Unable to add the Jpanel dynamically inside a single frame.

[sumanth kavikondala]

H Friends,
I am building a GUI application which consists of two panels "panel" and "panel1". "panel1" have a button "addTimer" when clicked it should add the "panel" to the frame if i gain click the button it should again add the "panel" without overlapping the previous "panel" rather it should be created below the previous "panel". If i click on the button "addTimer" n times it should add the panel n times. Along with this the frame size has to dynamically change depending on the number of panels produced. Below is the code i tried my level best to satisfy the above conditions.

Please give me your valuable suggestions. Thank you in advance.

package superTimerV2;
import javax.swing.*;

import java.awt.*;
import java.awt.event.*;

public class SuperTimer extends JFrame
{

	private static final long serialVersionUID = 1L;
	JLabel heading, time, user,timeup,invalid;
	int counter;
	JButton pause, start,resetAll,addTimer;
	JTextField input;
	Timer timer;
	private StartCountDown countdown;
	TimeClass tc;
	Halt halt;
	private long count;
	Long temp;
	Boolean startState=true, pauseState = true;
	JPanel panel,panel1;

	public SuperTimer()
	{
		super("Super Timer");
		panel = new JPanel(new GridBagLayout());
		panel1 = new JPanel(new GridBagLayout());
		panel.setBorder(BorderFactory.createLineBorder(Color.black));
		GridBagConstraints c = new GridBagConstraints();
		c.weightx=0.5;
		c.weighty=0.5;
		c.gridx=1;
		c.gridy =1;
		c.insets= new Insets(30, 10, 10, 10);

		heading = new JLabel("Super Timer");
		heading.setFont(heading.getFont().deriveFont(20f));
		heading.setFont(heading.getFont().deriveFont(400));
		panel1.add(heading,c);
		
		resetAll = new JButton("Reset All");
		c.gridx=0;
		c.gridy=7;
		panel1.add(resetAll,c);
		
		addTimer = new JButton("Add Timer");
		c.gridx=2;
		c.gridy=7;
		panel1.add(addTimer,c);

		
		
		AddTimer at = new AddTimer();
		addTimer.addActionListener(at);
		panel1.setSize(100, 100);
		
		
		getContentPane().add(panel1,BorderLayout.NORTH);
		
		
		pack();
		
	}
	
	public JPanel newPanel()
	{
		GridBagConstraints c = new GridBagConstraints();
		timeup = new JLabel("Times Up");
		timeup.setFont(timeup.getFont().deriveFont(15f));
		timeup.setForeground(Color.RED);
		timeup.setVisible(false);
		c.gridx=1;
		c.gridy=8;
		panel.add(timeup,c);


		time = new JLabel("00:00:00");
		time.setFont(time.getFont().deriveFont(29f));
		c.gridx=1;
		c.gridy=9;
		panel.add(time,c);

		pause = new JButton("Pause");
		c.gridx=2;
		c.gridy=9;
		c.anchor=GridBagConstraints.LAST_LINE_START;
		panel.add(pause,c);

		user = new JLabel("Time(Seconds):");
		c.gridx=0;
		c.gridy=12;
		c.anchor=GridBagConstraints.LAST_LINE_END;
		panel.add(user,c);

		invalid = new JLabel("Invalid input please enter only digits");
		c.gridx=1;
		c.gridy=11;
		c.anchor=GridBagConstraints.FIRST_LINE_END;
		invalid.setFont(invalid.getFont().deriveFont(10f));
		invalid.setForeground(Color.RED);
		invalid.setVisible(false);
		panel.add(invalid,c);

		input = new JTextField(13);
		c.gridx=1;
		c.gridy=12;
		panel.add(input,c);

		start = new JButton("Start");
		c.anchor=GridBagConstraints.LAST_LINE_START;
		c.gridx=2;
		c.gridy=12;
		panel.add(start,c);
		getContentPane().add(panel,BorderLayout.SOUTH);
        countdown= new StartCountDown();
		
		start.addActionListener(countdown);
		
		halt = new Halt();

		pause.addActionListener(halt);
		pack();
		return panel;
	}
	
	
	public class AddTimer implements ActionListener
	{
		public void actionPerformed(ActionEvent h)
		{
			
			
			newPanel();
			revalidate();
			 
		}
	}
}
}

[Campbell Ritchie]

Welcome to the Ranch

Don't add things dynamically. It looks very strange if the display changes suddenly like that. Consider a dialogue instead.

[sumanth kavikondala]

I have to add dynamically because this is the project given to me in my school. Please suggest me.

[Piet Souris]

hi Sumanth,

here is a small program that just adds a new panel when you click on a button.
It doesn't use a GridLayout, consider it as an example that you can use to
get an idea how to achieve your goal.

Greetz,
Piet

package javaranch;

import java.awt.Color;
import java.awt.Dimension;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 *
 * @author Piet
 */
public class Panels extends JPanel {
   public static void main(String... args) {
      new Panels();
   }
   
   int red, green, blue;
   JFrame frame;
   
   public Panels() {
      frame = new JFrame("Expanding panels");
      this.setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
      frame.setContentPane(this);
      JPanel knop = new JPanel();
      knop.setBackground(Color.red);
      JButton button = new JButton("Add Panel");
      button.addActionListener(e -> addPanel());   // change this if you do not have Java 8
      knop.add(button);
      this.add(knop);
      red = green = blue = 0;
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }
   
   private void addPanel() {
      JPanel panel = new JPanel();
      panel.setBackground(getColor());
      panel.setPreferredSize(new Dimension(400, 5));
      this.add(panel);
      frame.pack();
   }
   
   private Color getColor() {
      red = (red + 10) % 256;
      green = (green + 10) % 256;
      blue = (blue + 10) % 256;
      return new Color(red, green, blue);
   }
}