I am creating a JFrame, and when the window is expanded I want the content to stay centered, instead of staying the same distance away from the side. I am using WindowBuilder on Eclipse.
Is there a quick way to do this?
One way, have the container use a GridBagLayout and add the single content to the container without constraints.
For example:
import java.awt.GridBagLayout;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
public class CenteredContent extends JPanel {
public static final String IMG_PATH = "https://duke.kenai.com/iconSized/duke.gif";
public CenteredContent() throws IOException {
URL imgUrl = new URL(IMG_PATH);
BufferedImage img = ImageIO.read(imgUrl);
Icon imgIcon = new ImageIcon(img);
JLabel label = new JLabel(imgIcon);
setLayout(new GridBagLayout());
add(label);
}
private static void createAndShowGui() {
CenteredContent mainPanel = null;
try {
mainPanel = new CenteredContent();
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
JFrame frame = new JFrame("CenteredContent");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Related
SOLVED
So I have an issue where when I click the button, I want an image to replace the entire content of the window. But it's only replacing, what I believe to be, a part of a panel. Should I not use panels in this instance? I found some code online which didn't use panels which worked, but maybe there is a scenario where I can remove the panel and just cover the entire frame with my image when the button is clicked?
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
public class SatNav extends JFrame {
private JFrame frame;
private JPanel panel;
private JLabel satelliteLabel;
private JLabel aboutLabel;
private JButton satellite;
private JButton about;
public SatNav() {
frame = new JFrame("Work Package 5");
frame.setVisible(true);
frame.setSize(300, 380);
about = new JButton("About");
add(about);
event abo = new event();
about.addActionListener(abo);
panel = new JPanel();
frame.add(panel);
panel.add(about);
setLocationRelativeTo(null); //This is for centering the frame to your screen.
setDefaultCloseOperation(EXIT_ON_CLOSE); //This for closing your application after you closing the window.
}
public class event implements ActionListener {
public void actionPerformed(ActionEvent abo) {
ImagePanel imagePanel = new ImagePanel();
//JFrames methods
panel.add(imagePanel, BorderLayout.CENTER);
revalidate();
repaint();
about.setVisible(false);
//satellite.setVisible(false);
}
}
public class ImagePanel extends JPanel {
private BufferedImage image;
public ImagePanel() {
try {
image = ImageIO.read(new File("about.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
setBorder(BorderFactory.createLineBorder(Color.black, 2));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, getWidth(), getHeight(), null);
}
}
public static void main(String[] args) {
new SatNav();
}
}
Your problem is that you're treating the panel JPanel as if it has a BorderLayout when it doesn't. Rather it has JPanel's default FlowLayout which will size components to their preferred sizes (here [0, 0]) rather than have contained components fill the container. The simple solution: give your panel a BorderLayout:
panel = new JPanel(new BorderLayout());
Now when adding components, the BorderLayout constants will be respected by the container's layout.
Another and possibly better and more durable solution is to use a CardLayout to help you swap components.
For example:
import java.awt.CardLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
public class SatNav2 extends JPanel {
private static final long serialVersionUID = 1L;
// a publicly available example image for demonstration purposes:
public static final String SAT_PATH = "https://upload.wikimedia.org"
+ "/wikipedia/commons/1/18/AEHF_1.jpg";
private static final String INTRO_PANEL = "intro panel";
private static final String IMAGE_LABEL = "image label";
// our layout
private CardLayout cardLayout = new CardLayout();
// JLabel to display the image
private JLabel imgLabel = new JLabel();
public SatNav2(Image img) {
// put image into JLabel
imgLabel.setIcon(new ImageIcon(img));
// JPanel to hold JButton
JPanel introPanel = new JPanel();
// add button that does the swapping
introPanel.add(new JButton(new ShowImageAction("Show Image")));
// set the CardLayout and add the components. Order of adding
// is important since the first one is displayed
setLayout(cardLayout);
// add components w/ String constants
add(introPanel, INTRO_PANEL);
add(imgLabel, IMAGE_LABEL);
}
private class ShowImageAction extends AbstractAction {
public ShowImageAction(String text) {
super(text);
}
#Override
public void actionPerformed(ActionEvent e) {
// tell card layout to show next component
cardLayout.next(SatNav2.this);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
try {
createAndShowGui();
} catch (IOException e) {
e.printStackTrace();
}
});
}
private static void createAndShowGui() throws IOException {
// get the image
URL imgUrl = new URL(SAT_PATH);
Image img = ImageIO.read(imgUrl);
// pass image into our new JPanel
SatNav2 mainPanel = new SatNav2(img);
JFrame frame = new JFrame("Satellite");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
import javax.swing.*;
import java.awt.*;
public class Main
{
public static void main(String[] args)
{
//load the card image from the gif file.
final ImageIcon cardIcon = new ImageIcon("cardimages/tenClubs.gif");
//create a panel displaying the card image
JPanel panel = new JPanel()
{
//paintComponent is called automatically by the JRE whenever
//the panel needs to be drawn or redrawn
public void paintComponent(Graphics g) {
super.paintComponent(g);
cardIcon.paintIcon(this, g, 20, 20);
}
};
//create & make visible a JFrame to contain the panel
JFrame window = new JFrame("Title goes here");
window.add(panel);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setBackground(new Color(100, 200, 102));
window.setPreferredSize(new Dimension(200,200));
window.pack();
window.setVisible(true);
}
}
I am trying to make a java project that will display all 52 cards on a window. I have the window working but I cant get a card to appear on the window.
