Develop Reference

jsplitpane and paintcomponent conflicting with each other

I'm having issues with my code regarding the fact that when I instantiate my City class as an object and add it to the right side of my JSplitPane (or even the left), the circle that is supposed to be drawn is not showing up. My cities class uses paintComponent and should draw a circle just by calling the constructor. I have also tried putting the repaint in its own drawIt() method but the result is still the same. The buttons and spinner show up on the left side of the divider, but the circle I am trying to draw does not show up at all.
Here is my City class.
import javax.swing.*;
import java.awt.*;
public class City extends JPanel{
int xPos, yPos;
City(int x, int y){
xPos = x;
yPos = y;
repaint();
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillOval(xPos, yPos, 10, 10);
}
}
And here is my main.
Here I try to instantiate my city and add it to the right side of the JSplitPane (under Add Components) and that is where I am having issues with, as the black circle will not be drawn on the JSplitPane.
import java.awt.*;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.JSplitPane;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingUtilities;
public class TSP{
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new TSP();
}
});
}
TSP(){
JLabel instructions = new JLabel("Enter the number of cities: ");
instructions.setBounds(30, 150, 300, 40);
SpinnerNumberModel numMod = new SpinnerNumberModel(2, 2, 10, 1);
JSpinner numOfCities = new JSpinner(numMod);
numOfCities.setBounds(185, 150, 80, 40);
JButton start = new JButton("Start Simulation");
start.setBounds(50, 400, 200, 40);
JFrame frame = new JFrame("Travelling Salesperson");
JSplitPane sp = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
JPanel lp = new JPanel(null);
JPanel rp = new JPanel(null);
sp.setDividerLocation(300);
sp.setLeftComponent(lp);
sp.setRightComponent(rp);
sp.setEnabled(false);
frame.setDefaultCloseOperation(3);
frame.setSize(1100,600);
frame.setResizable(false);
////////////////Add Components//////////////////////////
lp.add(instructions);
lp.add(numOfCities);
lp.add(start);
City test = new City(301, 301);
rp.add(test);
frame.add(sp);
////////////////////////////////////////////////////////
frame.setVisible(true);
}
}
I feel like the circle is being drawn under the JSplitPane as if I add my cities object (test) to my frame instead of the JSplitPane(frame.add(test) instead of rp.add(test) under the Add Components section) the black circle will appear in the desired spot but the JSplitPane along with the buttons and spinners will disappear so I feel as if they are conflicting. Is there any fix to this or is there another way altogether to make the circle appear on the right side while the other components are on the left side.
I do not know why it is not drawing the circle on the JSplitPane, but any sort of help would be appreciated. Thanks!
Sorry if anything is unclear or there is any ambiguity in my code, or if I need to post more information as I am quite new to posting here. Let me know if there is anything else I need to add or if there are any questions regarding what I am asking!
EDIT:
It seems there is something blocking where I draw the circle, like another JPanel. Here is an image below. As you can see part of the circle looks as if it is being covered. The small box I drew is the only area that the dot is visible from (everywhere else the circle is covered up by white). Also, the coordinates for the circle in the image below is at (3, 0), i.e City test = new City(3, 0);
I am not quite sure why this is happening though.
the invisible JPanel?

