Merge branch 'feature/selectionmodel' into feature/selectionmodel-changed-notifications

src/Avalonia.Controls/ISelectionModel.cs

@@ -0,0 +1,47 @@
+// This source file is adapted from the WinUI project.
+// (https://github.com/microsoft/microsoft-ui-xaml)
+//
+// Licensed to The Avalonia Project under MIT License, courtesy of The .NET Foundation.
+
+using System;
+using System.Collections.Generic;
+
+namespace Avalonia.Controls
+{
+    public interface ISelectionModel
+    {
+        IndexPath AnchorIndex { get; set; }
+        IndexPath SelectedIndex { get; set; }
+        IReadOnlyList<IndexPath> SelectedIndices { get; }
+        object SelectedItem { get; }
+        IReadOnlyList<object> SelectedItems { get; }
+        bool SingleSelect { get; set; }
+        object Source { get; set; }
+
+        event EventHandler<SelectionModelChildrenRequestedEventArgs> ChildrenRequested;
+        event EventHandler<SelectionModelSelectionChangedEventArgs> SelectionChanged;
+
+        void ClearSelection();
+        void Deselect(int index);
+        void Deselect(int groupIndex, int itemIndex);
+        void DeselectAt(IndexPath index);
+        void DeselectRange(IndexPath start, IndexPath end);
+        void DeselectRangeFromAnchor(int index);
+        void DeselectRangeFromAnchor(int endGroupIndex, int endItemIndex);
+        void DeselectRangeFromAnchorTo(IndexPath index);
+        void Dispose();
+        bool? IsSelected(int index);
+        bool? IsSelected(int groupIndex, int itemIndex);
+        bool? IsSelectedAt(IndexPath index);
+        void Select(int index);
+        void Select(int groupIndex, int itemIndex);
+        void SelectAll();
+        void SelectAt(IndexPath index);
+        void SelectRange(IndexPath start, IndexPath end);
+        void SelectRangeFromAnchor(int index);
+        void SelectRangeFromAnchor(int endGroupIndex, int endItemIndex);
+        void SelectRangeFromAnchorTo(IndexPath index);
+        void SetAnchorIndex(int index);
+        void SetAnchorIndex(int groupIndex, int index);
+    }
+}

src/Avalonia.Controls/SelectionModel.cs

@@ -13,7 +13,7 @@ using Avalonia.Controls.Utils;
 
 namespace Avalonia.Controls
 {
-    public class SelectionModel : INotifyPropertyChanged, IDisposable
+    public class SelectionModel : ISelectionModel, INotifyPropertyChanged, IDisposable
     {
         private readonly SelectionNode _rootNode;
         private bool _singleSelect;
@@ -97,7 +97,6 @@ namespace Avalonia.Controls
             }
         }
 
-
         public IndexPath AnchorIndex
         {
             get
@@ -316,7 +315,7 @@ namespace Avalonia.Controls
                     _selectedIndicesCached = indices;
                 }
 
-                return _selectedIndicesCached; 
+                return _selectedIndicesCached;
             }
         }
 
@@ -594,7 +593,7 @@ namespace Avalonia.Controls
 
             RaisePropertyChanged(nameof(SelectedIndex));
             RaisePropertyChanged(nameof(SelectedIndices));
-            
+
             if (_rootNode.Source != null)
             {
                 RaisePropertyChanged(nameof(SelectedItem));
@@ -610,7 +609,7 @@ namespace Avalonia.Controls
             }
 
             var selected = _rootNode.Select(index, select);
-            
+
             if (selected)
             {
                 AnchorIndex = new IndexPath(index);
@@ -626,7 +625,7 @@ namespace Avalonia.Controls
 
             var childNode = _rootNode.GetAt(groupIndex, realizeChild: true);
             var selected = childNode!.Select(itemIndex, select);
-            
+
             if (selected)
             {
                 AnchorIndex = new IndexPath(groupIndex, itemIndex);
@@ -636,7 +635,7 @@ namespace Avalonia.Controls
         private void SelectWithPathImpl(IndexPath index, bool select)
         {
             bool selected = false;
-            
+
             if (_singleSelect)
             {
                 ClearSelection(resetAnchor: true);
@@ -665,7 +664,7 @@ namespace Avalonia.Controls
         {
             int anchorIndex = 0;
             var anchor = AnchorIndex;
-            
+
             if (anchor != null)
             {
                 anchorIndex = anchor.GetAt(0);
@@ -679,7 +678,7 @@ namespace Avalonia.Controls
             var startGroupIndex = 0;
             var startItemIndex = 0;
             var anchorIndex = AnchorIndex;
-            
+
             if (anchorIndex != null)
             {
                 startGroupIndex = anchorIndex.GetAt(0);