JTextArea seems to be invisible

Question

Hi,
Java programming is not my strength. However, I've been required to develop a design package of late. I've been updating the GUI to combine several programs into a tabbed pane layout. However, the JTextArea I want ot use to display the results of my claculations wont appear. Is any one able to help?
I've attached the two sets of code involved in this problem.
package frontend;
import javax.swing.*; //imported for buttons, labels, and images
import java.awt.*;
import java.awt.event.*;
import javax.swing.text.*;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;
import java.text.*;
public class Distill extends JPanel
    // Create Layout
    GridBagLayout layout;
    GridBagConstraints constraints;
    // Create Initial Variables
    double Finitial = 267583.3482;
    double dFinitial = 0.0;
    double Dinitial = 36703.45493;
    double dDinitial = 0.0;
    double dtinitial = 0.0;
    double Rinitial = 0.369514598;
    double Mwfinitial = 175.6623;
    double Ninitial = 12;
    double Pdinitial = 306;
    double Pbinitial = 321.3;
    double Fvinitial = 52355.3606;
    double Flinitial = 15357.0823;
    double RHOvinitial = 7.6287;
    double RHOlinitial = 632.4401;
    double PSinitial = 0.55;
    double PFinitial = 80;
    double DAinitial = 12;
    double Hainitial = 10;
    double Hwinitial = 0.05;
    double Dhinitial = 0.005;
    double Ptinitial = 0.005;
    double tdinitial = 70;
    double Wuinitial = 0.05;
    double Wcinitial = 0.05;
    // Buttons
    private JButton CalculateButton;
    // Create Text Fields
    private JFormattedTextField FField;
    private JFormattedTextField dFField;
    private JFormattedTextField DField;
    private JFormattedTextField dDField;
    private JFormattedTextField dtField;
    private JFormattedTextField RField;
    private JFormattedTextField MwfField;
    private JFormattedTextField NField;
    private JFormattedTextField PdField;
    private JFormattedTextField PbField;
    private JFormattedTextField FvField;
    private JFormattedTextField FlField;
    private JFormattedTextField RHOvField;
    private JFormattedTextField RHOlField;
    private JFormattedTextField PSField;
    private JFormattedTextField PFField;
    private JFormattedTextField DAField;
    private JFormattedTextField HaField;
    private JFormattedTextField HwField;
    private JFormattedTextField DhField;
    private JFormattedTextField PtField;
    private JFormattedTextField tdField;
    private JFormattedTextField WuField;
    private JFormattedTextField WcField;
    // Number Formats
    private NumberFormat amountFormat;
    public Distill()                                                            // Constructor Information
        // Layout Setup      
        layout = new GridBagLayout();
        setLayout( layout );
        setBackground(Color.white);
        constraints = new GridBagConstraints();
        // Initialize Buttons       
        CalculateButton = new JButton("Calculate");
        addComponent(CalculateButton, 12, 2, 1, 1);
        // Create Button Handler       
        ButtonHandler calculate = new ButtonHandler();
        CalculateButton.addActionListener( calculate );
        // Create Labels
        // Input Labels
        JLabel InputLabel = new JLabel(" << Required Input Variables>> ");
        JLabel FLabel = new JLabel("Feed Flow (kg/h)");
        JLabel DLabel = new JLabel("Distillate Flowrate (kg/h)");
        JLabel dtLabel = new JLabel("time over which change occurs (s)");
        JLabel MwfLabel = new JLabel ("Molecular Weight of Feed (kg/kmol)"); 
        JLabel NLabel = new JLabel ("Number of Real Stages");
        JLabel PdLabel = new JLabel ("Top Pressure (kPa)");
        JLabel PbLabel = new JLabel ("Bottom Pressure (kPa)");
        JLabel FvLabel = new JLabel ("Vapor Flowrate (kg/h)");
        JLabel FlLabel = new JLabel ("Liquid Flowrate (kg/h)");
        JLabel RHOvLabel = new JLabel ("Vapor Density (kg/m3)");
        JLabel RHOlLabel = new JLabel ("Liquid Density (kg/m3)");
        JLabel PSLabel = new JLabel ("Plate Spacing (m)");
        JLabel PFLabel = new JLabel ("Percent Flooding");
        JLabel DALabel = new JLabel ("Downcomer Area as a percentage of plate area ");
        JLabel HALabel = new JLabel ("Hole Active Area Percentage 6, 8 or 10 %" );
        JLabel HwLabel = new JLabel (" Weir Height (m)");
        JLabel DhLabel = new JLabel (" Hole Diameter (m)");
        JLabel PtLabel = new JLabel (" Plate Thickness (m)");
        JLabel tdLabel = new JLabel (" Percent Turndown");
        JLabel WuLabel = new JLabel (" Unperforated Strip Width (m)");
        JLabel WcLabel = new JLabel (" Calming Zone Width (m)");
        JLabel DyLabel = new JLabel (" <<< Dynamic Operation Variables >>>");
        JLabel dFLabel = new JLabel("Change in Feed Flow (kg/h)");
        JLabel dDLabel = new JLabel("Change in Distillate Flowrate (kg/h)");
        JLabel RLabel = new JLabel("Reflux Ratio");