I am using eclipse for OSX, inside the project src file I have a (default package) container with my Main.java file. Then I have my cardimages folder in the same src file.
How can I get the image to show in the window?
You should try to get the image as a URL, as a resource again using the Class method getResource(...). For example, test this:
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
public class DefaultFoo {
public static void main(String[] args) throws IOException {
String resource = "/cardimages/tenClubs.gif";
URL url = Class.class.getResource(resource);
BufferedImage img = ImageIO.read(url);
Icon icon = new ImageIcon(img);
JOptionPane.showMessageDialog(null, icon);
}
}
Also, don't use the default package like you're doing. Put your class into a valid package.
Then try something like this:
import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class PlayWithImages extends JLayeredPane {
private static final String RESOURCE = "/cardimages/tenClubs.gif";
private static final int PREF_W = 500;
private static final int PREF_H = PREF_W;
private static final int CARD_COUNT = 8;
public PlayWithImages() throws IOException {
URL url = getClass().getResource(RESOURCE);
BufferedImage img = ImageIO.read(url);
Icon icon = new ImageIcon(img);
for (int i = 0; i < CARD_COUNT; i++) {
JLabel label = new JLabel(icon);
label.setSize(label.getPreferredSize());
int x = PREF_W - 20 - i * 40 - label.getWidth();
int y = 20;
label.setLocation(x, y);
add(label);
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
PlayWithImages mainPanel = null;
try {
mainPanel = new PlayWithImages();
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
JFrame frame = new JFrame("PlayWithImages");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
I am trying to make an applet run as a JFrame. The code I have below is simple but should work. It will run as an JApplet but when I go to RUN AS --> nothing appears.
import java.awt.*;
import java.applet.Applet;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class LifeCycle extends Applet
{
private static final long serialVersionUID = 1L;
String output = "test";
String event;
public void init()
{
gui(); //I am not certain if this needs to be there.
event = "\nInitializing...";
printOutput();
}
public void start()
{
event = "\nStarting...";
printOutput();
}
public void stop()
{
event = "\nStopping...";
printOutput();
}
public void destroy()
{
event = "\nDestroying...";
printOutput();
}
private void printOutput()
{
System.out.println(event);
output += event;
repaint();
}
private void gui() {
JFrame f = new JFrame("Not resizable");
JPanel d = new JPanel();
// LifeCycle a = new LifeCycle();
// a.init();//not working
d.setLayout(new BorderLayout());
d.add(new JButton("a"));
d.add(new JButton("b"));
d.setBackground(Color.RED);
//f.add(new LifeCycle());
f.add(d);
f.setSize(545,340);
f.setResizable(false);
f.setLocationRelativeTo(null);
f.setTitle("Test");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//a.destroy();
}
public void paint(Graphics g)
{
System.out.println("Graphics Paint Method!");
g.drawString(output, 100, 100);
}
public static void main(String[] args) {
LifeCycle l = new LifeCycle();
l.gui();
}
}
I would like to see the code that should be changed, but I cannot seem to find why this will not work. I have added to buttons to the panel to be displayed.
Don't mix AWT (Applet) with Swing components. Stick with just Swing.
Gear your class towards creating JPanels. Then you can place it in a JApplet if you want an applet or a JFrame if you want a JFrame.
Read up on use of BorderLayout -- you're adding multiple components to the default BorderLayout.CENTER position, and only one component, the last one added, will show.
For example ...
LifeCycle2.java
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JPanel;
class LifeCycle2 {
private static final int GAP = 5;
private static final int PREF_W = 545;
private static final int PREF_H = 340;
private JPanel mainPanel = new JPanel() {
#Override
public Dimension getPreferredSize() {
return LifeCycle2.this.getPreferredSize();
}
};
public LifeCycle2() {
JPanel buttonPanel = new JPanel(new GridLayout(1, 0, GAP, 0));
buttonPanel.add(new JButton("A"));
buttonPanel.add(new JButton("B"));
buttonPanel.setOpaque(false);
JPanel flowLayoutPanel = new JPanel();
flowLayoutPanel.setOpaque(false);
flowLayoutPanel.add(buttonPanel);
mainPanel.setLayout(new BorderLayout());
mainPanel.setBorder(BorderFactory.createEmptyBorder(GAP, GAP, GAP, GAP));
mainPanel.setBackground(Color.red);
mainPanel.add(flowLayoutPanel, BorderLayout.NORTH);
}
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
public JComponent getMainPanel() {
return mainPanel;
}
}
Show as a JFrame,
LifeCycleFrame.java
import javax.swing.*;
public class LifeCycleFrame {
private static void createAndShowGui() {
LifeCycle2 lifeCycle2 = new LifeCycle2();
JFrame frame = new JFrame("LifeCycleTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(lifeCycle2.getMainPanel());
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Show as an applet,
LifeCycleApplet.java
import java.lang.reflect.InvocationTargetException;
import javax.swing.JApplet;
import javax.swing.SwingUtilities;
public class LifeCycleApplet extends JApplet {
#Override
public void init() {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
LifeCycle2 lifeCycle2 = new LifeCycle2();
getContentPane().add(lifeCycle2.getMainPanel());
}
});
} catch (InvocationTargetException | InterruptedException e) {
e.printStackTrace();
}
}
}
Add f.setVisible(true); to the end of the gui() method. Without this call your frame won't be shown.
