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Thread: Help with ExitButtonHandler

  1. #1
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    Default Help with ExitButtonHandler

    Im trying to make a program so that the user has to enter a number for the width and length and it will give the area and perimeter:


    import java.util.* ;

    import javax.swing.*;

    import java.awt.*;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;



    public class jframe extends JFrame {

    private static final int WIDTH = 400;
    private static final int HEIGHT = 300;

    private JLabel lengthL, widthL, areaL, perimeterL;
    private JTextField lengthTF, widthTF, areaTF, perimeterTF;

    private CalculateButtonHandler cbHandler;
    private ExitButtonHandler ebHandler;

    private JButton calculateB, exitB;

    public jframe () {

    lengthTF = new JTextField(10);
    widthTF = new JTextField(10);
    areaTF = new JTextField(10);
    perimeterTF = new JTextField(10);

    lengthL = new JLabel ("Enter the length: ", SwingConstants.RIGHT);
    widthL = new JLabel ("Enter the width: ", SwingConstants.RIGHT);
    areaL = new JLabel ("Area = ", SwingConstants.RIGHT);
    perimeterL = new JLabel ("Perimeter = ", SwingConstants.RIGHT);

    calculateB = new JButton("Calculate");
    cbHandler = new CalculateButtonHandler();
    calculateB.addActionListener(cbHandler);

    exitB = new JButton("Exit");
    ebHandler = new ExitButtonHandler();
    exitB.addActionListener(ebHandler);


    Container pane = getContentPane();
    pane.setLayout(new GridLayout (5,2));
    pane.add(lengthL);
    pane.add(lengthTF);
    pane.add(widthL);
    pane.add(widthTF);
    pane.add(areaL);
    pane.add(areaTF);
    pane.add(perimeterL);
    pane.add(perimeterTF);
    pane.add(calculateB);
    pane.add(exitB);

    setTitle("Area and perimeter of rectangle");
    setSize(WIDTH,HEIGHT);
    setVisible(true);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    private class CalculateButtonHandler implements ActionListener{

    public void actionPerformed(ActionEvent e) {
    double width, length, area, perimeter;

    length = Double.parseDouble(lengthTF.getText());
    width = Double.parseDouble(widthTF.getText());
    area = length*width;
    perimeter = 2 *(length+width);

    areaTF.setText("" + area);
    perimeterTF.setText("" + perimeter);


    }

    private class ExitButtonHandler implements ActionListener{

    public void actionPerformed(ActionEvent e) {
    System.exit(0);
    }

    }


    }

    public static void main (String [] args){

    jframe rectObject = new jframe();


    }

    }

    It is giving me an error saying that the ExitButtonHandler and ebHandler do not have classes but I don't understand why. Any help would be awesome on how to make this better.


  2. #2
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    Default Re: Help with ExitButtonHandler

    Welcome to the forum! Please read this topic to learn how to post code in code or highlight tags and other useful info for new members.

    Please post your code correctly. You can edit your post and fix it.

    Class ExitButtonHandler is a private inner class of CalculateButtonHandler which is a private inner class of jframe. (Java's naming convention is that class names begin with capital letters, variables and method names begin with lowercase letters. Please follow Java's naming convention.) Move ExitButtonHandler outside CalculateButtonHandler, and that error should go away.