Implement INotifyCollectionChanged and IDictionary by delegating to ColorSchemes

Terminal.Gui/Drawing/ColorScheme.Colors.cs

@@ -1,4 +1,6 @@
 #nullable enable
+using System.Collections;
+using System.Collections.Specialized;
 using System.Text.Json.Serialization;
 
 namespace Terminal.Gui;
@@ -7,7 +9,7 @@ namespace Terminal.Gui;
 ///     Holds the <see cref="ColorScheme"/>s that define the <see cref="Attribute"/>s that are used by views to render
 ///     themselves.
 /// </summary>
-public static class Colors
+public sealed class Colors : INotifyCollectionChanged, IDictionary<string, ColorScheme?>
 {
     static Colors ()
     {
@@ -60,11 +62,106 @@ public static class Colors
     ///     </para>
     /// </remarks>
     [SerializableConfigurationProperty (Scope = typeof (ThemeScope), OmitClassName = true)]
-    [JsonConverter (typeof (DictionaryJsonConverter<ColorScheme>))]
-    public static Dictionary<string, ColorScheme> ColorSchemes { get; private set; }
+    [JsonConverter (typeof (DictionaryJsonConverter<ColorScheme?>))]
+    public static Dictionary<string, ColorScheme?> ColorSchemes { get; }
+
+    /// <inheritdoc/>
+    public IEnumerator<KeyValuePair<string, ColorScheme?>> GetEnumerator () { return ColorSchemes.GetEnumerator (); }
+
+    /// <inheritdoc/>
+    IEnumerator IEnumerable.GetEnumerator () { return GetEnumerator (); }
+
+    /// <inheritdoc/>
+    public void Add (KeyValuePair<string, ColorScheme?> item)
+    {
+        ColorSchemes.Add (item.Key, item.Value);
+        CollectionChanged?.Invoke (this, new (NotifyCollectionChangedAction.Add, item));
+    }
+
+    /// <inheritdoc/>
+    public void Clear ()
+    {
+        ColorSchemes.Clear ();
+        CollectionChanged?.Invoke (this, new (NotifyCollectionChangedAction.Reset));
+    }
+
+    /// <inheritdoc/>
+    public bool Contains (KeyValuePair<string, ColorScheme?> item) { return ColorSchemes.Contains (item); }
+
+    /// <inheritdoc/>
+    public void CopyTo (KeyValuePair<string, ColorScheme?> [] array, int arrayIndex) { ((ICollection)ColorSchemes).CopyTo (array, arrayIndex); }
+
+    /// <inheritdoc/>
+    public bool Remove (KeyValuePair<string, ColorScheme?> item)
+    {
+        if (ColorSchemes.Remove (item.Key))
+        {
+            CollectionChanged?.Invoke (this, new (NotifyCollectionChangedAction.Remove, item));
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /// <inheritdoc/>
+    public int Count => ColorSchemes.Count;
+
+    /// <inheritdoc/>
+    public bool IsReadOnly => false;
+
+    /// <inheritdoc/>
+    public void Add (string key, ColorScheme? value) { Add (new (key, value)); }
+
+    /// <inheritdoc/>
+    public bool ContainsKey (string key) { return ColorSchemes.ContainsKey (key); }
+
+    /// <inheritdoc/>
+    public bool Remove (string key)
+    {
+        if (ColorSchemes.Remove (key))
+        {
+            CollectionChanged?.Invoke (this, new (NotifyCollectionChangedAction.Remove, key));
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /// <inheritdoc/>
+    public bool TryGetValue (string key, out ColorScheme? value) { return ColorSchemes.TryGetValue (key, out value); }
+
+    /// <inheritdoc/>
+    public ColorScheme? this [string key]
+    {
+        get => ColorSchemes [key];
+        set
+        {
+            if (ColorSchemes.TryAdd (key, value))
+            {
+                CollectionChanged?.Invoke (this, new (NotifyCollectionChangedAction.Add, new KeyValuePair<string, ColorScheme?> (key, value)));
+            }
+            else
+            {
+                ColorScheme? oldValue = ColorSchemes [key];
+                ColorSchemes [key] = value;
+                CollectionChanged?.Invoke (this, new (NotifyCollectionChangedAction.Replace, value, oldValue));
+            }
+        }
+    }
+
+    /// <inheritdoc/>
+    public ICollection<string> Keys => ColorSchemes.Keys;
+
+    /// <inheritdoc/>
+    public ICollection<ColorScheme?> Values => ColorSchemes.Values;
+
+    /// <inheritdoc/>
+    public event NotifyCollectionChangedEventHandler? CollectionChanged;
 
     /// <summary>Resets the <see cref="ColorSchemes"/> dictionary to the default values.</summary>
-    public static Dictionary<string, ColorScheme> Reset ()
+    public static Dictionary<string, ColorScheme?> Reset ()
     {
         ColorSchemes.Clear ();
         ColorSchemes.Add ("TopLevel", new ());