GD - Shape.java

package gd;

/**
 * This is a superclass: A shape. Cirlce, Rectangle and Triangle inherit from
 * it.
 * This class was from the beginning defined (by me) as an abstract class. This
 * is because this class should never exist: You can't just add a "shape". It
 * has to be a certain kind of shape (as "shape" doesn't tell you anything about
 * it's properties).
 * A new class has been defines: Coordinate. This holds an x and a y coordinate
 * for the movable classes (making the coordinate set returnable in one state-
 * ment).
 * @author hypesystem
 * @email  [email protected]
 */
public abstract class Shape implements Movable {
    protected Coordinate coordinates;

    /**
     * Creates a Shape.
     * @param coordinates a coordinate object holding the shapes position
     */
    public Shape(Coordinate coordinates) {
        if(coordinates != null) this.coordinates = coordinates;
        else this.coordinates = new Coordinate(0,0);
    }

    /**
     * Returns the area of the shape
     * @return area of shape
     */
    abstract double area();

    /**
     * Returns circumference of shape
     * @return circumference of shape
     */
    abstract double circumference();

    /**
     * Counts simple shapes in the shape
     * @return simple shapes in shape
     */
    abstract int countSimple();

    /**
     * Moves the shape's coordinates. Inherited from Movable interface.
     * @param dx distance to move horizontally
     * @param dy distance to move vertically
     */
    @Override
    public void move(int dx, int dy) {
        if(coordinates != null)
            coordinates.set(coordinates.getX() + dx,coordinates.getY() + dy);
    }

    /**
     * Gets the coordinates of the shape in a Coordinate-object. Inherited from
     * Movable interface
     * @return coordinates of shape
     */
    @Override
    public Coordinate getCoordinate() {
        return coordinates;
    }
}