1 files changed, 100 insertions, 0 deletions
diff --git a/Xamarin.Forms.Core/Interactivity/BindingCondition.cs b/Xamarin.Forms.Core/Interactivity/BindingCondition.cs
new file mode 100644
index 00000000..88b7cf36
--- /dev/null
+++ b/Xamarin.Forms.Core/Interactivity/BindingCondition.cs
@@ -0,0 +1,100 @@
+using System;
+using Xamarin.Forms.Xaml;
+
+namespace Xamarin.Forms
+{
+	public sealed class BindingCondition : Condition, IValueProvider
+	{
+		readonly BindableProperty _boundProperty;
+
+		BindingBase _binding;
+		object _triggerValue;
+
+		public BindingCondition()
+		{
+			_boundProperty = BindableProperty.CreateAttached("Bound", typeof(object), typeof(DataTrigger), null, propertyChanged: OnBoundPropertyChanged);
+		}
+
+		public BindingBase Binding
+		{
+			get { return _binding; }
+			set
+			{
+				if (_binding == value)
+					return;
+				if (IsSealed)
+					throw new InvalidOperationException("Can not change Binding once the Trigger has been applied.");
+				_binding = value;
+			}
+		}
+
+		public object Value
+		{
+			get { return _triggerValue; }
+			set
+			{
+				if (_triggerValue == value)
+					return;
+				if (IsSealed)
+					throw new InvalidOperationException("Can not change Value once the Trigger has been applied.");
+				_triggerValue = value;
+			}
+		}
+
+		internal IServiceProvider ServiceProvider { get; set; }
+
+		internal IValueConverterProvider ValueConverter { get; set; }
+
+		object IValueProvider.ProvideValue(IServiceProvider serviceProvider)
+		{
+			ValueConverter = serviceProvider.GetService(typeof(IValueConverterProvider)) as IValueConverterProvider;
+			ServiceProvider = serviceProvider;
+
+			return this;
+		}
+
+		internal override bool GetState(BindableObject bindable)
+		{
+			object newValue = bindable.GetValue(_boundProperty);
+			return EqualsToValue(newValue);
+		}
+
+		internal override void SetUp(BindableObject bindable)
+		{
+			if (Binding != null)
+				bindable.SetBinding(_boundProperty, Binding.Clone());
+		}
+
+		internal override void TearDown(BindableObject bindable)
+		{
+			bindable.RemoveBinding(_boundProperty);
+			bindable.ClearValue(_boundProperty);
+		}
+
+		bool EqualsToValue(object other)
+		{
+			if ((other == Value) || (other != null && other.Equals(Value)))
+				return true;
+
+			object converted = null;
+			if (ValueConverter != null)
+				converted = ValueConverter.Convert(Value, other != null ? other.GetType() : typeof(object), null, ServiceProvider);
+			else
+				return false;
+
+			return (other == converted) || (other != null && other.Equals(converted));
+		}
+
+		void OnBoundPropertyChanged(BindableObject bindable, object oldValue, object newValue)
+		{
+			bool oldState = EqualsToValue(oldValue);
+			bool newState = EqualsToValue(newValue);
+
+			if (newState == oldState)
+				return;
+
+			if (ConditionChanged != null)
+				ConditionChanged(bindable, oldState, newState);
+		}
+	}
+}
+\ No newline at end of file