EECS1030Z Test 4

Wednesday March 17, 2015, 14:30-15:45
Lab 02
Version C

package test4;

import java.awt.Color;
import java.util.ArrayList;
import java.util.List;

/**
 * A rectangle that changes color every time it is drawn. A
 * ColorChangingRectangle is a composition of a list of colors.
 * 
 * 

 * The first time that the rectangle is drawn, it is drawn using the first color
 * in its list of colors. The second time the rectangle is drawn, it is drawn
 * using the second color in its list of colors. This continues until the last
 * color in its list of colors is used to draw the rectangle; the cycle of
 * colors then repeats starting from the first color in the list.
 * 
 * @author EECS1030_2014_15W
 * 
 */
public class ColorChangingRectangle extends Rectangle {

	private List colors;
	private int currentColor;

	/**
	 * Constructs a rectangle whose bottom-left corner is given by
	 * position and its top-right corner is given by
	 * oppCorner. The initial color of the rectangle is
	 * Color.BLUE.
	 * 
	 * @param position
	 *            the coordinates of the bottom-left corner of the rectangle
	 * @param oppCorner
	 *            the coordinates of the top-right corner of the rectangle
	 */
	public ColorChangingRectangle(Point2D position, Point2D oppCorner) {
		super(position, oppCorner);
		this.colors = new ArrayList();
		this.colors.add(Color.BLUE);
		this.currentColor = -1;
	}

	/**
	 * Returns a list of colors that are used to draw this rectangle. Modifying
	 * the list returned by this method does not modify the list of
	 * colors used to draw this rectangle.
	 * 
	 * @return a list of colors that are used to draw this rectangle
	 */
	public List getColors() {
		return new ArrayList(this.colors);
	}

	/**
	 * Get the current color of the rectangle, assuming that the
	 * rectangle has already been drawn at least once. The current
	 * color is the color that was most recently used to draw the rectangle.
	 * 
	 * @pre. draw() has already been invoked for this rectangle
	 * @return the current color of the rectangle
	 */
	public Color getCurrentColor() {
		return this.colors.get(this.currentColor);
	}
	
	/**
	 * Get the next color of the rectangle. The next color is the color of
	 * the rectangle that the next invocation of draw()
	 * will produce (assuming that addColor is not
	 * invoked before the next invocation of draw). 
	 * 
	 * @return the color that the next invocation of draw()
	 * will use to draw this rectangle
	 */
	public Color getNextColor() {
		return this.colors.get((this.currentColor + 1) % this.colors.size());
	}

	private Color nextColor() {
		this.currentColor++;
		this.currentColor %= this.colors.size();
		return this.getCurrentColor();
	}

	/**
	 * Add a color to the end of the list of colors for this rectangle.
	 * 
	 * @param c the color to add
	 */
	public void addColor(Color c) {
		this.colors.add(c);
	}

	/**
	 * Draws a filled rectangle using the next color of the rectangle.
	 * Use the method StdDraw.setPenColor(Color) to change
	 * the pen color used by the StdDraw object. 
	 * 
	 * @see test4.Rectangle#draw()
	 */
	@Override
	public void draw() {
		StdDraw.setPenColor(this.getNextColor());
		super.draw();
		this.nextColor();
	}


}

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