Fixes #4814 - Adds 'Link' View providing OSC 8 Hyperlink Support

Examples/UICatalog/Scenarios/Links.cs

@@ -0,0 +1,87 @@
+#nullable enable
+
+namespace UICatalog.Scenarios;
+
+[ScenarioMetadata ("Links", "Demonstrates how Links work.")]
+[ScenarioCategory ("Controls")]
+[ScenarioCategory ("Mouse and Keyboard")]
+public class Links : Scenario
+{
+    private IApplication? _app;
+    private Window? _appWindow;
+    private Link? _link;
+
+    public override void Main ()
+    {
+        ConfigurationManager.Enable (ConfigLocations.All);
+        using IApplication app = Application.Create ();
+        app.Init ();
+        _app = app;
+
+        _appWindow = new Window { Title = GetName (), BorderStyle = LineStyle.None };
+
+        Label titleLabel = new () { Text = "_Title:", X = 1, Y = 1 };
+        _appWindow.Add (titleLabel);
+
+        TextField titleTextField = new () { X = Pos.Right (titleLabel) + 1, Y = Pos.Top (titleLabel), Width = Dim.Fill () };
+        _appWindow.Add (titleTextField);
+
+        Label textLabel = new () { Text = " Te_xt:", X = Pos.Left (titleLabel), Y = Pos.Bottom(titleLabel) };
+        _appWindow.Add (textLabel);
+
+        TextField textTextField = new () { X = Pos.Right (textLabel) + 1, Y = Pos.Top(textLabel), Width = Dim.Fill () };
+        _appWindow.Add (textTextField);
+
+        Label urlLabel = new () { Text = "  _Url:", X = 1, Y = Pos.Bottom (titleTextField) + 1 };
+        _appWindow.Add (urlLabel);
+
+        TextField urlTextField = new () { X = Pos.Right (urlLabel) + 1, Y = Pos.Bottom (titleTextField) + 1, Width = Dim.Fill () };
+        _appWindow.Add (urlTextField);
+
+        Label simpleUrlLabel = new () { X = 1, Y = Pos.Bottom (urlTextField) + 2 };
+        _appWindow.Add (simpleUrlLabel);
+
+        FrameView linkFrame = new ()
+        {
+            Title = "_Link Demo",
+            X = 0,
+            Y = Pos.Bottom (simpleUrlLabel) + 2,
+            Width = Dim.Fill(),
+            Height = Dim.Auto (),
+            AssignHotKeys = true,
+            TabStop = TabBehavior.TabStop
+        };
+
+        _link = new Link { X = 1, Y = 1, BorderStyle = LineStyle.Dotted };
+
+        _link.TextChanged += (s, e) => simpleUrlLabel.Text = $"This is just a Label with a URL in Text (WT automatically enables URLs) - {_link.Text}";
+        titleTextField.ValueChanged += (s, e) => _link.Title = e.NewValue ?? string.Empty;
+        textTextField.ValueChanged += (s, e) => _link.Text = e.NewValue ?? string.Empty;
+        urlTextField.ValueChanged += (s, e) => _link.Url = e.NewValue ?? Link.DEFAULT_URL;
+        linkFrame.Add (_link);
+
+        titleTextField.Text = "Title";
+        textTextField.Text = "GitHub repo";
+        urlTextField.Text = "https://github.com/gui-cs/Terminal.Gui";
+
+        Button copyButton = new () { Title = "_Copy", X = Pos.Center (), Y = Pos.AnchorEnd () };
+        copyButton.Accepting += (s, e) => _link.Copy ();
+
+        linkFrame.Add (copyButton);
+
+        _appWindow.Add (linkFrame);
+
+        // StatusBar
+        Shortcut urlIndicator = new (Key.Empty, "", null);
+
+        StatusBar statusBar = new ([new Shortcut (Application.QuitKey, "Quit", Quit), urlIndicator]);
+        _link.MouseEnter += (s, e) => urlIndicator.Title = _link.Text;
+        _link.MouseLeave += (s, e) => urlIndicator.Title = "";
+        _appWindow.Add (statusBar);
+
+        _app.Run (_appWindow);
+        _appWindow.Dispose ();
+    }
+
+    private void Quit () => _appWindow?.RequestStop ();
+}

Examples/UICatalog/UICatalogRunnable.cs

@@ -148,11 +148,11 @@ private MenuBar CreateMenuBar ()
                                                     [
                                                         new MenuItem ("_Documentation",
                                                                       "API docs",
-                                                                      () => OpenUrl ("https://gui-cs.github.io/Terminal.Gui"),
+                                                                      () => Link.OpenUrl ("https://gui-cs.github.io/Terminal.Gui"),
                                                                       Key.F1),
                                                         new MenuItem ("_README",
                                                                       "Project readme",
-                                                                      () => OpenUrl ("https://github.com/gui-cs/Terminal.Gui"),
+                                                                      () => Link.OpenUrl ("https://github.com/gui-cs/Terminal.Gui"),
                                                                       Key.F2),
                                                         new MenuItem ("_About...",
                                                                       "About UI Catalog",
@@ -401,7 +401,7 @@ View [] CreateLoggingMenuItems ()
             // add a separator
             menuItems.Add (new Line ());
 
