| /******************************************************************************* |
| * Copyright (c) 2008 Matthew Hall and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * Matthew Hall - initial API and implementation (bug 215531) |
| * Matthew Hall - bug 230267 |
| ******************************************************************************/ |
| |
| package org.eclipse.jface.internal.databinding.viewers; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.Set; |
| |
| import org.eclipse.core.databinding.observable.Diffs; |
| import org.eclipse.core.databinding.observable.Realm; |
| import org.eclipse.core.databinding.observable.set.AbstractObservableSet; |
| import org.eclipse.core.databinding.observable.set.IObservableSet; |
| import org.eclipse.core.databinding.observable.set.WritableSet; |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.jface.viewers.IElementComparer; |
| import org.eclipse.jface.viewers.StructuredViewer; |
| |
| /** |
| * An {@link IObservableSet} of elements in a {@link StructuredViewer}. |
| * Elements of the set are compared using an {@link IElementComparer} instead of |
| * {@link #equals(Object)}. |
| * <p> |
| * This class is <i>not</i> a strict implementation the {@link IObservableSet} |
| * interface. It intentionally violates the {@link Set} contract, which requires |
| * the use of {@link #equals(Object)} when comparing elements. This class is |
| * designed for use with {@link StructuredViewer} which uses |
| * {@link IElementComparer} for element comparisons. |
| * |
| * |
| * @since 1.2 |
| */ |
| public class ObservableViewerElementSet extends AbstractObservableSet { |
| private Set wrappedSet; |
| private Object elementType; |
| private IElementComparer comparer; |
| |
| /** |
| * Constructs an ObservableViewerElementSet on the given {@link Realm} which |
| * uses the given {@link IElementComparer} to compare elements. |
| * |
| * @param realm |
| * the realm of the constructed set. |
| * @param elementType |
| * the element type of the constructed set. |
| * @param comparer |
| * the {@link IElementComparer} used to compare elements. |
| */ |
| public ObservableViewerElementSet(Realm realm, Object elementType, |
| IElementComparer comparer) { |
| super(realm); |
| |
| Assert.isNotNull(comparer); |
| this.wrappedSet = new ViewerElementSet(comparer); |
| this.elementType = elementType; |
| this.comparer = comparer; |
| } |
| |
| protected Set getWrappedSet() { |
| return wrappedSet; |
| } |
| |
| public Object getElementType() { |
| return elementType; |
| } |
| |
| public Iterator iterator() { |
| getterCalled(); |
| final Iterator wrappedIterator = wrappedSet.iterator(); |
| return new Iterator() { |
| Object last; |
| |
| public boolean hasNext() { |
| getterCalled(); |
| return wrappedIterator.hasNext(); |
| } |
| |
| public Object next() { |
| getterCalled(); |
| return last = wrappedIterator.next(); |
| } |
| |
| public void remove() { |
| getterCalled(); |
| wrappedIterator.remove(); |
| fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, |
| Collections.singleton(last))); |
| } |
| }; |
| } |
| |
| public boolean add(Object o) { |
| getterCalled(); |
| boolean changed = wrappedSet.add(o); |
| if (changed) |
| fireSetChange(Diffs.createSetDiff(Collections.singleton(o), |
| Collections.EMPTY_SET)); |
| return changed; |
| } |
| |
| public boolean addAll(Collection c) { |
| getterCalled(); |
| Set additions = new ViewerElementSet(comparer); |
| for (Iterator iterator = c.iterator(); iterator.hasNext();) { |
| Object element = iterator.next(); |
| if (wrappedSet.add(element)) |
| additions.add(element); |
| } |
| boolean changed = !additions.isEmpty(); |
| if (changed) |
| fireSetChange(Diffs.createSetDiff(additions, Collections.EMPTY_SET)); |
| return changed; |
| } |
| |
| public boolean remove(Object o) { |
| getterCalled(); |
| boolean changed = wrappedSet.remove(o); |
| if (changed) |
| fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, |
| Collections.singleton(o))); |
| return changed; |
| } |
| |
| public boolean removeAll(Collection c) { |
| getterCalled(); |
| Set removals = new ViewerElementSet(comparer); |
| for (Iterator iterator = c.iterator(); iterator.hasNext();) { |
| Object element = iterator.next(); |
| if (wrappedSet.remove(element)) |
| removals.add(element); |
| } |
| boolean changed = !removals.isEmpty(); |
| if (changed) |
| fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removals)); |
| return changed; |
| } |
| |
| public boolean retainAll(Collection c) { |
| getterCalled(); |
| Set removals = new ViewerElementSet(comparer); |
| Object[] toRetain = c.toArray(); |
| outer: for (Iterator iterator = wrappedSet.iterator(); iterator |
| .hasNext();) { |
| Object element = iterator.next(); |
| // Cannot rely on c.contains(element) because we must compare |
| // elements using IElementComparer. |
| for (int i = 0; i < toRetain.length; i++) { |
| if (comparer.equals(element, toRetain[i])) |
| continue outer; |
| } |
| iterator.remove(); |
| removals.add(element); |
| } |
| boolean changed = !removals.isEmpty(); |
| if (changed) |
| fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removals)); |
| return changed; |
| } |
| |
| public void clear() { |
| getterCalled(); |
| if (!wrappedSet.isEmpty()) { |
| Set removals = wrappedSet; |
| wrappedSet = new ViewerElementSet(comparer); |
| fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removals)); |
| } |
| } |
| |
| /** |
| * Returns an {@link IObservableSet} for holding viewer elements, using the |
| * given {@link IElementComparer} for comparisons. |
| * |
| * @param realm |
| * the realm of the returned observable |
| * @param elementType |
| * the element type of the returned set |
| * @param comparer |
| * the element comparer to use in element comparisons (may be |
| * null). If null, the returned set will compare elements |
| * according to the standard contract for {@link Set} interface |
| * contract. |
| * @return a Set for holding viewer elements, using the given |
| * {@link IElementComparer} for comparisons. |
| */ |
| public static IObservableSet withComparer(Realm realm, Object elementType, |
| IElementComparer comparer) { |
| if (comparer == null) |
| return new WritableSet(realm, Collections.EMPTY_SET, elementType); |
| return new ObservableViewerElementSet(realm, elementType, comparer); |
| } |
| } |