Exposed CurrentCellSlot prop & CurrentCellSlotChanged event

Author: w-ahmad

src/EventArgs/TableViewCurrentCellChangedEventArgs.cs

@@ -155,6 +155,11 @@ public partial class TableView
     /// Identifies the CellStyle dependency property.
     /// </summary>
     public static readonly DependencyProperty CellStyleProperty = DependencyProperty.Register(nameof(CellStyle), typeof(Style), typeof(TableView), new PropertyMetadata(null, OnCellStyleChanged));
+    
+    /// <summary>
+    /// Identifies the CurrentCellSlot dependency property.
+    /// </summary>
+    public static readonly DependencyProperty CurrentCellSlotProperty = DependencyProperty.Register(nameof(CurrentCellSlot), typeof(TableViewCellSlot?), typeof(TableView), new PropertyMetadata(default, OnCurrentCellSlotChanged));
 
     /// <summary>
     /// Gets the collection view associated with the TableView.
@@ -177,9 +182,13 @@ public partial class TableView
     internal TableViewSelectionUnit LastSelectionUnit { get; set; }
 
     /// <summary>
-    /// Gets or sets the current cell slot.
+    /// Gets or sets the current cell slot associated with the table view.
     /// </summary>
-    internal TableViewCellSlot? CurrentCellSlot { get; set; }
+    public TableViewCellSlot? CurrentCellSlot
+    {
+        get => (TableViewCellSlot?)GetValue(CurrentCellSlotProperty);
+        set => SetValue(CurrentCellSlotProperty, value);
+    }
 
     /// <summary>
     /// Gets or sets the selection start cell slot.
@@ -579,7 +588,7 @@ private static void OnIsReadOnlyChanged(DependencyObject d, DependencyPropertyCh
                 || tableView.SelectionUnit is TableViewSelectionUnit.Row)
                 && tableView.IsReadOnly)
             {
-                tableView.SetCurrentCell(null);
+                tableView.CurrentCellSlot = null;
             }
         }
     }
@@ -682,6 +691,18 @@ private static void OnCellStyleChanged(DependencyObject d, DependencyPropertyCha
         }
     }
 
+    private static async void OnCurrentCellSlotChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is not TableView tableView) return;
+
+        tableView.CurrentCellChanged?.Invoke(d, e);
+
+        var oldSlot = e.OldValue as TableViewCellSlot?;
+        var newSlot = e.NewValue as TableViewCellSlot?;
+
+        await tableView.OnCurrentCellChanged(oldSlot, newSlot);
+    }
+
     /// <summary>
     /// Throws an exception if the base ItemsSource property is set directly.
     /// </summary>

src/TableView.Properties.cs

@@ -75,7 +75,7 @@ private void TableView_SelectionChanged(object sender, SelectionChangedEventArgs
             });
         }
 
-        SetCurrentCell(null);
+        CurrentCellSlot = null;
         OnCellSelectionChanged();
 
         if (SelectedIndex > 0)
@@ -192,7 +192,7 @@ private void HandleNavigations(KeyRoutedEventArgs e, bool shiftKey, bool ctrlKey
             if (isEditing && currentCell is not null)
             {
                 currentCell = GetCellFromSlot(newSlot);
-                currentCell.PrepareForEdit();
+                currentCell?.PrepareForEdit();
             }
 
             e.Handled = true;
@@ -803,7 +803,7 @@ public void RefreshFilter()
         if (SelectionUnit is TableViewSelectionUnit.Cell)
         {
             SelectAllCells();
-            SetCurrentCell(null);
+            CurrentCellSlot = null;
         }
         else
         {
@@ -886,7 +886,7 @@ private void DeselectAllCells()
     {
         SelectedCellRanges.Clear();
         OnCellSelectionChanged();
-        SetCurrentCell(null);
+        CurrentCellSlot = null;
     }
 
     /// <summary>
@@ -922,17 +922,17 @@ internal void MakeSelection(TableViewCellSlot slot, bool shiftKey, bool ctrlKey
             {
                 SelectRows(slot, shiftKey);
                 LastSelectionUnit = TableViewSelectionUnit.Row;
-                }
-                else
-                {
+            }
+            else
+            {
                 SelectCells(slot, shiftKey);
                 LastSelectionUnit = TableViewSelectionUnit.Cell;
             }
         }
         else if (!IsReadOnly)
         {
             SelectionStartCellSlot = slot;
-            DispatcherQueue.TryEnqueue(() => SetCurrentCell(slot));
+            CurrentCellSlot = slot;
         }
     }
 