        // Add Labels
        addComponent(InputLabel,1,0,1,1);
        addComponent(FLabel ,2,0,1,1);
        addComponent(DLabel,3,0,1,1);
        addComponent(RLabel ,4,0,1,1);
        addComponent(MwfLabel ,5,0,1,1); 
        addComponent(NLabel ,6,0,1,1);
        addComponent(PdLabel ,7,0,1,1);
        addComponent(PbLabel ,8,0,1,1);
        addComponent(FvLabel ,9,0,1,1);
        addComponent(FlLabel ,10,0,1,1);
        addComponent(RHOvLabel ,11,0,1,1);
        addComponent(RHOlLabel ,12,0,1,1);
        addComponent(PSLabel ,13,0,1,1);
        addComponent(PFLabel ,14,0,1,1);
        addComponent(DALabel ,15,0,1,1);
        addComponent(HALabel ,16,0,1,1);
        addComponent(HwLabel ,17,0,1,1);
        addComponent(DhLabel ,18,0,1,1);
        addComponent(PtLabel ,19,0,1,1);
        addComponent(tdLabel ,20,0,1,1);
        addComponent(WuLabel ,21,0,1,1);
        addComponent(WcLabel ,22,0,1,1);
        addComponent(DyLabel ,23,0,1,1);
        addComponent(dFLabel,24,0,1,1);
        addComponent(dDLabel ,25,0,1,1);
        addComponent(dtLabel ,26,0,1,1);
        // Create Text Fields
        FField = new JFormattedTextField(amountFormat);
        FField = new JFormattedTextField(amountFormat);
        dFField = new JFormattedTextField(amountFormat);
        DField = new JFormattedTextField(amountFormat);
        dDField = new JFormattedTextField(amountFormat);
        dtField = new JFormattedTextField(amountFormat);
        RField = new JFormattedTextField(amountFormat);
        MwfField = new JFormattedTextField(amountFormat);
        NField = new JFormattedTextField(amountFormat);
        PdField = new JFormattedTextField(amountFormat);
        PbField = new JFormattedTextField(amountFormat);
        FvField = new JFormattedTextField(amountFormat);
        FlField = new JFormattedTextField(amountFormat);
        RHOvField = new JFormattedTextField(amountFormat);
        RHOlField = new JFormattedTextField(amountFormat);
        PSField = new JFormattedTextField(amountFormat);
        PFField = new JFormattedTextField(amountFormat);
        DAField = new JFormattedTextField(amountFormat);
        HaField = new JFormattedTextField(amountFormat);
        HwField = new JFormattedTextField(amountFormat);
        DhField = new JFormattedTextField(amountFormat);
        PtField = new JFormattedTextField(amountFormat);
        tdField = new JFormattedTextField(amountFormat);
        WuField = new JFormattedTextField(amountFormat);
        WcField = new JFormattedTextField(amountFormat);
        // Set Initial values to Fields
        FField.setValue(Finitial);
        dFField.setValue( dFinitial);
        DField.setValue( Dinitial);
        dDField.setValue( dDinitial);
        dtField.setValue( dtinitial);
        RField.setValue( Rinitial);
        MwfField.setValue( Mwfinitial);
        NField.setValue( Ninitial);
        PdField.setValue( Pdinitial);
        PbField.setValue( Pbinitial);
        FvField.setValue( Fvinitial);
        FlField.setValue( Flinitial);
        RHOvField.setValue( RHOvinitial);
        RHOlField.setValue( RHOlinitial);
        PSField.setValue( PSinitial);
        PFField.setValue( PFinitial);
        DAField.setValue( DAinitial);
        HaField.setValue( Hainitial);
        HwField.setValue( Hwinitial);
        DhField.setValue( Dhinitial);
        PtField.setValue( Ptinitial);
        tdField.setValue( tdinitial);
        WuField.setValue( Wuinitial);
        WcField.setValue( Wcinitial);
        // Set Number of Columns
        FField.setColumns(12);
        dFField.setColumns(12);
        DField.setColumns(12);
        dDField.setColumns(12);
        dtField.setColumns(12);
        RField.setColumns(12);
        MwfField.setColumns(12);
        NField.setColumns(12);
        PdField.setColumns(12);
        PbField.setColumns(12);
        FvField.setColumns(12);
        FlField.setColumns(12);
        RHOvField.setColumns(12);
        RHOlField.setColumns(12);
        PSField.setColumns(12);
        PFField.setColumns(12);
        DAField.setColumns(12);
        HaField.setColumns(12);
        HwField.setColumns(12);
        DhField.setColumns(12);
        PtField.setColumns(12);
        tdField.setColumns(12);
        WuField.setColumns(12);
        WcField.setColumns(12);
        // Add Required Number Fields
        addComponent(FField ,2,1,1,1);
        addComponent(DField  ,3,1,1,1);
        addComponent(RField ,4,1,1,1);
        addComponent(MwfField ,5,1,1,1);
        addComponent(NField ,6,1,1,1);
        addComponent(PdField ,7,1,1,1);
        addComponent(PbField ,8,1,1,1);
        addComponent(FvField ,9,1,1,1);
        addComponent(FlField ,10,1,1,1);
        addComponent(RHOvField ,11,1,1,1);
        addComponent(RHOlField ,12,1,1,1);
        addComponent(PSField ,13,1,1,1);
        addComponent(PFField ,14,1,1,1);
        addComponent(DAField ,15,1,1,1);
        addComponent(HaField , 16,1,1,1);
        addComponent(HwField ,17,1,1,1);
        addComponent(DhField ,18,1,1,1);
