feat(Controls): Address rule CA1822

src/Avalonia.Controls/Automation/Peers/ComboBoxAutomationPeer.cs

@@ -18,7 +18,7 @@ namespace Avalonia.Automation.Peers
 
         public new ComboBox Owner => (ComboBox)base.Owner;
 
-        public ExpandCollapseState ExpandCollapseState => ToState(Owner.IsDropDownOpen);
+        public ExpandCollapseState ExpandCollapseState => ComboBoxAutomationPeer.ToState(Owner.IsDropDownOpen);
         public bool ShowsMenu => true;
         public void Collapse() => Owner.IsDropDownOpen = false;
         public void Expand() => Owner.IsDropDownOpen = true;
@@ -66,12 +66,12 @@ namespace Avalonia.Automation.Peers
             {
                 RaisePropertyChangedEvent(
                     ExpandCollapsePatternIdentifiers.ExpandCollapseStateProperty,
-                    ToState((bool)e.OldValue!),
-                    ToState((bool)e.NewValue!));
+                    ComboBoxAutomationPeer.ToState((bool)e.OldValue!),
+                    ComboBoxAutomationPeer.ToState((bool)e.NewValue!));
             }
         }
 
-        private ExpandCollapseState ToState(bool value)
+        private static ExpandCollapseState ToState(bool value)
         {
             return value ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed;
         }

src/Avalonia.Controls/Calendar/CalendarBlackoutDatesCollection.cs

@@ -122,7 +122,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void ClearItems()
         {
-            EnsureValidThread();
+            CalendarBlackoutDatesCollection.EnsureValidThread();
 
             base.ClearItems();
             _owner.UpdateMonths();
@@ -140,7 +140,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void InsertItem(int index, CalendarDateRange item)
         {
-            EnsureValidThread();
+            CalendarBlackoutDatesCollection.EnsureValidThread();
 
             if (!IsValid(item))
             {
@@ -162,7 +162,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void RemoveItem(int index)
         {
-            EnsureValidThread();
+            CalendarBlackoutDatesCollection.EnsureValidThread();
 
             base.RemoveItem(index);
             _owner.UpdateMonths();
@@ -182,7 +182,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void SetItem(int index, CalendarDateRange item)
         {
-            EnsureValidThread();
+            CalendarBlackoutDatesCollection.EnsureValidThread();
 
             if (!IsValid(item))
             {
@@ -206,7 +206,7 @@ namespace Avalonia.Controls.Primitives
             return true;
         }
         
-        private void EnsureValidThread()
+        private static void EnsureValidThread()
         {
             Dispatcher.UIThread.VerifyAccess();
         }

src/Avalonia.Controls/Calendar/SelectedDatesCollection.cs

@@ -133,7 +133,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void ClearItems()
         {
-            EnsureValidThread();
+            SelectedDatesCollection.EnsureValidThread();
 
             Collection<DateTime> addedItems = new Collection<DateTime>();
             Collection<DateTime> removedItems = new Collection<DateTime>();
@@ -170,7 +170,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void InsertItem(int index, DateTime item)
         {
-            EnsureValidThread();
+            SelectedDatesCollection.EnsureValidThread();
 
             if (!Contains(item))
             {
@@ -233,7 +233,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void RemoveItem(int index)
         {
-            EnsureValidThread();
+            SelectedDatesCollection.EnsureValidThread();
 
             if (index >= Count)
             {
@@ -284,7 +284,7 @@ namespace Avalonia.Controls.Primitives
         /// </remarks>
         protected override void SetItem(int index, DateTime item)
         {
-            EnsureValidThread();
+            SelectedDatesCollection.EnsureValidThread();
 
             if (!Contains(item))
             {
@@ -353,7 +353,7 @@ namespace Avalonia.Controls.Primitives
             return true;
         }
         
-        private void EnsureValidThread()
+        private static void EnsureValidThread()
         {
             Dispatcher.UIThread.VerifyAccess();
         }

src/Avalonia.Controls/ComboBox.cs

@@ -236,7 +236,7 @@ namespace Avalonia.Controls
             else if (IsDropDownOpen && SelectedIndex < 0 && ItemCount > 0 &&
                       (e.Key == Key.Up || e.Key == Key.Down) && IsFocused == true)
             {
-                var firstChild = Presenter?.Panel?.Children.FirstOrDefault(c => CanFocus(c));
+                var firstChild = Presenter?.Panel?.Children.FirstOrDefault(c => ComboBox.CanFocus(c));
                 if (firstChild != null)
                 {
                     FocusManager.Instance?.Focus(firstChild, NavigationMethod.Directional);
@@ -341,7 +341,7 @@ namespace Avalonia.Controls
         {
             _subscriptionsOnOpen.Clear();
 
