A newbie got stuck !

[Tirthankar Mukherjee]

I am trying to write a small java applications. I created my 1st JPanel, and added a JTextBox and a button to it, in a 2nd JPanel I added a JTextBox only, now I added this 2 JPanel to a JFrame, I want to want to put up the text in JtextBox of Panel1 to JtextBox of Panel2 on hitting the button of JPanel1. I am adding an image for clarification , this small piece of code is done except the event-handling (the most important part).



If someone clears my doubts, and provides some code/link how to write codes for this kind of event handling, then it would be very helpful.
Please help, thanks in Advance.

[Gregg Bolinger]

public void actionPerformed(ActionEvent event) {
    panel2.getMyTextArea2().setText(myTextArea1.getText());
}

Panel 1 needs a reference to panel 2 and panel 2 needs a getter for your text area for this to work.

[Tirthankar Mukherjee]

Thank you ... it really helped me ...

[Tirthankar Mukherjee]

ok , I did exactly the same, it works but there is a problem. When I try to get my Text (with SOP statements), of JtextArea2, I get what is expected, but in the UI it remains the same doesnot update.

[Rob Prime]

Can you show us the exact code you are using to update it?

[Tirthankar Mukherjee]

  private void MyButtonActionPerformed(java.awt.event.ActionEvent evt) {                                         

        Panel2.GetMyNewTextArea().setText(MyTextArea.getText());
        String s = Panel2.GetMyNewTextArea().getText();
        System.out.println(s);// Debugging and output is perfect !!
    }    

Panel2 is an instance variable, instantiated at the Constructor of Panel1

    
public JTextArea GetMyNewTextArea()
    {
        return MyNewTextArea;
    }

this is in my pannel2

[Rob Prime]

And Panel2 is the exact same instance you added to your GUI? You haven't created another, invisible panel?

[Tirthankar Mukherjee]

MynewPannel.java

   

import java.awt.Dimension;
import javax.swing.JTextArea;



/*
 * MyNewPanel.java
 *
 * Created on Jul 9, 2009, 8:54:01 PM
 */

/**
 *
 * @author Tirthankar Mukherjee
 */
public class MyNewPanel extends javax.swing.JPanel {

    /** Creates new form MyNewPanel */
    public MyNewPanel() {
        initComponents();
         this.setPreferredSize(new Dimension(200,200));
    }

    public JTextArea GetMyNewTextArea()
    {
        return MyNewTextArea;
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        jScrollPane1 = new javax.swing.JScrollPane();
        MyNewTextArea = new javax.swing.JTextArea();

        MyNewTextArea.setColumns(20);
        MyNewTextArea.setRows(5);
        MyNewTextArea.setText("Hello World !!");
        jScrollPane1.setViewportView(MyNewTextArea);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 380, Short.MAX_VALUE)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 278, Short.MAX_VALUE)
                .addContainerGap())
        );
    }// </editor-fold>


    // Variables declaration - do not modify
    private javax.swing.JTextArea MyNewTextArea;
    private javax.swing.JScrollPane jScrollPane1;
    // End of variables declaration

}

 

   

import java.awt.Dimension;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * MyPanel.java
 *
 * Created on Jul 9, 2009, 8:50:18 PM
 */

/**
 *
 * @author Tirthankar Mukherjee
 */
public class MyPanel extends javax.swing.JPanel {

    /** Creates new form MyPanel */
    MyNewPanel Panel2 ;
    public MyPanel() {
        initComponents();
        MyInitComponents();
        this.setPreferredSize(new Dimension(200,200));
    }

    private void MyInitComponents()
    {
        //Panel 1 needs a reference to panel 2 and panel 2 needs a getter for your text area 
        Panel2 = new MyNewPanel() ;
        
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        MyButton = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        MyTextArea = new javax.swing.JTextArea();

        MyButton.setText("Button");
        MyButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                MyButtonActionPerformed(evt);
            }
        });

        MyTextArea.setColumns(20);
        MyTextArea.setLineWrap(true);
        MyTextArea.setRows(5);
        MyTextArea.setText("Hello !!");
        jScrollPane1.setViewportView(MyTextArea);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(MyButton, javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 380, Short.MAX_VALUE))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 244, Short.MAX_VALUE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(MyButton)
                .addContainerGap())
        );
    }// </editor-fold>

    private void MyButtonActionPerformed(java.awt.event.ActionEvent evt) {                                         

        Panel2.GetMyNewTextArea().setText(MyTextArea.getText());
        String s = Panel2.GetMyNewTextArea().getText();
    }                                        


    // Variables declaration - do not modify
    private javax.swing.JButton MyButton;
    private javax.swing.JTextArea MyTextArea;
    private javax.swing.JScrollPane jScrollPane1;
    // End of variables declaration

}

 

  

import java.awt.BorderLayout;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * NewJFrame.java
 *
 * Created on Jul 9, 2009, 8:54:56 PM
 */

/**
 *
 * @author Tirthankar Mukherjee
 */
public class NewJFrame extends javax.swing.JFrame {

    /** Creates new form NewJFrame */
    public NewJFrame() {
        initComponents();
        this.setLayout(new BorderLayout());
        MyPanel MP = new MyPanel();
        this.add(MP,BorderLayout.WEST);
        this.add(new MyNewPanel(), BorderLayout.CENTER);
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 300, Short.MAX_VALUE)
        );

        pack();
    }// </editor-fold>

    /**
    * @param args the command line arguments
    */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify
    // End of variables declaration

}

  

I know the full code with "system genereted one" .. its pretty bad ... even I dislike it ... but please help

[Tirthankar Mukherjee]

This is my NetBeans Project file

My NetBeans Project

[Michael Dunn]

creating a new MyNewPanel() is not passing a reference of the one on the screen.

some changes

MyNewPanel mnp = new MyNewPanel();
//MyPanel MP = new MyPanel();
MyPanel MP = new MyPanel(mnp);
this.add(MP,BorderLayout.WEST);
//this.add(new MyNewPanel(), BorderLayout.CENTER);
this.add(mnp, BorderLayout.CENTER);

and

//public MyPanel() {
public MyPanel(MyNewPanel p) {
  Panel2 = p;
    initComponents();
    //MyInitComponents();//and remove the method
    this.setPreferredSize(new Dimension(200,200));
}

[Rob Prime]

Just what I though. Your MyPanel instance has its own copy of MyNewPanel that is not added to the GUI.

You should give it a reference to the actual panel:

   
public class MyPanel extends javax.swing.JPanel {

    /** Creates new form MyPanel */
    MyNewPanel Panel2 ;

    public MyPanel(MyNewPanel panel2) {
        initComponents();
        MyInitComponents(panel2);
        this.setPreferredSize(new Dimension(200,200));
    }

    private void MyInitComponents(MyNewPanel panel2)
    {
        //Panel 1 needs a reference to panel 2 and panel 2 needs a getter for your text area 
        Panel2 = panel2;
    }

    <SNIP>
} 

  
public class NewJFrame extends javax.swing.JFrame {

    /** Creates new form NewJFrame */
    public NewJFrame() {
        initComponents();
        this.setLayout(new BorderLayout());
        MyNewPanel MNP = new MyNewPanel();
        MyPanel MP = new MyPanel(MNP);
        this.add(MP,BorderLayout.WEST);
        this.add(MNP, BorderLayout.CENTER);
    }

    <SNIP>
}

Heh, Michael beat me to it

[Tirthankar Mukherjee]

Oh my GOD !!! Swing is swing pretty fast but I will hang on ... JavaRanch rocks !!

Most importantly many many thanks Rob and all of the above contributors.