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writing_classes_practice [2022/10/01 12:59] frchriswriting_classes_practice [2022/10/01 14:45] (current) – [Writing Classes Practice] frchris
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 ====== Writing Classes Practice ====== ====== Writing Classes Practice ======
 +
 +These are designed to be done with an actual computer.  You would need to write the class from scratch and use the Tester class to see how your work is progressing.  Usually when you write a class for a Quiz, Test, or Exam, the task will be simpler (since you have no computer).  You learn a lot by finding and fixing mistakes yourself on a computer, which is why this is such great practice.
  
 ===== Clock ===== ===== Clock =====
  
    - The Clock class should have three fields: hours minutes and seconds    - The Clock class should have three fields: hours minutes and seconds
-   - There should be a constructor that takes three values and initialize the fields +   - There should be a constructor that takes three values and initializes the fields 
-   - There should be a ''toString'' so that it returns a string with the current time.  (For example "12:52:34"+   - There should be a ''toString'' method so that it returns a string with the current time.  (For example "12:52:34"
    - There should be a method called ''tick'' that advances the seconds by one and sees if the minutes and hours need to be changed.  For example, if the current time is 11:59:59, after the method is called, the time should become "12:00:00";    - There should be a method called ''tick'' that advances the seconds by one and sees if the minutes and hours need to be changed.  For example, if the current time is 11:59:59, after the method is called, the time should become "12:00:00";
  
 <code java ClockTester.java> <code java ClockTester.java>
-import+import java.awt.Color; 
 +import java.awt.Font; 
 +import java.awt.Graphics; 
 +import java.awt.event.ActionEvent; 
 +import java.awt.event.ActionListener; 
 +import java.awt.event.KeyEvent; 
 +import java.awt.event.KeyListener; 
 +import javax.swing.JFrame; 
 +import javax.swing.JPanel; 
 +import javax.swing.Timer; 
 + 
 +public class ClockTester extends JPanel implements  ActionListener 
 +
 + public static int WIDTH=800; 
 + public static int HEIGHT=600; 
 + private Font titleFont, regularFont, clockFont; 
 + private int x; 
 + private Timer motion, pulse; 
 +    private Clock clock; 
 + 
 + public ClockTester()  
 +
 + 
 + //initialize variables here... 
 + titleFont = new Font("Roman", Font.BOLD, 18); 
 + clockFont = new Font("Roman", Font.BOLD, 72); 
 + regularFont = new Font("Helvetica", Font.PLAIN, 12); 
 + x=0; 
 + motion = new Timer(2, this); //1000=1 seconds 
 + pulse = new Timer(1000, this); //1000=1 seconds 
 + clock =new Clock(11, 59, 50); 
 +  
 + motion.start(); 
 + pulse.start(); 
 + 
 +
 + public static void main(String[] args) { 
 + ClockTester app= new ClockTester(); 
 + JFrame window = new JFrame("Clock Tester"); 
 + window.setSize(WIDTH, HEIGHT); 
 + window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
 + window.getContentPane().add(app); 
 + window.setVisible(true); 
 + 
 +
 + public void paintComponent(Graphics g){ 
 + super.paintComponent(g); 
 + g.setColor(Color.WHITE); 
 + g.fillRect(0, 0, getWidth(),getHeight()); 
 + g.setColor(Color.BLUE); 
 + g.setFont(titleFont); 
 + g.drawString("Clock Tester", 20, 20); 
 + g.setColor(Color.BLACK); 
 + g.setFont(regularFont); 
 + //g.drawString("pulse = "+x, 20, 40); 
 + g.fillOval(x, 200, 10, 10); 
 + g.setColor(Color.RED); 
 + g.setFont(clockFont); 
 + g.drawString(clock.toString(), getWidth()/3, getHeight()/2); 
 +  
 + 
 +
 +  
 +  
 + public void actionPerformed(ActionEvent e) { 
 + 
 +      if (e.getSource()==motion){ 
 +     x=(x+1)%WIDTH; 
 +      
 +      } else { 
 +     // call the tick method 
 +     clock.tick(); 
 +      } 
 +      repaint(); 
 +
 + 
 +}
 </code> </code>
  
writing_classes_practice.1664643553.txt.gz · Last modified: 2022/10/01 12:59 by frchris

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