driver.java

Java程序设计(美) David D. Riley著 机械工业出版社 书籍配套 代码

import java.awt.*;

/**	Author: David D. Riley
 *		Date: Jan, 2005
 *   Coffee Cup Program (Figure 4.29)
 */
	
public class Driver extends ThreeButtons  {
	private ThreeButtonFrame  window;
	private Container redCup, blueCup;

	/** post:	a window is created 
     *			and  redCup is repositioned at the top center of window
     *			and  blueCup is repositioned at the bottom center of window 
	 */
	public Driver()   {
		window = new ThreeButtonFrame( "Move the Cups" );
        window.setVisible(true);
		window.setLayout(null);
        window.setBackground(Color.white);
		redCup = newCup(Color.red);
		window.add(redCup, 0);
		blueCup = newCup(Color.blue);
		window.add(blueCup, 0);
		midAction();
	}
	
	/** post:	result is a new Container with a coffee cup colored c on top
     *			and  result.getWidth() == 40   and   result.getHeight() == 20 
	 */
	private  Container  newCup(Color c)   {
		Container background, cupBackground;
		Oval cup, handle, handleCenter, top;
		background = new Container();
		background.setBounds(0, 0, 40, 20);
		handle = new Oval(28, 1, 8, 13);
		handle.setBackground(c);
		handleCenter = new Oval(2, 2, 4, 9);
		handleCenter.setBackground(Color.white);
		handle.add(handleCenter, 0);
        background.add(handle, 0);
		cupBackground = new Container();
        cupBackground.setBounds(0, 5, 30, 15);
		cup = new Oval(0, -18, 30, 35);
		cup.setBackground(c);
        cupBackground.add(cup, 0);
        background.add(cupBackground, 0);
		top = new Oval(0, 1, 30, 6);
        background.add(top, 0);
		return background;
	}
		
	
	/**	pre:	redCup instantiated  and  blueCup instantiated	
	 *	post:	redCup.getY() == redCup.getY()@pre + 5
     *          and  blueCup.getY() == blueCup.getY()@pre - 5 
	 */
	public  void  leftAction()   {
		int newX, newY;
		newX = redCup.getX();
		newY = redCup.getY() + 5;
		redCup.setLocation(newX, newY);
		redCup.repaint();
		newX = blueCup.getX();
		newY = blueCup.getY() - 5;
		blueCup.setLocation(newX, newY);
		blueCup.repaint();
	}

	/**	pre:	redCup instantiated  and  blueCup instantiated	
	 *	post:	redCup is repositioned at the top center of window
	 *			and  blueCup is repositioned at the bottom center of window 
	 */
	public  void  midAction()   {
		redCup.setLocation(280, 30);
		redCup.repaint();
		blueCup.setLocation(280, 400);
		blueCup.repaint();
	}
	
	/**	pre:	redCup instantiated  and  blueCup instantiated	
	 *	post:	redCup.getX() == redCup.getX()@pre - 10
	 *			and  blueCup.getX() == blueCup.getX()@pre + 10 
	 */
	public  void  rightAction()   {
		int newX, newY;
		newX = redCup.getX() - 10;
		newY = redCup.getY();
		redCup.setLocation(newX, newY);
		redCup.repaint();
		newX = blueCup.getX() + 10;
		newY = blueCup.getY();
		blueCup.setLocation(newX, newY);
		blueCup.repaint();
	}
}