Develop Reference

add JScrollPane to Panel in JFrame

I want to add a JScrollPane to a JPanel. I have added some more code to this old question of mine.
I have a Panel class as follows:
import java.awt.*;
import javax.swing.JPanel;
public class Panel extends JPanel
{
public Panel()
{
super (true);
}
public void paintComponent (Graphics g)
{
super.paintComponent(g);
setBackground(Color.WHITE);
g.drawRect(250, 250, 10, 10);
}
}
and a JScrollPaneTest class as follows:
import javax.swing.*;
public class JScrollPaneTest extends JFrame
{
Panel panel = new Panel();
public JScrollPaneTest ()
{
super("Test JScrollPane");
add(new JScrollPane(panel, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS));
setSize(300,300);
setVisible(true);
}
public static void main (String[] args)
{
JScrollPaneTest test = new JScrollPaneTest();
test.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
I have drawn a small rectangle in the lower right corner on the Panel; apparently the JScrollPane does not work because when resizing the rectangle disappears.
Please let me know if you have any suggestions; thanks!

background image help, JPanel, JFrame, anything?

I want to make a background image for a game I'm designing but I cant figure out the right way to get the effect I want, I want a background that can be seen behind text etc. basically having the background cover the whole JFrame / JPanel not just one section of the layout (e.g. BorderLayout.Center) I think it does this anyway but if it does do that how do I make the background for those transparent to see the background which is behind...
Confusing i know but I hope someone here understands what I am trying to do and can help... this is my current code. I have been playing around with the background so dont read to much in how i have written it.
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
public class GamePanel extends JPanel {
private JTextPane playertext;
private JTextField wealthstring, currentwealth;
public GamePanel() {
super();
setLayout(new BorderLayout());
setBackground(Game.getBackgroundColor());
Border raised = BorderFactory.createRaisedBevelBorder();
Border lowered = BorderFactory.createLoweredBevelBorder();
setBorder(BorderFactory.createCompoundBorder(new EmptyBorder(4, 4, 4, 4), (BorderFactory.createCompoundBorder(raised, lowered))));
add(northpanel(), BorderLayout.NORTH);
add(eastpanel(), BorderLayout.EAST);
}
private JLabel northpanel() {
Font northfont = new Font("Engravers MT", Font.BOLD, 12);
ImageIcon banner = new ImageIcon("images/banner.png", "North Background");
playertext = new JTextPane();
playertext.setFont(northfont);
playertext.setEditable(false);
playertext.setText("Player: \n" + Game.getName());
playertext.setBackground(Game.getBackgroundColor());
playertext.setBorder(new EmptyBorder(10,10,10,10));
wealthstring = new JTextField("Money: ");
wealthstring.setFont(northfont);
wealthstring.setEditable(false);
wealthstring.setHorizontalAlignment(wealthstring.RIGHT);
wealthstring.setBorder(null);
wealthstring.setBackground(Game.getBackgroundColor());
currentwealth = new JTextField();
currentwealth.setFont(northfont);
currentwealth.setEditable(false);
currentwealth.setHorizontalAlignment(wealthstring.RIGHT);
currentwealth.setBackground(Game.getBackgroundColor());
currentwealth.setBorder(null);
String wealthrounded = String.format("%.2f", Game.getMoney());
currentwealth.setText(wealthrounded);
JPanel wealthtext = new JPanel();
wealthtext.setLayout(new GridLayout(2, 1));
wealthtext.setBackground(Game.getBackgroundColor());
wealthtext.setBorder(new EmptyBorder(10,10,10,10));
wealthtext.add(wealthstring);
wealthtext.add(currentwealth);
JLabel northpanel = new JLabel();
northpanel.setLayout(new BorderLayout());
northpanel.setIcon(banner);
northpanel.add(new JSeparator(), BorderLayout.PAGE_END);
northpanel.add(playertext, BorderLayout.WEST);
northpanel.add(wealthtext, BorderLayout.EAST);
return northpanel;
}
private JPanel eastpanel() {
JButton tab1 = new JButton("Tab 1");
JButton tab2 = new JButton("Tab 2");
JButton tab3 = new JButton("Tab 3");
JPanel easttabs = new JPanel();
easttabs.setLayout(new GridLayout(1, 3));
easttabs.add(tab1);
easttabs.add(tab2);
easttabs.add(tab3);
JPanel eastpanels = new JPanel();
eastpanels.setLayout(new BorderLayout());
eastpanels.setBackground(Game.getBackgroundColor());
eastpanels.add(easttabs, BorderLayout.NORTH);
return eastpanels;
}
}

