EECS1030Z Test 4

Thursday March 18, 2015, 14:30-15:45
Lab 01
Version G

package test4;

/**
 * A rectangle shape that can be scaled in size. A rectangle is a composition of
 * a Point2D object that stores the coordinates of the upper-right
 * corner of this rectangle.
 * 
 * The bounding box of this rectangle is the rectangular box formed by the
 * bottom-left corner of this rectangle (the Shape's position) and
 * the upper-right corner of this rectangle.
 * 
 * @author EECS1030_2014_15W
 * 
 */
public class ScalableRectangle extends ScalableShape {
  private Point2D oppCorner;

  /**
   * Create a scalable rectangle whose coordinates of the lower-left corner are
   * given by position and the upper-right corner are given by
   * oppCorner.
   * 
   * @param position
   *          the coordinates of the lower-left corner of this rectangle
   * @param oppCorner
   *          the coordinates of the upper-right corner of this rectangle
   * @pre. position.getX() < oppCorner.getX() && position.getY() < oppCorner.getY()
   * 
   */
  public ScalableRectangle(Point2D position, Point2D oppCorner) {
    super(position);
    this.oppCorner = new Point2D(oppCorner);
  }

  /**
   * Get the coordinates of the upper-corner of this rectangle. The coordinates
   * of the upper-corner of this rectangle cannot be changed using the
   * Point2D object returned by this method.
   * 
   * @return the coordinates of the upper-corner of this rectangle
   */
  public Point2D getOppositeCorner() {
    return new Point2D(this.oppCorner);
  }

  /**
   * Get the width of this rectangle. The width of the rectangle is equal to the
   * x coordinate of the upper-right corner minus the x coordinate of the
   * lower-left corner.
   * 
   * @return the width of this rectangle
   */
  public double getWidth() {
    return this.oppCorner.getX() - this.getPosition().getX();
  }

  /**
   * Get the height of this rectangle. The height of the rectangle is equal to
   * the y coordinate of the upper-right corner minus the y coordinate of the
   * lower-left corner.
   * 
   * @return the height of this rectangle
   */
  public double getHeight() {
    return this.oppCorner.getY() - this.getPosition().getY();
  }

  /**
   * Move the rectangle by an amount deltaX in the x direction and
   * an amount deltaY in the y direction. The size of the shape
   * does not change.
   * 
   * The rectangle is moved by moving both its lower-left corner and its
   * upper-right corner.
   * 
   * @param deltaX
   *          the amount to move this rectangle in the x direction
   * @param deltaY
   *          the amount to move this rectangle in the y direction
   */
  @Override
  public void move(double deltaX, double deltaY) {
    super.move(deltaX, deltaY);
    this.oppCorner.setX(this.oppCorner.getX() + deltaX);
    this.oppCorner.setY(this.oppCorner.getY() + deltaY);
  }

  /**
   * Scale the size of this rectangle by the given factor. The
   * width and height of the rectangle change by the given factor.
   * If factor > 1 then the size of the shape increases. If
   * factor < 1 then the size of the shape decreases.
   * 
   * After scaling, the position of this rectangle (its bottom-left corner) does
   * not change.
   * 
   * @param factor
   *          the factor by which to multiply the width and height of this
   *          rectangle
   * @pre. factor > 0
   */
  @Override
  public void scale(double factor) {
    Point2D p = this.getPosition();
    this.move(-p.getX(), -p.getY());
    this.oppCorner.setX(this.getWidth() * factor);
    this.oppCorner.setY(this.getHeight() * factor);
    this.move(p.getX(), p.getY());
  }

  /**
   * Draw this rectangle on the StdDraw instance using the color Color.BLACK.
   * 
   * This method first draws a filled rectangle on the StdDraw instance. This
   * method then draws a filled X in Color.BLUE marking the
   * position of the shape.
   * 
   * @see test4.Shape#draw()
   */
  @Override
  public void draw() {
    StdDraw.setPenColor(StdDraw.BLACK);
    StdDraw.filledRectangle(this.getPosition(), this.getOppositeCorner());
    super.draw();
  }
}

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