Now that I've seen what you're trying to do, I can provide a more proper answer.
You have a control panel on the left and a drawing panel on the right. Usually, you don't use a JSplitPane to separate the panels. To create your layout, you would add the control panel to the LINE_START of the JFrame BorderLayout and the drawing panel to the CENTER.
The reason for this is that you don't want to constantly recalculate the size of the drawing panel.
So let me show you one way to get a solid start. Here's the GUI I created.
Here are the things I did.
All Swing GUI applications must start with a call to the SwingUtilities invokeLater method. This method ensures that Swing components are created and executed on the Event Dispatch Thread.
I separated the creation of the JFrame, the control panel, and the drawing panel. That way, I could focus on one part of the GUI at a time.
The JFrame methods must be called in a certain order. This is the order that I use for most of my Swing applications.
The JFrame is not sized. It is packed. The Swing layout managers will calculate the size of the components and the JPanels.
I used a FlowLayout and a GridBagLayout to create the control panel. Yes, this looks more complicated than absolute positioning, but in the long run, layout managers allow the GUI to be more flexible.
I used the setPreferredSize method in the drawing panel to set the preferred size of the drawing panel. Because I know the drawing panel size, I can put the first city in the center of the drawing panel.
And here's the code. You don't have to code exactly like this, but this code should give you a good basis to start your project. Take a look at the model / view / controller pattern and see how to further separate your code into smaller pieces that allow you to focus on one part of your application at a time.
I put all the classes in one file to make it easier to paste. You should separate these classes into separate files.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingUtilities;
public class CitySimulation implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new CitySimulation());
}
private ControlPanel controlPanel;
private DrawingPanel drawingPanel;
private JFrame frame;
#Override
public void run() {
frame = new JFrame("Traveling Salesperson");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
controlPanel = new ControlPanel();
frame.add(controlPanel.getPanel(), BorderLayout.LINE_START);
drawingPanel = new DrawingPanel();
frame.add(drawingPanel, BorderLayout.CENTER);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public class ControlPanel {
private JPanel panel;
public ControlPanel() {
panel = new JPanel(new FlowLayout());
JPanel mainPanel = new JPanel(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.anchor = GridBagConstraints.LINE_START;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.gridx = 0;
gbc.gridy = 0;
gbc.insets = new Insets(10, 10, 10, 10);
JLabel instructions = new JLabel("Enter the number " +
"of cities:");
mainPanel.add(instructions, gbc);
gbc.gridx++;
gbc.insets = new Insets(10, 0, 10, 10);
SpinnerNumberModel numMod =
new SpinnerNumberModel(2, 2, 10, 1);
JSpinner numOfCities = new JSpinner(numMod);
mainPanel.add(numOfCities, gbc);
gbc.anchor = GridBagConstraints.CENTER;
gbc.gridx = 0;
gbc.gridy++;
gbc.gridwidth = 2;
gbc.insets = new Insets(10, 10, 10, 10);
JButton start = new JButton("Start Simulation");
mainPanel.add(start, gbc);
panel.add(mainPanel);
}
public JPanel getPanel() {
return panel;
}
}
public class DrawingPanel extends JPanel {
private static final long serialVersionUID = 1L;
public DrawingPanel() {
this.setBackground(Color.WHITE);
this.setPreferredSize(new Dimension(400, 400));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillOval(195, 195, 10, 10);
}
}
}

Nothing happens when setting the background of JScrollPane.getViewPort()

I have a JPanel with layout set to null and the background is white. Then I added that JPanel to JScrollPane.
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class TestJScollPane extends JPanel {
private static final long serialVersionUID = 1L;
public TestJScollPane() {
initUI();
}
private void initUI()
{
JScrollPane scrollPane = new JScrollPane();
scrollPane.getViewport().setBackground(Color.GRAY);
scrollPane.setBounds(1, 1, 200, 200);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
setBorder(BorderFactory.createEtchedBorder(Color.GREEN, Color.MAGENTA));
setBackground(Color.WHITE);
setLayout(null);
JFrame frame = new JFrame();
scrollPane.setViewportView(this);
frame.add(scrollPane);
frame.setLayout(null);
frame.setVisible(true);
frame.setSize(800, 500);
frame.getContentPane().setBackground(Color.BLACK);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(30,30);
}
public static void main(String[] args)
{
new TestJScollPane();
}
}
My scenario is I have a zoom tool that if I zoom out the JPanel and all its shapes that were painted were scaled using AffineTransform. So I expect that if I zoom out, the background of JScrollPane was color gray but the actual was color white.
Apologies, I added a sample. Actually, this is not the actual code I created this so that I can provide a sample for you guys to help me.
I set the preferred size of JPanel to 30x30 so I expect that the background of JScrollPane will become visible but it was not.
Thanks in advance for any help.

