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Position a JButton properly within a GridBagLayout | Java 8

I want to position a JButton "Start" in the lower center of my GUI.
Sadly the GridBagConstraints that I set seem to have no effect.
I'm working with jdk1.8.0_191 and the Eclipse IDE.
EDIT: I switched my snippet to a "minimal reproducible example".
Here the snippet of my code:
package gui.main;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test{
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(646, 509);
frame.setResizable(false);
frame.setTitle("Adventure Time");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
panel.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 1;
gbc.gridy = 5;
JButton button = new JButton("Start");
button.setBackground(Color.black);
button.setForeground(Color.white);
button.setPreferredSize(new Dimension(110, 60));
button.setMinimumSize(new Dimension(110, 60));
button.setVisible(true);
panel.add(button, gbc);
panel.setVisible(true);
frame.add(panel);
frame.setVisible(true);
}
}
Here is a picture where I approximately want the "Start" Button instead.

I created a simple, runnable example of a GUI with a start button on the lower fourth of the JPanel. Here's the example GUI.
Use Swing components. Don't extend Swing components, or any other Java class, unless you intend to override one of the methods in the class.
I used a BorderLayout for the JPanel. I used a calculated empty border to shift the start button down from the center.
I set the size of the JPanel in this example. I'm assuming you'll set the size of the game panel based on the size of your image.
Here's the code.
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class StartButtonExample implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new StartButtonExample());
}
#Override
public void run() {
JFrame frame = new JFrame("Game");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createMainPanel(), BorderLayout.CENTER);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private JPanel createMainPanel() {
JPanel panel = new JPanel(new BorderLayout());
Dimension panelSize = new Dimension(400, 400);
panel.setPreferredSize(panelSize);
JButton button = new JButton("Start");
Dimension buttonSize = button.getPreferredSize();
int height = panelSize.height - buttonSize.height;
int width = panelSize.width - buttonSize.width;
int top = height * 3 / 4;
int left = (width - buttonSize.width) / 2;
int bottom = height / 4;
int right = left;
panel.setBorder(BorderFactory.createEmptyBorder(
top, left, bottom, right));
panel.add(button, BorderLayout.CENTER);
return panel;
}
}

In my amateurish opinion:
I ended up using different insets for my small application.
It is more clean looking in my opinion.
//margin 400 top, rest 3
gbc.insets = new Insets(400,3,3,3);
gbc.gridy = 0;
getWrapperPanel().add(getBtnStart02(), gbc);
//margin 3 at all sides for all following gui objects
gbc.insets = new Insets(3,3,3,3);
gbc.gridy = 1;
getWrapperPanel().add(getBtnLoad(), gbc);
Works like a charm.

Automatically Resizing with BorderLayout in Java

This is my jFrame Form with BorderLayout where buttons will be placed in Navigation Bar Panel and jDesktopPane will be placed in Content Panel. The DesktopPane with CardLayout will be displaying different sizes of jPanel Form. I want Content Panel(including whole form) resize based on the different sizes of jPanel Form displayed. Is it possible to do this? If not then I've tried resizing the panel and even the whole form with codes, but it's not working.
I've trying playing with these few codes, but it's not working.
Main_Menu form = new Main_Menu();
form.pack();
form.setSize(900, 548);
form.setPreferredSize(new Dimension(900, 548));
form.validate();

