rotatefigure.java

国外的数据结构与算法分析用书

import dslib.exception.*;

/**	A Figure with rotation capabilities */
public class RotateFigure extends Figure
{
	/**	Constructor for the rotating figure
		Analysis : Time = O(1) */
	public RotateFigure(String x)
	{
		super(x);
	}

	/**	Rotate the figure deg degrees counter-clockwise. 
		Analysis: time = O(number of parts to the figure) */
	public void rotate(int deg)
	{
		parts.goFirst();
		while (!parts.after())
		{
			Shape item = (Shape) parts.item();
			if (item instanceof Rectangle)
			{
				Rectangle c = (Rectangle)item;
				/*	Code to rotate a rectangle. */
			}
			else if (item instanceof Circle)
			{
				Circle r = (Circle)item;
				/*	Code to rotate a circle. */
			}
			else if (item instanceof Square)
			{
				Square s = (Square)item;
				/*	Code to rotate a square. */
			}
				parts.goForth();
		}
	}
}