Exposed CellSelectionChanged evnet

Author: w-ahmad

src/EventArgs/TableViewCellSelectionChangedEvenArgs.cs

@@ -6,27 +6,27 @@ namespace WinUI.TableView;
 /// <summary>
 /// Provides data for the cell selection changed event.
 /// </summary>
-internal class TableViewCellSelectionChangedEvenArgs : EventArgs
+public class TableViewCellSelectionChangedEventArgs : EventArgs
 {
     /// <summary>
-    /// Initializes a new instance of the TableViewCellSelectionChangedEvenArgs class.
+    /// Initializes a new instance of the TableViewCellSelectionChangedEventArgs class.
     /// </summary>
-    /// <param name="oldSelection">The old selection of cells.</param>
-    /// <param name="newSelection">The new selection of cells.</param>
-    public TableViewCellSelectionChangedEvenArgs(HashSet<TableViewCellSlot> oldSelection,
-                                                 HashSet<TableViewCellSlot> newSelection)
+    /// <param name="removedCells">The list that contains the cells that were unselected.</param>
+    /// <param name="addedCells">The list that contains the cells that were selected.</param>
+    public TableViewCellSelectionChangedEventArgs(IList<TableViewCellSlot> removedCells,
+                                                  IList<TableViewCellSlot> addedCells)
     {
-        OldSelection = oldSelection;
-        NewSelection = newSelection;
+        RemovedCells = removedCells;
+        AddedCells = addedCells;
     }
 
     /// <summary>
-    /// Gets the old selection of cells.
+    /// Gets a list that contains the cells that were unselected.
     /// </summary>
-    public HashSet<TableViewCellSlot> OldSelection { get; }
+    public IList<TableViewCellSlot> RemovedCells { get; }
 
     /// <summary>
-    /// Gets the new selection of cells.
+    /// Gets a list that contains the cells that were selected.
     /// </summary>
-    public HashSet<TableViewCellSlot> NewSelection { get; }
+    public IList<TableViewCellSlot> AddedCells { get; }
 }

src/TableView.cs

@@ -1101,10 +1101,24 @@ private void OnCellSelectionChanged()
                 row?.ApplyCellsSelectionState();
             }
 
-            SelectedCellsChanged?.Invoke(this, new TableViewCellSelectionChangedEvenArgs(oldSelection, SelectedCells));
+            InvokeCellSelectionChangedEvent(oldSelection);
         });
     }
 
+    /// <summary>
+    /// Invokes the <see cref="CellSelectionChanged"/> event to notify subscribers of changes in the selected cells.
+    /// </summary>
+    private void InvokeCellSelectionChangedEvent(HashSet<TableViewCellSlot> oldSelection)
+    {
+        var removedCells = oldSelection.Except(SelectedCells).ToList();
+        var addedCells = SelectedCells.Except(oldSelection).ToList();
+
+        if (removedCells.Count > 0 || addedCells.Count > 0)
+        {
+            CellSelectionChanged?.Invoke(this, new TableViewCellSelectionChangedEventArgs(removedCells, addedCells));
+        }
+    }
+
     /// <summary>
     /// Scrolls the specified cell slot into view.
     /// </summary>
@@ -1475,9 +1489,9 @@ public virtual void OnClearSorting(TableViewClearSortingEventArgs eventArgs)
     public event EventHandler<TableViewClearSortingEventArgs>? ClearSorting;
 
     /// <summary>
-    /// Internal event triggered when selected cells change.
+    /// Event triggered when selected cells change.
     /// </summary>
-    internal event EventHandler<TableViewCellSelectionChangedEvenArgs>? SelectedCellsChanged;
+    public event EventHandler<TableViewCellSelectionChangedEventArgs>? CellSelectionChanged;
 
     /// <summary>
     /// Internal event triggered when the current cell changes.