So, based on the limited information available, I wrote a quick test which seems to work just fine
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
CardLayout layout = new CardLayout();
JDesktopPane pane = new JDesktopPane();
Navigator navigator = new Navigator(pane, layout);
pane.setLayout(layout);
pane.setBackground(Color.GREEN);
frame.add(new TopPane(), BorderLayout.NORTH);
frame.add(new NavigationPane(navigator), BorderLayout.WEST);
for (int index = 0; index < 5; index++) {
pane.add(new ContentPane(index), Integer.toString(index));
}
JLabel initial = new JLabel("All your content belong to us");
initial.setBorder(new EmptyBorder(20, 20, 20, 20));
pane.add(initial, "initial");
layout.show(pane, "initial");
frame.add(pane);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class Navigator {
private JComponent parent;
private CardLayout layout;
public Navigator(JComponent parent, CardLayout layout) {
this.parent = parent;
this.layout = layout;
}
public void show(String name) {
layout.show(parent, name);
}
}
public class TopPane extends JPanel {
public TopPane() {
setLayout(new GridBagLayout());
setBorder(new EmptyBorder(20, 20, 20, 20));
setBackground(Color.BLUE);
JLabel title = new JLabel("Top Panel");
title.setForeground(Color.WHITE);
add(title);
}
}
public class NavigationPane extends JPanel {
private Navigator navigator;
public NavigationPane(Navigator navigator) {
setLayout(new GridBagLayout());
setBorder(new EmptyBorder(20, 20, 20, 20));
setBackground(Color.ORANGE);
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.BOTH;
for (int index = 0; index < 5; index++) {
JButton btn = new JButton("Test " + index);
btn.setActionCommand(Integer.toString(index));
add(btn, gbc);
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
String name = e.getActionCommand();
navigator.show(name);
}
});
}
}
}
public class ContentPane extends JPanel {
public ContentPane(int value) {
setLayout(new GridBagLayout());
setBorder(new EmptyBorder(20, 20, 20, 20));
setBackground(Color.MAGENTA);
add(new JLabel("Hello from " + Integer.toString(value)));
}
}
}
Avoid setPreferred/Minimum/MaximumSize, you're overriding the work which the components and the layout managers do in order to provide dynamic sizing hints
If this fails to solve your issue, then consider providing a Minimal, Complete, and Verifiable example

Try to use pack(); not form.pack();. Or setLayout or use CardLayout

How to create a random sized buttons in the Y axis

import java.awt.Color;
import java.awt.Dimension;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Ships {
public static JPanel init(JPanel radioPanel){
radioPanel.add(addShips(2));
radioPanel.add(addShips(3));
radioPanel.add(addShips(4));
radioPanel.add(addShips(5));
return radioPanel;
}
public static JButton addShips(int size){
JButton but = new JButton();
but.setPreferredSize(new Dimension((40*size),40));
but.setBackground(Color.BLACK);
return but;
}
public static void main(String[] args){
JFrame frame = new JFrame();
frame.setVisible(true);
JPanel radioPanel = new JPanel();
radioPanel.setLayout(new BoxLayout(radioPanel, BoxLayout.Y_AXIS)); \\line 4
init(radioPanel);
frame.getContentPane().add(radioPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
}
}
I see that the buttons are placed in one single line. Need to place the buttons one after the other according to BoxLayout.Y_AXIS. When I remove //line 4, it creates correctly according to FlowLayout.

Try this:
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Ships {
public static JPanel init(JPanel radioPanel){
radioPanel.add(addShips(2));
radioPanel.add(addShips(3));
radioPanel.add(addShips(4));
radioPanel.add(addShips(5));
return radioPanel;
}
public static JButton addShips(int size){
JButton but = new JButton();
Dimension d = new Dimension((40*size),40);
but.setPreferredSize(d);
but.setMinimumSize(d);
but.setMaximumSize(d);
but.setBackground(Color.BLACK);
return but;
}
public static void main(String[] args){
JFrame frame = new JFrame();
JPanel radioPanel = new JPanel();
radioPanel.setLayout(new BoxLayout(radioPanel, BoxLayout.Y_AXIS)); //line 4
init(radioPanel);
frame.getContentPane().add(radioPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
When you pack components in JFrame, your layout manager may not honour preferred size of components, try setting minimum and maximum sizes too.
In vertical layout (y-axis), BoxLayout tries to make all components wide as widest component. As there is no text or icon in all buttons, button will shrink to default size, and all will have same width. So instruct box layout for particular sizes using maximum and minimum sizes.

