lightweight variant

CursorLang.Settings/Views/Converters.cs

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+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+using System.Windows.Media;
+using DrawingColor = System.Drawing.Color;
+
+namespace CursorLang.Settings.Views;
+
+/// <summary>
+/// Shows an element when the value matches one of those listed in the parameter,
+/// separated by commas. Needed so that the anchor point settings and the screen
+/// settings are not shown at the same time.
+/// </summary>
+public sealed class EnumToVisibilityConverter : IValueConverter
+{
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        string? current = value?.ToString();
+        bool matches = parameter?.ToString()?
+            .Split(',', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries)
+            .Any(expected => expected == current) ?? false;
+
+        return matches ? Visibility.Visible : Visibility.Collapsed;
+    }
+
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) =>
+        Binding.DoNothing;
+}
+
+/// <summary>
+/// A colour into a "#RRGGBB" notation: the alpha is not shown, because
+/// transparency is a separate setting.
+/// </summary>
+/// <remarks>
+/// The settings hold their colours as <see cref="System.Drawing.Color"/> — the agent
+/// reads the same file and must not be made to load WindowsBase for a colour. Turning
+/// them into something WPF can paint with is the job of this file and of
+/// <see cref="ColorToBrushConverter"/>, and of nothing else.
+/// </remarks>
+public sealed class ColorToHexConverter : IValueConverter
+{
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture) =>
+        value is DrawingColor color ? $"#{color.R:X2}{color.G:X2}{color.B:X2}" : string.Empty;
+
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) =>
+        Binding.DoNothing;
+}
+
+/// <summary>
+/// A colour into a brush — for the palette swatches in the list.
+/// </summary>
+public sealed class ColorToBrushConverter : IValueConverter
+{
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture) =>
+        value is DrawingColor color
+            ? new SolidColorBrush(Color.FromArgb(color.A, color.R, color.G, color.B))
+            : Brushes.Transparent;
+
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) =>
+        value is SolidColorBrush brush
+            ? DrawingColor.FromArgb(brush.Color.A, brush.Color.R, brush.Color.G, brush.Color.B)
+            : Binding.DoNothing;
+}