Sunlo

GRAPHICAL USER INTERFACE : CANVAS CLASS: import javax.swing.*; import java.awt.*; import java.util.List; import java.util.*; /**  * Canvas is a class to allow for simple graphical drawing on a canvas.  * This is a modification of the general purpose Canvas, specially made for  * the BlueJ "shapes" example.   *  * @author: Bruce Quig  * @author: Michael Kšlling (mik)  *  * @version 2011.07.31  */ public class Canvas {     // Note: The implementation of this class (specifically the handling of     // shape identity and colors) is slightly more complex than necessary. This     // is done on purpose to keep the interface and instance fields of the     // shape objects in this project clean and simple for educational purposes.     private static Canvas canvasSingleton;     /**      * Factory method to get t...