-            if (CanFocus(this))
+            if (ComboBox.CanFocus(this))
             {
                 Focus();
             }
@@ -403,14 +403,14 @@ namespace Avalonia.Controls
                     container = ItemContainerGenerator.ContainerFromIndex(selectedIndex);
                 }
 
-                if (container != null && CanFocus(container))
+                if (container != null && ComboBox.CanFocus(container))
                 {
                     container.Focus();
                 }
             }
         }
 
-        private bool CanFocus(IControl control) => control.Focusable && control.IsEffectivelyEnabled && control.IsVisible;
+        private static bool CanFocus(IControl control) => control.Focusable && control.IsEffectivelyEnabled && control.IsVisible;
 
         private void UpdateSelectionBoxItem(object? item)
         {

src/Avalonia.Controls/DateTimePickers/DateTimePickerPanel.cs

@@ -545,8 +545,8 @@ namespace Avalonia.Controls.Primitives
 
         private void OnItemTapped(object? sender, TappedEventArgs e)
         {
-            if (e.Source is IVisual source && 
-                GetItemFromSource(source) is ListBoxItem listBoxItem &&
+            if (e.Source is IVisual source &&
+                DateTimePickerPanel.GetItemFromSource(source) is ListBoxItem listBoxItem &&
                 listBoxItem.Tag is int tag)
             {
                 SelectedValue = tag;
@@ -555,7 +555,7 @@ namespace Avalonia.Controls.Primitives
         }
 
         //Helper to get ListBoxItem from pointerevent source
-        private ListBoxItem? GetItemFromSource(IVisual src)
+        private static ListBoxItem? GetItemFromSource(IVisual src)
         {
             var item = src;
             while (item != null && !(item is ListBoxItem))

src/Avalonia.Controls/Grid.cs

@@ -1117,7 +1117,7 @@ namespace Avalonia.Controls
             else
             {
                 //  otherwise...
-                cellMeasureWidth = GetMeasureSizeForRange(
+                cellMeasureWidth = Grid.GetMeasureSizeForRange(
                                         DefinitionsU,
                                         PrivateCells[cell].ColumnIndex,
                                         PrivateCells[cell].ColumnSpan);
@@ -1137,7 +1137,7 @@ namespace Avalonia.Controls
             }
             else
             {
-                cellMeasureHeight = GetMeasureSizeForRange(
+                cellMeasureHeight = Grid.GetMeasureSizeForRange(
                                         DefinitionsV,
                                         PrivateCells[cell].RowIndex,
                                         PrivateCells[cell].RowSpan);
@@ -1165,7 +1165,7 @@ namespace Avalonia.Controls
         /// <remarks>
         /// For "Auto" definitions MinWidth is used in place of PreferredSize.
         /// </remarks>
-        private double GetMeasureSizeForRange(
+        private static double GetMeasureSizeForRange(
             IReadOnlyList<DefinitionBase> definitions,
             int start,
             int count)

src/Avalonia.Controls/GridSplitter.cs

@@ -288,13 +288,13 @@ namespace Avalonia.Controls
                     _resizeData.Definition1 = GetGridDefinition(_resizeData.Grid, index1, _resizeData.ResizeDirection);
                     _resizeData.OriginalDefinition1Length =
                         _resizeData.Definition1.UserSizeValueCache; // Save Size if user cancels.
-                    _resizeData.OriginalDefinition1ActualLength = GetActualLength(_resizeData.Definition1);
+                    _resizeData.OriginalDefinition1ActualLength = GridSplitter.GetActualLength(_resizeData.Definition1);
 
                     _resizeData.Definition2Index = index2;
                     _resizeData.Definition2 = GetGridDefinition(_resizeData.Grid, index2, _resizeData.ResizeDirection);
                     _resizeData.OriginalDefinition2Length =
                         _resizeData.Definition2.UserSizeValueCache; // Save Size if user cancels.
-                    _resizeData.OriginalDefinition2ActualLength = GetActualLength(_resizeData.Definition2);
+                    _resizeData.OriginalDefinition2ActualLength = GridSplitter.GetActualLength(_resizeData.Definition2);
 
                     // Determine how to resize the columns.
                     bool isStar1 = IsStar(_resizeData.Definition1);
@@ -516,7 +516,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Retrieves the ActualWidth or ActualHeight of the definition depending on its type Column or Row.
         /// </summary>
-        private double GetActualLength(DefinitionBase definition)
+        private static double GetActualLength(DefinitionBase definition)
         {
             var column = definition as ColumnDefinition;
 
