Determine whether sixel is supported by issuing a Device Attributes Request

Terminal.Gui/ConsoleDrivers/ConsoleDriver.cs

@@ -484,6 +484,9 @@ public abstract class ConsoleDriver
     /// <summary>Gets whether the <see cref="ConsoleDriver"/> supports TrueColor output.</summary>
     public virtual bool SupportsTrueColor => true;
 
+    // TODO: make not static TODO: gets set in mouse logic in net driver :/
+    public static bool SupportsSixel { get; set; }
+
     // TODO: This makes ConsoleDriver dependent on Application, which is not ideal. This should be moved to Application.
     // BUGBUG: Application.Force16Colors should be bool? so if SupportsTrueColor and Application.Force16Colors == false, this doesn't override
     /// <summary>

Terminal.Gui/ConsoleDrivers/EscSeqUtils/EscSeqUtils.cs

@@ -47,6 +47,10 @@ public static class EscSeqUtils
     /// </summary>
     public const string CSI = "\u001B[";
 
+
+    public const string CSI_Device_Attributes_Request = CSI + "c";
+    public const string CSI_Device_Attributes_Request_Terminator = "c";
+
     /// <summary>
     ///     ESC [ ? 1047 h - Activate xterm alternative buffer (no backscroll)
     /// </summary>

Terminal.Gui/ConsoleDrivers/NetDriver.cs

@@ -632,6 +632,9 @@ internal class NetEvents : IDisposable
                         break;
                 }
 
+                break;
+            case EscSeqUtils.CSI_Device_Attributes_Request_Terminator:
+                ConsoleDriver.SupportsSixel = values.Any (v => v == "4");
                 break;
             default:
                 EnqueueRequestResponseEvent (c1Control, code, values, terminating);
@@ -1135,9 +1138,13 @@ internal class NetDriver : ConsoleDriver
         _mainLoopDriver = new NetMainLoop (this);
         _mainLoopDriver.ProcessInput = ProcessInput;
 
+        _mainLoopDriver._netEvents.EscSeqRequests.Add ("c");
+        // Determine if sixel is supported
+        Console.Out.Write (EscSeqUtils.CSI_Device_Attributes_Request);
+
         return new MainLoop (_mainLoopDriver);
     }
-
+    
     private void ProcessInput (InputResult inputEvent)
     {
         switch (inputEvent.EventType)
@@ -1338,6 +1345,7 @@ internal class NetDriver : ConsoleDriver
     }
 
     private CursorVisibility? _cachedCursorVisibility;
+    private static bool _supportsSixel;
 
     public override void UpdateCursor ()
     {

UICatalog/Scenarios/Images.cs

@@ -53,6 +53,18 @@ public class Images : Scenario
         };
         win.Add (cbSupportsTrueColor);
 
+        var cbSupportsSixel = new CheckBox
+        {
+            X = Pos.Right (lblDriverName) + 2,
+            Y = 1,
+            CheckedState = ConsoleDriver.SupportsSixel
+                ? CheckState.Checked : CheckState.UnChecked,
+            CanFocus = false,
+            Enabled = false,
+            Text = "Supports Sixel"
+        };
+        win.Add (cbSupportsSixel);
+
         var cbUseTrueColor = new CheckBox
         {
             X = Pos.Right (cbSupportsTrueColor) + 2,
@@ -69,7 +81,7 @@ public class Images : Scenario
 
         var tv = new TabView
         {
-            Y = Pos.Bottom (lblDriverName), Width = Dim.Fill (), Height = Dim.Fill ()
+            Y = Pos.Bottom (cbSupportsSixel), Width = Dim.Fill (), Height = Dim.Fill ()
         };
 
         tv.AddTab (tabBasic, true);