| /******************************************************************************* |
| * Copyright (c) 2009 Oracle. 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: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.common.utility.model.event; |
| |
| import java.util.Collection; |
| |
| import org.eclipse.jpt.common.utility.internal.StringTools; |
| import org.eclipse.jpt.common.utility.internal.iterables.ArrayIterable; |
| import org.eclipse.jpt.common.utility.model.Model; |
| |
| /** |
| * A "collection add" event gets delivered whenever a model adds items to a |
| * "bound" or "constrained" collection. A <code>CollectionAddEvent</code> is sent as an |
| * argument to the {@link org.eclipse.jpt.common.utility.model.listener.CollectionChangeListener}. |
| * <p> |
| * Provisional API: This class is part of an interim API that is still |
| * under development and expected to change significantly before reaching |
| * stability. It is available at this early stage to solicit feedback from |
| * pioneering adopters on the understanding that any code that uses this API |
| * will almost certainly be broken (repeatedly) as the API evolves. |
| */ |
| /* |
| * Design options: |
| * - create a collection to wrap a single added or removed item |
| * (this is the option we implemented below and in collaborating code) |
| * since there is no way to optimize downstream code for |
| * single items, we take another performance hit by building |
| * a collection each time (@see Collections#singleton(Object)) |
| * and forcing downstream code to use an iterator every time |
| * |
| * - fire a separate event for each item added or removed |
| * eliminates any potential for optimizations to downstream code |
| * |
| * - add protocol to support both single items and collections |
| * adds conditional logic to downstream code |
| */ |
| public final class CollectionAddEvent extends CollectionEvent { |
| |
| /** The items added to the collection. */ |
| private final Object[] items; |
| |
| private static final long serialVersionUID = 1L; |
| |
| |
| // ********** constructors ********** |
| |
| /** |
| * Construct a new collection add event. |
| * |
| * @param source The object on which the event initially occurred. |
| * @param collectionName The programmatic name of the collection that was changed. |
| * @param item The item added to the collection. |
| */ |
| public CollectionAddEvent(Model source, String collectionName, Object item) { |
| this(source, collectionName, new Object[] {item}); |
| } |
| |
| /** |
| * Construct a new collection add event. |
| * |
| * @param source The object on which the event initially occurred. |
| * @param collectionName The programmatic name of the collection that was changed. |
| * @param items The items added to the collection. |
| */ |
| public CollectionAddEvent(Model source, String collectionName, Collection<?> items) { |
| this(source, collectionName, items.toArray()); // NPE if 'items' is null |
| } |
| |
| private CollectionAddEvent(Model source, String collectionName, Object[] items) { |
| super(source, collectionName); |
| this.items = items; |
| } |
| |
| |
| // ********** standard state ********** |
| |
| /** |
| * Return the items added to the collection. |
| */ |
| public Iterable<?> getItems() { |
| return new ArrayIterable<Object>(this.items); |
| } |
| |
| /** |
| * Return the number of items added to the collection. |
| */ |
| public int getItemsSize() { |
| return this.items.length; |
| } |
| |
| @Override |
| protected void toString(StringBuilder sb) { |
| super.toString(sb); |
| sb.append(": "); //$NON-NLS-1$ |
| StringTools.append(sb, this.items); |
| } |
| |
| |
| // ********** cloning ********** |
| |
| /** |
| * Return a copy of the event with the specified source |
| * replacing the current source. |
| */ |
| public CollectionAddEvent clone(Model newSource) { |
| return this.clone(newSource, this.collectionName); |
| } |
| |
| /** |
| * Return a copy of the event with the specified source and collection name |
| * replacing the current source and collection name. |
| */ |
| public CollectionAddEvent clone(Model newSource, String newCollectionName) { |
| return new CollectionAddEvent(newSource, newCollectionName, this.items); |
| } |
| |
| } |