1 files changed, 135 insertions, 0 deletions
diff --git a/Xamarin.Forms.Core/ResourceDictionary.cs b/Xamarin.Forms.Core/ResourceDictionary.cs
new file mode 100644
index 00000000..b19773ff
--- /dev/null
+++ b/Xamarin.Forms.Core/ResourceDictionary.cs
@@ -0,0 +1,135 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+
+namespace Xamarin.Forms
+{
+	public sealed class ResourceDictionary : IResourceDictionary, IDictionary<string, object>
+	{
+		readonly Dictionary<string, object> _innerDictionary = new Dictionary<string, object>();
+
+		void ICollection<KeyValuePair<string, object>>.Add(KeyValuePair<string, object> item)
+		{
+			((ICollection<KeyValuePair<string, object>>)_innerDictionary).Add(item);
+			OnValuesChanged(item);
+		}
+
+		public void Clear()
+		{
+			_innerDictionary.Clear();
+		}
+
+		bool ICollection<KeyValuePair<string, object>>.Contains(KeyValuePair<string, object> item)
+		{
+			return ((ICollection<KeyValuePair<string, object>>)_innerDictionary).Contains(item);
+		}
+
+		void ICollection<KeyValuePair<string, object>>.CopyTo(KeyValuePair<string, object>[] array, int arrayIndex)
+		{
+			((ICollection<KeyValuePair<string, object>>)_innerDictionary).CopyTo(array, arrayIndex);
+		}
+
+		public int Count
+		{
+			get { return _innerDictionary.Count; }
+		}
+
+		bool ICollection<KeyValuePair<string, object>>.IsReadOnly
+		{
+			get { return ((ICollection<KeyValuePair<string, object>>)_innerDictionary).IsReadOnly; }
+		}
+
+		bool ICollection<KeyValuePair<string, object>>.Remove(KeyValuePair<string, object> item)
+		{
+			return ((ICollection<KeyValuePair<string, object>>)_innerDictionary).Remove(item);
+		}
+
+		public void Add(string key, object value)
+		{
+			_innerDictionary.Add(key, value);
+			OnValueChanged(key, value);
+		}
+
+		public bool ContainsKey(string key)
+		{
+			return _innerDictionary.ContainsKey(key);
+		}
+
+		[IndexerName("Item")]
+		public object this[string index]
+		{
+			get { return _innerDictionary[index]; }
+			set
+			{
+				_innerDictionary[index] = value;
+				OnValueChanged(index, value);
+			}
+		}
+
+		public ICollection<string> Keys
+		{
+			get { return _innerDictionary.Keys; }
+		}
+
+		public bool Remove(string key)
+		{
+			return _innerDictionary.Remove(key);
+		}
+
+		public ICollection<object> Values
+		{
+			get { return _innerDictionary.Values; }
+		}
+
+		IEnumerator IEnumerable.GetEnumerator()
+		{
+			return ((IEnumerable)_innerDictionary).GetEnumerator();
+		}
+
+		public IEnumerator<KeyValuePair<string, object>> GetEnumerator()
+		{
+			return _innerDictionary.GetEnumerator();
+		}
+
+		public bool TryGetValue(string key, out object value)
+		{
+			return _innerDictionary.TryGetValue(key, out value);
+		}
+
+		event EventHandler<ResourcesChangedEventArgs> IResourceDictionary.ValuesChanged
+		{
+			add { ValuesChanged += value; }
+			remove { ValuesChanged -= value; }
+		}
+
+		public void Add(Style style)
+		{
+			if (string.IsNullOrEmpty(style.Class))
+				Add(style.TargetType.FullName, style);
+			else
+			{
+				IList<Style> classes;
+				object outclasses;
+				if (!TryGetValue(Style.StyleClassPrefix + style.Class, out outclasses) || (classes = outclasses as IList<Style>) == null)
+					classes = new List<Style>();
+				classes.Add(style);
+				this[Style.StyleClassPrefix + style.Class] = classes;
+			}
+		}
+
+		void OnValueChanged(string key, object value)
+		{
+			OnValuesChanged(new KeyValuePair<string, object>(key, value));
+		}
+
+		void OnValuesChanged(params KeyValuePair<string, object>[] values)
+		{
+			if (values == null || values.Length == 0)
+				return;
+			ValuesChanged?.Invoke(this, new ResourcesChangedEventArgs(values));
+		}
+
+		event EventHandler<ResourcesChangedEventArgs> ValuesChanged;
+	}
+}
+\ No newline at end of file