Fixes #4258 - Glyphs drawn at mid-point of wide glyphs don't get drawn with clipping

Examples/UICatalog/Scenarios/Keys.cs

@@ -158,7 +158,7 @@ public override void Main ()
         appKeyListView.SchemeName = "Runnable";
         win.Add (onSwallowedListView);
 
-        Application.Driver!.InputProcessor.AnsiSequenceSwallowed += (s, e) => { swallowedList.Add (e.Replace ("\x1b", "Esc")); };
+        Application.Driver!.GetInputProcessor ().AnsiSequenceSwallowed += (s, e) => { swallowedList.Add (e.Replace ("\x1b", "Esc")); };
 
         Application.KeyDown += (s, a) => KeyDownPressUp (a, "Down");
         Application.KeyUp += (s, a) => KeyDownPressUp (a, "Up");

Examples/UICatalog/Scenarios/WideGlyphs.cs

@@ -25,7 +25,7 @@ public override void Main ()
         };
 
         // Build the array of codepoints once when subviews are laid out
-        appWindow.SubViewsLaidOut += (s, e) =>
+        appWindow.SubViewsLaidOut += (s, _) =>
         {
             View? view = s as View;
             if (view is null)
@@ -34,8 +34,8 @@ public override void Main ()
             }
 
             // Only rebuild if size changed or array is null
-            if (_codepoints is null || 
-                _codepoints.GetLength (0) != view.Viewport.Height || 
+            if (_codepoints is null ||
+                _codepoints.GetLength (0) != view.Viewport.Height ||
                 _codepoints.GetLength (1) != view.Viewport.Width)
             {
                 _codepoints = new Rune [view.Viewport.Height, view.Viewport.Width];
@@ -51,7 +51,9 @@ public override void Main ()
         };
 
         // Fill the window with the pre-built codepoints array
-        appWindow.DrawingContent += (s, e) =>
+        // For detailed documentation on the draw code flow from Application.Run to this event,
+        // see WideGlyphs.DrawFlow.md in this directory
+        appWindow.DrawingContent += (s, _) =>
         {
             View? view = s as View;
             if (view is null || _codepoints is null)
@@ -73,15 +75,15 @@ public override void Main ()
             }
         };
 
-        Line verticalLineAtEven = new Line ()
+        Line verticalLineAtEven = new ()
         {
             X = 10,
             Orientation = Orientation.Vertical,
             Length = Dim.Fill ()
         };
         appWindow.Add (verticalLineAtEven);
 
-        Line verticalLineAtOdd = new Line ()
+        Line verticalLineAtOdd = new ()
         {
             X = 25,
             Orientation = Orientation.Vertical,
@@ -97,8 +99,12 @@ public override void Main ()
             Y = 5,
             Width = 15,
             Height = 5,
-            BorderStyle = LineStyle.Dashed,
+            //BorderStyle = LineStyle.Dashed,
         };
+
+        // Proves it's not LineCanvas related
+        arrangeableViewAtEven!.Border!.Thickness = new (1);
+        arrangeableViewAtEven.Border.Add(new View () { Height = Dim.Auto(), Width = Dim.Auto(), Text = "Even" });
         appWindow.Add (arrangeableViewAtEven);
 
         View arrangeableViewAtOdd = new ()
@@ -112,6 +118,70 @@ public override void Main ()
             BorderStyle = LineStyle.Dashed,
         };
         appWindow.Add (arrangeableViewAtOdd);
+
+        var superView = new View
+        {
+            CanFocus = true,
+            X = 30, // on an even column to start
+            Y = Pos.Center (),
+            Width = Dim.Auto () + 4,
+            Height = Dim.Auto () + 1,
+            BorderStyle = LineStyle.Single,
+            Arrangement = ViewArrangement.Movable | ViewArrangement.Resizable
+        };
+
+        Rune codepoint = Glyphs.Apple;
+
+        superView.DrawingContent += (s, e) =>
+                                    {
+                                        var view = s as View;
+                                        for (var r = 0; r < view!.Viewport.Height; r++)
+                                        {
+                                            for (var c = 0; c < view.Viewport.Width; c += 2)
+                                            {
+                                                if (codepoint != default (Rune))
+                                                {
+                                                    view.AddRune (c, r, codepoint);
+                                                }
+                                            }
+                                        }
+                                        e.DrawContext?.AddDrawnRectangle (view.Viewport);
+                                        e.Cancel = true;
+                                    };
+        appWindow.Add (superView);
+
+        var viewWithBorderAtX0 = new View
+        {
+            Text = "viewWithBorderAtX0",
+            BorderStyle = LineStyle.Dashed,
+            X = 0,
+            Y = 1,
+            Width = Dim.Auto (),
+            Height = 3
+        };
+
+        var viewWithBorderAtX1 = new View
+        {
+            Text = "viewWithBorderAtX1",
+            BorderStyle = LineStyle.Dashed,
+            X = 1,
+            Y = Pos.Bottom (viewWithBorderAtX0) + 1,
+            Width = Dim.Auto (),
+            Height = 3
+        };
+
+        var viewWithBorderAtX2 = new View
+        {
+            Text = "viewWithBorderAtX2",
+            BorderStyle = LineStyle.Dashed,
+            X = 2,
+            Y = Pos.Bottom (viewWithBorderAtX1) + 1,
+            Width = Dim.Auto (),
+            Height = 3
+        };
+
+        superView.Add (viewWithBorderAtX0, viewWithBorderAtX1, viewWithBorderAtX2);
+
         // Run - Start the application.
         Application.Run (appWindow);
         appWindow.Dispose ();
@@ -124,6 +194,6 @@ private Rune GetRandomWideCodepoint ()
     {
         Random random = new ();
         int codepoint = random.Next (0x4E00, 0x9FFF);
-        return new Rune (codepoint);
+        return new (codepoint);
     }
 }

