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How do I make the elements automatically adapt their sizes according to the size of window in JAVA swing?

The IDE I use is Intellij.
Here I created a small program of converting currency.
I used BorderLayout as the root panel and flowLayout for the bottom buttons. For west and east panel I used GridLayout(Intellij).
When I run the program, it can display normally like this:
After changing its size, the gap between elements begin to expand like this:
How do I make them adjust the distance automatically?
Here are my codes:
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
/**
* Created by Bob on 2017/5/11.
*/
public class layout {
private JPanel converterRootPanel;
private JPanel westPanel;
private JLabel selectNationPanel;
private JLabel currencyToConvett;
private JLabel currencyConverted;
private JComboBox currencyType;
private JTextField input;
private JTextField output;
private JPanel eastPanel;
private JPanel southPanel;
private JButton convertButton;
private JButton clearButton;
private JLabel convertToLabel;
private JComboBox convertType;
private JPanel northPanel;
public int selection1;
public int selection2;
public Double toConvert;
public double[][] rate1={{0,0.1335,0.1449,16.5172,163.4922},{7.4927,0,1.0857,123.7900,
1225.0380},{6.9029,0.9382,0,114.01,1129.19},{0.06053,0.00808,0.008771,0,9.9043},{0.006112,
0.0008158,0.0008856,0.101,0}};
public layout() {
currencyType.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
selection1 = currencyType.getSelectedIndex();
}
});
convertType.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
selection2 = convertType.getSelectedIndex();
}
});
convertButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if(selection1==selection2){
JOptionPane.showConfirmDialog(null, "You have to choose different currency types!", "Error Alert", JOptionPane.CANCEL_OPTION);
}
output.setText("");
toConvert = Double.parseDouble(input.getText().toString());
Double convertResult = toConvert*rate1[selection1][selection2];
output.setText(convertResult.toString());
}
});
clearButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
output.setText("");
input.setText("");
convertType.setSelectedIndex(0);
currencyType.setSelectedIndex(0);
}
});
}
public static void main(String[] args) {
JFrame frame = new JFrame("layout");
frame.setContentPane(new layout().converterRootPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
//layout lay = new layout();
}
private void createUIComponents() {
// TODO: place custom component creation code here
}
}

What you want to do is done through a layout manager. There are several of these for Java that are part of the standard library and there are also other custom ones such as MigLayout.
The Java tutorials have a whole section on layout managers here
A basic example of the GridBagLayout would be the following.
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Basic {
JFrame frame;
JPanel panel;
JLabel label;
JButton button;
public void createAndRun() {
frame = new JFrame("Basic Example");
setUp();
frame.getContentPane().add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private void setUp() {
panel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
label = new JLabel("I am a JLabel");
c.gridx = 0;
c.gridy = 0;
c.fill = GridBagConstraints.BOTH;
c.weightx = 0.5;
c.weighty = 0;
panel.add(label, c);
button = new JButton("I am a JButton");
c.gridx = 0;
c.gridy = 1;
c.weighty = 0.5;
panel.add(button, c);
}
public static void main(String[] args) {
Basic b = new Basic();
b.createAndRun();
}
}
However, as the tutorials put it.
"GridBagLayout is one of the most flexible — and complex — layout managers the Java platform provides."
So if you are having problems with GridBagLayout it may be worth looking at other layout managers beforehand.
Finally, I would like to suggest some ways that you might look at improving your code.
The part that caught my eye the most was this line.
frame.setContentPane(new layout().converterRootPanel);
I would recommend not creating the JFrame and initialising you Layout class in the main method. Instead, it would be worth initialising the class first and then calling a method to create the frame.
Layout l = new Layout();
l.createFrame();
This is shown in the example code above.

