Merge pull request #107 from atc-net/feature/Improve-AutoScrollListVi…

…ewBehavior

Feature/improve auto scroll list view behavior

src/Atc.Wpf.Controls/Behaviors/AutoScrollListViewBehavior.cs

@@ -2,7 +2,31 @@ namespace Atc.Wpf.Controls.Behaviors;
 
 public class AutoScrollListViewBehavior : Behavior<ListView>
 {
-    public bool ScrollToBottom { get; set; } = true;
+    public static readonly DependencyProperty ScrollDirectionProperty =
+        DependencyProperty.Register(
+            nameof(ScrollDirection),
+            typeof(ScrollDirectionType),
+            typeof(AutoScrollListViewBehavior),
+            new PropertyMetadata(ScrollDirectionType.Bottom));
+
+    public ScrollDirectionType ScrollDirection
+    {
+        get => (ScrollDirectionType)GetValue(ScrollDirectionProperty);
+        set => SetValue(ScrollDirectionProperty, value);
+    }
+
+    public static readonly DependencyProperty IsEnabledProperty =
+        DependencyProperty.Register(
+            nameof(IsEnabled),
+            typeof(bool),
+            typeof(AutoScrollListViewBehavior),
+            new PropertyMetadata(BooleanBoxes.FalseBox));
+
+    public bool IsEnabled
+    {
+        get => (bool)GetValue(IsEnabledProperty);
+        set => SetValue(IsEnabledProperty, value);
+    }
 
     protected override void OnAttached()
     {
@@ -22,13 +46,18 @@ private void OnCollectionChanged(
         object? sender,
         NotifyCollectionChangedEventArgs e)
     {
+        if (!IsEnabled)
+        {
+            return;
+        }
+
         var listView = AssociatedObject;
         if (listView.Items.Count <= 1)
         {
             return;
         }
 
-        var targetItem = ScrollToBottom
+        var targetItem = ScrollDirection == ScrollDirectionType.Bottom
             ? listView.Items[^1]!
             : listView.Items[0]!;
 

src/Atc.Wpf/Enums/ScrollDirectionType.cs

@@ -0,0 +1,8 @@
+// ReSharper disable CheckNamespace
+namespace Atc.Wpf;
+
+public enum ScrollDirectionType
+{
+    Top,
+    Bottom,
+}

src/Atc.Wpf/Mvvm/ViewModelBase.cs

@@ -3,7 +3,7 @@
 namespace Atc.Wpf.Mvvm;
 
 /// <summary>
-/// A base class for a the ViewModel class, to be used in the MVVM pattern design.
+/// A base class for the ViewModel class, to be used in the MVVM pattern design.
 /// </summary>
 public abstract class ViewModelBase : ObservableObject, IViewModelBase
 {