SortedList.java

/*
 * Copyright 2013 serso aka se.solovyev
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * ---------------------------------------------------------------------
 * Contact details
 *
 * Email: se.solovyev@gmail.com
 * Site:  http://se.solovyev.org
 */

package org.solovyev.common.collections;

import javax.annotation.Nonnull;
import java.util.*;

public class SortedList<T> implements List<T> {

    @Nonnull
    private final Comparator<? super T> comparator;
    @Nonnull
    private List<T> list = new ArrayList<T>();

    private SortedList(@Nonnull Comparator<? super T> comparator) {
        this.comparator = comparator;
    }

    private SortedList(@Nonnull List<T> list, @Nonnull Comparator<? super T> comparator) {
        this.list = list;
        this.comparator = comparator;
    }

    @Nonnull
    public static <T> SortedList<T> newInstance(@Nonnull Comparator<? super T> comparator) {
        return new SortedList<T>(comparator);
    }

    @Nonnull
    public static <T> SortedList<T> newInstance(@Nonnull List<T> list, @Nonnull Comparator<? super T> comparator) {
        return new SortedList<T>(list, comparator);
    }

    @Override
    public int size() {
        return list.size();
    }

    @Override
    public boolean isEmpty() {
        return list.isEmpty();
    }

    @Override
    public boolean contains(Object o) {
        return list.contains(o);
    }

    @Nonnull
    @Override
    public Iterator<T> iterator() {
        final Iterator<T> it = list.iterator();
        return new Iterator<T>() {
            @Override
            public boolean hasNext() {
                return it.hasNext();
            }

            @Override
            public T next() {
                return it.next();
            }

            @Override
            public void remove() {
                it.remove();
                // todo serso: think
                sort();
            }
        };
    }

    @Nonnull
    @Override
    public Object[] toArray() {
        return list.toArray();
    }

    @Nonnull
    @Override
    public <T> T[] toArray(@Nonnull T[] a) {
        return list.toArray(a);
    }

    @Override
    public boolean add(T t) {
        boolean result = list.add(t);
        sort();
        return result;
    }

    @Override
    public boolean remove(Object o) {
        boolean result = list.remove(o);
        sort();
        return result;
    }

    @Override
    public boolean containsAll(@Nonnull Collection<?> c) {
        return this.list.containsAll(c);
    }

    @Override
    public boolean addAll(@Nonnull Collection<? extends T> c) {
        boolean result = this.list.addAll(c);
        sort();
        return result;
    }

    @Override
    public boolean addAll(int index, @Nonnull Collection<? extends T> c) {
        boolean result = this.list.addAll(index, c);
        sort();
        return result;
    }

    @Override
    public boolean removeAll(@Nonnull Collection<?> c) {
        boolean result = this.list.removeAll(c);
        sort();
        return result;
    }

    @Override
    public boolean retainAll(@Nonnull Collection<?> c) {
        boolean result = this.list.retainAll(c);
        sort();
        return result;
    }

    @Override
    public void clear() {
        this.list.clear();
    }

    @Override
    public T get(int index) {
        return this.list.get(index);
    }

    @Override
    public T set(int index, T element) {
        T result = this.list.set(index, element);
        sort();
        return result;
    }

    @Override
    public void add(int index, T element) {
        this.list.add(index, element);
        sort();
    }

    @Override
    public T remove(int index) {
        T result = this.list.remove(index);
        sort();
        return result;
    }

    @Override
    public int indexOf(Object o) {
        return this.list.indexOf(o);
    }

    @Override
    public int lastIndexOf(Object o) {
        return this.list.lastIndexOf(o);
    }

    @Nonnull
    @Override
    public ListIterator<T> listIterator() {
        return listIterator(0);
    }

    @Nonnull
    @Override
    public ListIterator<T> listIterator(int index) {
        final ListIterator<T> it = this.list.listIterator(index);
        return new ListIterator<T>() {
            @Override
            public boolean hasNext() {
                return it.hasNext();
            }

            @Override
            public T next() {
                return it.next();
            }

            @Override
            public boolean hasPrevious() {
                return it.hasPrevious();
            }

            @Override
            public T previous() {
                return it.previous();
            }

            @Override
            public int nextIndex() {
                return it.nextIndex();
            }

            @Override
            public int previousIndex() {
                return it.previousIndex();
            }

            @Override
            public void remove() {
                it.remove();
                sort();
            }

            @Override
            public void set(T t) {
                it.set(t);
                sort();
            }

            @Override
            public void add(T t) {
                it.add(t);
                sort();
            }
        };
    }

    public void sort() {
        Collections.sort(list, comparator);
    }

    @Nonnull
    @Override
    public List<T> subList(int fromIndex, int toIndex) {
        return this.list.subList(fromIndex, toIndex);
    }
}