bundles/org.eclipse.core.databinding.property/src/org/eclipse/core/databinding/property/set/SetProperty.java

/*******************************************************************************
 * 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 (bug 194734)
 *     Matthew Hall - bug 195222
 ******************************************************************************/

package org.eclipse.core.databinding.property.set;

import java.util.Collections;
import java.util.Set;

import org.eclipse.core.databinding.observable.Diffs;
import org.eclipse.core.databinding.observable.IObservable;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.masterdetail.IObservableFactory;
import org.eclipse.core.databinding.observable.masterdetail.MasterDetailObservables;
import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.core.databinding.observable.set.SetDiff;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.core.databinding.property.map.IMapProperty;
import org.eclipse.core.databinding.property.value.IValueProperty;
import org.eclipse.core.internal.databinding.identity.IdentitySet;
import org.eclipse.core.internal.databinding.property.SetPropertyDetailValuesMap;

/**
 * Abstract implementation of ISetProperty
 * 
 * @since 1.2
 */
public abstract class SetProperty implements ISetProperty {
	/**
	 * @since 1.3
	 */
	public final Set getSet(Object source) {
		if (source == null) {
			return Collections.EMPTY_SET;
		}
		return Collections.unmodifiableSet(doGetSet(source));
	}

	/**
	 * Returns a Set with the current contents of the source's set property
	 * 
	 * @param source
	 *            the property source
	 * @return a Set with the current contents of the source's set property
	 * @since 1.3
	 * @noreference This method is not intended to be referenced by clients.
	 */
	protected Set doGetSet(Object source) {
		IObservableSet observable = observe(source);
		try {
			return new IdentitySet(observable);
		} finally {
			observable.dispose();
		}
	}

	/**
	 * @since 1.3
	 */
	public final void setSet(Object source, Set set) {
		if (source != null) {
			doSetSet(source, set);
		}
	}

	/**
	 * Updates the property on the source with the specified change.
	 * 
	 * @param source
	 *            the property source
	 * @param set
	 *            the new set
	 * @since 1.3
	 * @noreference This method is not intended to be referenced by clients.
	 */
	protected void doSetSet(Object source, Set set) {
		doUpdateSet(source, Diffs.computeSetDiff(doGetSet(source), set));
	}

	/**
	 * @since 1.3
	 */
	public final void updateSet(Object source, SetDiff diff) {
		if (source != null && !diff.isEmpty()) {
			doUpdateSet(source, diff);
		}
	}

	/**
	 * Updates the property on the source with the specified change.
	 * 
	 * @param source
	 *            the property source
	 * @param diff
	 *            a diff describing the change
	 * @since 1.3
	 * @noreference This method is not intended to be referenced by clients.
	 */
	protected void doUpdateSet(Object source, SetDiff diff) {
		IObservableSet observable = observe(source);
		try {
			diff.applyTo(observable);
		} finally {
			observable.dispose();
		}
	}

	public IObservableSet observe(Object source) {
		return observe(Realm.getDefault(), source);
	}

	public IObservableFactory setFactory() {
		return new IObservableFactory() {
			public IObservable createObservable(Object target) {
				return observe(target);
			}
		};
	}

	public IObservableFactory setFactory(final Realm realm) {
		return new IObservableFactory() {
			public IObservable createObservable(Object target) {
				return observe(realm, target);
			}
		};
	}

	public IObservableSet observeDetail(IObservableValue master) {
		return MasterDetailObservables.detailSet(master, setFactory(master
				.getRealm()), getElementType());
	}

	public final IMapProperty values(IValueProperty detailValues) {
		return new SetPropertyDetailValuesMap(this, detailValues);
	}
}