So if you already have a JPanel that has your image as Background and you want to add another panel over it with your components you can use Opacity to achieve this. Only the components added to this panel will be visible. Here's the code :
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JPanel;
public class TransparentPane extends JPanel {
public TransparentPane() {
setOpaque(false);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0f));
g2d.setColor(getBackground());
g2d.fill(getBounds());
g2d.dispose();
}
}

Create a class that extends from JPanel and in its paint method draw an image over it.
Now create a class the extends from JFrame and in its constructor set its contentpane to the object of that JPanel class like below. Now you can add components to jframe.
class SimpleTest extends JFrame {
JButton btn = new JButton("A Game");
public SimpleTest() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setContentPane(new CPane());
getContentPane().setBackground(Color.red);
getContentPane().add(btn, BorderLayout.NORTH);
setSize(new Dimension(300, 300));
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new SimpleTest();
}
});
}
}
class CPane extends JPanel {
Image back;
public void paintComponent(Graphics g) {
super.paintComponent(g);
try {
back = ImageIO.read(getClass().getResource("back.jpg"));
} catch (Exception ex) {
}
g.drawImage(back, 0, 0, this);
}
}
If you want to make a jpanel transparent then do
panel.setOpaque(false);

How do you limit a component to be in a certain spot

I'm creating a slideshow using swing and trying to place it in the center of my JFrame. The slideshow works fine, but it's taking up the entire center section. How would I limit it to a small place under the banner?
Here's a picture of what it looks like.
Here's a picture of what I want it to look like
This is what I have so far, you run this class.
package com.RBV2.engine;
import javax.swing.*;
import com.RBV2.Settings;
import com.RBV2.panels.News;
import com.RBV2.panels.SlideShow;
import com.RBV2.panels.SlideShow.MovingPanel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.io.*;
/*
* Author Jon & David
*
*/
#SuppressWarnings("serial")
public class Client extends JFrame implements ActionListener {
private JPanel bottomPanel, news;
private JButton launch;
private JLabel loading, banner;
private MovingPanel slideshow;
protected boolean updated = false;
private void createLayout() {
createPanel();
addPanel();
setVisible(true);
}
private void createPanel() {
bottomPanel = new JPanel(new BorderLayout());
news = new News();
slideshow = new SlideShow.MovingPanel();
launch = new JButton(new URL("http://www.runerebellion.com/clientImages/launch.png"));
loading = new JLabel(new URL("http://www.runerebellion.com/clientImages/loader.gif"));
banner = new JLabel(new URL("http://www.runerebellion.com/clientImages/201457.gif"));
launch.addActionListener(this);
}
private void addPanel() {
setTitle("RuneRebellionV2 Launcher");
setDefaultCloseOperation(EXIT_ON_CLOSE);
setResizable(false);
//Bottom Panel
add(bottomPanel, BorderLayout.SOUTH);
bottomPanel.add(new JLabel(" Launcher, release " + Settings.version), BorderLayout.WEST);
bottomPanel.setBackground(Color.BLACK);
bottomPanel.add(launch, BorderLayout.EAST);
launch.setPreferredSize(new Dimension(120, 40));
//News Feed
add(news, BorderLayout.CENTER);
news.add(banner, BorderLayout.CENTER);
banner.setPreferredSize(new Dimension(500, 70));
//slideshow
slideshow.setPreferredSize(new Dimension(610, 331));
add(slideshow, BorderLayout.CENTER);
//Sets size
setSize(Settings.width, Settings.height);
}
public Client() throws IOException {
createLayout();
}
public static void main(String args[]) throws IOException {
final Client l = new Client();
l.setVisible(true);
SwingUtilities.invokeLater(new Runnable() {
public void run() {
l.setVisible(true);
}
});
}
These specific lines of code call the slideshow(I commented out exactly where)
private void addPanel() {
setTitle("RuneRebellionV2 Launcher");
setDefaultCloseOperation(EXIT_ON_CLOSE);
setResizable(false);
//Bottom Panel
add(bottomPanel, BorderLayout.SOUTH);
bottomPanel.add(new JLabel(" Launcher, release " + Settings.version), BorderLayout.WEST);
bottomPanel.setBackground(Color.BLACK);
bottomPanel.add(launch, BorderLayout.EAST);
launch.setPreferredSize(new Dimension(120, 40));
//News Feed
add(news, BorderLayout.CENTER);
news.add(banner, BorderLayout.CENTER);
banner.setPreferredSize(new Dimension(500, 70));
//slideshow here
slideshow.setPreferredSize(new Dimension(610, 331));
add(slideshow, BorderLayout.CENTER);
//Sets size
setSize(Settings.width, Settings.height);
}
Here is my slideshow class, you may need this also.
package com.RBV2.panels;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
#SuppressWarnings("serial")
public class SlideShow extends JFrame {
public static class MovingPanel extends JPanel {
public int i = 0;
public MovingPanel() {
Timer timer = new Timer(3000, new TimerListener());
timer.start();
}
protected void paintComponent(Graphics x) {
super.paintComponent(x);
int y = i % 25;
Image showImg = new ImageIcon("bin/slide/" + y + ".png").getImage();
x.drawImage(showImg, 0, 0, getWidth(), getHeight(), 0, 0, 610, 331, null);
}
class TimerListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
i++;
repaint();
if (i >= 5)
i = 1;
}
}
}
}
So my question is how would I limit the slideshow to be in a box in the very center under the banner.

