primefield.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 javax.swing.JTextField;
import java.awt.event.*;

public class PrimeField  extends JTextField implements ActionListener  {
     private Driver driver;

	/**	pre:    m != null
	 *	post:   driver == d
     *          and  getX() == x   and   getY() == y
     *          and  getWidth() == 60   and   getHeight() == 25 
     */
    public PrimeField( int x, int y, Driver d )  {
    	super();
        setBounds(x, y, 60, 25);
        addActionListener(this);
        driver = d;
    }

	/** pre:    driver != null
	 *	post:   the displayFactors method from driver is performed
     *          upon the intValue of this. 
     */
	public void actionPerformed( ActionEvent e )   {
        driver.displayPrimes( (new Integer(getText())).intValue() );
	}
}