indexbasedbidirectionaliterator.java

来自「java 的源代码」· Java 代码 · 共 53 行

package com.reddragon2046.base.utilities.data.collections;

import java.util.NoSuchElementException;

// Referenced classes of package com.reddragon2046.base.utilities.data.collections:
//            IndexBasedForwardIterator, AbstractIndexBasedIterator, AbstractIteratorAdapter, IterationState

class IndexBasedBidirectionalIterator extends IndexBasedForwardIterator
{

    public IndexBasedBidirectionalIterator(IterationState state)
    {
        super(state);
    }

    public boolean hasPrevious()
    {
        return !atBegin();
    }

    public Object previous()
    {
        if(!atBegin())
        {
            retreat();
            return get();
        } else
        {
            throw new NoSuchElementException();
        }
    }

    public void add(Object obj)
    {
        throw new UnsupportedOperationException();
    }

    public int nextIndex()
    {
        return getInternalIndex() + 1;
    }

    public int previousIndex()
    {
        return getInternalIndex() - 1;
    }

    public void set(Object obj)
    {
        throw new UnsupportedOperationException();
    }
}