JButton size not changed by setLayout()

I'm trying to learn Java and I decided to write my first program. I'm attempting to make a window with a title and a JButton. But the button position doesn't get changed by setBounds(), it still stays in one spot no matter what I change it to. I heard that adding frame.getcontentPane().setLayout(null) fixes this, but it doesn't.

Can you please tell me what the problem is? (line 37)

package com.myprojects;
import javax.swing.*;
import java.awt.*;
import java.awt.Font;
public class Main extends JFrame {
public static void main(String[] args) {
//frame
JPanel panel = new JPanel();
JFrame frame = new JFrame();
frame.setSize(1366,768);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setIconImage(new ImageIcon("filedirectory").getImage());
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setUndecorated(true);
frame.add(panel);
//panel
panel.setBackground(new Color(34, 212, 187));
Font titleFont = new Font("Batang", Font.BOLD,120);
Font font = new Font("Batang",Font.PLAIN, 12);
//label
JLabel title = new JLabel("Title");
title.setBounds(10,20,80,25);
title.setFont(titleFont);
title.setForeground(new Color(0xFFB700));
panel.add(title);
//play button
JButton play = new JButton("Play");
play.setFont(font);
play.setBounds(500,500,250,100);
panel.add(play);
frame.setVisible(true);
}

> I decided to write my first program.

Then you should learn how to use Swing the way it was designed to be used. This means, DON"T use a null layout. Don't use setBounds()! Swing was designed to be used with layout managers. By default the layout manager for a JPanel is the FlowLayout. So you will see the label and the button on the same line.

Based on your code it looks like you are trying to put the label at the top of the frame and the button at the bottom.

So to get started:

1. get rid of the JPanel
2. Add the label to the frame using: frame.add(title, BorderLayout.PAGE_START)
3. Add the button to the frame using: frame.add(play, BorderLayout.PAGE_END)

Run your program to see how this looks.

The default layout for the content pane of the frame is the BorderLayout. Read the section from the Swing tutorial on Layout Managers to understand what the second parameter for the add(...) method means.

If you don't like the layout, then change the layout manager of the frame to a different layout manager and experiment.

I'd take a somewhat different approach to that described by camickr. Still using layouts of course, but using different layouts that get closer to the effect the code seems to be describing.

import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
public class ButtonCompoundLayout {
public ButtonCompoundLayout() {
//frame
JFrame frame = new JFrame();
//panel
JPanel panel = new JPanel(new BorderLayout());
panel.setBorder(new TitledBorder("BorderLayout"));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(panel);
//label
JLabel title = new JLabel("Title");
title.setFont(title.getFont().deriveFont(50f));
panel.add(title, BorderLayout.PAGE_START);
title.setBorder(new TitledBorder("BorderLayout.PAGE_START"));
//play button
JButton play = new JButton("Play");
Insets insets = new Insets(20,30,30,30);
play.setMargin(insets);
JPanel controlPanel = new JPanel(new GridBagLayout());
CompoundBorder compoundBorder = new CompoundBorder(
new TitledBorder("GridBagLayout"), 
new EmptyBorder(15, 50, 15, 50)
);
controlPanel.setBorder(compoundBorder);
controlPanel.add(play);
panel.add(controlPanel, BorderLayout.CENTER);
frame.pack();
frame.setMinimumSize(frame.getSize());
frame.setVisible(true);
}
public static void main(String[] args) {
Runnable r = () -> {
new ButtonCompoundLayout();
};
SwingUtilities.invokeLater(r);
}
}

Carefully review the code itself and check each of the methods and classes used for white-space, but here are some general tips / observations.

• The call to setBounds on the JFrame seemed to be fighting the call to setExtendedState(..)
• An icon image won't be seen in an undecorated GUI when it is on-screen, was it only for the title bar?
• Odd choice of setting the colors. One is specified as RGB integers, the other as a Hex value. Use one or the other.
• By the size and position of the button it appears the intent was to center it. It wasn't centered.
• Don't presume fonts are available unless supplying the font with the app. and loading it at runtime.

You should never use a null layout, because it does not adapt to different screen sizes. I suggest you should learn how to use a layout. For example, I use GridBagLayout everytime I design a gui.