Thread: MouseListener

Yeah, here ya go, and thank you.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.text.*;
import java.lang.Math;
 
public class StudentScoresApp	{
    public static void main(String[] args)	    {
 
		System.out.println("  List of Student Scores Entered");
        JFrame frame = new StudentScoresFrame();
        frame.setVisible(true);
    }
 
}
class StudentScoresFrame extends JFrame		{
    public StudentScoresFrame()		{
        setTitle("Test Scores");
        setSize(310, 220);
        centerWindow(this);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new StudentScoresPanel();
        this.add(panel);
 
    }
private void centerWindow(Window w) {
	Toolkit tk = Toolkit.getDefaultToolkit();
	Dimension d = tk.getScreenSize();
	setLocation((d.width-w.getWidth())/2, (d.height-w.getHeight())/2);
	}
}
 class StudentScoresPanel extends JPanel implements ActionListener	{
    private JTextField  scoreTextField,
                        countTextField,
                        averageTextField,
                        bestTextField,
                        lowestTextField;
    private JLabel      scoreLabel,
                        countLabel,
                        averageLabel,
                        bestLabel,
                        lowestLabel;
    private JButton     enterScoreButton,
    					clearButton,
                        exitButton;
 
	private int count = 0;
 
	private double total = 0;
 
	// total is a double to prevent truncation when
	// calculating the average
	private double average = 0;
	private int best = 0;
	private int lowest = 100;
 
    public StudentScoresPanel()	   {
        // display panel
        JPanel displayPanel = new JPanel();
        displayPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
 
 
        // score label
        scoreLabel = new JLabel("Test Score:");
        displayPanel.add(scoreLabel);
 
        // score text field
        scoreTextField = new JTextField(13);
        displayPanel.add(scoreTextField);
		scoreTextField.addMouseListener(new AutoSelect());
 
 
 
        // count label
        countLabel = new JLabel("Number of Scores:");
        displayPanel.add(countLabel);
 
        // count text field
        countTextField = new JTextField(10);
        countTextField.setEditable(false);
        countTextField.setFocusable(false);
        displayPanel.add(countTextField);
 
        // average label
        averageLabel = new JLabel("Average Score:");
        displayPanel.add(averageLabel);
 
        // average text field
        averageTextField = new JTextField(13);
        averageTextField.setEditable(false);
        averageTextField.setFocusable(false);
        displayPanel.add(averageTextField);
 
        // best label
        bestLabel = new JLabel("Highest score:");
        displayPanel.add(bestLabel);
 
        // best text field
        bestTextField = new JTextField(12);
        bestTextField.setEditable(false);
        bestTextField.setFocusable(false);
        displayPanel.add(bestTextField);
 
        // lowest label
        lowestLabel = new JLabel("Lowest score:");
        displayPanel.add(lowestLabel);
 
        // lowest text field
        lowestTextField = new JTextField(10);
        lowestTextField.setEditable(false);
        lowestTextField.setFocusable(false);
        displayPanel.add(lowestTextField);
 
        // button panel
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
 
        // enter score button
        enterScoreButton = new JButton("Enter Score");
        enterScoreButton.addActionListener(this);
        buttonPanel.add(enterScoreButton);
 
        // clear button
        clearButton = new JButton("End/Clear Entries");
        clearButton.addActionListener(this);
        buttonPanel.add(clearButton);
 
        // exit button
        exitButton = new JButton("Exit");
        exitButton.addActionListener(this);
        buttonPanel.add(exitButton);
 
        // add panels to main panel
        this.setLayout(new BorderLayout());
        this.add(displayPanel, BorderLayout.CENTER);
        this.add(buttonPanel, BorderLayout.SOUTH);
    }
 
    public void actionPerformed(ActionEvent e)	{
        Object source = e.getSource();
 
        if (source == exitButton){
        	if (count == 0){
				lowest = 0;}
 
			NumberFormat ef = NumberFormat.getNumberInstance();
            ef = new DecimalFormat("###.00");
			System.out.println("\n  Highest: " + best + "  Lowest: " + lowest + "  Average: " + ef.format(average) + "\n");
 
				System.out.printf("  Program terminated by the User.");
				System.out.printf("\n");
				System.exit(0);
 
            System.exit(0);
		}
      else if (source == enterScoreButton)	{
            // parse the score
            int score = Integer.parseInt(scoreTextField.getText());
            // Validate the number is in proper range
            if (score < 0)
            	JOptionPane.showMessageDialog(null, "The lowest possible score for data entry is 0-Points. Please re-enter.", "Invalid Entry", JOptionPane.ERROR_MESSAGE);
 
			else if (score > 100)
				JOptionPane.showMessageDialog(null, "The highest possible score for data entry is 100-Points. Please re-enter.", "Invalid Entry", JOptionPane.ERROR_MESSAGE);
 
			else
			// calculate the results
            total += score;
            count++;
            average = total / count;
            if (score > best)
            	best = score;
 
            if (score < lowest)
            	lowest = score;
 
			NumberFormat df = NumberFormat.getNumberInstance();
            NumberFormat nf = NumberFormat.getNumberInstance();
            df = new DecimalFormat("###.00");
            countTextField.setText(nf.format(count));
            averageTextField.setText(df.format(average));
            bestTextField.setText(nf.format(best));
            lowestTextField.setText(nf.format(lowest));
            System.out.println("  " + nf.format(count) + ". " + score);
 
        }
        else if (source == clearButton)		{
			if (count == 0)
				lowest = 0;
			NumberFormat df = NumberFormat.getNumberInstance();
            df = new DecimalFormat("###.00");
			System.out.println("\n  Highest: " + best + "  Lowest: " + lowest + "  Average: " + df.format(average) + "\n");
			System.out.println("  Scores were cleared...\n  Next Set:");
			count = 0;
			total = 0;
			average = 0;
			best = 0;
			lowest = 0;
 
            scoreTextField.setText("");
			countTextField.setText("");
            averageTextField.setText("");
            bestTextField.setText("");
            lowestTextField.setText("");
		}
 
    }
 
}
 class AutoSelect extends MouseAdapter {
	public void mouseClicked(MouseEvent e)
			{
				if (e.getComponent() instanceof JTextField)
				{
					JTextField t = (JTextField) e.getComponent();
					t.selectAll();
				}
			}
 
	}