| /******************************************************************************* |
| * Copyright (c) 2008, 2010 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 |
| * Matthew Hall - bugs 195222, 247997, 265561 |
| * Ovidio Mallo - bug 301774 |
| ******************************************************************************/ |
| |
| package org.eclipse.core.databinding.property.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.set.IObservableSet; |
| import org.eclipse.core.databinding.observable.set.SetDiff; |
| import org.eclipse.core.databinding.property.INativePropertyListener; |
| import org.eclipse.core.databinding.property.ISimplePropertyListener; |
| import org.eclipse.core.internal.databinding.property.set.SimplePropertyObservableSet; |
| |
| /** |
| * Simplified abstract implementation of ISetProperty. This class takes care of |
| * most of the functional requirements for an ISetProperty implementation, |
| * leaving only the property-specific details to subclasses. |
| * <p> |
| * Subclasses must implement these methods: |
| * <ul> |
| * <li> {@link #getElementClass()} |
| * <li> {@link #doGetSet(Object)} |
| * <li> {@link #doSetSet(Object, Set, SetDiff)} |
| * <li> {@link #adaptListener(ISimplePropertyListener)} |
| * </ul> |
| * <p> |
| * In addition, we recommended overriding {@link #toString()} to return a |
| * description suitable for debugging purposes. |
| * |
| * @param <S> |
| * type of the source object |
| * @param <E> |
| * type of the elements in the set |
| * @since 1.2 |
| */ |
| public abstract class SimpleSetProperty<S, E> extends SetProperty<S, E> { |
| public IObservableSet<E> observe(Realm realm, S source) { |
| return new SimplePropertyObservableSet<S, E>(realm, source, this); |
| } |
| |
| // Accessors |
| |
| protected abstract Set<E> doGetSet(S source); |
| |
| // Mutators |
| |
| /** |
| * Updates the property on the source with the specified change. |
| * |
| * @param source |
| * the property source |
| * @param set |
| * the new set |
| * @param diff |
| * a diff describing the change |
| * @noreference This method is not intended to be referenced by clients. |
| */ |
| public final void setSet(S source, Set<E> set, SetDiff<E> diff) { |
| if (source != null && !diff.isEmpty()) |
| doSetSet(source, set, diff); |
| } |
| |
| /** |
| * Updates the property on the source with the specified change. |
| * |
| * @param source |
| * the property source |
| * @param set |
| * the new set |
| * @param diff |
| * a diff describing the change |
| * @noreference This method is not intended to be referenced by clients. |
| */ |
| protected abstract void doSetSet(S source, Set<E> set, SetDiff<E> diff); |
| |
| protected void doSetSet(S source, Set<E> set) { |
| SetDiff<E> diff = Diffs.computeLazySetDiff(doGetSet(source), set); |
| doSetSet(source, set, diff); |
| } |
| |
| protected void doUpdateSet(S source, SetDiff<E> diff) { |
| Set<E> set = new HashSet<E>(doGetSet(source)); |
| diff.applyTo(set); |
| doSetSet(source, set, diff); |
| } |
| |
| // Listeners |
| |
| /** |
| * Returns a listener capable of adding or removing itself as a listener on |
| * a source object using the the source's "native" listener API. Events |
| * received from the source objects are parlayed to the specified listener |
| * argument. |
| * <p> |
| * This method returns null if the source object has no listener APIs for |
| * this property. |
| * |
| * @param listener |
| * the property listener to receive events |
| * @return a native listener which parlays property change events to the |
| * specified listener, or null if the source object has no listener |
| * APIs for this property. |
| * @noreference This method is not intended to be referenced by clients. |
| */ |
| public abstract INativePropertyListener<S> adaptListener( |
| ISimplePropertyListener<SetDiff<E>> listener); |
| } |