By default the panel is sized to fit the viewport so you will not see the background of the viewport.
You need to implement the Scrollable interface of your JPanel to tell the scroll pane you want the panel displayed at its preferred size.
Or, instead of implementing the Scrollable interface yourself you can use the Scrollable Panel which, by default, will display the panel at its preferred size.
Changes to your code would be:
ScrollablePanel panel = new ScrollablePanel();
panel.setPreferredSize( new Dimension(30, 30) );
panel.setBorder(BorderFactory.createEtchedBorder(Color.GREEN, Color.MAGENTA));
panel.setBackground(Color.WHITE);
//panel.setLayout(null);
scrollPane.setViewportView(panel);
//scrollPane.setViewportView(this);

Change:
scrollPane.setViewportView(this);
To something like:
JPanel centerPanel = new JPanel(new GridBagLayout());
centerPanel.add(this);
scrollPane.setViewportView(centerPanel);
A GridBagLayout (by default, unless configured otherwise) will respect the preferred size of the child components and won't stretch them to fill the 'cell'. A scroll pane on the other hand, will stretch the content to (at least) fill the visible area.
Result:
But seriously, drop the use of null layouts. If the effect cannot be achieved using an existing layout (inbuilt or 3rd party) or a combination of layouts, it must have such esoteric positioning constraints that it deserves a custom layout manager.

Why do my images not display in my panels?

I want to set a background for my game.
Scenario:
First of all, I have to read from a text file, and then draw my tile map and images on it base on that texts. Second, my map is 3600*2400 pixels and it's larger than my screen so I have to scroll it. Third, there must be a mini map on the corner of my screen showing me where i am. (I guess I should use panels and awt.container.)
Here is my code:
public class bkg extends Panel implements ImageObserver {
//i Initialize my variables here
// then read my images with image buffer in constructor
public static void main(String[] args) {
//my three panels and frame settings
Frame frame = new Frame();
frame.setLayout(null);
frame.setSize(1350, 700);
frame.setTitle("age of empires");
frame.setVisible(true);
frame.setLayout(null);
Panel p1 = new Panel();
Panel p2 = new Panel();
p2.setLayout(null);
JPanel p3 = new JPanel();
p3.setLayout(null);
p1.setSize(1350, 700); // i divide my screen in to 3 parts , one biggest panel, and two small. the biggest one is for main map
p1.setLayout(null);
p2.setBackground(Color.cyan);//just wanna test showing my panel.
p2.setSize(675, 350);
p3.setSize(675, 350);
p1.setLocation(0, 0);
p2.setLocation(0, 350);// this small panel must be under the main pannel.
p3.setLocation(675, 350);// this is with p2.
frame.add(p1);
p1.add(p2);
p2.add(p3);
tilemap = new int[60][75];// it creat my tilemap in console.
filereader();// it reads the text file.
}
#Override
public void paint(Graphics g) {
super.paint(g);
for (int i = 0; i < rows; i++) {
for (int j = 0; j < columns; j++) {
int mod_i = 100 * i;// based on images sizes
int mod_j = 50 * j;// based on images sizes
//now i start to draw images base on the text file numbers
switch (tilemap[i][j]) {
case 1:
g.drawImage(tree, mod_i, mod_j, null);
break;
.........
}
}
}
}
Question: Seems that my code can't even see the paint method. It doesn't draw any images on my panels. What's the problem?

