Point2DDoubleState.java

package ecologylab.serialization.library.geom;

import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;

import ecologylab.serialization.ElementState;
import ecologylab.serialization.annotations.simpl_scalar;

/**
 * Encapsulates a Point2D.Double for use in translating to/from XML.
 * 
 * ***WARNING!!!***
 * 
 * Performing transformations (such as setLocation()) on the result of getPoint() will cause this
 * object to become out of synch with its underlying Point2D. DO NOT DO THIS!
 * 
 * If other transformation methods are required, either notify me, or implement them yourself. :D
 * 
 * Accessor methods (such as contains()) on the result of getPoint() are fine.
 * 
 * @author Zachary O. Toups (zach@ecologylab.net)
 */
public class Point2DDoubleState extends ElementState
{
	private Point2D.Double	point	= null;

	/**
	 * Location and dimensions of the point.
	 */
	protected @simpl_scalar
	double									x			= 0;

	protected @simpl_scalar
	double									y			= 0;

	public Point2DDoubleState()
	{
		super();
	}

	public Point2DDoubleState(double x, double y)
	{
		setLocation(x, y);
	}

	public void setLocation(double x, double y)
	{
		this.x = x;
		this.y = y;
	}

	/**
	 * Returns an Ellipse2D object represented by this.
	 */
	public Point2D.Double point()
	{
		if (point == null)
		{
			point = new Point2D.Double(x, y);
		}
		else if (point.x != x || point.y != y)
		{
			point.setLocation(x, y);
		}

		return point;
	}
	
	public void transform(AffineTransform at)
	{
		this.point();
		
		at.transform(this.point, this.point);
		
		this.x = this.point.x;
		this.y = this.point.y;
	}

	public double x()
	{
		return x;
	}

	public double y()
	{
		return y;
	}
}