SparseIterableArray.java

/*
 * Copyright (C) 2013 Google Inc.
 *
 * 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.
 */

package com.android.utils;

import android.support.v4.util.SparseArrayCompat;

import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * Extension of {@link SparseArrayCompat} that implements {@link Iterable}.
 */
public class SparseIterableArray<T> extends SparseArrayCompat<T> implements Iterable<T> {
    @Override
    public Iterator<T> iterator() {
        return new SparseIterator();
    }

    private class SparseIterator implements Iterator<T> {
        private int mIndex = 0;

        @Override
        public boolean hasNext() {
            return (mIndex < size());
        }

        @Override
        public T next() {
            if (mIndex >= size()) {
                throw new NoSuchElementException();
            }

            return valueAt(mIndex++);
        }

        @Override
        public void remove() {
            if ((mIndex < 0) || (mIndex >= size())) {
                throw new IllegalStateException();
            }

            removeAt(mIndex--);
        }
    }
}