Terminal.Gui/UICatalog/Scenarios/VkeyPacketSimulator.cs

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Terminal.Gui;
using Terminal.Gui.ConsoleDrivers;

namespace UICatalog.Scenarios; 

[ScenarioMetadata ("VkeyPacketSimulator", "Simulates the Virtual Key Packet")]
[ScenarioCategory ("Mouse and Keyboard")]
public class VkeyPacketSimulator : Scenario {
	List<int> _keyboardStrokes = new ();
	bool _outputStarted = false;
	bool _wasUnknown = false;
	static ManualResetEventSlim _stopOutput = new (false);

	public override void Setup ()
	{
		var label = new Label ("Input") {
			X = Pos.Center ()
		};
		Win.Add (label);

		var btnInput = new Button ("Select Input") {
			X = Pos.AnchorEnd (16)
		};
		Win.Add (btnInput);

		const string ruler = "|123456789";

		var inputHorizontalRuler = new Label ("") {
			Y = Pos.Bottom (btnInput),
			Width = Dim.Fill (),
			ColorScheme = Colors.Error,
			AutoSize = false
		};
		Win.Add (inputHorizontalRuler);

		var inputVerticalRuler = new Label ("", TextDirection.TopBottom_LeftRight) {
			Y = Pos.Bottom (btnInput),
			Width = 1,
			ColorScheme = Colors.Error,
			AutoSize = false
		};
		Win.Add (inputVerticalRuler);

		var tvInput = new TextView {
			Title = "Input",
			X = 1,
			Y = Pos.Bottom (inputHorizontalRuler),
			Width = Dim.Fill (),
			Height = Dim.Percent (50) - 1
		};
		Win.Add (tvInput);

		label = new Label ("Output") {
			X = Pos.Center (),
			Y = Pos.Bottom (tvInput)
		};
		Win.Add (label);

		var btnOutput = new Button ("Select Output") {
			X = Pos.AnchorEnd (17),
			Y = Pos.Top (label)
		};
		Win.Add (btnOutput);

		var outputHorizontalRuler = new Label ("") {
			Y = Pos.Bottom (btnOutput),
			Width = Dim.Fill (),
			ColorScheme = Colors.Error,
			AutoSize = false
		};
		Win.Add (outputHorizontalRuler);

		var outputVerticalRuler = new Label ("", TextDirection.TopBottom_LeftRight) {
			Y = Pos.Bottom (btnOutput),
			Width = 1,
			Height = Dim.Fill (),
			ColorScheme = Colors.Error,
			AutoSize = false
		};
		Win.Add (outputVerticalRuler);

		var tvOutput = new TextView {
			Title = "Output",
			X = 1,
			Y = Pos.Bottom (outputHorizontalRuler),
			Width = Dim.Fill (),
			Height = Dim.Fill (),
			ReadOnly = true
		};

		// Detect unknown keys and reject them.
		tvOutput.KeyDown += (s, e) => {
			//System.Diagnostics.Debug.WriteLine ($"Output - KeyDown: {e.Key}");
			//e.Handled = true;
			if (e == Key.Empty) {
				_wasUnknown = true;
			}
		};

		tvOutput.KeyUp += (s, e) => {
			//System.Diagnostics.Debug.WriteLine ($"Output - KeyPress - _keyboardStrokes: {_keyboardStrokes.Count}");
			if (_outputStarted && _keyboardStrokes.Count > 0) {
				//// TODO: Tig: I don't understand what this is trying to do
				//if (!tvOutput.ProcessKeyDown (e)) {
				//	Application.Invoke (() => {
				//		MessageBox.Query ("Keys", $"'{KeyEventArgs.ToString (e.ConsoleDriverKey, MenuBar.ShortcutDelimiter)}' pressed!", "Ok");
				//	});
				//}
				e.Handled = true;
				_stopOutput.Set ();
			}
			//System.Diagnostics.Debug.WriteLine ($"Output - KeyPress - _keyboardStrokes: {_keyboardStrokes.Count}");
		};

		Win.Add (tvOutput);