@@ -537,11 +537,11 @@ namespace Avalonia.Controls
         /// </summary>
         private void GetDeltaConstraints(out double minDelta, out double maxDelta)
         {
-            double definition1Len = GetActualLength(_resizeData!.Definition1!);
+            double definition1Len = GridSplitter.GetActualLength(_resizeData!.Definition1!);
             double definition1Min = _resizeData.Definition1!.UserMinSizeValueCache;
             double definition1Max = _resizeData.Definition1.UserMaxSizeValueCache;
 
-            double definition2Len = GetActualLength(_resizeData.Definition2!);
+            double definition2Len = GridSplitter.GetActualLength(_resizeData.Definition2!);
             double definition2Min = _resizeData.Definition2!.UserMinSizeValueCache;
             double definition2Max = _resizeData.Definition2.UserMaxSizeValueCache;
 
@@ -590,7 +590,7 @@ namespace Avalonia.Controls
                     }
                     else if (IsStar(definition))
                     {
-                        SetDefinitionLength(definition, new GridLength(GetActualLength(definition), GridUnitType.Star));
+                        SetDefinitionLength(definition, new GridLength(GridSplitter.GetActualLength(definition), GridUnitType.Star));
                     }
                 }
             }
@@ -629,8 +629,8 @@ namespace Avalonia.Controls
 
             if (definition1 != null && definition2 != null)
             {
-                double actualLength1 = GetActualLength(definition1);
-                double actualLength2 = GetActualLength(definition2);
+                double actualLength1 = GridSplitter.GetActualLength(definition1);
+                double actualLength2 = GridSplitter.GetActualLength(definition2);
                 double pixelLength = 1 / _resizeData.Scaling;
                 double epsilon = pixelLength + LayoutHelper.LayoutEpsilon;
 

src/Avalonia.Controls/Platform/InProcessDragSource.cs

@@ -64,12 +64,12 @@ namespace Avalonia.Platform
             var tl = root.GetSelfAndVisualAncestors().OfType<TopLevel>().FirstOrDefault();
             tl?.PlatformImpl?.Input?.Invoke(rawEvent);
 
-            var effect = GetPreferredEffect(rawEvent.Effects & _allowedEffects, modifiers);
+            var effect = InProcessDragSource.GetPreferredEffect(rawEvent.Effects & _allowedEffects, modifiers);
             UpdateCursor(root, effect);
             return effect;
         }
 
-        private DragDropEffects GetPreferredEffect(DragDropEffects effect, RawInputModifiers modifiers)
+        private static DragDropEffects GetPreferredEffect(DragDropEffects effect, RawInputModifiers modifiers)
         {
             if (effect == DragDropEffects.Copy || effect == DragDropEffects.Move || effect == DragDropEffects.Link || effect == DragDropEffects.None)
                 return effect; // No need to check for the modifiers.

src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs

@@ -295,7 +295,7 @@ namespace Avalonia.Controls.Presenters
                 // arrange then that change wasn't just due to scrolling (as scrolling doesn't adjust
                 // relative positions within Child).
                 if (_anchorElement != null &&
-                    TranslateBounds(_anchorElement, Child!, out var updatedBounds) &&
+                    ScrollContentPresenter.TranslateBounds(_anchorElement, Child!, out var updatedBounds) &&
                     updatedBounds.Position != _anchorElementBounds.Position)
                 {
                     var offset = updatedBounds.Position - _anchorElementBounds.Position;
@@ -588,7 +588,7 @@ namespace Avalonia.Controls.Presenters
 
         private bool GetViewportBounds(IControl element, out Rect bounds)
         {
-            if (TranslateBounds(element, Child!, out var childBounds))
+            if (ScrollContentPresenter.TranslateBounds(element, Child!, out var childBounds))
             {
                 // We want the bounds relative to the new Offset, regardless of whether the child
                 // control has actually been arranged to this offset yet, so translate first to the
@@ -605,7 +605,7 @@ namespace Avalonia.Controls.Presenters
 
         private Rect TranslateBounds(IControl control, IControl to)
         {
-            if (TranslateBounds(control, to, out var bounds))
+            if (ScrollContentPresenter.TranslateBounds(control, to, out var bounds))
             {
                 return bounds;
             }
@@ -613,7 +613,7 @@ namespace Avalonia.Controls.Presenters
             throw new InvalidOperationException("The control's bounds could not be translated to the requested control.");
         }
 
