Terminal.Gui/UICatalog/Scenarios/Keys.cs

using System.Collections.ObjectModel;
using Terminal.Gui;

namespace UICatalog.Scenarios;

[ScenarioMetadata ("Keys", "Shows keyboard input handling.")]
[ScenarioCategory ("Mouse and Keyboard")]
public class Keys : Scenario
{
    public override void Main ()
    {
        Application.Init ();
        ObservableCollection<string> keyPressedList = [];
        ObservableCollection<string> invokingKeyBindingsList = new ();

        var win = new Window { Title = GetQuitKeyAndName () };
        var editLabel = new Label { X = 0, Y = 0, Text = "Type text here:" };
        win.Add (editLabel);

        var edit = new TextField { X = Pos.Right (editLabel) + 1, Y = Pos.Top (editLabel), Width = Dim.Fill (2) };
        win.Add (edit);

        edit.KeyDown += (s, a) => { keyPressedList.Add (a.ToString ()); };

        edit.InvokingKeyBindings += (s, a) =>
                                    {
                                        if (edit.KeyBindings.TryGet (a, out KeyBinding binding))
                                        {
                                            invokingKeyBindingsList.Add ($"{a}: {string.Join (",", binding.Commands)}");
                                        }
                                    };

        // Last KeyPress: ______
        var keyPressedLabel = new Label
        {
            X = Pos.Left (editLabel), Y = Pos.Top (editLabel) + 1, Text = "Last TextView.KeyPressed:"
        };
        win.Add (keyPressedLabel);
        var labelTextViewKeypress = new Label { X = Pos.Right (keyPressedLabel) + 1, Y = Pos.Top (keyPressedLabel) };
        win.Add (labelTextViewKeypress);

        edit.KeyDown += (s, e) => labelTextViewKeypress.Text = e.ToString ();

        keyPressedLabel = new Label
        {
            X = Pos.Left (keyPressedLabel), Y = Pos.Bottom (keyPressedLabel), Text = "Last Application.KeyDown:"
        };
        win.Add (keyPressedLabel);
        var labelAppKeypress = new Label { X = Pos.Right (keyPressedLabel) + 1, Y = Pos.Top (keyPressedLabel) };
        win.Add (labelAppKeypress);

        Application.KeyDown += (s, e) => labelAppKeypress.Text = e.ToString ();

        // Key stroke log:
        var keyLogLabel = new Label
        {
            X = Pos.Left (editLabel), Y = Pos.Top (editLabel) + 4, Text = "Application Key Events:"
        };
        win.Add (keyLogLabel);
        int maxKeyString = Key.CursorRight.WithAlt.WithCtrl.WithShift.ToString ().Length;
        var yOffset = 1;
        ObservableCollection<string> keyEventlist = new ();

        var keyEventListView = new ListView
        {
            X = 0,
            Y = Pos.Top (keyLogLabel) + yOffset,
            Width = "Key Down:".Length + maxKeyString,
            Height = Dim.Fill (),
            Source = new ListWrapper<string> (keyEventlist)
        };
        keyEventListView.ColorScheme = Colors.ColorSchemes ["TopLevel"];
        win.Add (keyEventListView);

        // OnKeyPressed
        var onKeyPressedLabel = new Label
        {
            X = Pos.Right (keyEventListView) + 1, Y = Pos.Top (editLabel) + 4, Text = "TextView KeyDown:"
        };
        win.Add (onKeyPressedLabel);

        yOffset = 1;

        var onKeyPressedListView = new ListView
        {
            X = Pos.Left (onKeyPressedLabel),
            Y = Pos.Top (onKeyPressedLabel) + yOffset,
            Width = maxKeyString,
            Height = Dim.Fill (),
            Source = new ListWrapper<string> (keyPressedList)
        };
        onKeyPressedListView.ColorScheme = Colors.ColorSchemes ["TopLevel"];
        win.Add (onKeyPressedListView);

        // OnInvokeKeyBindings
        var onInvokingKeyBindingsLabel = new Label
        {
            X = Pos.Right (onKeyPressedListView) + 1,
            Y = Pos.Top (editLabel) + 4,
            Text = "TextView InvokingKeyBindings:"
        };
        win.Add (onInvokingKeyBindingsLabel);

        var onInvokingKeyBindingsListView = new ListView
        {
            X = Pos.Left (onInvokingKeyBindingsLabel),
            Y = Pos.Top (onInvokingKeyBindingsLabel) + yOffset,
            Width = Dim.Fill (1),
            Height = Dim.Fill (),
            Source = new ListWrapper<string> (invokingKeyBindingsList)
        };
        onInvokingKeyBindingsListView.ColorScheme = Colors.ColorSchemes ["TopLevel"];
        win.Add (onInvokingKeyBindingsListView);

        //Application.KeyDown += (s, a) => KeyDownPressUp (a, "Down");
        Application.KeyDown += (s, a) => KeyDownPressUp (a, "Down");
        Application.KeyUp += (s, a) => KeyDownPressUp (a, "Up");

        void KeyDownPressUp (Key args, string updown)
        {
            // BUGBUG: KeyEvent.ToString is badly broken
            var msg = $"Key{updown,-7}: {args}";
            keyEventlist.Add (msg);
            keyEventListView.MoveDown ();
            onKeyPressedListView.MoveDown ();
            onInvokingKeyBindingsListView.MoveDown ();
        }

        Application.Run (win);
        win.Dispose ();
        Application.Shutdown ();
    }
}