fix: DataGrid does NOT scroll when navigation target is the same as current selected in Views.Histories. (#58)

Author: love-linger

src/ViewModels/Histories.cs

@@ -61,6 +61,12 @@ public Models.Commit AutoSelectedCommit
             private set => SetProperty(ref _autoSelectedCommit, value);
         }
 
+        public long NavigationId
+        {
+            get => _navigationId;
+            private set => SetProperty(ref _navigationId, value);
+        }
+
         public object DetailContext
         {
             get => _detailContext;
@@ -98,6 +104,7 @@ public void NavigateTo(string commitSHA)
             if (commit != null)
             {
                 AutoSelectedCommit = commit;
+                NavigationId = _navigationId + 1;
 
                 if (_detailContext is CommitDetail detail)
                 {
@@ -597,6 +604,7 @@ private void FillTagMenu(ContextMenu menu, Models.Tag tag)
         private List<Models.Commit> _commits = new List<Models.Commit>();
         private Models.CommitGraph _graph = null;
         private Models.Commit _autoSelectedCommit = null;
+        private long _navigationId = 0;
         private object _detailContext = null;
     }
 }

src/Views/Histories.axaml.cs

@@ -3,6 +3,7 @@
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Primitives;
+using Avalonia.Data;
 using Avalonia.Media;
 using Avalonia.VisualTree;
 
@@ -258,9 +259,31 @@ private void DrawCurves(DrawingContext context, double top, double bottom)
 
     public partial class Histories : UserControl
     {
+        public static readonly StyledProperty<long> NavigationIdProperty =
+            AvaloniaProperty.Register<Histories, long>(nameof(NavigationId), 0);
+
+        public long NavigationId
+        {
+            get => GetValue(NavigationIdProperty);
+            set => SetValue(NavigationIdProperty, value);
+        }
+
+        static Histories()
+        {
+            NavigationIdProperty.Changed.AddClassHandler<Histories>((h, _) =>
+            {
+                // Force scroll selected item (current head) into view. see issue #58
+                var datagrid = h.commitDataGrid;
+                if (datagrid != null && datagrid.SelectedItems.Count == 1)
+                    datagrid.ScrollIntoView(datagrid.SelectedItems[0], null);
+            });
+        }
+
         public Histories()
         {
             InitializeComponent();
+
+            this.Bind(NavigationIdProperty, new Binding("NavigationId", BindingMode.OneWay));
         }
 
         private void OnCommitDataGridLayoutUpdated(object sender, EventArgs e)