| /******************************************************************************* |
| * Copyright (c) 2006, 2017 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| * Stefan Xenos <sxenos@gmail.com> - Bug 335792 |
| *******************************************************************************/ |
| |
| package org.eclipse.core.databinding.observable.set; |
| |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| import org.eclipse.core.databinding.observable.Diffs; |
| import org.eclipse.core.databinding.observable.Realm; |
| import org.eclipse.core.databinding.observable.list.IListChangeListener; |
| import org.eclipse.core.databinding.observable.list.IObservableList; |
| import org.eclipse.core.databinding.observable.list.ListDiffEntry; |
| |
| /** |
| * Observable set backed by an observable list. The wrapped list must not |
| * contain duplicate elements. |
| * |
| * <p> |
| * This class is thread safe. All state accessing methods must be invoked from |
| * the {@link Realm#isCurrent() current realm}. Methods for adding and removing |
| * listeners may be invoked from any thread. |
| * </p> |
| * |
| * @param <E> |
| * the type of elements in the collection |
| * @since 1.0 |
| * |
| */ |
| public class ListToSetAdapter<E> extends ObservableSet<E> { |
| |
| private final IObservableList<E> list; |
| |
| private IListChangeListener<E> listener = event -> { |
| Set<E> added = new HashSet<>(); |
| Set<E> removed = new HashSet<>(); |
| ListDiffEntry<? extends E>[] differences = event.diff.getDifferences(); |
| for (ListDiffEntry<? extends E> entry : differences) { |
| E element = entry.getElement(); |
| if (entry.isAddition()) { |
| if (wrappedSet.add(element)) { |
| if (!removed.remove(element)) |
| added.add(element); |
| } |
| } else if (wrappedSet.remove(element)) { |
| removed.add(element); |
| added.remove(element); |
| } |
| } |
| fireSetChange(Diffs.createSetDiff(added, removed)); |
| }; |
| |
| /** |
| * @param list the list to adapt |
| */ |
| public ListToSetAdapter(IObservableList<E> list) { |
| super(list.getRealm(), new HashSet<E>(), list.getElementType()); |
| this.list = list; |
| wrappedSet.addAll(list); |
| this.list.addListChangeListener(listener); |
| } |
| |
| @Override |
| public synchronized void dispose() { |
| super.dispose(); |
| if (list != null && listener != null) { |
| list.removeListChangeListener(listener); |
| listener = null; |
| } |
| } |
| |
| } |