make SparseArray can be used in enhanced-for

SparseArrayUtils.java

import java.util.Iterator;

import android.util.SparseArray;

public class SparseArrayUtils {

    private static abstract class IndexIterator<IterType, Type> implements Iterator<IterType> {
        protected int mIndex = 0;
        protected SparseArray<Type> mArray;

        public IndexIterator(SparseArray<Type> array) {
            mArray = array;
        }

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

        @Override
        public void remove() {
            mArray.removeAt(mIndex);
        }
    }

    public static class Entry<Type> {
        final int key;
        final Type value;

        Entry(int key, Type value) {
            this.key = key;
            this.value = value;
        }
    }

    private static <IterType> Iterable<IterType> createIterable(final Iterator<IterType> iter) {
        return new Iterable<IterType>() {
            @Override
            public Iterator<IterType> iterator() {
                return iter;
            }
        };
    }

    public static <Type> Iterable<Type> values(SparseArray<Type> array) {
        return createIterable(new IndexIterator<Type, Type>(array) {
            @Override
            public Type next() {
                return mArray.valueAt(mIndex++);
            }
        });
    }

    public static <Type> Iterable<Integer> keys(SparseArray<Type> array) {
        return createIterable(new IndexIterator<Integer, Type>(array) {
            @Override
            public Integer next() {
                return mArray.keyAt(mIndex++);
            }
        });
    }

    public static <Type> Iterable<Entry<Type>> entries(SparseArray<Type> array) {
        return createIterable(new IndexIterator<Entry<Type>, Type>(array) {
            @Override
            public Entry<Type> next() {
                Entry<Type> e = new Entry<Type>(mArray.keyAt(mIndex), mArray.valueAt(mIndex));
                mIndex++;
                return e;
            }
        });
    }
}