].IsDirty = true;
         }
     }
@@ -273,17 +281,7 @@ private void WriteWideGrapheme (int col, int row, string grapheme)
         if (!Clip!.Contains (col + 1, row))
         {
             // Second column is outside clip - can't fit wide char here
-            Contents! [row, col].Grapheme = Rune.ReplacementChar.ToString ();
-        }
-        else if (!Clip.Contains (col, row))
-        {
-            // First column is outside clip but second isn't
-            // Mark second column as replacement to indicate partial overlap
-            if (col + 1 < Cols)
-            {
-                Contents! [row, col + 1].Grapheme = Rune.ReplacementChar.ToString ();
-                Contents! [row, col + 1].IsDirty = true;
-            }
+            Contents! [row, col].Grapheme = _column1ReplacementChar.ToString ();
         }
         else
         {

@@ -256,7 +256,7 @@ protected virtual void OnMouseLeave () { }
     ///         <item>
     ///             <description>
     ///                 Invokes commands bound to mouse clicks via <see cref="MouseBindings"/>
-    ///                 (default: <see cref="Command.Select"/> → <see cref="Selecting"/> event)
+    ///                 (default: <see cref="Command.Activate"/> → <see cref="Activating"/> event)
     ///             </description>
     ///         </item>
     ///         <item>
@@ -295,7 +295,7 @@ protected virtual void OnMouseLeave () { }
     /// <seealso cref="MouseEvent"/>
     /// <seealso cref="OnMouseEvent"/>
     /// <seealso cref="MouseBindings"/>
-    /// <seealso cref="Selecting"/>
+    /// <seealso cref="Activating"/>
     /// <seealso cref="WantContinuousButtonPressed"/>
     /// <seealso cref="HighlightStates"/>
     public bool? NewMouseEvent (MouseEventArgs mouseEvent)
@@ -414,8 +414,8 @@ public bool RaiseMouseEvent (MouseEventArgs mouseEvent)
     /// <summary>
     ///     INTERNAL: For cases where the view is grabbed and the mouse is pressed, this method handles the pressed events from
     ///     the driver.
-    ///     When  <see cref="WantContinuousButtonPressed"/> is set, this method will raise the Clicked/Selecting event
-    ///     via <see cref="Command.Select"/> each time it is called (after the first time the mouse is pressed).
+    ///     When  <see cref="WantContinuousButtonPressed"/> is set, this method will raise the Clicked/Activating event
+    ///     via <see cref="Command.Activate"/> each time it is called (after the first time the mouse is pressed).
     /// </summary>
     /// <param name="mouseEvent"></param>
     /// <returns><see langword="true"/>, if processing should stop, <see langword="false"/> otherwise.</returns>
@@ -531,7 +531,7 @@ internal bool WhenGrabbedHandleClicked (MouseEventArgs mouseEvent)
     /// <summary>
     ///     INTERNAL API: Converts mouse click events into <see cref="Command"/>s by invoking the commands bound
     ///     to the mouse button via <see cref="MouseBindings"/>. By default, all mouse clicks are bound to
-    ///     <see cref="Command.Select"/> which raises the <see cref="Selecting"/> event.
+    ///     <see cref="Command.Activate"/> which raises the <see cref="Activating"/> event.
     /// </summary>
     protected bool RaiseCommandsBoundToMouse (MouseEventArgs args)
     {

@@ -178,6 +178,7 @@ public void FillRect_Fills_HonorsClip (int x, int y, int width, int height)
     public void Clipping_Wide_Runes ()
     {
         Application.Driver!.SetScreenSize (30, 1);
+        Application.Driver!.GetOutputBuffer ().SetWideGlyphReplacement ((Rune)'①');
 
         var top = new View
         {
@@ -231,9 +232,9 @@ public void Clipping_Wide_Runes ()
         //                            012 34 56 78 90 12 34 56 78 90 12 34 56 78
         //                            │こ れ  は 広 い  ル ー ン  ラ イ ン で  す 。
         //                            01 2345678901234 56 78 90 12 34 56 
-        //                            │� |0123456989│� ン  ラ イ ン で  す 。
+        //                            │① |0123456989│① ン  ラ イ ン で  す 。
         expectedOutput = """
-                         │�│0123456789│ ンラインです。
+                         │①│0123456789│ ンラインです。
                          """;
 