A GridBagLayout uses the weightx and weighty properties of GridBagConstraints to determine how extra space is distributed. GridBagLayout uses the largest weightx of all cells in a column to determine the column’s actual horizontal weight for all cells in that column, and similarly, the largest weighty of all cells in a row determines that row’s vertical weight. If all columns have a zero weightx, they are all centered horizontally. If all rows have a zero weighty, they are all centered vertically.
Usually a good design is to have the input fields stretch horizontally, while the labels remain the same size at all times. You probably want the rows to have same vertical spacing at all times, and have all extra space appear above or below the entire set of rows.
To make all cells of a particular column stretch, you only need to set the weightx of one cell in that column:
JPanel buttonPanel = new JPanel();
buttonPanel.add(convertButton);
buttonPanel.add(clearButton);
converterRootPanel = new JPanel(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.LINE_END;
// First row
converterRootPanel.add(selectNationPanel, gbc);
gbc.weightx = 1;
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;
converterRootPanel.add(currencyType, gbc);
gbc.weightx = 0;
gbc.insets.top = 3;
// Second row
gbc.gridwidth = 1;
gbc.fill = GridBagConstraints.NONE;
converterRootPanel.add(convertToLabel, gbc);
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;
converterRootPanel.add(convertType, gbc);
// Third row
gbc.gridwidth = 1;
gbc.fill = GridBagConstraints.NONE;
converterRootPanel.add(currencyToConvett, gbc);
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;
converterRootPanel.add(input, gbc);
// Fourth row
gbc.gridwidth = 1;
gbc.fill = GridBagConstraints.NONE;
converterRootPanel.add(currencyConverted, gbc);
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;
converterRootPanel.add(output, gbc);
// Button row
gbc.fill = GridBagConstraints.NONE;
gbc.anchor = GridBagConstraints.CENTER;
converterRootPanel.add(buttonPanel, gbc);

How to create new and dispose jcomponents multiple times?

(Sorry if this question is not done properly, I'm new. But at least I researched a lot before asking my own question)
Hello. I'm writing a blackjack game in java and it's turning quite massive. My problem is how to handle multiple instances of swing components, I guess you can call it. I can't figure out wether to create the components (such as jpanels and jbuttons) as class level, or in specific methods.
If I create them in their corresponding method, then my action listener can't see them, but if I create them as class level, then they get deleted when I call dispose().
class BlackjackGame extends JFrame implements ActionListener{
public void mainMenu(){
JPanel menuPane = new JPanel(new GridBagLayout()); //Init of main menu
GridBagConstraints c = new GridBagConstraints();
menuPane.setBackground(new Color(125,0,0));
menuPane.setBounds(620,220,175,250);
JLabel menuTitle = new JLabel("Welcome to Blackjack!");//Main menu-content
c.gridx = 1;
c.gridy = 0;
c.insets = new Insets(0,0,20,0);
menuPane.add(menuTitle, c);
JButton playButton = new JButton("Play!");
playButton.addActionListener(this);
c.gridx = 0;
c.gridy = 1;
c.gridwidth = 3;
c.ipadx = 25;
c.ipady = 25;
c.insets = new Insets(0,0,0,0);
menuPane.add(playButton, c);
JButton exitButton = new JButton("Exit!");
exitButton.addActionListener(this);
c.gridx = 0;
c.gridy = 2;
c.gridwidth = 3;
menuPane.add(exitButton, c);
JButton rulesButton = new JButton("Set rules.");
rulesButton.addActionListener(this);
c.gridx = 0;
c.gridy = 3;
c.gridwidth = 3;
menuPane.add(rulesButton, c);
this.add(menuPane,0);
}
//This is where I get problems
public void actionPerformed (ActionEvent event){
if(event.getSource() == playButton){
//I want the menuPane to disappear, and a transition into the game.
menuPane.dispose();
//Call method for the rest of the game.
}else if(event .getSource() etcetera etcetera){
etcetera etcetera
}
}
}
When done this way, the actionlistener cannot find my components, such as playButton or menuPane. But if I had introduced them as class level objects:
class BlackjackGame extends JFrame implements ActionListener{
JPanel menuPane = new JPanel(new GridBagLayout());
JLabel menuTitle = new JLabel("Welcome to Blackjack!");
JButton playButton = new JButton("Play!");
JButton exitButton = new JButton("Exit!");
JButton rulesButton = new JButton("Set rules.");
public void mainMenu(){
//Rest of code
}
public void actionPerformed(ActionEvent event){
menuPane.dispose();
//Rest of code
}
}
...then as I call menuPane.dispose(), how can I get it back when I want to call mainMenu() again? If I want to go back to the main menu, then I would need to create a new instance of menuPane, as well as all the buttons, but as they are class level and already disposed I can't.
Please help me, and thank you!
PS. I can post my full code as it is atm if it would help.
Edit: Dan's answer has been accepted, as it was indeed the correct answer and it worked for my specific program very well. Thank you and merry christmas!

