The 2 implementations can now be switched

Added a bool property DiffView.UseChangeBlocks.
It's not bound from UI yet, but could be used for runtime switching between the two different implementations of prev/next change.
The buttons are now using the OnGoto[Prev|Next]Change Click-handler, regardless of implementation.

Author: goran-w

src/Views/DiffView.axaml.cs

@@ -11,30 +11,48 @@ public DiffView()
             InitializeComponent();
         }
 
+        public bool UseChangeBlocks { get; set; } = true;
+
         private void OnGotoPrevChange(object _, RoutedEventArgs e)
         {
-            var textDiff = this.FindDescendantOfType<ThemedTextDiffPresenter>();
-            if (textDiff == null)
-                return;
+            if (UseChangeBlocks)
+            {
+                if (DataContext is ViewModels.DiffContext diffCtx)
+                    diffCtx.PrevChange();
+            }
+            else
+            {
+                var textDiff = this.FindDescendantOfType<ThemedTextDiffPresenter>();
+                if (textDiff == null)
+                    return;
 
-            textDiff.GotoPrevChange();
-            if (textDiff is SingleSideTextDiffPresenter presenter)
-                presenter.ForceSyncScrollOffset();
+                textDiff.GotoPrevChange();
+                if (textDiff is SingleSideTextDiffPresenter presenter)
+                    presenter.ForceSyncScrollOffset();
 
-            e.Handled = true;
+                e.Handled = true;
+            }
         }
 
         private void OnGotoNextChange(object _, RoutedEventArgs e)
         {
-            var textDiff = this.FindDescendantOfType<ThemedTextDiffPresenter>();
-            if (textDiff == null)
-                return;
+            if (UseChangeBlocks)
+            {
+                if (DataContext is ViewModels.DiffContext diffCtx)
+                    diffCtx.NextChange();
+            }
+            else
+            {
+                var textDiff = this.FindDescendantOfType<ThemedTextDiffPresenter>();
+                if (textDiff == null)
+                    return;
 
-            textDiff.GotoNextChange();
-            if (textDiff is SingleSideTextDiffPresenter presenter)
-                presenter.ForceSyncScrollOffset();
+                textDiff.GotoNextChange();
+                if (textDiff is SingleSideTextDiffPresenter presenter)
+                    presenter.ForceSyncScrollOffset();
 
-            e.Handled = true;
+                e.Handled = true;
+            }
         }
     }
 }