Copyright (c) 2000, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ltk.core.refactoring;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.core.runtime.Assert;

A special set to manage group categories. Group category sets are value objects and are therefore best used as static final fields to share a group category set between n TextEditBasedChangeGroups. 

Note: this class is not intended to be subclassed

Since:
3.2
@noextend
This class is not intended to be subclassed by clients./**
 * A special set to manage group categories. Group category sets are value
 * objects and are therefore best used as static final fields to share a
 * group category set between n {@link TextEditBasedChangeGroup}s.
 * <p>
 * Note: this class is not intended to be subclassed
 * </p>
 *
 * @since 3.2
 *
 * @noextend This class is not intended to be subclassed by clients.
 */
public class GroupCategorySet {

	
Constant representing a group category set containing no
group categories.
/**
	 * Constant representing a group category set containing no
	 * group categories.
	 */
	public static final GroupCategorySet NONE= new GroupCategorySet() {
		@Override
		public boolean contains(GroupCategory category) {
			return false;
		}
		@Override
		public List<GroupCategory> asList() {
			return Collections.emptyList();
		}
	};

	
Creates a new group category set containing the union of the given two
group category sets
Params:
one – the first set of group categories
two – the second set of group categories
Returns:
the union/**
	 * Creates a new group category set containing the union of the given two
	 * group category sets
	 *
	 * @param one the first set of group categories
	 * @param two the second set of group categories
	 *
	 * @return the union
	 */
	public static GroupCategorySet union(GroupCategorySet one, GroupCategorySet two) {
		Assert.isNotNull(one);
		Assert.isNotNull(two);
		// for performance we are using identity here. This is
		// valid since group categories are value objects and
		// therefore best used as static final fields.
		if (one == two)
			return one;
		if (one == NONE)
			return two;
		if (two == NONE)
			return one;

		Set<GroupCategory> combined= new HashSet<>();
		combined.addAll(one.asList());
		combined.addAll(two.asList());
		return new GroupCategorySet(combined);
	}

	private List<GroupCategory> fContent;

	private GroupCategorySet() {
		fContent= Collections.emptyList();
	}

	private GroupCategorySet(Set<GroupCategory> categories) {
		fContent= new ArrayList<>(categories);
	}

	
Creates a new list of group categories initialized
with the given group category.
Params:
category – the first category/**
	 * Creates a new list of group categories initialized
	 * with the given group category.
	 *
	 * @param category the first category
	 */
	public GroupCategorySet(GroupCategory category) {
		Assert.isNotNull(category);
		fContent= new ArrayList<>(1);
		fContent.add(category);
	}

	
Creates a new set of group categories initialized
from the given array of group categories
Params:
categories – the initial group categories/**
	 * Creates a new set of group categories initialized
	 * from the given array of group categories
	 *
	 * @param categories the initial group categories
	 */
	public GroupCategorySet(GroupCategory[] categories) {
		Assert.isNotNull(categories);
		fContent= new ArrayList<>(categories.length);
		for (GroupCategory categorie : categories) {
			if (!fContent.contains(categorie)) {
				fContent.add(categorie);
			}
		}
	}

	
Returns whether the given category is contained
in this set of group categories
Params:
category – the category to test containment for
Returns:
true if the category is contained
 in this set; otherwise false/**
	 * Returns whether the given category is contained
	 * in this set of group categories
	 *
	 * @param category the category to test containment for
	 *
	 * @return <code>true</code> if the category is contained
	 *  in this set; otherwise <code>false</code>
	 */
	public boolean contains(GroupCategory category) {
		return fContent.contains(category);
	}

	
Returns whether one of the given categories is contained
in this set of group categories
Params:
categories – the categories to test containment for
Returns:
true if one of the given categories is
 contained in this set; otherwise false/**
	 * Returns whether one of the given categories is contained
	 * in this set of group categories
	 *
	 * @param categories the categories to test containment for
	 *
	 * @return <code>true</code> if one of the given categories is
	 *  contained in this set; otherwise <code>false</code>
	 */
	public boolean containsOneCategory(List<GroupCategory> categories) {
		for (GroupCategory category : categories) {
			if(contains(category))
				return true;
		}
		return false;
	}

	
Converts the group categories into a a unmodifiable
list.
Returns:
an unmodifiable list containing all group
 categories/**
	 * Converts the group categories into a a unmodifiable
	 * list.
	 *
	 * @return an unmodifiable list containing all group
	 *  categories
	 */
	public List<GroupCategory> asList() {
		return Collections.unmodifiableList(fContent);
	}
}