Have a look at this picture (from Border layout Tutorial)
As you are only adding panels to the Center and South(PAGE_END) regions of the layout manager there is no other components to stop the center panel from stretching out as far as it can.
Note this relevant sentence of the tutorial
If the window is enlarged, the center area gets as much of the available space as possible. The other areas expand only as much as necessary to fill all available space. Often a container uses only one or two of the areas of the BorderLayout object — just the center, or the center and the bottom.
You either need to add blank panels on the other sides or make use of an empty border within your Center panel. See here about how to use borders.

I painted the background, then painted the images over the background
protected void paintComponent(Graphics x) {
super.paintComponent(x);
int y = i % 25;
Image showImg = new ImageIcon("bin/slide/" + y + ".png").getImage();
super.paintComponent(x);
x.drawImage((Settings.background).getImage(), 0, 0, getWidth(), getHeight(), this);
x.drawImage(showImg, 360, 260, getWidth(), getHeight(), 0, 0, 110, 31, null);
}

Adding a JPanel to a JLayeredPane causes paints and resizes to have no effect

I am trying to add a JPanel (well, several) to a JLayeredPane. However, when I do so, the paint component method of the JPanel seems to have no effect. An example is included below:
import javax.swing.*;
import java.awt.*;
public class Example {
public static void main(String[] args) {
// This Works as expected
JFrame usingPanel = new JFrame();
JPanel p = new JPanel();
p.add(new BluePanel());
usingPanel.setContentPane(p);
usingPanel.pack();
usingPanel.setVisible(true);
// This makes the frame but does not paint the BluePanel
JFrame usingLayer = new JFrame();
JLayeredPane l = new JLayeredPane();
l.setPreferredSize(new Dimension(200,200));
l.add(new BluePanel(), JLayeredPane.DEFAULT_LAYER);
JPanel p2 = new JPanel();
p2.add(l);
usingLayer.setContentPane(p2);
usingLayer.pack();
usingLayer.setVisible(true);
}
static class BluePanel extends JPanel{
public BluePanel(){
setPreferredSize(new Dimension(200,200));
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.BLUE);
g.fillRect(0, 0, 200, 200);
}
}
}
Why is this? and what are the possible solutions?

JLayeredPane does not have a LayoutManager, so you need to set the location and size of your panels yourself.
See the tutorial

you hardcoded the size on the screen and have to change from
g.fillRect(0, 0, 200, 200);
to
g.fillRect(0, 0, getWidth(), getHeight());
(a minor change) add the method
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
and then remove of code line setPreferredSize(new Dimension(200,200));

How can I properly center a JPanel ( FIXED SIZE ) inside a JFrame?

Hi all!
I'm trying to solve an -apparently- simple problem, but I cannot fix it.
I'm working on a sample application with Java/Swing libraries;
I have a JFrame and a JPanel.
I just want to achieve the following objectives:
JPanel MUST be centered inside the JFrame.
JPanel MUST have ALWAYS the size that is specified with
setPreferredSize() method. It MUST NOT be resized under this size.
I tried by using a GridBagLayout: it's the ONLY way I can do it.
See the sample below:
/* file StackSample01.java */
import java.awt.*;
import javax.swing.*;
public class StackSample01 {
public static void main(String [] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(100, 100));
panel.setBackground(Color.RED);
frame.setLayout(new GridBagLayout());
frame.add(panel, new GridBagConstraints());
frame.setSize(new Dimension(200, 200));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Here a screenshot:
I would not use a GridBagLayout to do a thing too simple.
I tried a simplest solution, by using a Box, but this does not work:
Sample code:
/* file StackSample02.java */
import java.awt.*;
import javax.swing.*;
public class StackSample02 {
public static void main(String [] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(100, 100));
panel.setBackground(Color.RED); // for debug
panel.setAlignmentX(JComponent.CENTER_ALIGNMENT); // have no effect
Box box = new Box(BoxLayout.Y_AXIS);
box.add(Box.createVerticalGlue());
box.add(panel);
box.add(Box.createVerticalGlue()); // causes a deformation
frame.add(box);
frame.setSize(new Dimension(200, 200));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Here a screenshot,
Any ideas? Thanks to all :-)

