DataGrid: implement missed pseudoclasses

src/Avalonia.Controls.DataGrid/DataGrid.cs

@@ -2753,7 +2753,7 @@ namespace Avalonia.Controls
                         //We don't need to refresh the state of AutoGenerated column headers because they're up-to-date
                         if (!column.IsAutoGenerated && column.HasHeaderCell)
                         {
-                            column.HeaderCell.ApplyState();
+                            column.HeaderCell.UpdatePseudoClasses();
                         }
                     }
 
@@ -5417,7 +5417,7 @@ namespace Avalonia.Controls
             }
             else if (displayedElement is DataGridRowGroupHeader groupHeader)
             {
-                groupHeader.ApplyState(useTransitions: true);
+                groupHeader.UpdatePseudoClasses();
                 if (AreRowHeadersVisible)
                 {
                     groupHeader.ApplyHeaderStatus();

src/Avalonia.Controls.DataGrid/DataGridCell.cs

@@ -180,7 +180,18 @@ namespace Avalonia.Controls
 
         internal void UpdatePseudoClasses()
         {
+            if (OwningGrid == null || OwningColumn == null || OwningRow == null || !OwningRow.IsVisible || OwningRow.Slot == -1)
+            {
+                return;
+            }
+
+            PseudoClasses.Set(":selected", OwningRow.IsSelected);
+
+            PseudoClasses.Set(":current", IsCurrent);
+
+            PseudoClasses.Set(":edited", IsEdited);
 
+            // PseudoClasses.Set(":invalid", !IsValid);
         }
 
         // Makes sure the right gridline has the proper stroke and visibility. If lastVisibleColumn is specified, the 

src/Avalonia.Controls.DataGrid/DataGridColumnHeader.cs

@@ -13,6 +13,7 @@ using System.Diagnostics;
 using Avalonia.Utilities;
 using System;
 using Avalonia.Controls.Utils;
+using Avalonia.Controls.Mixins;
 
 namespace Avalonia.Controls
 {
@@ -68,6 +69,7 @@ namespace Avalonia.Controls
         static DataGridColumnHeader()
         {
             AreSeparatorsVisibleProperty.Changed.AddClassHandler<DataGridColumnHeader>((x, e) => x.OnAreSeparatorsVisibleChanged(e));
+            PressedMixin.Attach<DataGridColumnHeader>();
         }
 
         /// <summary>
@@ -149,8 +151,7 @@ namespace Avalonia.Controls
             }
         }
 
-        //TODO Implement
+        internal void UpdatePseudoClasses()
-        internal void ApplyState()
         {
             CurrentSortingState = null;
             if (OwningGrid != null
@@ -441,7 +442,7 @@ namespace Avalonia.Controls
 
             Point mousePosition = e.GetPosition(this);
             OnMouseEnter(mousePosition);
-            ApplyState();
+            UpdatePseudoClasses();
         }
 
         private void DataGridColumnHeader_PointerLeave(object sender, PointerEventArgs e)
@@ -452,7 +453,7 @@ namespace Avalonia.Controls
             }
 
             OnMouseLeave();
-            ApplyState();
+            UpdatePseudoClasses();
         }
 
         private void DataGridColumnHeader_PointerPressed(object sender, PointerPressedEventArgs e)
@@ -467,7 +468,7 @@ namespace Avalonia.Controls
             OnMouseLeftButtonDown(ref handled, e, mousePosition);
             e.Handled = handled;
 
-            ApplyState();
+            UpdatePseudoClasses();
         }
 
         private void DataGridColumnHeader_PointerReleased(object sender, PointerReleasedEventArgs e)
@@ -483,7 +484,7 @@ namespace Avalonia.Controls
             OnMouseLeftButtonUp(ref handled, e, mousePosition, mousePositionHeaders);
             e.Handled = handled;
 
-            ApplyState();
+            UpdatePseudoClasses();
         }
 
         private void DataGridColumnHeader_PointerMove(object sender, PointerEventArgs e)

src/Avalonia.Controls.DataGrid/DataGridDataConnection.cs

@@ -610,7 +610,7 @@ namespace Avalonia.Controls
             // refresh sort description
             foreach (DataGridColumn column in _owner.ColumnsItemsInternal)
             {
-                column.HeaderCell.ApplyState();
+                column.HeaderCell.UpdatePseudoClasses();
             }
         }
 

src/Avalonia.Controls.DataGrid/DataGridRow.cs

@@ -624,17 +624,17 @@ namespace Avalonia.Controls
         {
             if (_headerElement != null && OwningGrid.AreRowHeadersVisible)
             {
-                _headerElement.ApplyOwnerStatus();
+                _headerElement.UpdatePseudoClasses();
             }
         }
 
-        //TODO Implement
         internal void UpdatePseudoClasses()
         {
-            PseudoClasses.Set(":selected", IsSelected);
-            PseudoClasses.Set(":editing", IsEditing);
             if (RootElement != null && OwningGrid != null && IsVisible)
             {
+                PseudoClasses.Set(":selected", IsSelected);
+                PseudoClasses.Set(":editing", IsEditing);
+                PseudoClasses.Set(":invalid", !IsValid);
                 ApplyHeaderStatus();
             } 
         }

src/Avalonia.Controls.DataGrid/DataGridRowGroupHeader.cs

@@ -3,6 +3,7 @@
 // Please see http://go.microsoft.com/fwlink/?LinkID=131993 for details.
 // All other rights reserved.
 
