Question

I created a chat panel and added to Jframe but the panel is not displaying. But my sop in the chat panel are displaying in the console. Any one please let me know what could be the problem

My Frame

public class MyFrame extends JFrame {

MyPanel chatClient;
  String input;

public MyFrame() {

    input = (String)JOptionPane.showInputDialog(null, "Name:", "Connect to chat                  
server", JOptionPane.QUESTION_MESSAGE, null,null, "Test");
input=input.trim();
chatClient = new MyPanel("localhost",input);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
add(chatClient);

 }
  public static void main(String...args){
    new MyFrame();
  }
}

MyPanel:

public class MyPanel extends JPanel{
  ChatClient chatClient;

  public MyPanel(String host, String uid) {
    chatClient= new ChatClient(host,uid);
    add(chatClient.getChatPanel());
    this.setVisible(true);
  }
}

chat panel:

public class ChatClient  {

  Client client;
  String name;
  ChatPanel chatPanel;
  String hostid;

  public ChatClient(String host,String uid){
    client = new Client();
    client.start();
    System.out.println("in constructor");
    Network.register(client);

    client.addListener(new Listener(){

      public void connected(Connection connection){
        System.out.println("in client connected method");
        Network.RegisterName registerName = new Network.RegisterName();
        registerName.name=name;
        client.sendTCP(registerName);
      }

      public void received(Connection connection,Object object){
        System.out.println("in client received method");

          if (object instanceof Network.UpdateNames) {
                  Network.UpdateNames updateNames = (Network.UpdateNames)object;
                  //chatFrame.setNames(updateNames.names);

                  System.out.println("got it message");
                  return;
          }

          if (object instanceof Network.ChatMessage) {
                  Network.ChatMessage chatMessage = (Network.ChatMessage)object;
                  //chatFrame.addMessage(chatMessage.text);
                    System.out.println("send it message");
                  return;
          }

      }



    }); // end of listner

    name=uid.trim();
    hostid=host.trim();
    chatPanel = new ChatPanel(hostid,name);

    chatPanel.setSendListener(new Runnable(){

      public void run(){
        Network.ChatMessage chatMessage = new Network.ChatMessage();
        chatMessage.chatMessage=chatPanel.getSendText();
        client.sendTCP(chatMessage);
      }
    });

    new Thread("connect"){
      public void run(){
        try{
          client.connect(5000, hostid,Network.port);
        }catch(IOException e){
          e.printStackTrace();
        }
      }
    }.start();

  }//end of constructor

  static public class ChatPanel extends JPanel{

    CardLayout cardLayout;
    JList messageList,nameList;
    JTextField sendText;
    JButton sendButton;
    JPanel topPanel,bottomPanel,panel;

    public ChatPanel(String host,String user){
      setSize(600, 200);
      this.setVisible(true);
      System.out.println("Chat panel "+host+"user: "+user);
      {
        panel = new JPanel(new BorderLayout());
        {
          topPanel = new JPanel(new GridLayout(1,2));
          panel.add(topPanel); 
          {
            topPanel.add(new JScrollPane(messageList=new JList()));
            messageList.setModel(new DefaultListModel());
          } 
          {
            topPanel.add(new JScrollPane(nameList=new JList()));
            nameList.setModel(new DefaultListModel());
          }
          DefaultListSelectionModel disableSelections = new DefaultListSelectionModel() {
                                                          public void setSelectionInterval (int index0, int index1) {
                                                          }
                                                  };

          messageList.setSelectionModel(disableSelections);
          nameList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        } 
        {
          bottomPanel = new JPanel(new GridBagLayout());
          panel.add(bottomPanel,BorderLayout.SOUTH);

          bottomPanel.add(sendText=new JTextField(),new GridBagConstraints(0,0,1,1,1,0,GridBagConstraints.CENTER,GridBagConstraints.BOTH,new Insets(0,0,0,0),0,0));
          bottomPanel.add(sendButton=new JButton(),new GridBagConstraints(1,0,1,1,0,0,GridBagConstraints.CENTER,0,new Insets(0,0,0,0),0,0));
        }

      }

      sendText.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e){
          sendButton.doClick();
        }
      });

    }


    public void setSendListener (final Runnable listener) {
            sendButton.addActionListener(new ActionListener() {
                    public void actionPerformed (ActionEvent evt) {
                            if (getSendText().length() == 0) return;
                            listener.run();
                            sendText.setText("");
                            sendText.requestFocus();
                    }
            });
    }

    public String getSendText () {
            return sendText.getText().trim();
    }

    public void setNames (final String[] names) {
      EventQueue.invokeLater(new Runnable(){
        public void run(){
          DefaultListModel model = (DefaultListModel)nameList.getModel();
          model.removeAllElements();
          for(String name:names)
            model.addElement(name);
        }
      });

    }

    public void addMessage (final String message) {
            EventQueue.invokeLater(new Runnable() {
                    public void run () {
                            DefaultListModel model = (DefaultListModel)messageList.getModel();
                            model.addElement(message);
                            messageList.ensureIndexIsVisible(model.size() - 1);
                    }
            });
    }

  }

  public JPanel getChatPanel(){
    return chatPanel;
  }

}

EDIT 1

public class ChatPanel {
  ChatP caht;
  public ChatPanel1() {
    caht=new ChatP();
  }
  static class ChatP extends JPanel{
    JPanel panel;
    public ChatP(){
      panel = new JPanel();
      panel.add(new JLabel("hi from chat panel"));
    }
  }

  public JPanel getChatPanel(){
    return caht;
  }
}

Answer 1

Call pack(). The cobbled together code still has many problems, and odd aspects, but shows..

import java.awt.*;
import javax.swing.*;

public class MyFrame extends JFrame {

    MyPanel chatClient;
    String input;

    public MyFrame() {
        chatClient = new MyPanel("localhost","input");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        add(chatClient);

        pack();
        // Do last!
        setVisible(true);
    }
    public static void main(String...args){
        new MyFrame();
    }
}

class MyPanel extends JPanel{

    public MyPanel(String host, String uid) {
        ChatPanel chatPanel = new ChatPanel();
        add(chatPanel.getChatPanel());
    }
}

class ChatPanel {
    ChatP caht;

    public ChatPanel() {
        caht=new ChatP();
    }

    static class ChatP extends JPanel{
        public ChatP(){
            add(new JLabel("hi from chat panel"));
        }
    }

    public JPanel getChatPanel(){
        return caht;
    }
}

Notes

Batteries not included. That source was the minimalist code needed to diagnose the problem and suggest a solution. For better help sooner, post an SSCCE.

• Don’t extend frame or panel, simply keep a reference to each.
• Start and update GUIs on the EDT. See Concurrency in Swing for more details.