I have changed your LayoutManager to GridBagLayout and it works fine. Is it suitable for you? :
public class Ships {
public static JPanel init(JPanel radioPanel){
GridBagConstraints c = new GridBagConstraints();
c.anchor = GridBagConstraints.WEST;
radioPanel.add(addShips(2),c);
c.gridy = 1;
radioPanel.add(addShips(6),c);
c.gridy = 2;
radioPanel.add(addShips(4),c);
c.gridy = 3;
radioPanel.add(addShips(5),c);
return radioPanel;
}
public static JButton addShips(int size){
JButton but = new JButton();
but.setPreferredSize(new Dimension((40*size),40));
but.setBackground(Color.BLACK);
return but;
}
public static void main(String[] args){
JFrame frame = new JFrame();
frame.setVisible(true);
JPanel radioPanel = new JPanel();
radioPanel.setLayout(new GridBagLayout());
init(radioPanel);
frame.getContentPane().add(radioPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
}
}
EDIT: change horizontal to vertical align.
Result:

Java Swing BorderLayout resize difficulties

I want to have my screen split in two so I used a BorderLayout with East and West sections. I had problems resizing and here I eventually found out that width is not changed in the East and West panels and height is not changed in the North and South panels and both are changed in the Center panel.
However, I want both width and height to be changed upon resize, and have two panels side by side. I have tried various levels of nesting to try getting it to work but I do not think it will work with BorderLayout.
It seems like this should be easy for the default layout manager but maybe I should try a different layout (e.g. BoxLayout) to achieve what I want.
Also here is some code which replicates the problem I am talking about (try resizing the window):
import java.awt.BorderLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Main extends JFrame {
public static void main(String[] args) {
JFrame window = new Main();
window.setVisible(true);
}
public Main() {
JButton east = new JButton("East");
JButton west = new JButton("West");
JPanel content = new JPanel();
content.setLayout(new BorderLayout());
content.add(east, BorderLayout.EAST);
content.add(west, BorderLayout.WEST);
setContentPane(content);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
}
}
Edit: I do not want the two sides to be equal, roughly 2:1 is the ratio which I want.

What you can use in your case is GridLayout, here two JButtons will resize themselves as the JFrame resizes.
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Main extends JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
JFrame window = new Main();
window.setVisible(true);
}
});
}
public Main() {
JButton east = new JButton("East");
JButton west = new JButton("West");
JPanel content = new JPanel();
content.setLayout(new GridLayout(1, 2));
content.add(east);
content.add(west);
setContentPane(content);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
}
}
Moreover, it's always best to run your GUI related code from the EDT - Event Dispatch Thread, and not from the Main Thread. Do read Concurrency in Swing, for more info on the topic.
LATEST EDIT : As per requested comment
Use GridBagLayout to specify the size that you want to give
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Main extends JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
JFrame window = new Main();
window.setVisible(true);
}
});
}
public Main() {
JPanel east = new JPanel();
east.setOpaque(true);
east.setBackground(Color.WHITE);
JPanel west = new JPanel();
west.setOpaque(true);
west.setBackground(Color.BLUE);
JPanel content = new JPanel();
content.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.FIRST_LINE_START;
gbc.fill = GridBagConstraints.BOTH;
gbc.weightx = 0.3;
gbc.weighty = 1.0;
gbc.gridx = 0;
gbc.gridy = 0;
content.add(east, gbc);
gbc.weightx = 0.7;
gbc.gridx = 1;
content.add(west, gbc);
setContentPane(content);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
}
}

Why don't you try with JSplitPane:
import javax.swing.*;
import java.awt.*;
public class AppDemo {
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
JFrame frame = new JFrame();
JButton eastButton = new JButton("East");
JButton westButton = new JButton("West");
JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, eastButton, westButton);
JPanel content = new JPanel();
content.setLayout(new BorderLayout());
content.add(splitPane, BorderLayout.CENTER);
frame.setContentPane(content);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setPreferredSize(new Dimension(500, 400));
frame.pack();
frame.setVisible(true);
});
}
}
You will get this:

If you want to keep your BorderLayout you can use something like the following object:
public class ResizablePanel extends JPanel {
public ResizablePanel(JComponent body) {
setLayout(new BorderLayout());
JButton resize = new JButton();
resize.setPreferredSize(new Dimension(Integer.MAX_VALUE, 4));
resize.addMouseMotionListener(new MouseAdapter() {
public void mouseDragged(MouseEvent e) {
Dimension preferredSize = ResizablePanel.this.getPreferredSize();
ResizablePanel.this.setPreferredSize(new Dimension(preferredSize.width, preferredSize.height-e.getY()));
ResizablePanel.this.revalidate();
}
});
add(resize, BorderLayout.PAGE_START);
add(body, BorderLayout.CENTER);
}
}
Now wrap the part you want to resize with an instance of ResizablePanel and you'll be able to resize it by dragging the thin button.
Note that this is code is for resizing the height of a panel that you put at the bottom (PAGE_END) part of a border layout, but it should be fairly straightforward to change it for resizing the width.

Sorry about replying to an old post.
My fix is to still use BorderLayout but to throw in the following line after the Component is resized
getLayout().layoutContainer(this);

How to create vertical TitledBorder in JPanel (javax swing)

I'm trying to figure out how to create a vertical TitledBorder in a JPanel.
I've got this situation:
I'd like to have "Actuators st..." placed vertically, so user can read it.
Is there a way to do it, or should I implement my own customized JPanel & TitledBorder?

maybe crazy idea but is possible with JSeparator too :-)
required proper LayoutManager, maybe GridBagLayout (JComponent placed without GBC can take PreferrredSize from JComponent, but isn't resiziable), not GridLayout
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSeparator;
import javax.swing.SwingUtilities;
public class NestedLayout {
private JFrame frame = new JFrame();
private JPanel leftPanel = new JPanel();
private JSeparator sep = new JSeparator();
private JLabel label = new JLabel("<html> L<br>a<br>b<br>e<br>l<br></html>");
public NestedLayout() {
label.setOpaque(true);
sep.setOrientation(JSeparator.VERTICAL);
sep.setLayout(new GridLayout(3, 1));
sep.add(new JLabel());
sep.add(label);
sep.add(new JLabel());
leftPanel.setLayout(new BorderLayout());
leftPanel.setBorder(BorderFactory.createEmptyBorder(
10, //top
10, //left
10, //bottom
10)); //right
leftPanel.add(sep, BorderLayout.CENTER);
leftPanel.setPreferredSize(new Dimension(40, 220));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(leftPanel, BorderLayout.WEST);
//frame.add(label);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
NestedLayout nestedLayout = new NestedLayout();
}
});
}
}

As shown in How to Use Borders, you can create a compound border using an empty border and a titled border.
Addendum: As an alternative, you can use the border's getMinimumSize() method to ensure that the title is visible. See also this related Q&A.
f.add(createPanel("Actuator status"), BorderLayout.WEST);
f.add(createPanel("Indicator result"), BorderLayout.EAST);
...
private Box createPanel(String s) {
Box box = new Box(BoxLayout.Y_AXIS);
TitledBorder title = BorderFactory.createTitledBorder(null, s,
TitledBorder.CENTER, TitledBorder.DEFAULT_POSITION);
box.setBorder(title);
for (int i = 0; i < 6; i++) {
JButton b = new JButton(null, UIManager.getIcon("html.pendingImage"));
b.setAlignmentX(JButton.CENTER_ALIGNMENT);
box.add(b);
}
box.validate();
Dimension db = box.getPreferredSize();
int max = Math.max(title.getMinimumSize(box).width, db.width);
box.setPreferredSize(new Dimension(max, db.height));
return box;
}