Terminal.Gui/Examples/UICatalog/Scenarios/TextStyles.cs

#nullable enable
using Terminal.Gui;

namespace UICatalog.Scenarios;

[ScenarioMetadata ("Text Styles", "Shows Attribute.TextStyles including bold, italic, etc...")]
[ScenarioCategory ("Text and Formatting")]
[ScenarioCategory ("Colors")]
public sealed class TestStyles : Scenario
{
    private CheckBox? _drawDirectly;

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

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

        //appWindow.ContentSizeTracksViewport = false;
        appWindow.VerticalScrollBar.AutoShow = true;
        appWindow.HorizontalScrollBar.AutoShow = true;

        appWindow.SubViewsLaidOut += (sender, _) =>
                                     {
                                         if (sender is View sendingView)
                                         {
                                             sendingView.SetContentSize (new Size(sendingView.GetContentSize().Width, sendingView.GetHeightRequiredForSubViews()));
                                         }
                                     };

        appWindow.DrawingContent += OnAppWindowOnDrawingContent;
        appWindow.DrawingSubViews += OnAppWindowOnDrawingSubviews;

        _drawDirectly = new ()
        {
            Title = "_Draw styled text directly using DrawingContent vs. Buttons",
            CheckedState = CheckState.UnChecked
        };

        appWindow.Add (_drawDirectly);
        AddButtons (appWindow);

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

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

    private void AddButtons (Window appWindow)
    {
        var y = 1;

        TextStyle [] allStyles = Enum.GetValues (typeof (TextStyle))
                                     .Cast<TextStyle> ()
                                     .Where (style => style != TextStyle.None)
                                     .ToArray ();

        // Add individual flags as labels
        foreach (TextStyle style in allStyles)
        {
            y++;

            var button = new Button
            {
                X = 0,
                Y = y,
                Title = $"{Enum.GetName (typeof (TextStyle), style)}",
                Visible = _drawDirectly!.CheckedState != CheckState.Checked
            };

            button.GettingAttributeForRole += (sender, args) =>
                                              {
                                                  if (sender is not Button buttonSender)
                                                  {
                                                      return;
                                                  }
                                                  args.NewValue = args.NewValue with { Style = style };
                                                  args.Cancel = true;
                                              };

            appWindow.Add (button);
        }

        // Add a blank line
        y += 1;

        // Generate all combinations of TextStyle (excluding individual flags)
        int totalCombinations = 1 << allStyles.Length; // 2^n combinations

        for (var i = 1; i < totalCombinations; i++) // Start from 1 to skip "None"
        {
            var combination = (TextStyle)0;
            List<string> styleNames = [];

            for (var bit = 0; bit < allStyles.Length; bit++)
            {
                if ((i & (1 << bit)) != 0)
                {
                    combination |= allStyles [bit];
                    styleNames.Add (Enum.GetName (typeof (TextStyle), allStyles [bit])!);
                }
            }

            // Skip individual flags
            if (styleNames.Count == 1)
            {
                continue;
            }

            y++;

            var button = new Button
            {
                X = 0,
                Y = y,
                Text = $"[{string.Join (" | ", styleNames)}]",
                Visible = _drawDirectly!.CheckedState != CheckState.Checked
            };
            button.GettingAttributeForRole += (_, args) =>
                                              {
                                                  args.NewValue = args.NewValue with { Style = combination };
                                                  args.Cancel = true;
                                              };
            appWindow.Add (button);
        }
    }

    private void OnAppWindowOnDrawingSubviews (object? sender, DrawEventArgs e)
    {
        if (sender is not View sendingVioew)
        {
            return;
        }

        foreach (Button view in sendingVioew.SubViews.OfType<Button> ())
        {
            view.Visible = _drawDirectly!.CheckedState != CheckState.Checked;
        }

        e.Cancel = false;
    }

    private void OnAppWindowOnDrawingContent (object? sender, DrawEventArgs args)
    {
        if (sender is View { } sendingView && _drawDirectly!.CheckedState == CheckState.Checked)
        {
            int y = 2 - args.NewViewport.Y; // Start drawing below the checkbox

            TextStyle [] allStyles = Enum.GetValues (typeof (TextStyle))
                                         .Cast<TextStyle> ()
                                         .Where (style => style != TextStyle.None)
                                         .ToArray ();

            // Draw individual flags, one per line
            foreach (TextStyle style in allStyles)
            {
                string text = Enum.GetName (typeof (TextStyle), style)!;

                sendingView.Move (0, y);

                var attr = new Attribute (sendingView.GetAttributeForRole (VisualRole.Normal))
                {
                    Style = style
                };
                sendingView.SetAttribute (attr);
                sendingView.AddStr (text);

                y++; // Move to the next line
            }

            // Add a blank line
            y++;

            // Generate all combinations of TextStyle (excluding individual flags)
            int totalCombinations = 1 << allStyles.Length; // 2^n combinations

            for (var i = 1; i < totalCombinations; i++) // Start from 1 to skip "None"
            {
                var combination = (TextStyle)0;
                List<string> styleNames = [];

                for (var bit = 0; bit < allStyles.Length; bit++)
                {
                    if ((i & (1 << bit)) != 0)
                    {
                        combination |= allStyles [bit];
                        styleNames.Add (Enum.GetName (typeof (TextStyle), allStyles [bit])!);
                    }
                }

                // Skip individual flags
                if (styleNames.Count == 1)
                {
                    continue;
                }

                var text = $"[{string.Join (" | ", styleNames)}]";

                sendingView.Move (00, y);

                var attr = new Attribute (sendingView.GetAttributeForRole (VisualRole.Normal))
                {
                    Style = combination
                };
                sendingView.SetAttribute (attr);
                sendingView.AddStr (text);

                y++; // Move to the next line
            }

            args.Cancel = true;
        }
    }
}