Terminal.Gui/UICatalog/Scenarios/ContextMenus.cs

using System.Collections.Generic;
using System.Globalization;
using System.Threading;
using Terminal.Gui;

namespace UICatalog.Scenarios;

[ScenarioMetadata ("ContextMenus", "Context Menu Sample.")]
[ScenarioCategory ("Menus")]
public class ContextMenus : Scenario
{
    private readonly List<CultureInfo> _cultureInfos = Application.SupportedCultures;
    private ContextMenu _contextMenu = new ();
    private bool _forceMinimumPosToZero = true;
    private MenuItem _miForceMinimumPosToZero;
    private MenuItem _miUseSubMenusSingleFrame;
    private TextField _tfTopLeft, _tfTopRight, _tfMiddle, _tfBottomLeft, _tfBottomRight;
    private bool _useSubMenusSingleFrame;

    public override void Main ()
    {
        // Init
        Application.Init ();

        // Setup - Create a top-level application window and configure it.
        Window appWindow = new ()
        {
            Title = GetQuitKeyAndName ()
        };

        var text = "Context Menu";
        var width = 20;
        var winContextMenuKey = (KeyCode)Key.Space.WithCtrl;

        var label = new Label
        {
            X = Pos.Center (), Y = 1, Text = $"Press '{winContextMenuKey}' to open the Window context menu."
        };
        appWindow.Add (label);

        label = new()
        {
            X = Pos.Center (),
            Y = Pos.Bottom (label),
            Text = $"Press '{ContextMenu.DefaultKey}' to open the TextField context menu."
        };
        appWindow.Add (label);

        _tfTopLeft = new() { Width = width, Text = text };
        appWindow.Add (_tfTopLeft);

        _tfTopRight = new() { X = Pos.AnchorEnd (width), Width = width, Text = text };
        appWindow.Add (_tfTopRight);

        _tfMiddle = new() { X = Pos.Center (), Y = Pos.Center (), Width = width, Text = text };
        appWindow.Add (_tfMiddle);

        _tfBottomLeft = new() { Y = Pos.AnchorEnd (1), Width = width, Text = text };
        appWindow.Add (_tfBottomLeft);

        _tfBottomRight = new() { X = Pos.AnchorEnd (width), Y = Pos.AnchorEnd (1), Width = width, Text = text };
        appWindow.Add (_tfBottomRight);

        Point mousePos = default;

        appWindow.KeyDown += (s, e) =>
                             {
                                 if (e.KeyCode == winContextMenuKey)
                                 {
                                     ShowContextMenu (mousePos.X, mousePos.Y);
                                     e.Handled = true;
                                 }
                             };

        appWindow.MouseClick += (s, e) =>
                                {
                                    if (e.MouseEvent.Flags == _contextMenu.MouseFlags)
                                    {
                                        ShowContextMenu (e.MouseEvent.Position.X, e.MouseEvent.Position.Y);
                                        e.Handled = true;
                                    }
                                };

        Application.MouseEvent += ApplicationMouseEvent;

        void ApplicationMouseEvent (object sender, MouseEvent a) { mousePos = a.Position; }

        appWindow.WantMousePositionReports = true;

        appWindow.Closed += (s, e) =>
                            {
                                Thread.CurrentThread.CurrentUICulture = new ("en-US");
                                Application.MouseEvent -= ApplicationMouseEvent;
                            };

        // Run - Start the application.
        Application.Run (appWindow);
        appWindow.Dispose ();

        // Shutdown - Calling Application.Shutdown is required.
        Application.Shutdown ();
    }

    private MenuItem [] GetSupportedCultures ()
    {
        List<MenuItem> supportedCultures = new ();
        int index = -1;

        foreach (CultureInfo c in _cultureInfos)
        {
            var culture = new MenuItem { CheckType = MenuItemCheckStyle.Checked };

            if (index == -1)
            {
                culture.Title = "_English";
                culture.Help = "en-US";
                culture.Checked = Thread.CurrentThread.CurrentUICulture.Name == "en-US";
                CreateAction (supportedCultures, culture);
                supportedCultures.Add (culture);
                index++;
                culture = new() { CheckType = MenuItemCheckStyle.Checked };
            }

            culture.Title = $"_{c.Parent.EnglishName}";
            culture.Help = c.Name;
            culture.Checked = Thread.CurrentThread.CurrentUICulture.Name == c.Name;
            CreateAction (supportedCultures, culture);
            supportedCultures.Add (culture);
        }

        return supportedCultures.ToArray ();

        void CreateAction (List<MenuItem> supportedCultures, MenuItem culture)
        {
            culture.Action += () =>
                              {
                                  Thread.CurrentThread.CurrentUICulture = new (culture.Help);
                                  culture.Checked = true;

