fixing up selection behavior based on selection modes

Author: w-ahmad

src/WinUI.TableView/TableView.cs

@@ -127,7 +127,6 @@ protected override void OnPreviewKeyDown(KeyRoutedEventArgs e)
 
             if (isEditing && currentCell is not null)
             {
-                currentCell.SetElement();
                 currentCell = GetCellFromSlot(newSlot);
                 currentCell.PrepareForEdit();
             }
@@ -655,9 +654,10 @@ internal async void SelectCells(TableViewCellSlot slot, bool shiftKey, bool ctrl
             SelectedCellRanges.Remove(selectionRange);
             selectionRange.Clear();
             SelectionStartCellSlot ??= CurrentCellSlot;
+            SelectionStartCellSlot ??= slot;
             if (shiftKey && SelectionMode is ListViewSelectionMode.Multiple or ListViewSelectionMode.Extended)
             {
-                var currentSlot = SelectionStartCellSlot ?? slot;
+                var currentSlot = SelectionStartCellSlot.Value;
                 var startRow = Math.Min(slot.Row, currentSlot.Row);
                 var endRow = Math.Max(slot.Row, currentSlot.Row);
                 var startCol = Math.Min(slot.Column, currentSlot.Column);
@@ -677,7 +677,7 @@ internal async void SelectCells(TableViewCellSlot slot, bool shiftKey, bool ctrl
             }
             else
             {
-                SelectionStartCellSlot = null;
+                SelectionStartCellSlot = slot;
                 selectionRange.Add(slot);
 
                 if (SelectedCellRanges.LastOrDefault(x => x.Contains(slot)) is { } range)
@@ -713,6 +713,8 @@ internal void DeselectCell(TableViewCellSlot slot)
     internal void SetCurrentCell(TableViewCellSlot? slot)
     {
         var oldSlot = CurrentCellSlot;
+        var currentCell = oldSlot.HasValue ? GetCellFromSlot(oldSlot.Value) : default;
+        currentCell?.SetElement();
         CurrentCellSlot = slot;
         CurrentCellChanged?.Invoke(this, new TableViewCurrentCellChangedEventArgs(oldSlot, slot));
     }
@@ -832,7 +834,7 @@ void ViewChanged(object? _, ScrollViewerViewChangedEventArgs e)
         return default;
     }
 
-    private TableViewCell GetCellFromSlot(TableViewCellSlot slot)
+    internal TableViewCell GetCellFromSlot(TableViewCellSlot slot)
     {
         return ContainerFromIndex(slot.Row) is TableViewRow row ? row.Cells[slot.Column] : default!;
     }

src/WinUI.TableView/TableViewCell.cs

@@ -82,8 +82,6 @@ protected override void OnPointerPressed(PointerRoutedEventArgs e)
         {
             TableView.SelectionStartCellSlot = Slot;
         }
-
-        e.Handled = TableView.SelectionUnit != TableViewSelectionUnit.Row;
     }
 
     protected override void OnPointerReleased(PointerRoutedEventArgs e)
@@ -94,6 +92,8 @@ protected override void OnPointerReleased(PointerRoutedEventArgs e)
         {
             TableView.SelectionStartCellSlot = null;
         }
+
+        e.Handled = TableView.SelectionUnit != TableViewSelectionUnit.Row;
     }
 
     protected override void OnPointerMoved(PointerRoutedEventArgs e)

src/WinUI.TableView/TableViewRow.cs

@@ -1,6 +1,5 @@
 using Microsoft.UI.Xaml;
 using Microsoft.UI.Xaml.Controls;
-using Microsoft.UI.Xaml.Controls.Primitives;
 using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
@@ -10,21 +9,13 @@ namespace WinUI.TableView;
 public class TableViewRow : ListViewItem
 {
     private TableViewCellPresenter? _cellPresenter;
-    private ListViewItemPresenter _itemPresenter = null!;
 
     public TableViewRow()
     {
         DefaultStyleKey = typeof(TableViewRow);
         SizeChanged += OnSizeChanged;
     }
 
-    protected override void OnApplyTemplate()
-    {
-        base.OnApplyTemplate();
-
-        _itemPresenter = (ListViewItemPresenter)GetTemplateChild("Root");
-    }
-
     protected override void OnContentChanged(object oldContent, object newContent)
     {
         if (TableView is null)

src/WinUI.TableView/Themes/TableView.xaml

@@ -41,6 +41,8 @@
                 Value="{ThemeResource TableViewGridLinesBrush}" />
         <Setter Property="BorderThickness"
                 Value="1" />
+        <Setter Property="SingleSelectionFollowsFocus"
+                Value="False" />
         <Setter Property="ItemContainerTransitions">
             <Setter.Value>
                 <TransitionCollection>