BoxLayout can pretty to hold your setXxxSize(), then just add panel.setMaximumSize(new Dimension(100, 100));
and your output would be
Removed by setMinimumSize(notice if Container has greater size as ... )
import java.awt.*;
import javax.swing.*;
public class CustomComponent12 extends JFrame {
private static final long serialVersionUID = 1L;
public CustomComponent12() {
Box box = new Box(BoxLayout.Y_AXIS);
box.setAlignmentX(JComponent.CENTER_ALIGNMENT);
box.add(Box.createVerticalGlue());
box.add(new CustomComponents12());
box.add(Box.createVerticalGlue());
add(box);
pack();
setTitle("Custom Component Test / BoxLayout");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setMaximumSize(getMinimumSize());
setMinimumSize(getMinimumSize());
setPreferredSize(getPreferredSize());
setLocation(150, 150);
setVisible(true);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
CustomComponent12 main = new CustomComponent12();
}
};
javax.swing.SwingUtilities.invokeLater(r);
}
}
class CustomComponents12 extends JPanel {
private static final long serialVersionUID = 1L;
#Override
public Dimension getMinimumSize() {
return new Dimension(100, 100);
}
#Override
public Dimension getMaximumSize() {
return new Dimension(100, 100);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(100, 100);
}
#Override
public void paintComponent(Graphics g) {
int margin = 10;
Dimension dim = getSize();
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(margin, margin, dim.width - margin * 2, dim.height - margin * 2);
}
}

First of all, thanks to all.
I reply another time to my own question, to show everyone the choice I have made.
See the sample code below;
As you can see, I have included only minimal steps which are absolutely necessary to achieve the goal.
/* file StackResponse.java */
import java.awt.*;
import javax.swing.*;
public class StackResponse {
public static void main(String [] args) {
JPanel panel = new JPanel();
Dimension expectedDimension = new Dimension(100, 100);
panel.setPreferredSize(expectedDimension);
panel.setMaximumSize(expectedDimension);
panel.setMinimumSize(expectedDimension);
panel.setBackground(Color.RED); // for debug only
Box box = new Box(BoxLayout.Y_AXIS);
box.add(Box.createVerticalGlue());
box.add(panel);
box.add(Box.createVerticalGlue());
JFrame frame = new JFrame();
frame.add(box);
frame.setSize(new Dimension(200, 200));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setMinimumSize(frame.getMinimumSize()); // cannot be resized-
frame.setVisible(true);
}
}
Here you can see a screenshot.
Problem solved.
Many thanks again to all.
IT

create a panel by name "FixedPanel" with GridBagLayout and set preferred size to frame size
then add your frame into FixedPanel.
Frame = new JFrame("CenterFrame");
Frame.setLocation(0, 0);
Frame.setSize(new Dimension(400,400));//dim
JPanel FixedPanel = new JPanel(new GridBagLayout());
FixedPanel.setPreferredSize(Frame.getSize());
JPanel myPanel = new JPanel();
myPanel.setPreferredSize(new Dimension(100,100));
myPanel.setBackground(Color.BLACK);
FixedPanel.add(myPanel);
Frame.add(FixedPanel);
Frame.setVisible(true);

You can do this. I had to make a chess game, and I wanted the chess piece piece to always go in the center of a cell which was a JlayeredPane:
private void formMouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
if (jl != null)
{
jl.setLocation(evt.getX()+10, evt.getY()+10);
Component com = findComponentAt(evt.getPoint());
if (com instanceof JPanel)
{
// System.out.println("Yes, it's a jpanel");
((JPanel)com).add(jl);
((JPanel)com).validate();
}
}
}

Its Just Having
jPanel.setBounds(x, y, 1046, 503);
Where x is space for right side and y is space for left side.
you have to calculate the space from both side according to screen height and width

use
panel.setMaximumSize(new Dimension(200,200));
panel.setResizable(false)
instead?