code_style: it's not necessary to make GetLines virtual

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Views/TextDiffView.axaml.cs

@@ -478,11 +478,6 @@ public ThemedTextDiffPresenter(TextArea area, TextDocument doc) : base(area, doc
             TextArea.TextView.LineTransformers.Add(_lineStyleTransformer);
         }
 
-        public virtual List<Models.TextDiffLine> GetLines()
-        {
-            return [];
-        }
-
         public virtual void UpdateSelectedChunk(double y)
         {
         }
@@ -745,6 +740,17 @@ protected void TrySetChunk(ViewModels.TextDiffSelectedChunk chunk)
                 SetCurrentValue(SelectedChunkProperty, chunk);
         }
 
+        private List<Models.TextDiffLine> GetLines()
+        {
+            if (DataContext is ViewModels.CombinedTextDiff combined)
+                return combined.Data.Lines;
+
+            if (DataContext is ViewModels.TwoSideTextDiff twoSides)
+                return IsOld ? twoSides.Old : twoSides.New;
+
+            return [];
+        }
+
         private void UpdateTextMate()
         {
             if (UseSyntaxHighlighting)
@@ -883,13 +889,6 @@ public class CombinedTextDiffPresenter : ThemedTextDiffPresenter
             TextArea.LeftMargins.Add(new LineModifyTypeMargin());
         }
 
-        public override List<Models.TextDiffLine> GetLines()
-        {
-            if (DataContext is ViewModels.CombinedTextDiff { Data: { } diff })
-                return diff.Lines;
-            return [];
-        }
-
         public override void UpdateSelectedChunk(double y)
         {
             if (DataContext is not ViewModels.CombinedTextDiff { Data: { } diff } combined)
@@ -1062,13 +1061,6 @@ public class SingleSideTextDiffPresenter : ThemedTextDiffPresenter
             TextArea.LeftMargins.Add(new LineModifyTypeMargin());
         }
 
-        public override List<Models.TextDiffLine> GetLines()
-        {
-            if (DataContext is ViewModels.TwoSideTextDiff diff)
-                return IsOld ? diff.Old : diff.New;
-            return [];
-        }
-
         public override void UpdateSelectedChunk(double y)
         {
             if (DataContext is not ViewModels.TwoSideTextDiff diff)