Your code is so full of errors that I started from the beginning to create a GUI divided into 3 areas.
You must start a Swing application with a call to the SwingUtilities invokeLater method. This ensures that the Swing application starts on the Event Dispatch thread (EDT).
A Java class name starts with a capital letter. Java method names and variable names start with a lowercase letter.
Don't put everything in your main method. Break your code up into methods that do one thing well. My run method creates the JFrame. My createMainPanel method creates the main panel.
I used Swing layout managers to position the JPanels. Yes, using absolute positioning seems like it's easier, but you can't move your application to any other computer with a different screen resolution.
I decided to stop at this point. You would create further methods and / or classes to further define the 3 JPanels. In those JPanel methods / classes, you would override the paintComponent method, not the paint method.
Here's the code.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class AgeOfEmpires implements Runnable {
private JFrame frame;
public static void main(String[] args) {
SwingUtilities.invokeLater(new AgeOfEmpires());
}
#Override
public void run() {
frame = new JFrame();
frame.setTitle("Age of Empires");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createMainPanel());
frame.pack();
frame.setVisible(true);
}
private JPanel createMainPanel() {
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new BorderLayout());
JPanel upperPanel = new JPanel();
upperPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 0, 0));
JPanel tilePanel = new JPanel();
tilePanel.setBackground(Color.CYAN);
tilePanel.setPreferredSize(new Dimension(800, 300));
upperPanel.add(tilePanel);
JPanel lowerPanel = new JPanel();
lowerPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 0, 0));
JPanel miniMapPanel = new JPanel();
miniMapPanel.setBackground(Color.BLUE);
miniMapPanel.setPreferredSize(new Dimension(400, 300));
JPanel unknownPanel = new JPanel();
unknownPanel.setBackground(Color.GREEN);
unknownPanel.setPreferredSize(new Dimension(400, 300));
lowerPanel.add(miniMapPanel);
lowerPanel.add(unknownPanel);
mainPanel.add(upperPanel, BorderLayout.CENTER);
mainPanel.add(lowerPanel, BorderLayout.SOUTH);
return mainPanel;
}
}

Trouble with borders

I'm trying to get clarification as to how borders work, specifically the insets, and in searching through the Java docs and numerous websites I can't seem to find a clear explanation. Looking at this code:
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
public class ShadowWindow {
public static void main(String[] args) {
new ShadowWindow();
}
public ShadowWindow() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setUndecorated(true);
frame.setBackground(new Color(0, 0, 0, 0));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new ShadowPane());
JPanel panel = new JPanel(new GridBagLayout());
panel.add(new JLabel("Look ma, no hands"));
frame.add(panel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ShadowPane extends JPanel {
public ShadowPane() {
setLayout(new BorderLayout());
setOpaque(false);
setBackground(Color.BLACK);
setBorder(new EmptyBorder(0, 0, 10, 10));
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setComposite(AlphaComposite.SrcOver.derive(0.5f));
g2d.fillRect(10, 10, getWidth(), getHeight());
g2d.dispose();
}
}
}
The way I interpret it this is what is happening:
JFrame frame (200 x 200) is created
JPanel shadowPane is created (also 200 x 200) with an empty border of 10 pixels created on the inside bottom and inside right of the JPanel
A second JPanel is created (200 x 200) and added on top of shadowPane
A rectangle is drawn (200 x 200) starting at x = 10 and y = 10
So my question in how is the shadowPane going past the range of the JFrame? Does the border go 10 pixels outside the JFrame or does it exist inside the JFrame. From everything I've found it should be inside, but that doesn't make sense based on how this code generates a shadow behind the frame. can anybody walk me through this? Thanks.

So my question in how is the shadowPane going past the range of the JFrame?
It's not. pack determines the preferred layout size of the content and makes the window big enough to accommodate it, because the frame is undercoated AND it's background is transparent, it "appears" as if the shadow hangs past the frame, it's an illusion.
The empty border is making sure that content added to the ShadowPane is "forced" into a small space.
Lets change the code slightly...
JFrame frame = new JFrame("Testing");
JPanel content = new JPanel(new BorderLayout());
content.setBackground(Color.RED);
//frame.setUndecorated(true);
//frame.setBackground(new Color(0, 0, 0, 0));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(content);
//frame.setContentPane(new ShadowPane());
JPanel panel = new JPanel(new GridBagLayout());
panel.add(new JLabel("Look ma, no hands"));
ShadowPane shadowPane = new ShadowPane();
shadowPane.add(panel);
frame.add(shadowPane);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
What this does, is creates a new background panel, filled with the color red. It also adds the window decoration back in.
As you can see, the shadow pane and the label are are all rendered within the confines of the window.
If we once again remove the window decoration...
You can see that it's still the same...
So what's going on?
getPreferredSize is providing the core information about how the component would like to be size (in this case 200x200)
The EmptyBorder is defining a usable space within the ShadowPane which defines an area within which content can be displayed, it's leaving 10 pixels to the right and bottom of the component, in which components can't be displayed. This is take care of automatically by the layout manager. This means that the ShadowPane can actually paint here itself, but components added to it will never be displayed here, hence the shadow board.
Basically, it's smoke and mirrors and used to generate the illusion of a drop shadow behind the content added to the frame (or the ShadowPane in this case)

