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Java

Posted by Fatimah Anwar
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Fatimah Anwar
Android Development Techdegree Student 10,416 Points

I need a small help with Java JFrame

I work on my project and I stuck here, I don't understand why I have to hide something to show the error message that associate to calculateButton. if i dont hide any component the error message never appear. I don't know where is the wrong

package com.company;

import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class Main {

    public static void main(String[] args) {

        JFrame frame = new JFrame("Lona");
        JPanel panel = new JPanel();
        JLabel label = new JLabel();
        JTextField textField = new JTextField();
        JButton clickButton = new JButton();
        JButton calculateButton = new JButton();
        JLabel label1 = new JLabel();



        panel.setBackground(Color.decode("#CFB095"));
        panel.setBorder(new EmptyBorder(30, 30, 30, 30));
        frame.getContentPane().add(panel);


        frame.setSize(new Dimension(600, 300));
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setTitle("Lona Salem");
        frame.setResizable(false);

        //sets elements
        label.setText("Please enter the number of courses that you complete in Full 17/18 ");
        label.setFont(new Font("Arial", Font.BOLD, 16));
        label.setBorder(new EmptyBorder(20,0,10,0));
        textField.setPreferredSize(new Dimension(300, 30));
        clickButton.setText("CLICK");
        calculateButton.setText("CALCULATE THE AVAREGE");
        label1.setText("");


        clickButton.addActionListener(new ActionListener() {

            public JLabel headLabel = new JLabel();
            public JTextField nameTextField1;
            public JTextField gradeTextField;
            public JLabel courseNameLabel;
            public JLabel courseGradeLabel;
            public JLabel error;

            @Override
            public void actionPerformed(ActionEvent actionEvent) {

               label.setVisible(false);
               textField.setVisible(false);
               calculateButton.setVisible(false);
               clickButton.setVisible(false);

               headLabel.setText("Enter your courses names and your grades according to SIS");
               headLabel.setFont(new Font("Arial", Font.BOLD, 16));
               headLabel.setBorder(new EmptyBorder(0,0,0,0));
               panel.add(headLabel);

               for( int i = 0 ; i < Integer.parseInt(textField.getText()); i++){

                   nameTextField1 = new JTextField();
                   gradeTextField = new JTextField();
                   courseNameLabel = new JLabel();
                   courseGradeLabel = new JLabel();

                   courseNameLabel.setText("Course name");
                   nameTextField1.setPreferredSize(new Dimension(150,30));
                   courseGradeLabel.setText("Course Grade");
                   gradeTextField.setPreferredSize(new Dimension(150,30));

                   panel.add(courseNameLabel);
                   panel.add(nameTextField1);
                   panel.add(courseGradeLabel);
                   panel.add(gradeTextField);
               }

            }
        });

        calculateButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                label1.setVisible(false);
                JLabel errorLabel = new JLabel();
                errorLabel.setText("Opes .. You must enter your grades first");
                errorLabel.setFont(new Font("Arial", Font.BOLD, 20));
                errorLabel.setForeground(Color.decode("#800000"));
                panel.add(errorLabel);
            }
        });

        //add elements to JPanel
        panel.add(label);
        panel.add(textField);
        panel.add(clickButton);
        panel.add(calculateButton);
        panel.add(label1);

    }
}