/*******************************************************************************
 * Copyright (c) 2006-2008 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *     Brad Reynolds - bug 147515
 *     Matthew Hall - bug 221351
 *******************************************************************************/

module org.eclipse.core.databinding.observable.set.WritableSet;

import java.lang.all;

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import org.eclipse.core.databinding.observable.Diffs;
import org.eclipse.core.databinding.observable.Realm;

/**
 * Mutable (writable) implementation of {@link IObservableSet}.
 * 
 * <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>
 * 
 * @since 1.0
 */
public class WritableSet : ObservableSet {

    /**
     * Constructs a new empty instance in the default realm with a
     * <code>null</code> element type.
     * 
     */
    public this() {
        this(Realm.getDefault());
    }

    /**
     * Constructs a new instance in the default realm containing the
     * elements of the given collection. Changes to the given collection after
     * calling this method do not affect the contents of the created WritableSet.
     * 
     * @param c
     * @param elementType
     *            can be <code>null</code>
     */
    public this(Collection c, Object elementType) {
        this(Realm.getDefault(), new HashSet(c), elementType);
    }

    /**
     * Constructs a new empty instance in the given realm and a
     * <code>null</code> element type.
     * 
     * @param realm
     */
    public this(Realm realm) {
        this(realm, new HashSet(), null);
    }

    /**
     * Constructs a new instance in the default realm with the given element
     * type, containing the elements of the given collection. Changes to the
     * given collection after calling this method do not affect the contents of
     * the created WritableSet.
     * 
     * @param realm
     * @param c
     * @param elementType
     *            can be <code>null</code>
     */
    public this(Realm realm, Collection c, Object elementType) {
        super(realm, new HashSet(c), elementType);
        this.elementType = elementType;
    }

    public bool add(Object o) {
        getterCalled();
        bool added = wrappedSet.add(o);
        if (added) {
            fireSetChange(Diffs.createSetDiff(Collections.singleton(o), Collections.EMPTY_SET));
        }
        return added;
    }

    public bool addAll(Collection c) {
        getterCalled();
        Set additions = new HashSet();
        Iterator it = c.iterator();
        while (it.hasNext()) {
            Object element = it.next();
            if (wrappedSet.add(element)) {
                additions.add(element);
            }
        }
        if (additions.size() > 0) {
            fireSetChange(Diffs.createSetDiff(additions, Collections.EMPTY_SET));
            return true;
        }
        return false;
    }

    public bool remove(Object o) {
        getterCalled();
        bool removed = wrappedSet.remove(o);
        if (removed) {
            fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, Collections
                    .singleton(o)));
        }
        return removed;
    }

    public bool removeAll(Collection c) {
        getterCalled();
        Set removes = new HashSet();
        Iterator it = c.iterator();
        while (it.hasNext()) {
            Object element = it.next();
            if (wrappedSet.remove(element)) {
                removes.add(element);
            }
        }
        if (removes.size() > 0) {
            fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removes));
            return true;
        }
        return false;
    }

    public bool retainAll(Collection c) {
        getterCalled();
        Set removes = new HashSet();
        Iterator it = wrappedSet.iterator();
        while (it.hasNext()) {
            Object element = it.next();
            if (!c.contains(element)) {
                it.remove();
                removes.add(element);
            }
        }
        if (removes.size() > 0) {
            fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removes));
            return true;
        }
        return false;
    }

    public void clear() {
        getterCalled();
        Set removes = new HashSet(wrappedSet);
        wrappedSet.clear();
        fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removes));
    }

    /**
     * @param elementType can be <code>null</code>
     * @return new instance with the default realm
     */
    public static WritableSet withElementType(Object elementType) {
        return new WritableSet(Realm.getDefault(), new HashSet(), elementType);
    }
}