First, unless I've misunderstood your code, menuPane.dispose() shouldn't work as JPanel does not have a function called dispose()
The best way to do what you want to do if you want to use the same menuPane for the menu. Instead of menuPane.dispose(); use remove(menuPane); and then add(yourOtherPanel);
Working Example
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class BlackjackGame extends JFrame implements ActionListener {
private JPanel menuPane;
private JLabel menuTitle;
private JButton playButton;
private JButton exitButton;
private JButton rulesButton;
private JPanel otherPane;
private JLabel otherTitle;
private JButton otherButton;
public BlackjackGame() {
mainMenu();
otherPanel();
setSize(400, 400);
setVisible(true);
}
private void mainMenu() {
menuPane = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
menuPane.setBackground(new Color(125,0,0));
menuPane.setBounds(620,220,175,250);
menuTitle = new JLabel("Welcome to Blackjack!");
c.gridx = 1;
c.gridy = 0;
c.insets = new Insets(0,0,20,0);
menuPane.add(menuTitle, c);
playButton = new JButton("Play!");
playButton.addActionListener(this);
c.gridx = 0;
c.gridy = 1;
c.gridwidth = 3;
c.ipadx = 25;
c.ipady = 25;
c.insets = new Insets(0,0,0,0);
menuPane.add(playButton, c);
exitButton = new JButton("Exit!");
exitButton.addActionListener(this);
c.gridx = 0;
c.gridy = 2;
c.gridwidth = 3;
menuPane.add(exitButton, c);
rulesButton = new JButton("Set rules.");
rulesButton.addActionListener(this);
c.gridx = 0;
c.gridy = 3;
c.gridwidth = 3;
menuPane.add(rulesButton, c);
add(menuPane);
}
private void otherPanel() {
otherPane = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
otherPane.setBackground(new Color(125,0,0));
otherPane.setBounds(620,220,175,250);
otherTitle = new JLabel("Welcome to Second Pane!");
c.gridx = 1;
c.gridy = 0;
c.insets = new Insets(0,0,20,0);
otherPane.add(otherTitle, c);
otherButton = new JButton("Go Back!");
otherButton.addActionListener(this);
c.gridx = 0;
c.gridy = 1;
c.gridwidth = 3;
c.ipadx = 25;
c.ipady = 25;
c.insets = new Insets(0,0,0,0);
otherPane.add(otherButton, c);
}
public void actionPerformed (ActionEvent event) {
if(event.getSource() == playButton) {
remove(menuPane);
add(otherPane);
validate();
repaint();
} else if(event.getSource() == otherButton) {
remove(otherPane);
add(menuPane);
validate();
repaint();
}
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> new BlackjackGame());
}
}
Edit for comments
So the java method remove() only removes the object from the container, which in this case is the JFrame. This method does not effect the object it moves so the object can be reused later. Hence why in the code above I can just use the remove() and add() methods without redeclaring or remaking menuPane and otherPane.
As for why I declare the objects like this
`private JPanel menuPane;`
And then initialize like this
menuPane = new JPanel(new GridBagLayout());
This is because I want the ActionListener to be able to see the objects without initializing them straight away. The line private JPanel menuPane; makes the object a global variable and the line menuPane = new JPanel(new GridBagLayout()); makes it into what I am going to use. Doing it this way instead of JPanel menuPane = new JPanel(new GridBagLayout()); also means I can reuse the same variable in multiple methods. For example
private JPanel panel;
private void createPanelOne() {
panel = new JPanel(new FlowLayout());
...
add(panel);
}
private void createPanelTwo() {
panel = new JPanel(new GridBagLayout());
...
add(panel);
}
After doing this, you will have two JPanels in your JFrame and they will be different, but you only need to use one JPanel
This is the other way of declaring it and it makes a local variable. Local variables aren't visible to other methods outside of the method you are using unless you pass them through.
JPanel panel = new JPanel();
I wouldn't say this is a con in the slightest. I think sometimes it is good to use local variables in a method that shouldn't be visible to other methods.
Finally to pass local variables through to other methods you can use arguments in a method you have made. For example
public void setSomeValue(int val) {
someValue = val;
}

