How to add two panels with different layouts in one frame?

Question

I have one panel whit gridBagLayout and second with null gridlayout. When I add that to main panel, and main panel to frame one panel disappears. Why is that? And how to add two panels with different layouts setings in one frame?

Here is the code main @Beowolve:

import java.awt.BorderLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class PrikazGUI {

    JFrame frejm;
    JPanel k;
    JButton b1,b2;

    public PrikazGUI(){
        frejm = new JFrame("Lala");
        k = new JPanel();

        KvadratPravi p = new KvadratPravi();
        JPanel grid = new JPanel();
        grid.setLayout(new GridBagLayout());
        grid.add(p);
//      Kvadrat l = new Kvadrat();
        JosJedanKvadrat jos = new JosJedanKvadrat();
//      k.setLayout(null);
//      k.setBounds(0, 444,444, 445);
        k.add(jos);
        k.add(grid);
        JPanel main = new JPanel();
        main.setLayout(null);
        k.setBounds(0, 0,1000, 1900);
        main.setBounds(0, 0,1000, 1900);
        main.add(k);



        frejm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frejm.setSize(1900, 1000);
        frejm.getContentPane().add(main);
//      frejm.getContentPane().add(k);
//      frejm.pack();
        frejm.setVisible(true);


    }


    public static void main(String[] args) {
        PrikazGUI a = new PrikazGUI();

    }

}

Second class:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JPanel;

public class KvadratPravi extends JPanel {

    int sizeH = 60;
    int sizeW = 60;
    public GridBagConstraints cst = new GridBagConstraints();

    public KvadratPravi() {
        JPanel j = new JPanel();
        j.setLayout(new GridBagLayout());
         cst.gridx = 0;
         cst.gridy = 0;

         add(j,cst);

    }



    @Override
    protected void paintComponent(Graphics g) {
        // TODO Auto-generated method stub
        super.paintComponent(g);
            g.setColor(Color.PINK);
           g.drawRect(0, 0, sizeH, sizeW);
           g.fillRect(0, 0, sizeH, sizeW);
    }

     @Override
     public Dimension getPreferredSize() {
         return new Dimension(sizeH,sizeW);
     }

}

Third class:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;

import javax.swing.JPanel;

public class JosJedanKvadrat extends JPanel {

    int sizeH = 60;
    int sizeW = 60;
    int x,y;


     public JosJedanKvadrat() {

         setBounds(33, 44,444, 445);
         JPanel j = new JPanel();

         setLayout(null);

         add(j);
         addMouseListener(new MouseAdapter() {
                public void mousePressed(MouseEvent e) {
                if(!e.isMetaDown()){
                x = e.getX();
                y = e.getY();
                }
                }
                });
                addMouseMotionListener(new MouseMotionAdapter() {
                public void mouseDragged(MouseEvent e) {
                if(!e.isMetaDown()){
                Point p = getLocation();
                setLocation(p.x + e.getX() - x,
                p.y + e.getY() - y);
                }
                }
                });



    }



    @Override
    protected void paintComponent(Graphics g) {
        // TODO Auto-generated method stub
        super.paintComponent(g);
            g.setColor(Color.BLUE);
           g.drawOval(0, 0, sizeH, sizeW);


    }

     @Override
     public Dimension getPreferredSize() {
         return new Dimension(sizeH,sizeW);
     }

}

So I whant second class be in center of panel,and to have gridBagLayout, and third class I whant to move around the objects,so that class dont have gridlayout...when I and that two panels to main pane its seems that second class whit gridBagLayout does not working.

Answer 1

You are currently adding two JPanel into a JFrame.

JFrame f = new JFrame();

This frame, by default, use a BorderLayout. So if you call f.add(new Panel()); multiple time only the last one will be visible since the center area of this layout can only show one JComponent. You need to use a different layout.