/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.

 */

package com.oracle.solaris.vp.util.swing;

import java.util.*;

import javax.swing.ListModel;

import javax.swing.event.*;

import com.oracle.solaris.vp.util.misc.CollectionUtil;

import com.oracle.solaris.vp.util.misc.predicate.*;

import com.oracle.solaris.vp.util.swing.event.ListDataListeners;

/**

 * The {@code FilteredListModel} class applies a {@link Predicate} filter to a

 * {@code Collection} to produce the contents of a {@code ListModel}.

 */

public class FilteredListModel<T> implements ListModel {

    //

    // Instance data

    //

    private ListDataListeners listeners = new ListDataListeners();

    private Collection<T> items;

    private List<T> filtered = Collections.emptyList();

    private Predicate<T> predicate;

    //

    // Constructors

    //

    /**

     * Constructs a {@code FilteredListModel} for the given items and filter.

     * Note: the behavior of this class is undefined if the given {@code

     * Collection} changes after this object's construction.

     *

     * @param	    items

     *		    the unfiltered data {@code Collection}

     *

     * @param	    predicate

     *		    an initial filter to apply, or {@code null} to apply no

     *		    filter

     */

    public FilteredListModel(Collection<T> items, Predicate<T> predicate) {

	this.items = items;

	setPredicate(predicate);

    }

    /**

     * Constructs a {@code FilteredListModel} for the given items and no filter.

     *

     * @param	    items

     *		    the unfiltered data {@code Collection}

     */

    public FilteredListModel(Collection<T> items) {

	this(items, null);

    }

    //

    // ListModel methods

    //

    @Override

    public void addListDataListener(ListDataListener l) {

	listeners.add(l);

    }

    @Override

    public T getElementAt(int index) {

	return filtered.get(index);

    }

    @Override

    public int getSize() {

	return filtered.size();

    }

    @Override

    public void removeListDataListener(ListDataListener l) {

	listeners.remove(l);

    }

    //

    // FilteredListModel methods

    //

    protected void fireContentsChanged(int start, int end) {

	ListDataEvent event = new ListDataEvent(this,

	    ListDataEvent.CONTENTS_CHANGED, start, end);

	listeners.contentsChanged(event);

    }

    protected void fireIntervalAdded(int start, int end) {

	ListDataEvent event = new ListDataEvent(this,

	    ListDataEvent.INTERVAL_ADDED, start, end);

	listeners.intervalAdded(event);

    }

    protected void fireIntervalRemoved(int start, int end) {

	ListDataEvent event = new ListDataEvent(this,

	    ListDataEvent.INTERVAL_REMOVED, start, end);

	listeners.intervalRemoved(event);

    }

    protected List<T> getFiltered() {

	return Collections.unmodifiableList(filtered);

    }

    protected ListDataListeners getListeners() {

	return listeners;

    }

    /**

     * Gets the {@link Predicate} applied to the data {@code Collection} for

     * this {@code FilteredListModel}.

     *

     * @return	    a {@link Predicate}, or {@code null} if no filter is applied

     */

    public Predicate<T> getPredicate() {

	return predicate;

    }

    /**

     * Sets the {@link Predicate} to apply to the data {@code Collection} for

     * this {@code FilteredListModel}.

     *

     * @param	    predicate

     *		    a {@link Predicate}, or {@code null} if no filter should be

     *		    applied

     */

    public void setPredicate(Predicate<T> predicate) {

	this.predicate = predicate;

	if (predicate == null) {

	    predicate = TruePredicate.getInstance();

	}

	int size = filtered.size();

	if (size > 0) {

	    filtered = Collections.emptyList();

	    fireIntervalRemoved(0, size - 1);

	}

	filtered = CollectionUtil.filter(items, predicate);

	size = filtered.size();

	if (size > 0) {

	    fireIntervalAdded(0, size - 1);

	}

    }

}