void addShape(Shape shape) {
// Add the shape to the canvas, and set its size/position and color.
// The shape is added at the top-left corner, with size 80-by-50.
// Then redraw the canvas to show the newly added shape.
shape.setColor(currentColor);
shape.reshape(3, 3, 80, 50);
shapes.add(shape);
repaint();
}
/**
* On click, if a shape has been clicked, change its color to the Drawing object's current set
* color.
*/
public void executeClick(Point p, Drawing dwg) {
Shape clickedShape = dwg.getFrontmostContainer(p);
if (clickedShape != null) clickedShape.setColor(dwg.getColor());
}