abstractiterationstate.java

java 的源代码

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

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.*;

// Referenced classes of package com.reddragon2046.base.utilities.data.collections:
//            IterationState

abstract class AbstractIterationState
    implements IterationState
{

    public abstract Object clone();

    public abstract Iterator getIterator();

    public abstract Collection getCollection();

    public abstract ListIterator getListIterator();

    protected AbstractIterationState(Collection c, Object currentObject, int index)
    {
        if(c == null)
            throw new IllegalArgumentException("Collection cannot be null");
        if(c.size() == 0)
        {
            m_object = null;
            m_index = 0;
            m_atBegin = true;
            m_atEnd = true;
        } else
        {
            m_index = index;
            if(m_index == 0)
                m_atBegin = true;
            else
                m_atBegin = false;
            if(m_index < c.size())
            {
                m_atEnd = false;
                m_object = currentObject;
            } else
            {
                m_atEnd = true;
                m_object = null;
            }
        }
        m_lastDirection = 0;
    }

    protected AbstractIterationState(Collection c, Iterator iterator, int index)
    {
        if(c == null)
            throw new IllegalArgumentException("Collection cannot be null");
        if(iterator == null && index < c.size())
            throw new IllegalArgumentException("Iterator cannot be null, except finish iterator.");
        if(c.size() == 0)
        {
            m_object = null;
            m_index = 0;
            m_atBegin = true;
            m_atEnd = true;
        } else
        {
            m_index = index;
            if(m_index == 0)
                m_atBegin = true;
            else
                m_atBegin = false;
            if(m_index < c.size() && iterator != null && iterator.hasNext())
            {
                m_atEnd = false;
                m_object = iterator.next();
            } else
            {
                m_atEnd = true;
                m_object = null;
            }
        }
        m_lastDirection = 0;
    }

    protected AbstractIterationState(IterationState other)
    {
        m_index = other.getIndex();
        m_object = other.getObject();
        m_atBegin = other.getAtBegin();
        m_atEnd = other.getAtEnd();
        m_lastDirection = other.getLastDirection();
    }

    public String toString()
    {
        StringWriter buf = new StringWriter();
        PrintWriter writer = new PrintWriter(buf);
        writer.print("index=" + m_index + ", dir=" + m_lastDirection + ", atBegin=" + m_atBegin + ", atEnd=" + m_atEnd + ", obj=" + m_object);
        return buf.toString();
    }

    public boolean getAtBegin()
    {
        return m_atBegin;
    }

    public void setAtBegin(boolean atBegin)
    {
        m_atBegin = atBegin;
    }

    public boolean getAtEnd()
    {
        return m_atEnd;
    }

    public void setAtEnd(boolean atEnd)
    {
        m_atEnd = atEnd;
    }

    public int getIndex()
    {
        return m_index;
    }

    public void setIndex(int index)
    {
        int originalIndex = m_index;
        m_index = index;
        int distance = m_index - originalIndex;
        if(distance > 0)
            m_lastDirection = 1;
        else
        if(distance < 0)
            m_lastDirection = -1;
        else
            m_lastDirection = 0;
    }

    public void incrementIndex()
    {
        m_index++;
        m_lastDirection = 1;
    }

    public void decrementIndex()
    {
        m_index--;
        m_lastDirection = -1;
        if(m_index == 0)
            setAtBegin(true);
    }

    public int getLastDirection()
    {
        return m_lastDirection;
    }

    public Object getObject()
    {
        return m_object;
    }

    public void setObject(Object object)
    {
        m_object = object;
    }

    protected boolean m_atBegin;
    protected boolean m_atEnd;
    protected Object m_object;
    protected int m_index;
    protected int m_lastDirection;
}