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Is there an option to add ScrollPane without disabling CardLayout?

I have a card layout where I switch panels with a button. However, the code (switching panels) works only when lines:
JScrollPane scrPane = new JScrollPane(card1);
frame.add(scrPane);
are removed. In other case, clicking button achieves nothing. Is there an option to keep the scrolling (I need this, since the main application will have a lot of wrapped text) without disabling an option to switch cards?
package com.code;
import javax.swing.*;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.awt.event.*;
public class Card {
public static void main(String[] args) {
JFrame frame = new JFrame("App");
frame.setVisible(true);
frame.setSize(1200, 800);//Give it a size
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JPanel mainPanel = new JPanel(new CardLayout());
frame.add(mainPanel);
JPanel menu = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel card1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel card2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
mainPanel.add(menu, "menu");
mainPanel.add(card1, "card1");
mainPanel.add(card2, "card2");
JLabel l1 = new JLabel("label 1");
JLabel l2 = new JLabel("label 2");
card1.add(l1);
card2.add(l2);
JButton click = new JButton("Click!");
menu.add(click);
JScrollPane scrPane = new JScrollPane(card1);
frame.add(scrPane);
click.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
CardLayout cardLayout = (CardLayout) mainPanel.getLayout();
cardLayout.show(mainPanel, "card1");
}
});
}
}

A JFrame (its content pane) uses BorderLayout by default. That means you can have only 1 component at BorderLayout.CENTER. When you frame.add(component) the default constraints is BorderLayout.CENTER.
Now, you frame.add(mainPanel); and then frame.add(scrPane);. So main panel is removed, since scrPane is being added after it.
Doing JScrollPane scrPane = new JScrollPane(card1); it means you add a scrollpane to card1, and not in content pane. I guess that you want it to the content pane (the whole frame). So the fix is to delete frame.add(mainPanel); and do the following:
JScrollPane scrPane = new JScrollPane(mainPanel);
frame.add(scrPane);
Now, the main panel is added to scrPane and scrPane is added to the frame.
However, your GUI will be empty after that, because you frame.setVisible(true); before you are finished adding components to it. Take a look at Why shouldn't I call setVisible(true) before adding components?
Eventually, full code is:
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
JFrame frame = new JFrame("App");
frame.setSize(1200, 800);//Give it a size
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
JPanel mainPanel = new JPanel(new CardLayout());
JPanel menu = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel card1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
JPanel card2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
mainPanel.add(menu, "menu");
mainPanel.add(card1, "card1");
mainPanel.add(card2, "card2");
JLabel l1 = new JLabel("label 1");
JLabel l2 = new JLabel("label 2");
card1.add(l1);
card2.add(l2);
JButton click = new JButton("Click!");
menu.add(click);
JScrollPane scrPane = new JScrollPane(mainPanel);
frame.add(scrPane);
click.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
CardLayout cardLayout = (CardLayout) mainPanel.getLayout();
cardLayout.show(mainPanel, "card1");
}
});
frame.setVisible(true);
});
}
Some good links I suggest you to read are the Initial Threads and What does .pack() do?

How to get JTabbedPane in JSplitPane to fill the whole window?

My JTabbedPane is in a JSplitPane in a JPanel, like this, but I don't want it to be small like that:
I want it to look like this:
How do I do that?
Here is my code:
Tabbed_Tables.java
public void setupWidow(){
JPanel left = new JPanel();
JPanel right = new JPanel();
JTabbedPane EntryTabs = new JTabbedPane();
JTabbedPane ViewTabs = new JTabbedPane();
EntryTabs.addTab("Form Entry", new FormEntry());
EntryTabs.setOpaque(true);
EntryTabs.addTab("Table Entry", new TableEntry());
//EntryTabs.setSize(new Dimension(500,500));
//ViewTabs.setSize(new Dimension(200,200));
ViewTabs.add("Help Window", new HelpWindow());
left.add(EntryTabs);
right.add(ViewTabs);
JSplitPane splitPane= new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,left, right);
splitPane.setSize(new Dimension(pane.getWidth(),pane.getHeight()));
//((JFrame) pane).setContentPane(splitPane);
pane.add(splitPane,BorderLayout.CENTER);
//this.setSize(500, 500);
this.setVisible(true);
this.revalidate();
}