-        private bool TranslateBounds(IControl control, IControl to, out Rect bounds)
+        private static bool TranslateBounds(IControl control, IControl to, out Rect bounds)
         {
             if (!control.IsVisible)
             {

src/Avalonia.Controls/Primitives/AdornerLayer.cs

@@ -211,7 +211,7 @@ namespace Avalonia.Controls.Primitives
                     {
                         child.RenderTransform = new MatrixTransform(info.Bounds.Value.Transform);
                         child.RenderTransformOrigin = new RelativePoint(new Point(0, 0), RelativeUnit.Absolute);
-                        UpdateClip(child, info.Bounds.Value, isClipEnabled);
+                        AdornerLayer.UpdateClip(child, info.Bounds.Value, isClipEnabled);
                         child.Arrange(info.Bounds.Value.Bounds);
                     }
                     else
@@ -232,7 +232,7 @@ namespace Avalonia.Controls.Primitives
             layer?.UpdateAdornedElement(adorner, adorned);
         }
 
-        private void UpdateClip(IControl control, TransformedBounds bounds, bool isEnabled)
+        private static void UpdateClip(IControl control, TransformedBounds bounds, bool isEnabled)
         {
             if (!isEnabled)
             {

src/Avalonia.Controls/Primitives/Popup.cs

@@ -475,7 +475,7 @@ namespace Avalonia.Controls.Primitives
 
             _openState = new PopupOpenState(placementTarget, topLevel, popupHost, cleanupPopup);
 
-            WindowManagerAddShadowHintChanged(popupHost, WindowManagerAddShadowHint);
+            Popup.WindowManagerAddShadowHintChanged(popupHost, WindowManagerAddShadowHint);
 
             popupHost.Show();
 
@@ -639,7 +639,7 @@ namespace Avalonia.Controls.Primitives
             return Disposable.Create((unsubscribe, target, handler), state => state.unsubscribe(state.target, state.handler));
         }
 
-        private void WindowManagerAddShadowHintChanged(IPopupHost host, bool hint)
+        private static void WindowManagerAddShadowHintChanged(IPopupHost host, bool hint)
         {
             if(host is PopupRoot pr && pr.PlatformImpl is not null)
             {

src/Avalonia.Controls/Repeater/RecyclePool.cs

@@ -32,7 +32,7 @@ namespace Avalonia.Controls
 
         public void PutElement(IControl element, string key, IControl? owner)
         {
-            var ownerAsPanel = EnsureOwnerIsPanelOrNull(owner);
+            var ownerAsPanel = RecyclePool.EnsureOwnerIsPanelOrNull(owner);
             var elementInfo = new ElementInfo(element, ownerAsPanel);
 
             if (!_elements.TryGetValue(key, out var pool))
@@ -56,7 +56,7 @@ namespace Avalonia.Controls
                     var elementInfo = elements.FirstOrDefault(x => x.Owner == owner) ?? elements.LastOrDefault();
                     elements.Remove(elementInfo!);
 
-                    var ownerAsPanel = EnsureOwnerIsPanelOrNull(owner);
+                    var ownerAsPanel = RecyclePool.EnsureOwnerIsPanelOrNull(owner);
                     if (elementInfo!.Owner != null && elementInfo.Owner != ownerAsPanel)
                     {
                         // Element is still under its parent. remove it from its parent.
@@ -80,10 +80,10 @@ namespace Avalonia.Controls
             return null;
         }
 
-        internal string GetReuseKey(IControl element) => ((Control)element).GetValue(ReuseKeyProperty);
-        internal void SetReuseKey(IControl element, string value) => ((Control)element).SetValue(ReuseKeyProperty, value);
+        internal static string GetReuseKey(IControl element) => ((Control)element).GetValue(ReuseKeyProperty);
+        internal static void SetReuseKey(IControl element, string value) => ((Control)element).SetValue(ReuseKeyProperty, value);
 
-        private IPanel? EnsureOwnerIsPanelOrNull(IControl? owner)
+        private static IPanel? EnsureOwnerIsPanelOrNull(IControl? owner)
         {
             if (owner is IPanel panel)
             {

src/Avalonia.Controls/Repeater/RecyclingElementFactory.cs

@@ -72,7 +72,7 @@ namespace Avalonia.Controls
                 element = dataTemplate.Build(args.Data)!;
 