JScrollPane & Graphics2D

I am trying to draw graphics that is bigger than the JFrame and use JScrollPane to scroll the entire graphics. I created a simple example with two lines. The scroll bars appear but the graphics do not show.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class Test extends JPanel{
public static void main(String... args) {
Test test = new Test();
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.add(test);
JScrollPane scrollPane = new JScrollPane(panel);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrollPane.setBounds(0, 0, 1350, 700);
JPanel contentPane = new JPanel(null);
contentPane.setPreferredSize(new Dimension(1400, 700));
contentPane.add(scrollPane);
frame.setContentPane(contentPane);
frame.pack();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setVisible(true);
}
#Override
protected void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D)g;
g2.drawLine(30,30,30,3000);
g2.drawLine(30, 400, 500, 3000);
}
}

Welcome to a wonderful example of why null layouts suck...
Avoid using null layouts, pixel perfect layouts are an illusion within modern ui design. There are too many factors which affect the individual size of components, none of which you can control. Swing was designed to work with layout managers at the core, discarding these will lead to no end of issues and problems that you will spend more and more time trying to rectify
Also see Why is it frowned upon to use a null layout in SWING? for more details...
The basic problem is, the JScrollPane, has a JViewport, which actually contains your component. The JViewport uses your components sizing hints to make determinations about how big it should be and the JScrollPane uses the decisions the JViewport makes to make determinations about whether it needs to display the scrollbars or not.
The JViewport is taking a look at your component and has decided, because you've not told it otherwise, that it should be 0x0 in size.
You can prove this by adding a LineBorder to your component, setBorder(new LineBorder(Color.RED));, you won't see it either (or if you do, it will be a little red square)
Start by overriding the getPrefferedSize method of the Test panel and return some appropriate size
Next, call super.paintComponent before you perform any custom painting, otherwise you'll end up with some awesome, but annoying, paint artifacts...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test extends JPanel {
public static void main(String... args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
Test test = new Test();
JFrame frame = new JFrame();
JScrollPane scrollPane = new JScrollPane(test);
frame.add(scrollPane);
frame.pack();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setVisible(true);
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(3000, 3000);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.drawLine(30, 30, 30, 3000);
g2.drawLine(30, 400, 500, 3000);
}
}
You'll probably want to take a look at the Scrollable interface next, so you can control the default size of the JViewport, so it won't try and fill the entire screen.
Take a look at Implementing a Scrolling-Savvy Client for more details

The problem comes from the lines
JPanel panel = new JPanel();
panel.add(test);
JScrollPane scrollPane = new JScrollPane(panel);
You are adding test to panel which uses FlowLayout by default. This layout does not strech the components in it, so test on which you draw has dimensions 0x0 and what you see in the scroll pane is the empty panel.
To fix this you can set panel to use BorderLayout which stretches the center component:
JPanel panel = new JPanel(new BorderLayout());
panel.add(test);
JScrollPane scrollPane = new JScrollPane(panel);
or add test directly to the scroll pane:
JScrollPane scrollPane = new JScrollPane(test);
Additionally:
Always call super.paintComponent(g) as the first line when overriding paintComponent.
Don't use null layouts (and consequently don't set bounds on components).
When you use setPreferredSize remember that if the dimensions are too large they will "flow off" the screen.