Either add the JTabbedPanes directly to the JSplitPane
JSplitPane splitPane= new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true, EntryTabs, ViewTabs);
Or change the layout managers for left and right to BorderLayout
JPanel left = new JPanel(new BorderLayout());
JPanel right = new JPanel(new BorderLayout());
See How to Use BorderLayout for more details

use this code
import java.awt.*;
import javax.swing.*;
class MyLayout extends JFrame
{
JPanel p1,p2;
JTabbedPane jtp;
public MyLayout()
{
setTitle("Tabed pane example");
setSize(750,400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
p1 = new JPanel();
p2 = new JPanel();
jtp = new JTabbedPane(JTabbedPane.TOP);
jtp.addTab("Table Entry",p1);
jtp.addTab("Chart Entry",p2);
add(jtp);
setVisible(true);
}
public static void main(String args[])
{
MyLayout m = new MyLayout();
}
}
you are not set frame size

How to align JPanel in java

I have a JPanel which is in a box layout but I am unsure how to align the JPanel to center of the window (and stay centered even if window is resized) I've tried looking for a solution but all questions seem over complicated compared to what it is that I'm looking for.
import java.awt.*;
import javax.swing.*;
public class Stacker extends JFrame {
public Stacker() {
super("Stacker");
setSize(430, 200);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// create top panel
JPanel commandPane = new JPanel();
BoxLayout vertical = new BoxLayout(commandPane,
BoxLayout.Y_AXIS);
commandPane.setLayout(vertical);
JButton subscribe = new JButton("Subscribe");
JButton unsubscribe = new JButton("Unsubscribe");
JButton refresh = new JButton("Refresh");
JButton save = new JButton("Save");
commandPane.add(subscribe);
commandPane.add(unsubscribe);
commandPane.add(refresh);
commandPane.add(save);
JMenuItem j1 = new JMenuItem("File");
JMenuItem j2 = new JMenuItem("Open");
JMenuItem j3 = new JMenuItem("Close");
JMenuBar menubar = new JMenuBar();
JMenu menu = new JMenu("Feeds");
menu.add(j1);
menu.add(j2);
menu.add(j3);
menubar.add(menu);
setJMenuBar(menubar);
// create bottom panel
/*JPanel textPane = new JPanel();
JTextArea text = new JTextArea(4, 70);
JScrollPane scrollPane = new JScrollPane(text);
// put them together
FlowLayout flow = new FlowLayout();
setLayout(flow);
add(commandPane);
add(scrollPane); */
setJMenuBar(menubar);
add(commandPane);
setVisible(true);
}
public static void main(String[] arguments) {
Stacker st = new Stacker();
}
}

You say you're using a BoxLayout, but is the JPanel with the BoxLayout the JPanel you want to center, or does it contain the JPanel you want to center?
If it contains the JPanel you want to center, then you can add a glue on either side of the JPanel to be centered. If it is the JPanel you want to center, then you can use GridBagLayout or BoxLayout to achieve the effect you're talking about.
Googling something like "Java center component" will give you a ton of results.

for this idea (still not clear from your description) use GridBagLayout without set for GridBagConstraints
.
.
.
import java.awt.*;
import javax.swing.*;
public class CenteredJPanel {
private JFrame frame = new JFrame("Test");
private JPanel panel = new JPanel();
private JButton subscribe = new JButton("Subscribe");
private JButton unsubscribe = new JButton("Unsubscribe");
private JButton refresh = new JButton("Refresh");
private JButton save = new JButton("Save");
public CenteredJPanel() {
panel.setLayout(new GridBagLayout());
panel.add(subscribe);
panel.add(unsubscribe);
panel.add(refresh);
panel.add(save);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
CenteredJPanel centeredJLabel = new CenteredJPanel();
}
});
}
}

How can I align elements in JPanels / JFrames?

