Resolve generics inheritance conflicts for JavaFX21+ and avoid reflection

Author: anishthecoder

modules/core/org.eclipse.fx.core/src/main/java/org/eclipse/fx/core/collection/internal/VirtualObservableList.java

@@ -12,8 +12,6 @@
  *******************************************************************************/
 package org.eclipse.fx.core.collection.internal;
 
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.OptionalLong;
@@ -104,6 +102,37 @@ public void moveBy(long delta) {
 			// TODO need to handle long overflow
 			this.index.set(Math.max(0, this.index.get() + delta));
 		}
+
+		// Overrides to resolve diamond inheritance conflicts with JavaFX 21+ default methods
+		@Override
+		public javafx.beans.value.ObservableValue<T> when(javafx.beans.value.ObservableValue<Boolean> condition) {
+			return super.when(condition);
+		}
+
+		@Override
+		public javafx.util.Subscription subscribe(java.util.function.Consumer<? super T> subscriber) {
+			return super.subscribe(subscriber);
+		}
+
+		@Override
+		public javafx.util.Subscription subscribe(java.util.function.BiConsumer<? super T, ? super T> subscriber) {
+			return super.subscribe(subscriber);
+		}
+
+		@Override
+		public <U> javafx.beans.value.ObservableValue<U> map(java.util.function.Function<? super T, ? extends U> mapper) {
+			return super.map(mapper);
+		}
+
+		@Override
+		public javafx.beans.value.ObservableValue<T> orElse(T value) {
+			return super.orElse(value);
+		}
+
+		@Override
+		public <U> javafx.beans.value.ObservableValue<U> flatMap(java.util.function.Function<? super T, ? extends javafx.beans.value.ObservableValue<? extends U>> mapper) {
+			return super.flatMap(mapper);
+		}
 	}
 
 	class ListViewImpl extends ObservableListBase<T> implements IndexRangeView<T> {
@@ -119,9 +148,7 @@ public ListViewImpl(long startIndex, int length) {
 			FXObservableUtil.onInvalidate(this.length, v -> updateList());
 			FXObservableUtil.onInvalidate(VirtualObservableList.this.list, o -> updateList());
 
-			this.listener = (c) -> {
-				fireChange(new SourceChangeEvent<T>(this, c));
-			};
+			this.listener = (c) -> fireChange(new SourceChangeEvent<T>(this, c));
 			this.data.addListener(this.listener);
 			updateList();
 		}
@@ -134,7 +161,7 @@ private void updateList() {
 						(int) Math.min(_endIndex() + 1, VirtualObservableList.this.list.size())));
 			}
 
-			// Fill up the reset of the list
+			// Fill up the rest of the list
 			if (list.size() < size()) {
 				for (int i = list.size(); i < size(); i++) {
 					list.add(null);
@@ -209,22 +236,30 @@ public T get(int index) {
 		public int size() {
 			return this.length.get();
 		}
+
+		// Overrides to resolve diamond inheritance conflicts with JavaFX 21+ default methods
+		@Override
+		public javafx.collections.transformation.FilteredList<T> filtered(java.util.function.Predicate<T> predicate) {
+			return super.filtered(predicate);
+		}
+
+		@Override
+		public javafx.collections.transformation.SortedList<T> sorted(java.util.Comparator<T> comparator) {
+			return super.sorted(comparator);
+		}
+
+		@Override
+		public javafx.collections.transformation.SortedList<T> sorted() {
+			return super.sorted();
+		}
 	}
 
 	static class SourceChangeEvent<T> extends ListChangeListener.Change<T> {
 		private final Change<? extends T> change;
-		private final Method getPermutation;
 
 		public SourceChangeEvent(ObservableList<T> list, Change<? extends T> change) {
 			super(list);
 			this.change = change;
-			try {
-				// TODO We should use MethodHandles
-				this.getPermutation = ListChangeListener.Change.class.getDeclaredMethod("getPermutation"); //$NON-NLS-1$
-				this.getPermutation.setAccessible(true);
-			} catch (NoSuchMethodException | SecurityException e) {
-				throw new IllegalStateException(e);
-			}
 		}
 
 		@Override
@@ -255,11 +290,18 @@ public List<T> getRemoved() {
 
 		@Override
 		protected int[] getPermutation() {
-			try {
-				return (int[]) this.getPermutation.invoke(this.change);
-			} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
-				throw new IllegalStateException(e);
+			// Use the public getPermutation(int) method instead of reflection
+			// to access the protected getPermutation() method
+			if (!this.change.wasPermutated()) {
+				return new int[0];
+			}
+			int from = this.change.getFrom();
+			int to = this.change.getTo();
+			int[] perm = new int[to - from];
+			for (int i = from; i < to; i++) {
+				perm[i - from] = this.change.getPermutation(i);
 			}
+			return perm;
 		}
 
 		@Override