Terminal.Gui/Drivers/DotNetDriver/NetOutput.cs

@@ -109,6 +109,7 @@ protected override void AppendOrWriteAttribute (StringBuilder output, Attribute
     /// <inheritdoc />
     protected override void Write (StringBuilder output)
     {
+        base.Write (output);
         try
         {
             Console.Out.Write (output);
@@ -140,7 +141,7 @@ protected override bool SetCursorPositionImpl (int col, int row)
             }
             catch (Exception)
             {
-                return false;
+                return true;
             }
         }
 

Terminal.Gui/Drivers/DriverImpl.cs

@@ -45,19 +45,19 @@ public DriverImpl (
         ISizeMonitor sizeMonitor
     )
     {
-        InputProcessor = inputProcessor;
+        _inputProcessor = inputProcessor;
         _output = output;
         OutputBuffer = outputBuffer;
         _ansiRequestScheduler = ansiRequestScheduler;
 
-        InputProcessor.KeyDown += (s, e) => KeyDown?.Invoke (s, e);
-        InputProcessor.KeyUp += (s, e) => KeyUp?.Invoke (s, e);
+        GetInputProcessor ().KeyDown += (s, e) => KeyDown?.Invoke (s, e);
+        GetInputProcessor ().KeyUp += (s, e) => KeyUp?.Invoke (s, e);
 
-        InputProcessor.MouseEvent += (s, e) =>
-                                     {
-                                         //Logging.Logger.LogTrace ($"Mouse {e.Flags} at x={e.ScreenPosition.X} y={e.ScreenPosition.Y}");
-                                         MouseEvent?.Invoke (s, e);
-                                     };
+        GetInputProcessor ().MouseEvent += (s, e) =>
+                                           {
+                                               //Logging.Logger.LogTrace ($"Mouse {e.Flags} at x={e.ScreenPosition.X} y={e.ScreenPosition.Y}");
+                                               MouseEvent?.Invoke (s, e);
+                                           };
 
         SizeMonitor = sizeMonitor;
         SizeMonitor.SizeChanged += OnSizeMonitorOnSizeChanged;
@@ -73,15 +73,18 @@ ISizeMonitor sizeMonitor
     public void Init () { throw new NotSupportedException (); }
 
     /// <inheritdoc/>
-    public void Refresh () { _output.Write (OutputBuffer); }
+    public void Refresh ()
+    {
+        _output.Write (OutputBuffer);
+    }
 
     /// <inheritdoc/>
-    public string? GetName () => InputProcessor.DriverName?.ToLowerInvariant ();
+    public string? GetName () => GetInputProcessor ().DriverName?.ToLowerInvariant ();
 
     /// <inheritdoc/>
     public virtual string GetVersionInfo ()
     {
-        string type = InputProcessor.DriverName ?? throw new ArgumentNullException (nameof (InputProcessor.DriverName));
+        string type = GetInputProcessor ().DriverName ?? throw new InvalidOperationException ("Driver name is not set.");
 
         return type;
     }
@@ -143,8 +146,12 @@ public void Dispose ()
 
     private readonly IOutput _output;
 
+    public IOutput GetOutput () => _output;
+
+    private readonly IInputProcessor _inputProcessor;
+
     /// <inheritdoc/>
-    public IInputProcessor InputProcessor { get; }
+    public IInputProcessor GetInputProcessor () => _inputProcessor;
 
     /// <inheritdoc/>
     public IOutputBuffer OutputBuffer { get; }
@@ -157,7 +164,7 @@ public void Dispose ()
 
     private void CreateClipboard ()
     {
-        if (InputProcessor.DriverName is { } && InputProcessor.DriverName.Contains ("fake"))
+        if (GetInputProcessor ().DriverName is { } && GetInputProcessor ()!.DriverName!.Contains ("fake"))
         {
             if (Clipboard is null)
             {
@@ -414,7 +421,7 @@ public bool SetCursorVisibility (CursorVisibility visibility)
     public event EventHandler<Key>? KeyUp;
 