        addComponent(PtField ,19,1,1,1);
        addComponent(tdField ,20,1,1,1);
        addComponent(WuField ,21,1,1,1);
        addComponent(WcField ,22,1,1,1);
        addComponent(dFField ,24,1,1,1);
        addComponent(dDField ,25,1,1,1);
        addComponent(dtField ,26,1,1,1);
        // Create Ouput Field
        //create text area
     String header = "Results appear here";
     JTextArea textArea = new JTextArea(header);
     textArea.setEditable(false);
     textArea.setMargin(new Insets(1, 4, 26, 4));
        textArea.setBackground(Color.RED);
//     //create panel to contain text area
//     JPanel textAreaPane = new JPanel();
//     textAreaPane.add(textArea);
//        textAreaPane.setBorder(BorderFactory.createCompoundBorder(
//                BorderFactory.createTitledBorder("Output Results"),
//                BorderFactory.createEmptyBorder(0, 5, 5, 5)));
    private void setUpFormats()
        amountFormat = NumberFormat.getNumberInstance();
    private void addComponent( Component component,
            int row, int column, int width, int height )
        constraints.gridx = column;
        constraints.gridy = row;
        layout.setConstraints( component, constraints);
        add ( component );
    private class ButtonHandler implements ActionListener
        public void actionPerformed( ActionEvent event )
            double F = ((Number)FField.getValue()).doubleValue();
            double D = ((Number)DField.getValue()).doubleValue();
            double R = ((Number)RField.getValue()).doubleValue();
            double Mw = ((Number)MwfField.getValue()).doubleValue();
            double N = ((Number)NField.getValue()).doubleValue();
            double Pd = ((Number)PdField.getValue()).doubleValue();
            double Pb = ((Number)PbField.getValue()).doubleValue();
            double Fv = ((Number)FvField.getValue()).doubleValue();
            double Fl = ((Number)FlField.getValue()).doubleValue();
            double RHOv = ((Number)RHOvField.getValue()).doubleValue();
            double RHOl = ((Number)RHOlField.getValue()).doubleValue();
            double PS = ((Number)PSField.getValue()).doubleValue();
            double PF = ((Number)PFField.getValue()).doubleValue();
            double DA = ((Number)DAField.getValue()).doubleValue();
            double Ha = ((Number)HaField.getValue()).doubleValue();
            double Hw = ((Number)HwField.getValue()).doubleValue();
            double Dh = ((Number)DhField.getValue()).doubleValue();
            double Pt = ((Number)PtField.getValue()).doubleValue();
            double td = ((Number)tdField.getValue()).doubleValue();
            double Wu = ((Number)WuField.getValue()).doubleValue();
            double Wc = ((Number)WcField.getValue()).doubleValue();
            double dF = ((Number)dFField.getValue()).doubleValue();;
            double dD = ((Number)dDField.getValue()).doubleValue();
            double dt = ((Number)dtField.getValue()).doubleValue();
            JOptionPane.showMessageDialog(null, "Import Successful " + F);
}and the part that this plugs into so to speak
package frontend;
import java.awt.*;                                                              // Import Relevant Libraries
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
import javax.swing.border.*;
public class Front extends JFrame{                                              // Setup Main Frame
    private JTabbedPane tabbedPane;
    public Front()                                                             
        super("Chemical Design Workshop");                                      // Set Conditions On Main Window
        setExtendedState(javax.swing.JFrame.MAXIMIZED_BOTH);
        addWindowListener(new WindowAdapter()
            public void WindowClosing(WindowEvent e)
                System.exit(0);
        tabbedPane = new JTabbedPane(SwingConstants.LEFT);
        tabbedPane.setBackground(Color.blue);
        tabbedPane.setForeground(Color.white);
        populateTabbedPane();
        buildMenu();
        getContentPane().add(tabbedPane);
    private void populateTabbedPane()
        tabbedPane.addTab("Distillation",null,new Distill(), "Distillation");
        tabbedPane.addTab("Decanter",null,new Decant(), "Decanter");
    private void buildMenu()
        JMenuBar mb = new JMenuBar();
        JMenu menu = new JMenu("File");
        JMenuItem item = new JMenuItem("Exit");                                 //Closes the application from the Exit
        item.addActionListener(new ActionListener()
            public void actionPerformed(ActionEvent e)
            System.exit(0);
    menu.add(item);
    mb.add(menu);
    setJMenuBar(mb);
    public static void main(String args[]){
    Front frame = new Front();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
}

Answer 1

I just had one more question. Now that the field is added (thank you by the way) I was wondering why it is only the size of the text string inside it?