From a7733365b6f418af56ccc17f5fd4bb5ac686db3a Mon Sep 17 00:00:00 2001
From: Curtis Wensley <curtis.wensley@gmail.com>
Date: Wed, 11 Dec 2024 02:05:06 -0800
Subject: [PATCH] Fix issue mapping view to model in SelectableFilterCollection

Fixes #2676
---
 src/Eto/Forms/FilterCollection.cs             | 11 ++--
 .../Controls/GridViewSelectableFilterTests.cs | 54 ++++++++++++++++---
 2 files changed, 56 insertions(+), 9 deletions(-)

diff --git a/src/Eto/Forms/FilterCollection.cs b/src/Eto/Forms/FilterCollection.cs
index cd8638e5db..d6cf272ffd 100644
--- a/src/Eto/Forms/FilterCollection.cs
+++ b/src/Eto/Forms/FilterCollection.cs
@@ -173,15 +173,20 @@ protected override void Rebuild()
 			viewToModel = new Dictionary<T, int>(Count);
 			for (int i = 0; i < Count; i++)
 			{
+				// used for lookup below, this index is not correct yet
 				viewToModel.Add(this[i], i);
 			}
 
 			modelToView = new Dictionary<int, int>(Count);
-			for (int i = 0; i < Items.Count; i++)
+			for (int j = 0; j < Items.Count; j++)
 			{
 				int index;
-				if (viewToModel.TryGetValue(Items[i], out index))
-					modelToView.Add(i, index);
+				if (viewToModel.TryGetValue(Items[j], out index))
+				{
+					modelToView.Add(j, index);
+					// update index with real index in model
+					viewToModel[Items[j]] = j;
+				}
 			}
 		}
 		else
diff --git a/test/Eto.Test/UnitTests/Forms/Controls/GridViewSelectableFilterTests.cs b/test/Eto.Test/UnitTests/Forms/Controls/GridViewSelectableFilterTests.cs
index 04a1ae18c2..0513d48919 100644
--- a/test/Eto.Test/UnitTests/Forms/Controls/GridViewSelectableFilterTests.cs
+++ b/test/Eto.Test/UnitTests/Forms/Controls/GridViewSelectableFilterTests.cs
@@ -8,7 +8,7 @@ namespace Eto.Test.UnitTests.Forms.Controls
 	/// <copyright>(c) 2014 by Vivek Jhaveri</copyright>
 	/// <license type="BSD-3">See LICENSE for full terms</license>
 	[TestFixture]
-	public class GridViewSelectableFilterTests
+	public class GridViewSelectableFilterTests : TestBase
 	{
 		GridView grid;
 		ObservableCollection<DataItem> model;
@@ -21,7 +21,7 @@ public class GridViewSelectableFilterTests
 		[SetUp]
 		public void Setup()
 		{
-			TestBase.Invoke(() =>
+			Invoke(() =>
 			{
 				grid = new GridView();
 				// Some platforms need at least one column for selection to work
@@ -40,7 +40,7 @@ public void Setup()
 		[Test]
 		public void InsertItemShouldNotChangeSelection()
 		{
-			TestBase.Invoke(() =>
+			Invoke(() =>
 			{
 				grid.SelectRow(0);
 				var selectedItem = grid.SelectedItem;
@@ -52,7 +52,7 @@ public void InsertItemShouldNotChangeSelection()
 		[Test]
 		public void DeleteSelectedItemsShouldRemoveSelectedItems()
 		{
-			TestBase.Invoke(() =>
+			Invoke(() =>
 			{
 				grid.AllowMultipleSelection = true;
 
@@ -88,7 +88,7 @@ public void DeleteSelectedItemsShouldRemoveSelectedItems()
 		[TestCase(2)]
 		public void SortItemsShouldNotChangeSelection(int rowToSelect)
 		{
-			TestBase.Invoke(() =>
+			Invoke(() =>
 			{
 				filtered.Sort = GridViewUtils.SortItemsAscending;
 				grid.SelectRow(rowToSelect);
@@ -111,7 +111,7 @@ public void SortItemsShouldNotChangeSelection(int rowToSelect)
 		[Test]
 		public void FilterItemsShouldNotChangeSelection()
 		{
-			TestBase.Invoke(() =>
+			Invoke(() =>
 			{
 				grid.AllowMultipleSelection = true;
 
@@ -137,5 +137,47 @@ public void FilterItemsShouldNotChangeSelection()
 				Assert.AreEqual(0, modelSelectionChangedCount, "Model SelectionChanged event should not fire when changing filter");
 			});
 		}
+		
+		[Test]
+		public void SortedCollectionShouldGetCorrectRow()
+		{
+			GridView grid = null;
+			Shown(form =>
+			{
+				grid = new GridView { Size = new Size(200, 200) };
+				var collection = new SelectableFilterCollection<GridItem>(grid)
+				{
+					new("Hello"),
+					new("There"),
+					new("Fine"),
+					new("World"),
+					new("Of"),
+					new("Eto")
+				};
+				
+				grid.Columns.Add(new GridColumn
+				{
+					DataCell = new TextBoxCell(0)
+				});
+				grid.DataStore = collection;
+				collection.Sort = (x, y) => string.Compare((string)x.Values[0], (string)y.Values[0], StringComparison.Ordinal);
+				// goes to this order:
+				// Eto
+				// Fine
+				// Hello
+				// Of
+				// There
+				// World
+
+				collection.SelectRow(4);
+				form.Content = grid;
+			}, () => {
+				
+				Assert.AreEqual(3, grid.SelectedRow, "#1");
+				Assert.NotNull(grid.SelectedItem, "#2");
+				Assert.AreEqual("Of", ((GridItem)grid.SelectedItem).Values[0], "#3");
+			});
+		}
+		
 	}
 }
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