         DriverAssert.AssertDriverContentsWithFrameAre (expectedOutput, _output);

@@ -181,9 +181,9 @@ public void AddStr_Glyph_On_Second_Cell_Of_Wide_Glyph_Outputs_Correctly ()
     {
         IDriver? driver = CreateFakeDriver ();
         driver.SetScreenSize (6, 3);
+        driver.GetOutputBuffer ().SetWideGlyphReplacement ((Rune)'①');
 
         driver!.Clip = new (driver.Screen);
-
         driver.Move (1, 0);
         driver.AddStr ("┌");
         driver.Move (2, 0);
@@ -197,14 +197,14 @@ public void AddStr_Glyph_On_Second_Cell_Of_Wide_Glyph_Outputs_Correctly ()
 
         DriverAssert.AssertDriverContentsAre (
                                               """
-                                              �┌─┐🍎
+                                              ①┌─┐🍎
                                               """,
                                               output,
                                               driver);
 
         driver.Refresh ();
 
-        DriverAssert.AssertDriverOutputIs (@"\x1b[38;2;0;0;0m\x1b[48;2;0;0;0m�┌─┐🍎\x1b[38;2;255;255;255m\x1b[48;2;0;0;0m",
+        DriverAssert.AssertDriverOutputIs (@"\x1b[38;2;0;0;0m\x1b[48;2;0;0;0m①┌─┐🍎\x1b[38;2;255;255;255m\x1b[48;2;0;0;0m",
                                            output, driver);
     }
 }
@@ -1,4 +1,5 @@
 #nullable enable
+using System.Text;
 using UnitTests;
 using Xunit.Abstractions;
 
@@ -104,6 +105,7 @@ public void All_Drivers_When_Clipped_AddStr_Glyph_On_Second_Cell_Of_Wide_Glyph_O
         IApplication? app = Application.Create ();
         app.Init (driverName);
         IDriver driver = app.Driver!;
+        driver.GetOutputBuffer ().SetWideGlyphReplacement ((Rune)'①');
 
         // Need to force "windows" driver to override legacy console mode for this test
         driver.IsLegacyConsole = false;
@@ -127,14 +129,14 @@ public void All_Drivers_When_Clipped_AddStr_Glyph_On_Second_Cell_Of_Wide_Glyph_O
 
         DriverAssert.AssertDriverContentsAre (
                                               """
-                                              �┌─┐🍎
+                                              ①┌─┐🍎
                                               """,
                                               output,
                                               driver);
 
         driver.Refresh ();
 
-        DriverAssert.AssertDriverOutputIs (@"\x1b[38;2;0;0;0m\x1b[48;2;0;0;0m�┌─┐🍎\x1b[38;2;255;255;255m\x1b[48;2;0;0;0m",
+        DriverAssert.AssertDriverOutputIs (@"\x1b[38;2;0;0;0m\x1b[48;2;0;0;0m①┌─┐🍎\x1b[38;2;255;255;255m\x1b[48;2;0;0;0m",
                                            output, driver);
     }
 }

@@ -1,4 +1,7 @@
-namespace DriverTests;
+using System.Text;
+using Terminal.Gui.Drivers;
+
+namespace DriverTests;
 
 public class OutputBaseTests
 {
@@ -161,6 +164,8 @@ public void Write_Virtual_Or_NonVirtual_Uses_WriteToConsole_And_Clears_Dirty_Fla
         // FakeOutput exposes this because it's in test scope
         var output = new FakeOutput { IsLegacyConsole = isLegacyConsole };
         IOutputBuffer buffer = output.GetLastBuffer ()!;
+        buffer.SetWideGlyphReplacement ((Rune)'①');
+
         buffer.SetSize (3, 1);
 
         // Write '🦮' at col 0 and 'A' at col 2
@@ -209,7 +214,7 @@ public void Write_Virtual_Or_NonVirtual_Uses_WriteToConsole_And_Clears_Dirty_Fla
 
         output.Write (buffer);
 
-        Assert.Contains ("�", output.GetLastOutput ());
+        Assert.Contains ("①", output.GetLastOutput ());
         Assert.Contains ("X", output.GetLastOutput ());
 
         // Dirty flags cleared for the written cells