Can not figure out a simple 4 box JPanel layout

I have been trying for hours to get JPanel in Java to contain these 4 other panels in this configuration (see picture)
The blue box should never change size.
The white box should never change height, can get wider though.
The dark grey box should never change widths, can get taller though.
The light grey box can get taller or wider.
Seems pretty simple to me, I did it in C# the other day and it was a breeze. Set the position, the width, height, and whether a certain side was anchored or not, boom done, I was starting to like java more than C until I ran into this.
I've tried countless combinations of GridBagLayout, multiple nested BoxLayout instances. They all seem to do very strange things, like make each panel a tiny 4 x 4 square, or there is crazy padding around them, or the ones that need to re-size with the window, don't.
Is there some kind of magic combination that can achieve this? Does the null layout do anchoring or percent dimensions.
The closest I've gotten is the bottom image with GridBagLayout, which looks good when it loads, but does that when you re-size the window.
Here is the code that got the above images
class MainPanel extends JPanel {
public MainPanel(){
this.setBackground(new Color(216,216,216));
this.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
JPanel topTitle = new JPanel();
topTitle.setPreferredSize(new Dimension(140, 40));
topTitle.setMinimumSize(new Dimension(140, 40));
topTitle.setBackground(new Color(174, 216, 249));
c.weightx = 0.5;
c.gridx = 0;
c.gridy = 0;
this.add(topTitle,c);
JPanel mainHeader = new JPanel();
mainHeader.setPreferredSize(new Dimension(1060, 40));
mainHeader.setMinimumSize(new Dimension(1060, 40));
mainHeader.setBackground(Color.WHITE);
c.gridx = 1;
c.gridy = 0;
this.add(mainHeader,c);
JPanel sideNav = new JPanel();
sideNav.setPreferredSize(new Dimension(140, 760));
sideNav.setMinimumSize(new Dimension(140, 760));
sideNav.setBackground(new Color(110,110,110));
c.gridx = 0;
c.gridy = 1;
this.add(sideNav,c);
JPanel dataPanel = new JPanel();
dataPanel.setPreferredSize(new Dimension(1060, 760));
dataPanel.setMinimumSize(new Dimension(1060, 760));
dataPanel.setBackground(new Color(216,216,216));
c.gridx = 1;
c.gridy = 1;
this.add(dataPanel,c);
}
}

GUI at minimum size
GUI stretched wider & taller
It's all about getting appropriate resize weights & fill values..
import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class FourPanelLayout {
private JComponent ui = null;
FourPanelLayout() {
initUI();
}
public void initUI() {
if (ui!=null) return;
ui = new JPanel(new GridBagLayout());
// It appears you don't want space around the panels.
// If not, commment out or remove this line.
ui.setBorder(new EmptyBorder(4,4,4,4));
// create the panels, each with a transparent image to suggest a size
JPanel bluePanel = new JPanel();
bluePanel.setBackground(Color.CYAN);
bluePanel.add(new JLabel(new ImageIcon(getTransparentImage(40, 20))));
JPanel darkGrayPanel = new JPanel();
darkGrayPanel.setBackground(Color.DARK_GRAY);
darkGrayPanel.add(new JLabel(new ImageIcon(getTransparentImage(40, 20))));
JPanel whitePanel = new JPanel();
whitePanel.setBackground(Color.WHITE);
whitePanel.add(new JLabel(new ImageIcon(getTransparentImage(40, 20))));
JPanel grayPanel = new JPanel();
grayPanel.setBackground(Color.GRAY);
grayPanel.add(new JLabel(new ImageIcon(getTransparentImage(360, 80))));
GridBagConstraints gbc = new GridBagConstraints();
gbc.fill = GridBagConstraints.BOTH;
gbc.weightx = 0.0f;
gbc.weighty = 0.0f;
gbc.gridx = 0;
gbc.gridy = 0;
ui.add(bluePanel, gbc);
gbc.weightx = .5f;
gbc.gridx = 1;
ui.add(whitePanel, gbc);
gbc.weighty = .5f;
gbc.gridy = 1;
ui.add(grayPanel, gbc);
gbc.weightx = 0f;
gbc.gridx = 0;
//gbc.gridy
ui.add(darkGrayPanel, gbc);
}
/* We use transparent images to give panels a natural size. */
private Image getTransparentImage(int w, int h) {
return new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
}
public JComponent getUI() {
return ui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception useDefault) {
}
FourPanelLayout o = new FourPanelLayout();
JFrame f = new JFrame(o.getClass().getSimpleName());
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o.getUI());
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}

