Implement enumerator for legacy resource manager.

Assets/Cryville/Crtr/Browsing/LegacyResourceManager.cs

@@ -24,6 +24,7 @@ namespace Cryville.Crtr.Browsing {
 		static bool _init;
 
 		public event Action ItemChanged;
+		int _version;
 
 		public LegacyResourceManager(string rootPath) {
 			_rootPath = rootPath;
@@ -38,6 +39,7 @@ namespace Cryville.Crtr.Browsing {
 			cd = new DirectoryInfo(_rootPath + "/charts/" + string.Join("/", dir));
 			items = cd.GetDirectories();
 			ItemChanged?.Invoke();
+			_version++;
 		}
 
 		public void OpenDirectory(int id) {
@@ -174,18 +176,39 @@ namespace Cryville.Crtr.Browsing {
 
 		public struct Enumerator : IEnumerator<ChartDetail> {
 			readonly LegacyResourceManager _list;
-			public ChartDetail Current => throw new NotImplementedException();
+			int _index;
+			readonly int _version;
+			ChartDetail _current;
+			public ChartDetail Current => _current;
 			object IEnumerator.Current => Current;
 
-			public Enumerator(LegacyResourceManager list) { _list = list; }
+			public Enumerator(LegacyResourceManager list) {
+				_list = list;
+				_index = 0;
+				_version = list._version;
+				_current = default(ChartDetail);
+			}
 			public void Dispose() { }
 
 			public bool MoveNext() {
-				throw new NotImplementedException();
+				LegacyResourceManager list = _list;
+				if (_version != list._version)
+					throw new InvalidOperationException("Collection was changed.");
+				if (_index < list.Count) {
+					_current = list[_index++];
+					return true;
+				}
+				else {
+					_current = default(ChartDetail);
+					return false;
+				}
 			}
 
-			public void Reset() {
-				throw new NotImplementedException();
+			void IEnumerator.Reset() {
+				if (_version != _list._version)
+					throw new InvalidOperationException("Collection was changed.");
+				_index = 0;
+				_current = default(ChartDetail);
 			}
 		}