@@ -948,14 +948,14 @@ private void SelectRows(TableViewCellSlot slot, bool shiftKey)
         if (selectionRange is not null)
         {
             DeselectRange(selectionRange);
-        } 
+        }
 
         if (shiftKey && SelectionMode is ListViewSelectionMode.Multiple or ListViewSelectionMode.Extended)
         {
             var min = Math.Min(SelectionStartRowIndex.Value, slot.Row);
             var max = Math.Max(SelectionStartRowIndex.Value, slot.Row);
 
-            SelectRange(new ItemIndexRange(min, (uint)(max - min) + 1)); 
+            SelectRange(new ItemIndexRange(min, (uint)(max - min) + 1));
         }
         else
         {
@@ -968,11 +968,11 @@ private void SelectRows(TableViewCellSlot slot, bool shiftKey)
             {
                 SelectRange(new ItemIndexRange(slot.Row, 1));
             }
-            }
+        }
 
         if (!IsReadOnly && slot.IsValid(this))
         {
-            DispatcherQueue.TryEnqueue(() => SetCurrentCell(slot));
+            CurrentCellSlot = slot;
         }
         else
         {
@@ -1033,7 +1033,7 @@ private void SelectCells(TableViewCellSlot slot, bool shiftKey)
 
         SelectedCellRanges.Add(selectionRange);
         OnCellSelectionChanged();
-        DispatcherQueue.TryEnqueue(() => SetCurrentCell(slot));
+        CurrentCellSlot = slot;
     }
 
     /// <summary>
@@ -1049,38 +1049,32 @@ internal void DeselectCell(TableViewCellSlot slot)
             SelectedCellRanges.Remove(selectionRange);
         }
 
-        SetCurrentCell(slot);
+        CurrentCellSlot = slot;
         OnCellSelectionChanged();
     }
 
     /// <summary>
-    /// Sets the current cell based on the specified cell slot.
+    /// Handles changes to the current cell in the table view.
     /// </summary>
-    internal async void SetCurrentCell(TableViewCellSlot? slot)
+    private async Task OnCurrentCellChanged(TableViewCellSlot? oldSlot, TableViewCellSlot? newSlot)
     {
-        if (slot == CurrentCellSlot)
+        if (oldSlot == newSlot)
         {
             return;
         }
 
-        var oldSlot = CurrentCellSlot;
-        var currentCell = oldSlot.HasValue ? GetCellFromSlot(oldSlot.Value) : default;
-        currentCell?.SetElement();
-        CurrentCellSlot = slot;
-
-        if (oldSlot is { })
+        if (oldSlot.HasValue)
         {
-            var row = _rows.FirstOrDefault(x => x.Index == oldSlot.Value.Row);
-            row?.ApplyCurrentCellState(oldSlot.Value);
+            var cell = GetCellFromSlot(oldSlot.Value);
+            cell?.SetElement();
+            cell?.ApplyCurrentCellState();
         }
 
-        if (slot is { })
+        if (newSlot.HasValue)
         {
-            var cell = await ScrollCellIntoView(slot.Value);
+            var cell = await ScrollCellIntoView(newSlot.Value);
             cell?.ApplyCurrentCellState();
         }
-
-        CurrentCellChanged?.Invoke(this, new TableViewCurrentCellChangedEventArgs(oldSlot, slot));
     }
 
     /// <summary>
@@ -1241,9 +1235,9 @@ void ViewChanged(object? _, ScrollViewerViewChangedEventArgs e)
     /// <summary>
     /// Gets the cell based on the specified cell slot.
     /// </summary>
-    internal TableViewCell GetCellFromSlot(TableViewCellSlot slot)
+    internal TableViewCell? GetCellFromSlot(TableViewCellSlot slot)
     {
-        return slot.IsValid(this) && ContainerFromIndex(slot.Row) is TableViewRow row ? row.Cells[slot.Column] : default!;
+        return slot.IsValid(this) && ContainerFromIndex(slot.Row) is TableViewRow row ? row.Cells[slot.Column] : default;
     }
 
     /// <summary>
@@ -1494,7 +1488,7 @@ public virtual void OnClearSorting(TableViewClearSortingEventArgs eventArgs)
     public event EventHandler<TableViewCellSelectionChangedEventArgs>? CellSelectionChanged;
 
     /// <summary>
-    /// Internal event triggered when the current cell changes.
+    /// Event triggered when the current cell changes.
     /// </summary>
-    internal event EventHandler<TableViewCurrentCellChangedEventArgs>? CurrentCellChanged;
+    public event DependencyPropertyChangedEventHandler? CurrentCellChanged;
 }