I'm completely new to using the GUI in java, so I'm having a bit of trouble figuring out how to align everything that I need to. I have to panels in my JFrame that I need to align (One to the left, one to the right) and a few buttons in one of the panels that I need to be centered in the panel. Here is my code.
package application;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.io.*;
import java.nio.*;
import java.util.*;
public class Main extends JPanel
{
public static void main(String[] args)
{
//set the ui to the native OS
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}catch(ClassNotFoundException | InstantiationException | IllegalAccessException
| UnsupportedLookAndFeelException e)
{
}
JFrame frame = new JFrame("Application Name");
Menu menu = new Menu();
JPanel iconPanel = new JPanel();
final JPanel grid = new JPanel(new FlowLayout());
JButton firewallButton = new JButton("Firewall");
JButton networkButton = new JButton("Network");
JButton printerButton = new JButton("Printer");
int iconPanelSizeX;
int iconPanelSizeY;
int gridSizeX;
int gridSizeY;
int gridPosition;
//frame setting
frame.setSize(800, 600);
frame.setMinimumSize(new Dimension(800, 600));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
//add grid and iconPanel JPanels to the frame
frame.add(iconPanel);
iconPanel.add(firewallButton);
iconPanel.add(networkButton);
iconPanel.add(printerButton);
frame.add(grid);
//iconPanel settings
iconPanel.setBorder(BorderFactory.createLoweredSoftBevelBorder());
iconPanel.setBackground(Color.gray);
iconPanel.setLayout(new FlowLayout());
iconPanel.setSize(new Dimension(100, 600));
iconPanel.setVisible(true);
//grid setting
grid.setBackground(Color.red);
grid.setSize(new Dimension(700, 600));
grid.setVisible(true);
//this is for resizing components when the user resizes the window
int counter = 0;
while(counter == 0)
{
firewallButton.setSize(new Dimension(iconPanel.getWidth(), 50));
networkButton.setSize(new Dimension(iconPanel.getWidth(), 50));
printerButton.setSize(new Dimension(iconPanel.getWidth(), 50));
iconPanelSizeX = frame.getWidth() / 10;
iconPanelSizeY = frame.getHeight();
gridSizeX = (frame.getWidth() / 10) * 9;
gridSizeY = frame.getHeight();
iconPanel.setSize(new Dimension(iconPanelSizeX, iconPanelSizeY));
grid.setSize(new Dimension(gridSizeX, gridSizeY));
}
}
}
As you can see, the second JPanel (grid) doesn't line up with the right side of the frame, and the buttons inside iconTray don't center either. I realize these are both probably simple layout fixes, but I have no clue where to start.

For simple splitting of JFrame you can use GridLayout with 1 row and 2 colums.
frame.setLayout(new GridLayout(1,2,3,3)); //3,3 are gaps
frame.add(grid);
frame.add(iconPanel);
For centering components in panels you can use FlowLayout which is by default set on JPanels:
Doing it manualy:
grid.setLayout(new FlowLayout()); //Centered components
grid.setLayout(new FlowLayout(FlowLayout.LEFT,3,3)); //Components aligned to left
grid.setLayout(new FlowLayout(FlowLayout.RIGHT,3,3)); //Components aligned to right
This is how it looks:
Also, few observations:
Never call setXXXSize() methods for your components;
Try to avoid calling setSize(); for JFrame, call pack(); instead;
Call setVisible(true); in the end of code;
All your huge code can be "stripped" to this:
import javax.swing.*;
import java.awt.*;
public class Main extends JPanel
{
public static void main(String[] args)
{
JFrame frame = new JFrame("Application Name");
JPanel iconPanel = new JPanel();
JPanel grid = new JPanel(new FlowLayout());
JButton firewallButton = new JButton("Firewall");
JButton networkButton = new JButton("Network");
JButton printerButton = new JButton("Printer");
frame.add(iconPanel);
iconPanel.add(firewallButton);
iconPanel.add(networkButton);
iconPanel.add(printerButton);
grid.setBackground(Color.GREEN);
frame.setLayout(new GridLayout(1,2,3,3));
frame.add(grid);
frame.add(iconPanel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}