     /// <inheritdoc/>
-    public void EnqueueKeyEvent (Key key) { InputProcessor.EnqueueKeyDownEvent (key); }
+    public void EnqueueKeyEvent (Key key) { GetInputProcessor ().EnqueueKeyDownEvent (key); }
 
     #endregion Input Events
 

Terminal.Gui/Drivers/FakeDriver/FakeOutput.cs

@@ -7,29 +7,29 @@ namespace Terminal.Gui.Drivers;
 /// </summary>
 public class FakeOutput : OutputBase, IOutput
 {
-    private readonly StringBuilder _output = new ();
+   // private readonly StringBuilder _outputStringBuilder = new ();
     private int _cursorLeft;
     private int _cursorTop;
     private Size _consoleSize = new (80, 25);
+    private IOutputBuffer? _lastBuffer;
 
     /// <summary>
     /// 
     /// </summary>
     public FakeOutput ()
     {
-        LastBuffer = new OutputBufferImpl ();
-        LastBuffer.SetSize (80, 25);
+        _lastBuffer = new OutputBufferImpl ();
+        _lastBuffer.SetSize (80, 25);
     }
 
     /// <summary>
-    ///     Gets or sets the last output buffer written.
+    ///     Gets or sets the last output buffer written. The <see cref="IOutputBuffer.Contents"/> contains
+    ///     a reference to the buffer last written with <see cref="Write(IOutputBuffer)"/>.
     /// </summary>
-    public IOutputBuffer? LastBuffer { get; set; }
+    public IOutputBuffer? GetLastBuffer () => _lastBuffer;
 
-    /// <summary>
-    ///     Gets the captured output as a string.
-    /// </summary>
-    public string Output => _output.ToString ();
+    ///// <inheritdoc cref="IOutput.GetLastOutput"/>
+    //public override string GetLastOutput () => _outputStringBuilder.ToString ();
 
     /// <inheritdoc />
     public Point GetCursorPosition ()
@@ -61,28 +61,28 @@ protected override bool SetCursorPositionImpl (int col, int row)
     /// <inheritdoc/>
     public void Write (ReadOnlySpan<char> text)
     {
-        _output.Append (text);
+//        _outputStringBuilder.Append (text);
     }
 
-    /// <inheritdoc cref="IDriver"/>
+    /// <inheritdoc cref="IOutput.Write(IOutputBuffer)"/>
     public override void Write (IOutputBuffer buffer)
     {
-        LastBuffer = buffer;
+        _lastBuffer = buffer;
         base.Write (buffer);
     }
 
+    ///// <inheritdoc/>
+    //protected override void Write (StringBuilder output)
+    //{
+    //    _outputStringBuilder.Append (output);
+    //}
+
     /// <inheritdoc cref="IDriver"/>
     public override void SetCursorVisibility (CursorVisibility visibility)
     {
         // Capture but don't act on it in fake output
     }
 
-    /// <inheritdoc/>
-    public void Dispose ()
-    {
-        // Nothing to dispose
-    }
-
     /// <inheritdoc/>
     protected override void AppendOrWriteAttribute (StringBuilder output, Attribute attr, TextStyle redrawTextStyle)
     {
@@ -123,8 +123,8 @@ protected override void AppendOrWriteAttribute (StringBuilder output, Attribute
     }
 
     /// <inheritdoc/>
-    protected override void Write (StringBuilder output)
+    public void Dispose ()
     {
-        _output.Append (output);
+        // Nothing to dispose
     }
 }

Terminal.Gui/Drivers/IDriver.cs

@@ -61,7 +61,12 @@ public interface IDriver : IDisposable
     ///     e.g. <see cref="ConsoleKeyInfo"/> into <see cref="Key"/> events
     ///     and detecting and processing ansi escape sequences.
     /// </summary>
-    IInputProcessor InputProcessor { get; }
+    IInputProcessor GetInputProcessor ();
+
+    /// <summary>
+    ///     Gets the output handler responsible for writing to the terminal.
+    /// </summary>
+    IOutput GetOutput ();
 
     /// <summary>Get the operating system clipboard.</summary>
     IClipboard? Clipboard { get; }

Terminal.Gui/Drivers/IOutput.cs

@@ -65,6 +65,12 @@ public interface IOutput : IDisposable
     /// <param name="buffer"></param>
     void Write (IOutputBuffer buffer);
 
+    /// <summary>
+    ///     Gets a string containing the ANSI escape sequences and content most recently written
+    ///     to the terminal via <see cref="Write(IOutputBuffer)"/>
+    /// </summary>
+    string GetLastOutput ();
+
     /// <summary>
     ///     Generates an ANSI escape sequence string representation of the given <paramref name="buffer"/> contents.
     ///     This is the same output that would be written to the terminal to recreate the current screen contents.