+using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Media;
@@ -96,6 +97,7 @@ namespace Avalonia.Controls
         static DataGridRowGroupHeader()
         {
             SublevelIndentProperty.Changed.AddClassHandler<DataGridRowGroupHeader>((x,e) => x.OnSublevelIndentChanged(e));
+            PressedMixin.Attach<DataGridRowGroupHeader>();
         }
 
         /// <summary>
@@ -205,14 +207,18 @@ namespace Avalonia.Controls
         {
             if (_headerElement != null && OwningGrid.AreRowHeadersVisible)
             {
-                _headerElement.ApplyOwnerStatus();
+                _headerElement.UpdatePseudoClasses();
             }
         }
 
-        //TODO Implement
+        internal void UpdatePseudoClasses()
-        internal void ApplyState(bool useTransitions)
         {
+            PseudoClasses.Set(":current", IsCurrent);
 
+            if (RowGroupInfo?.CollectionViewGroup != null)
+            {
+                PseudoClasses.Set(":expanded", RowGroupInfo.IsVisible && RowGroupInfo.CollectionViewGroup.ItemCount > 0);
+            }
         }
 
         protected override Size ArrangeOverride(Size finalSize)
@@ -344,7 +350,7 @@ namespace Avalonia.Controls
         {
             EnsureExpanderButtonIsChecked();
             EnsureHeaderVisibility();
-            ApplyState(useTransitions: false);
+            UpdatePseudoClasses();
             ApplyHeaderStatus();
         }
 
@@ -353,7 +359,7 @@ namespace Avalonia.Controls
             if (IsEnabled)
             {
                 IsMouseOver = true;
-                ApplyState(useTransitions: true);
+                UpdatePseudoClasses();
             }
 
             base.OnPointerEnter(e);
@@ -364,7 +370,7 @@ namespace Avalonia.Controls
             if (IsEnabled)
             {
                 IsMouseOver = false;
-                ApplyState(useTransitions: true);
+                UpdatePseudoClasses();
             }
 
             base.OnPointerLeave(e);
@@ -402,7 +408,7 @@ namespace Avalonia.Controls
 
                 EnsureExpanderButtonIsChecked();
 
-                ApplyState(true /*useTransitions*/);
+                UpdatePseudoClasses();
             }
         }
 

src/Avalonia.Controls.DataGrid/DataGridRowHeader.cs

@@ -99,7 +99,7 @@ namespace Avalonia.Controls.Primitives
             _rootElement = e.NameScope.Find<Control>(DATAGRIDROWHEADER_elementRootName);
             if (_rootElement != null)
             {
-                ApplyOwnerStatus();
+                UpdatePseudoClasses();
             }
         } 
 
@@ -131,12 +131,27 @@ namespace Avalonia.Controls.Primitives
             return measuredSize;
         }
 
-        //TODO Implement
+        internal void UpdatePseudoClasses()
-        internal void ApplyOwnerStatus()
         {
             if (_rootElement != null && Owner != null && Owner.IsVisible)
             {
+                if (OwningRow != null)
+                {
+                    PseudoClasses.Set(":invalid", !OwningRow.IsValid);
+
+                    PseudoClasses.Set(":selected", OwningRow.IsSelected);
+
+                    PseudoClasses.Set(":editing", OwningRow.IsEditing);
 
+                    if (OwningGrid != null)
+                    {
+                        PseudoClasses.Set(":current", OwningRow.Slot == OwningGrid.CurrentSlot);
+                    }
+                }
+                else if (OwningRowGroupHeader != null && OwningGrid != null)
+                {
+                    PseudoClasses.Set(":current", OwningRowGroupHeader.RowGroupInfo.Slot == OwningGrid.CurrentSlot);
+                }
             }
         }
 

src/Avalonia.Controls.DataGrid/DataGridRows.cs

@@ -1912,7 +1912,7 @@ namespace Avalonia.Controls
             {
                 // Assume it's a RowGroupHeader
                 DataGridRowGroupHeader groupHeader = element as DataGridRowGroupHeader;
-                groupHeader.ApplyState(useTransitions: true);
+                groupHeader.UpdatePseudoClasses();
             }
         }