To implement this, I recommended to use FormLayout.
FormLayout is a powerful, flexible and precise general purpose layout manager. It places components in a grid of columns and rows, allowing specified components to span multiple columns or rows. Not all columns/rows necessarily have the same width/height.
Note: It good to use Windowbuilder in Eclipse or GUI Form in Intellij to automatically place and set the components properties.

how to put components in the center in a CardLayout panel

I have a frame that has couple of panels and they change by CardLayout.
Inside each panel i will have different components. To design the GUI of the panel I used GridBagLayout. But the problem is any component or Layout I use for these paneles, they all stay at the top of the page. So basically the panel size of the CardLayout is some small amount of the frame. I want to make the sub panel size as large as the main CardLayout size.
Code for main CardLayout:
public class MainPanel extends JPanel {
private CardLayout cl = new CardLayout();
private JPanel panelHolder = new JPanel(cl);
public MainPanel() {
NewSession session = new NewSession(this);
ChooseSource chooseSource = new ChooseSource(this);
panelHolder.add(session, "1");
panelHolder.add(chooseSource, "2");
cl.show(panelHolder, "dan");
add(panelHolder);
}
public void showPanel(String panelIdentifier){
cl.show(panelHolder, panelIdentifier);
}
}
A sub panel:
public class ChooseSource extends JPanel {
MainPanel ob2;
JButton btn;
JLabel label;
JTextField field;
public ChooseSource(MainPanel mainPanel){
this.ob2 = mainPanel;
btn = new JButton("Browse");
label = new JLabel("Folder ");
field = new JTextField();
btn.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e){
ob2.showPanel("1");
}
});
GridBagLayout layout = new GridBagLayout();
setLayout(layout);
GridBagConstraints c = new GridBagConstraints();
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 0;
c.gridy = 0;
c.ipady = 20;
c.gridheight = 2;
add(btn, c);
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 1;
c.gridy = 0;
c.ipady = 10;
c.gridheight = 1;
c.insets = new Insets(0,10,0,0);
add(label, c);
c.fill = GridBagConstraints.HORIZONTAL;
c.gridx = 1;
c.gridy = 1;
c.ipady = 0;
c.gridheight = 1;
c.insets = new Insets(0,10,0,0);
add(field, c);
}
}
The left image shows how it is not, and right one is the one I am trying to make. basically I want to have access to all the available space of the panel.
Any idea?

Change the layout manager of MainPanel to something like BorderLayout or GridBagLayout

GridBagLayout alignment and Button style

I am trying to align a button using the GridBagLayout but it look I just can't achieve that. Also I want to remove the JButton's texture from my custom button, but I can not.. This is what it looks like:
I want the buttons to be at the top( but using GridBagLayout) and also on the left and right margin of the green button there is the remains of the JButton style and I can't remove it completely.
Also, this is my code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TestPanel{
public TestPanel(){
JFrame frame = new JFrame();
frame.add(new Panel1());
frame.setVisible(true);
frame.setSize(300, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
new TestPanel();
}
public class Panel1 extends JPanel{
/**
*
*/
private static final long serialVersionUID = 1L;
public Panel1(){
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
ImageIcon im = new ImageIcon("Start.png");
ImageIcon i = new ImageIcon("Start-Pressed.png");
JButton button = new JButton(im);
JButton but = new JButton("BUT");
button.setRolloverEnabled(true);
Insets margin = new Insets(-15,-10,-10,-10);
button.setBorderPainted(false);
button.setMargin(margin);
button.setRolloverIcon(i);
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx=0.5;
c.gridx=0;
c.gridy=0;
add(button, c);
c.gridx=2;
c.gridy=1;
add(but,c);
}
}
}
Edit:
c.gridy++;
c.fill = GridBagConstraints.VERTICAL;
c.weighty = 1;
c.add(new JLabel(" "),c);
c.gridy++;
c.weighty = 1;
c.fill = GridBagConstraints.NONE;
add(eButton, c);

You can achive it with help of dummy JLabel at bottom, like next(add to the end of constructor):
c.gridy++;
c.fill = GridBagConstraints.VERTICAL;
c.weighty = 1;
add(new JLabel(" "), c);
To remove margin you can try setContentAreaFilled() method
Instead of ImageIcon im = new ImageIcon("Start.png"); use ImageIcon im = new ImageIcon(Panel1.class.getResource("Start.png"));
Also see that answer.