                                  foreach (MenuItem item in supportedCultures)
                                  {
                                      item.Checked = item.Help == Thread.CurrentThread.CurrentUICulture.Name;
                                  }
                              };
        }
    }

    private void ShowContextMenu (int x, int y)
    {
        _contextMenu = new()
        {
            Position = new (x, y),
            MenuItems = new (
                             new []
                             {
                                 new (
                                      "_Configuration",
                                      "Show configuration",
                                      () => MessageBox.Query (
                                                              50,
                                                              5,
                                                              "Info",
                                                              "This would open settings dialog",
                                                              "Ok"
                                                             )
                                     ),
                                 new MenuBarItem (
                                                  "More options",
                                                  new MenuItem []
                                                  {
                                                      new (
                                                           "_Setup",
                                                           "Change settings",
                                                           () => MessageBox
                                                               .Query (
                                                                       50,
                                                                       5,
                                                                       "Info",
                                                                       "This would open setup dialog",
                                                                       "Ok"
                                                                      ),
                                                           shortcut: KeyCode.T
                                                                     | KeyCode
                                                                         .CtrlMask
                                                          ),
                                                      new (
                                                           "_Maintenance",
                                                           "Maintenance mode",
                                                           () => MessageBox
                                                               .Query (
                                                                       50,
                                                                       5,
                                                                       "Info",
                                                                       "This would open maintenance dialog",
                                                                       "Ok"
                                                                      )
                                                          )
                                                  }
                                                 ),
                                 new MenuBarItem (
                                                  "_Languages",
                                                  GetSupportedCultures ()
                                                 ),
                                 _miForceMinimumPosToZero =
                                     new (
                                          "ForceMinimumPosToZero",
                                          "",
                                          () =>
                                          {
                                              _miForceMinimumPosToZero
                                                      .Checked =
                                                  _forceMinimumPosToZero =
                                                      !_forceMinimumPosToZero;

                                              _tfTopLeft.ContextMenu
                                                        .ForceMinimumPosToZero =
                                                  _forceMinimumPosToZero;

                                              _tfTopRight.ContextMenu
                                                         .ForceMinimumPosToZero =
                                                  _forceMinimumPosToZero;

                                              _tfMiddle.ContextMenu
                                                       .ForceMinimumPosToZero =
                                                  _forceMinimumPosToZero;

                                              _tfBottomLeft.ContextMenu
                                                           .ForceMinimumPosToZero =
                                                  _forceMinimumPosToZero;

                                              _tfBottomRight
                                                      .ContextMenu
                                                      .ForceMinimumPosToZero =
                                                  _forceMinimumPosToZero;
                                          }
                                         )
                                     {
                                         CheckType =
                                             MenuItemCheckStyle
                                                 .Checked,
                                         Checked =
                                             _forceMinimumPosToZero
                                     },
                                 _miUseSubMenusSingleFrame =
                                     new (
                                          "Use_SubMenusSingleFrame",
                                          "",
                                          () => _contextMenu
                                                        .UseSubMenusSingleFrame =
                                                    (bool)
                                                    (_miUseSubMenusSingleFrame
                                                             .Checked =
                                                         _useSubMenusSingleFrame =
                                                             !_useSubMenusSingleFrame)
                                         )
                                     {
                                         CheckType = MenuItemCheckStyle
                                             .Checked,
                                         Checked =
                                             _useSubMenusSingleFrame
                                     },
                                 null,
                                 new (
                                      "_Quit",
                                      "",
                                      () => Application.RequestStop ()
                                     )
                             }
                            ),
            ForceMinimumPosToZero = _forceMinimumPosToZero,
            UseSubMenusSingleFrame = _useSubMenusSingleFrame
        };

        _tfTopLeft.ContextMenu.ForceMinimumPosToZero = _forceMinimumPosToZero;
        _tfTopRight.ContextMenu.ForceMinimumPosToZero = _forceMinimumPosToZero;
        _tfMiddle.ContextMenu.ForceMinimumPosToZero = _forceMinimumPosToZero;
        _tfBottomLeft.ContextMenu.ForceMinimumPosToZero = _forceMinimumPosToZero;
        _tfBottomRight.ContextMenu.ForceMinimumPosToZero = _forceMinimumPosToZero;

        _contextMenu.Show ();
    }
}