-            menuItems.Add (new MenuItem ("_Open Log Folder", string.Empty, () => OpenUrl (UICatalog.LOGFILE_LOCATION)));
+            menuItems.Add (new MenuItem ("_Open Log Folder", string.Empty, () => Link.OpenUrl (UICatalog.LOGFILE_LOCATION)));
 
             return menuItems.ToArray ()!;
 
@@ -747,34 +747,6 @@ _______                  _             _   _____       _
         return msg.ToString ();
     }
 
-    public static void OpenUrl (string url)
-    {
-        if (PlatformDetection.IsWindows ())
-        {
-            url = url.Replace ("&", "^&");
-            Process.Start (new ProcessStartInfo ("cmd", $"/c start {url}") { CreateNoWindow = true });
-        }
-        else if (PlatformDetection.IsMac ())
-        {
-            Process.Start ("open", url);
-        }
-        else if (PlatformDetection.IsLinux ())
-        {
-            using Process process = new ();
-
-            process.StartInfo = new ProcessStartInfo
-            {
-                FileName = "xdg-open",
-                Arguments = url,
-                RedirectStandardError = true,
-                RedirectStandardOutput = true,
-                CreateNoWindow = true,
-                UseShellExecute = false
-            };
-            process.Start ();
-        }
-    }
-
     /// <summary>
     ///     Shows a dialog displaying error logs from a scenario run.
     /// </summary>

Terminal.Gui/Drivers/DriverImpl.cs

@@ -229,11 +229,15 @@ public virtual void SetScreenSize (int width, int height)
     /// <inheritdoc/>
     public Region? Clip { get => _outputBuffer.Clip; set => _outputBuffer.Clip = value; }
 
+    /// <inheritdoc/>
+    public string? CurrentUrl { get => _outputBuffer.CurrentUrl; set => _outputBuffer.CurrentUrl = value; }
+
     /// <summary>Clears the <see cref="IDriver.Contents"/> of the driver.</summary>
     public void ClearContents ()
     {
         _outputBuffer.ClearContents ();
         ClearedContents?.Invoke (this, EventArgs.Empty);
+        CurrentUrl = null;
     }
 
     /// <inheritdoc/>

Terminal.Gui/Drivers/IDriver.cs

@@ -187,6 +187,13 @@ public interface IDriver : IDisposable
     /// </summary>
     Attribute CurrentAttribute { get; set; }
 
+    /// <summary>
+    ///     Gets or sets the URL that will be associated with cells added via <see cref="AddRune(Rune)"/> or <see cref="AddStr(string)"/>.
+    ///     When set, subsequent cells will include this URL for OSC 8 hyperlink rendering.
+    ///     Set to <see langword="null"/> to stop associating URLs with cells.
+    /// </summary>
+    string? CurrentUrl { get; set; }
+
     /// <summary>
     ///     Updates <see cref="IDriver.Col"/> and <see cref="IDriver.Row"/> to the specified column and row in
     ///     <see cref="IDriver.Contents"/>.

Terminal.Gui/Drivers/Output/IOutputBuffer.cs

@@ -115,6 +115,21 @@ public interface IOutputBuffer
     /// <summary>The number of rows visible in the terminal.</summary>
     int Rows { get; set; }
 
+    /// <summary>
+    ///     Gets or sets the URL that will be associated with cells added via <see cref="AddRune(Rune)"/> or <see cref="AddStr(string)"/>.
+    ///     When set, subsequent cells will include this URL for OSC 8 hyperlink rendering.
+    /// </summary>
+    string? CurrentUrl { get; set; }
+
+    /// <summary>
+    ///     Gets the URL associated with the cell at the specified position.
+    ///     Returns <see langword="null"/> if no URL is associated with the cell.
+    /// </summary>
+    /// <param name="col">The column position.</param>
+    /// <param name="row">The row position.</param>
+    /// <returns>The URL associated with the cell, or <see langword="null"/> if none exists.</returns>
+    string? GetCellUrl (int col, int row);
+
     /// <summary>
     ///     Changes the size of the buffer to the given size
     /// </summary>

Terminal.Gui/Drivers/Output/OutputBase.cs

@@ -55,6 +55,9 @@ public bool IsLegacyConsole
     // Last text style used, for updating style with EscSeqUtils.CSI_AppendTextStyleChange().
     private TextStyle _redrawTextStyle = TextStyle.None;
 
