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

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

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

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

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

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

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

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

        Point mousePos = default;

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

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

        Application.MouseEvent += ApplicationMouseEvent;

        void ApplicationMouseEvent (object sender, MouseEvent a) { mousePos = new Point (a.X, a.Y); }

        Win.WantMousePositionReports = true;

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

    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 MenuItem { 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 CultureInfo (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 ContextMenu
        {
            Position = new Point (x, y),
            MenuItems = new MenuBarItem (
                                         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 MenuItem (
                                                               "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 MenuItem (
                                                               "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 ();
    }
}