		Key unknownChar = null;

		tvInput.KeyUp += (s, e) => {
			//System.Diagnostics.Debug.WriteLine ($"Input - KeyUp: {e.Key}");
			//var ke = e;

			if (e == Key.Empty) {
				_wasUnknown = true;
				e.Handled = true;
				return;
			}
			if (_wasUnknown && _keyboardStrokes.Count == 1) {
				_wasUnknown = false;
			} else if (_wasUnknown && char.IsLetter ((char)e.KeyCode)) {
				_wasUnknown = false;
			}
			if (_keyboardStrokes.Count == 0) {
				AddKeyboardStrokes (e);
			} else {
				_keyboardStrokes.Insert (0, 0);
			}
			if (_wasUnknown && (int)e.KeyCode - (int)(e.KeyCode & (KeyCode.AltMask | KeyCode.CtrlMask | KeyCode.ShiftMask)) != 0) {
				unknownChar = e;
			}
			e.Handled = true;
			if (!_wasUnknown && _keyboardStrokes.Count > 0) {
				_outputStarted = true;
				tvOutput.ReadOnly = false;
				tvOutput.SetFocus ();
				tvOutput.SetNeedsDisplay ();

				Task.Run (() => {
					while (_outputStarted) {
						try {
							var mod = new ConsoleModifiers ();
							if (e.KeyCode.HasFlag (KeyCode.ShiftMask)) {
								mod |= ConsoleModifiers.Shift;
							}
							if (e.KeyCode.HasFlag (KeyCode.AltMask)) {
								mod |= ConsoleModifiers.Alt;
							}
							if (e.KeyCode.HasFlag (KeyCode.CtrlMask)) {
								mod |= ConsoleModifiers.Control;
							}
							for (int i = 0; i < _keyboardStrokes.Count; i++) {
								var consoleKeyInfo = ConsoleKeyMapping.GetConsoleKeyFromKey ((uint)_keyboardStrokes [i], mod, out _);
								Application.Driver.SendKeys (consoleKeyInfo.KeyChar, ConsoleKey.Packet, mod.HasFlag (ConsoleModifiers.Shift),
									mod.HasFlag (ConsoleModifiers.Alt), mod.HasFlag (ConsoleModifiers.Control));
							}
							//}
						} catch (Exception) {
							Application.Invoke (() => {
								MessageBox.ErrorQuery ("Error", "Couldn't send the keystrokes!", "Ok");
								Application.RequestStop ();
							});
						}
						_stopOutput.Wait ();
						_stopOutput.Reset ();
						_keyboardStrokes.RemoveAt (0);
						if (_keyboardStrokes.Count == 0) {
							_outputStarted = false;
							Application.Invoke (() => {
								tvOutput.ReadOnly = true;
								tvInput.SetFocus ();
							});
						}
					}
					//System.Diagnostics.Debug.WriteLine ($"_outputStarted: {_outputStarted}");
				});
			}
		};

		btnInput.Clicked += (s, e) => {
			if (!tvInput.HasFocus && _keyboardStrokes.Count == 0) {
				tvInput.SetFocus ();
			}
		};

		btnOutput.Clicked += (s, e) => {
			if (!tvOutput.HasFocus && _keyboardStrokes.Count == 0) {
				tvOutput.SetFocus ();
			}
		};

		tvInput.SetFocus ();

		void Win_LayoutComplete (object sender, LayoutEventArgs obj)
		{
			inputHorizontalRuler.Text = outputHorizontalRuler.Text = ruler.Repeat ((int)Math.Ceiling ((double)inputHorizontalRuler.Bounds.Width / (double)ruler.Length)) [0..inputHorizontalRuler.Bounds.Width];
			inputVerticalRuler.Height = tvInput.Frame.Height + 1;
			inputVerticalRuler.Text = ruler.Repeat ((int)Math.Ceiling ((double)inputVerticalRuler.Bounds.Height / (double)ruler.Length)) [0..inputVerticalRuler.Bounds.Height];
			outputVerticalRuler.Text = ruler.Repeat ((int)Math.Ceiling ((double)outputVerticalRuler.Bounds.Height / (double)ruler.Length)) [0..outputVerticalRuler.Bounds.Height];
		}

		Win.LayoutComplete += Win_LayoutComplete;
	}

	void AddKeyboardStrokes (Key e)
	{
		int keyChar = (int)e.KeyCode;
		int mK = (int)(e.KeyCode & (KeyCode.AltMask | KeyCode.CtrlMask | KeyCode.ShiftMask));
		keyChar &= ~mK;
		_keyboardStrokes.Add (keyChar);
	}
}