From b52fb5b8def9d2c04a0103a825605c2e591a6c7f Mon Sep 17 00:00:00 2001
From: Curtis Wensley <curtis.wensley@gmail.com>
Date: Mon, 27 May 2024 14:39:20 -0700
Subject: [PATCH] Trigger DataContextChanged when parent change causes
 DataContext to be null

---
 src/Eto/Forms/Binding/BindableWidget.cs       |  3 ++-
 .../UnitTests/Forms/DataContextTests.cs       | 24 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/Eto/Forms/Binding/BindableWidget.cs b/src/Eto/Forms/Binding/BindableWidget.cs
index 5abad73682..1efdecaf9c 100644
--- a/src/Eto/Forms/Binding/BindableWidget.cs
+++ b/src/Eto/Forms/Binding/BindableWidget.cs
@@ -93,9 +93,10 @@ public Widget Parent
 		get => Properties.Get<Widget>(Parent_Key);
 		internal protected set
 		{
+			var dataContext = DataContext;
 			if (Properties.TrySet(Parent_Key, value))
 			{
-				if (!HasDataContext && !(DataContext is null))
+				if (!HasDataContext && !ReferenceEquals(DataContext, dataContext))
 				{
 					IsDataContextChanging = true;
 					OnDataContextChanged(EventArgs.Empty);
diff --git a/test/Eto.Test/UnitTests/Forms/DataContextTests.cs b/test/Eto.Test/UnitTests/Forms/DataContextTests.cs
index 82808b70fd..754d21c1d5 100644
--- a/test/Eto.Test/UnitTests/Forms/DataContextTests.cs
+++ b/test/Eto.Test/UnitTests/Forms/DataContextTests.cs
@@ -436,6 +436,30 @@ public void ChangingDataContextShouldNotSetValues() => Shown(
 				Assert.AreEqual(0, model1.SelectedIndex, "#3 - Model 1 was changed");
 				Assert.AreEqual(1, model2.SelectedIndex, "#4 - Model 2 was changed");
 			});
+			
+		[Test]
+		public void RemovingFromParentShouldTriggerBindingChanged() => Invoke(() =>
+		{
+			int parentDataContextChanged = 0;
+			int childDataContextChanged = 0;
+			var panel = new Panel();
+			panel.DataContextChanged += (sender, e) => parentDataContextChanged++;
+
+			panel.DataContext = new MyViewModelWithEquals { ID = 10 };
+			Assert.AreEqual(1, parentDataContextChanged);
+
+			var child = new Panel();
+			child.DataContextChanged += (sender, e) => childDataContextChanged++;
+
+			panel.Content = child;
+			Assert.AreEqual(1, childDataContextChanged);
+			Assert.AreSame(child.DataContext, panel.DataContext);
+
+			panel.Content = null;
+			Assert.AreEqual(2, childDataContextChanged);
+			Assert.AreEqual(1, parentDataContextChanged);
+			Assert.IsNull(child.DataContext);
+		});
 	}
 }