// Note: this is a slightly backwards way of maintaining the shape
// objects. It is carefully designed to keep the visible shape interfaces
// in this project clean and simple for educational purposes.
public void draw(Object referenceObject, String color, Shape shape) {
objects.remove(referenceObject); // just in case it was already there
objects.add(referenceObject); // add at the end
shapes.put(referenceObject, new ShapeDescription(shape, color));
redraw();
}
/**
* Erase a given shape's from the screen.
*
* @param referenceObject the shape object to be erased
*/
public void erase(Object referenceObject) {
objects.remove(referenceObject); // just in case it was already there
shapes.remove(referenceObject);
redraw();
}