[Core] Ignore raw value changes from direct input

And mark .Value as for direct input only. Any other method of changing
the value needs its own path. Fixes #255

1 files changed, 26 insertions, 0 deletions

diff --git a/Xamarin.PropertyEditing.Tests/PropertyViewModelTests.cs b/Xamarin.PropertyEditing.Tests/PropertyViewModelTests.cs
index 6b8cda3..29c0a18 100644
--- a/Xamarin.PropertyEditing.Tests/PropertyViewModelTests.cs
+++ b/Xamarin.PropertyEditing.Tests/PropertyViewModelTests.cs
@@ -454,6 +454,32 @@ namespace Xamarin.PropertyEditing.Tests
 		}
 
 		[Test]
+		public async Task ValueNotChangedForSameValueDifferentSource ()
+		{
+			var value = GetNonDefaultRandomTestValue ();
+
+			var mockProperty = GetPropertyMock ();
+
+			var editor = new MockObjectEditor (mockProperty.Object);
+			await editor.SetValueAsync (mockProperty.Object, new ValueInfo<TValue> {
+				Source = ValueSource.Resource,
+				Value = value
+			});
+
+			var vm = GetViewModel (mockProperty.Object, new[] { editor });
+			Assume.That (vm.Value, Is.EqualTo (value));
+
+			bool changed = false;
+			vm.PropertyChanged += (sender, args) => {
+				changed = true;
+			};
+
+			vm.Value = value;
+
+			Assert.That (changed, Is.False, "PropertyChanged raised when value set to same value");
+		}
+
+		[Test]
 		public void ValueChanged ()
 		{
 			var value = GetNonDefaultRandomTestValue ();