+    // Last URL used for tracking hyperlink state
+    private string? _lastUrl = null;
+
     private readonly StringBuilder _lastOutputStringBuilder = new ();
     private bool _clearLastOutputPending;
 
@@ -83,6 +86,7 @@ public virtual void Write (IOutputBuffer buffer)
             }
 
             outputStringBuilder.Clear ();
+            _lastUrl = null; // Reset URL state at the start of each row
 
             // Process columns in row
             for (int col = left; col < cols; col++)
@@ -121,6 +125,29 @@ public virtual void Write (IOutputBuffer buffer)
                         lastCol = col;
                     }
 
+                    // Handle URL hyperlink state changes
+                    if (!IsLegacyConsole)
+                    {
+                        string? cellUrl = buffer.GetCellUrl (col, row);
+
+                        if (cellUrl != _lastUrl)
+                        {
+                            // If we were in a hyperlink, end it
+                            if (_lastUrl is { })
+                            {
+                                outputStringBuilder.Append (EscSeqUtils.OSC_EndHyperlink ());
+                            }
+
+                            // If starting a new hyperlink, begin it
+                            if (!string.IsNullOrEmpty (cellUrl))
+                            {
+                                outputStringBuilder.Append (EscSeqUtils.OSC_StartHyperlink (cellUrl));
+                            }
+
+                            _lastUrl = cellUrl;
+                        }
+                    }
+
                     // Append dirty cell as ANSI and mark clean
                     Cell cell = buffer.Contents [row, col];
                     buffer.Contents [row, col].IsDirty = false;
@@ -149,6 +176,13 @@ public virtual void Write (IOutputBuffer buffer)
             {
                 SetCursorPositionImpl (lastCol, row);
 
+                // Close any open hyperlink before processing URLs
+                if (_lastUrl is { })
+                {
+                    outputStringBuilder.Append (EscSeqUtils.OSC_EndHyperlink ());
+                    _lastUrl = null;
+                }
+
                 // Wrap URLs with OSC 8 hyperlink sequences
                 StringBuilder processed = Osc8UrlLinker.WrapOsc8 (outputStringBuilder);
                 Write (processed);

Terminal.Gui/Drivers/Output/OutputBufferImpl.cs

@@ -25,6 +25,41 @@ public class OutputBufferImpl : IOutputBuffer
     /// </summary>
     public Attribute CurrentAttribute { get; set; }
 
+    /// <summary>
+    ///     Gets or sets the URL that will be associated with cells added via <see cref="AddRune(Rune)"/> or <see cref="AddStr(string)"/>.
+    ///     When set, subsequent cells will include this URL for OSC 8 hyperlink rendering.
+    /// </summary>
+    public string? CurrentUrl { get; set; }
+
+    /// <summary>
+    ///     Maps cell positions to URLs for OSC 8 hyperlink support.
+    ///     Only stores entries for cells that actually have URLs, minimizing memory overhead.
+    /// </summary>
+    private Dictionary<Point, string>? _urlMap;
+
+    /// <summary>
+    ///     Gets the URL associated with the cell at the specified position.
+    /// </summary>
+    /// <param name="col">The column.</param>
+    /// <param name="row">The row.</param>
+    /// <returns>The URL if one exists, otherwise null.</returns>
+    public string? GetCellUrl (int col, int row)
+    {
+        return _urlMap?.TryGetValue (new Point (col, row), out string? url) == true ? url : null;
+    }
+
+    /// <summary>
+    ///     Sets the URL for the cell at the specified position.
+    /// </summary>
+    /// <param name="col">The column.</param>
+    /// <param name="row">The row.</param>
+    /// <param name="url">The URL to associate with this cell.</param>
+    private void SetCellUrl (int col, int row, string url)
+    {
+        _urlMap ??= [];
+        _urlMap [new Point (col, row)] = url;
+    }
+
     /// <summary>The leftmost column in the terminal.</summary>
     public virtual int Left { get; set; } = 0;
 
@@ -214,6 +249,12 @@ private void SetAttributeAndDirty (int col, int row)
     {
         Contents! [row, col].Attribute = CurrentAttribute;
         Contents [row, col].IsDirty = true;
+
+        // If CurrentUrl is set, store it in the URL map
+        if (!string.IsNullOrEmpty (CurrentUrl))
+        {
+            SetCellUrl (col, row, CurrentUrl);
+        }
     }
 
     /// <summary>
@@ -321,6 +362,9 @@ public void ClearContents ()
 
         DirtyLines = new bool [Rows];
 
+        // Clear the URL map
+        _urlMap?.Clear ();
+
         lock (Contents)
         {
             for (var row = 0; row < Rows; row++)