                 // Associate ReuseKey with element
-                RecyclePool.SetReuseKey(element, templateKey);
+                Avalonia.Controls.RecyclePool.SetReuseKey(element, templateKey);
             }
 
             return element;
@@ -81,7 +81,7 @@ namespace Avalonia.Controls
         protected override void RecycleElementCore(ElementFactoryRecycleArgs args)
         {
             var element = args.Element!;
-            var key = RecyclePool.GetReuseKey(element);
+            var key = Avalonia.Controls.RecyclePool.GetReuseKey(element);
             RecyclePool.PutElement(element, key, args.Parent);
         }
 

src/Avalonia.Controls/SplitView.cs

@@ -431,7 +431,7 @@ namespace Avalonia.Controls
             }
         }
 
-        private string GetPseudoClass(SplitViewDisplayMode mode)
+        private static string GetPseudoClass(SplitViewDisplayMode mode)
         {
             return mode switch
             {
@@ -463,8 +463,8 @@ namespace Avalonia.Controls
 
         private void OnDisplayModeChanged(AvaloniaPropertyChangedEventArgs e)
         {
-            var oldState = GetPseudoClass(e.GetOldValue<SplitViewDisplayMode>());
-            var newState = GetPseudoClass(e.GetNewValue<SplitViewDisplayMode>());
+            var oldState = SplitView.GetPseudoClass(e.GetOldValue<SplitViewDisplayMode>());
+            var newState = SplitView.GetPseudoClass(e.GetNewValue<SplitViewDisplayMode>());
 
             PseudoClasses.Remove($":{oldState}");
             PseudoClasses.Add($":{newState}");

src/Avalonia.Controls/TextBox.cs

@@ -397,9 +397,9 @@ namespace Avalonia.Controls
                 var selectionStart = SelectionStart;
                 var selectionEnd = SelectionEnd;
 
-                CaretIndex = CoerceCaretIndex(caretIndex, value);
-                SelectionStart = CoerceCaretIndex(selectionStart, value);
-                SelectionEnd = CoerceCaretIndex(selectionEnd, value);
+                CaretIndex = TextBox.CoerceCaretIndex(caretIndex, value);
+                SelectionStart = TextBox.CoerceCaretIndex(selectionStart, value);
+                SelectionEnd = TextBox.CoerceCaretIndex(selectionEnd, value);
 
                 var textChanged = SetAndRaise(TextProperty, ref _text, value);
 
@@ -1380,9 +1380,9 @@ namespace Avalonia.Controls
             }
         }
 
-        private int CoerceCaretIndex(int value) => CoerceCaretIndex(value, Text);
+        private int CoerceCaretIndex(int value) => TextBox.CoerceCaretIndex(value, Text);
 
-        private int CoerceCaretIndex(int value, string? text)
+        private static int CoerceCaretIndex(int value, string? text)
         {
             if (text == null)
             {

src/Avalonia.Controls/TopLevel.cs

@@ -429,7 +429,7 @@ namespace Avalonia.Controls
             LayoutHelper.InvalidateSelfAndChildrenMeasure(this);
         }
 
-        private bool TransparencyLevelsMatch (WindowTransparencyLevel requested, WindowTransparencyLevel received)
+        private static bool TransparencyLevelsMatch (WindowTransparencyLevel requested, WindowTransparencyLevel received)
         {
             if(requested == received)
             {
@@ -449,7 +449,7 @@ namespace Avalonia.Controls
             {
                 if(transparencyLevel == WindowTransparencyLevel.None || 
                     TransparencyLevelHint == WindowTransparencyLevel.None || 
-                    !TransparencyLevelsMatch(TransparencyLevelHint, transparencyLevel))
+                    !TopLevel.TransparencyLevelsMatch(TransparencyLevelHint, transparencyLevel))
                 {
                     _transparencyFallbackBorder.Background = TransparencyBackgroundFallback;
                 }

src/Avalonia.Controls/TreeView.cs

@@ -284,7 +284,7 @@ namespace Avalonia.Controls
 
                     foreach (IControl container in ItemContainerGenerator.Index!.Containers)
                     {
-                        MarkContainerSelected(container, false);
+                        TreeView.MarkContainerSelected(container, false);
                     }
 
                     if (SelectedItems.Count > 0)
@@ -339,7 +339,7 @@ namespace Avalonia.Controls
         {
             var container = ItemContainerGenerator.Index!.ContainerFromItem(item)!;
 
-            MarkContainerSelected(container, selected);
+            TreeView.MarkContainerSelected(container, selected);
         }
 
         private void SelectedItemsAdded(IList items)
@@ -826,7 +826,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="container">The container.</param>
         /// <param name="selected">Whether the control is selected</param>
-        private void MarkContainerSelected(IControl container, bool selected)
+        private static void MarkContainerSelected(IControl container, bool selected)
         {
             if (container == null)
             {

src/Avalonia.Controls/UserControl.cs

@@ -1,4 +1,3 @@
-using System;
 using Avalonia.Styling;
 
 namespace Avalonia.Controls