how to align buttons vertically?
This example uses a vertical Box in the WEST area of the frame's default BorderLayout:
import java.awt.*;
import javax.swing.*;
/** #see http://stackoverflow.com/a/14927280/230513 */
public class Main {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
display();
}
});
}
private static void display() throws HeadlessException {
JFrame frame = new JFrame("Application Name");
JButton firewallButton = new JButton("Firewall");
JButton networkButton = new JButton("Network");
JButton printerButton = new JButton("Printer");
//iconPanel settings
Box iconPanel = new Box(BoxLayout.Y_AXIS);
iconPanel.add(firewallButton);
iconPanel.add(networkButton);
iconPanel.add(printerButton);
iconPanel.setBackground(Color.gray);
iconPanel.setVisible(true);
frame.add(iconPanel, BorderLayout.WEST);
//grid setting
JPanel grid = new JPanel() {
#Override
// arbitrary placeholder size
public Dimension getPreferredSize() {
return new Dimension(320, 230);
}
};
grid.setBackground(Color.red);
frame.add(grid, BorderLayout.CENTER);
//frame setting
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}

I suggest you take some time going through A Visual Guide to Layout Managers. This will help you become familiar with the layout managers which are available with the Standard API. It takes some experience and hard work to figure out which of these is the right tool to get the exact look you want. Once you become comfortable with what is available from the Standard API, you should also look around for third-party Layout Manager APIs which provide other options.

I have to panels in my JFrame that I need to align (One to the left,
one to the right) and a few buttons in one of the panels that I need
to be centered in the panel. Here is my code.
I realize these are both probably simple layout fixes, but I have no
clue where to start.
Use more complex layout than simple FlowLayout which you actually using. I suggest to you use
GridBagLayout
BoxLayout
Check references here

JScrollPane won't work

Hey guys I wanted to create a JScrollPane but it won't work... and I don't know why... here's my code...
public class test extends JFrame{
public test(){
setSize(1000,600);
}
private static JButton[] remove;
private static JPanel p = new JPanel();
public static void main(String[]args){
p.setLayout(null);
JFrame t=new test();
remove = new JButton[25];
for(int i=0;i<25;i++){
remove[i]=new JButton("Remove");
remove[i].setBounds(243,92+35*i,85,25);
p.add(remove[i]);
}
JScrollPane scrollPane = new JScrollPane(p);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
t.add(scrollPane);
t.setVisible(true);
}
Umm and Im pretty sure the frame isn't big enough for these 25 buttons... But if i delete that p.setLayout(null); A horizontal scroll bar will be created automatically... I don't really know what is wrong with my code... Pls help thank you very much!

You need to set p's preferredSize for this to work.
p.setPreferredSize(new Dimension(800, 2000));
Or you could have p extend JPanel and then override the getPreferredSize() method to return the proper dimension.
And I agree -- get rid of your null layouts. Learn about and use the layout managers if you want to use Swing correctly and have robust Swing GUI's.
e.g.,
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Foo extends JFrame {
private static final int BUTTON_COUNT = 25;
public static void main(String[] args) {
JPanel btnPanel = new JPanel(new GridLayout(0, 1, 0, 20));
btnPanel.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
AbstractAction removeAction = new AbstractAction("Remove") {
#Override
public void actionPerformed(ActionEvent evt) {
JButton src = (JButton) evt.getSource();
JPanel container = (JPanel) src.getParent();
container.remove(src);
container.revalidate();
container.repaint();
}
};
for (int i = 0; i < BUTTON_COUNT; i++) {
JButton removeBtn = new JButton(removeAction);
btnPanel.add(removeBtn);
}
JPanel borderPanel = new JPanel(new BorderLayout());
borderPanel.add(btnPanel, BorderLayout.NORTH);
JScrollPane scrollpane = new JScrollPane(borderPanel,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scrollpane.setPreferredSize(new Dimension(400, 800));
JFrame frame = new JFrame("Foo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(scrollpane);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}

The issue is that a scroll pane checks the component inside it for a "preferred size" so a pane with a null layout has a preferred size of (0,0). Which it ignores.
You should do something along the lines of:
p.setPreferredSize(1000,600);
And you should see some scroll bars appear, I'm not sure how accurate they will be though.