Please read the "How to Make Frames" Tutorial
I want to add a vertical scroll-bar on my JFrame with null layout.
Is it possible or not? please help!
Just set the JScrollPane as ContentPane for JFrame as it is described here:
public class TabbedPaneTest {
public static void main(String [] a) {
final JFrame frame = new JFrame();
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JScrollPane pane = new JScrollPane(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
frame.setContentPane(pane);
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
frame.setVisible(true);
}
});
}
}
In eclipse IDE you can use following code
import java.awt.Dimension;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JLabel;
public class Test {
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Test window = new Test();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public Test() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel container = new JPanel();
JScrollPane jsp = new JScrollPane(container);
container.setPreferredSize(new Dimension(500, 250));
container.setLayout(null);
JLabel lblHelloWorld = new JLabel("Hello World");
lblHelloWorld.setBounds(10, 11, 101, 14);
container.add(lblHelloWorld);
frame.getContentPane().add(jsp);
}
}
I have a problem with my JLayeredPane, I am probably doing something incredibly simple but I cannot wrap my head around it. The problem i have is that all the components are merged together and have not order. Could you please rectify this as I have no idea. The order I am trying to do is have a layout like this
output
label1 (behind)
input (in Front)
import java.awt.BorderLayout;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.IOException;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class window extends JFrame implements KeyListener {
/**
*
*/
private static final long serialVersionUID = 7092006413113558324L;
private static int NewSize;
public static String MainInput;
public static JLabel label1 = new JLabel();
public static JTextField input = new JTextField(10);
public static JTextArea output = new JTextArea(main.Winx, NewSize);
public window() {
super("Satine. /InDev-01/");
JLabel label1;
NewSize = main.Winy - 20;
setLayout(new BorderLayout());
output.setToolTipText("");
add(input, BorderLayout.PAGE_END);
add(output, BorderLayout.CENTER);
input.addKeyListener(this);
input.requestFocus();
ImageIcon icon = new ImageIcon("C:\\Users\\" + System.getProperty("user.name") + "\\AppData\\Roaming\\.Satine\\img\\textbox.png", "This is the desc");
label1 = new JLabel(icon);
add(label1, BorderLayout.PAGE_END);
}
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_ENTER) {
try {
MainMenu.start();
} catch (IOException e1) {
System.out.print(e1.getCause());
}
}
}
#Override
public void keyReleased(KeyEvent e) {
}
#Override
public void keyTyped(KeyEvent e) {
}
}
And the main class.
import java.awt.Container;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JLayeredPane;
public class main {
public static int Winx, Winy;
private static JLayeredPane lpane = new JLayeredPane();
public static void main(String[] args) throws IOException{
Winx = window.WIDTH;
Winy = window.HEIGHT;
window Mth= new window();
Mth.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Mth.setSize(1280,720);
Mth.setVisible(true);
lpane.add(window.label1);
lpane.add(window.input);
lpane.add(window.output);
lpane.setLayer(window.label1, 2, -1);
lpane.setLayer(window.input, 1, 0);
lpane.setLayer(window.output, 3, 0);
Mth.pack();
}
}
Thank you for your time and I don't expect the code to be written for me, all I want is tips on where I am going wrong.
I recommend that you not use JLayeredPane as the overall layout of your GUI. Use BoxLayout or BorderLayout, and then use the JLayeredPane only where you need layering. Also, when adding components to the JLayeredPane, use the add method that takes a Component and an Integer. Don't call add(...) and then setLayer(...).
Edit: it's ok to use setLayer(...) as you're doing. I've never used this before, but per the API, it's one way to set the layer.
e.g.,
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridBagLayout;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
public class LayeredPaneFun extends JPanel {
public static final String IMAGE_PATH = "http://duke.kenai.com/" +
"misc/Bullfight.jpg";
public LayeredPaneFun() {
try {
BufferedImage img = ImageIO.read(new URL(IMAGE_PATH));
ImageIcon icon = new ImageIcon(img);
JLabel backgrndLabel = new JLabel(icon);
backgrndLabel.setSize(backgrndLabel.getPreferredSize());
JPanel forgroundPanel = new JPanel(new GridBagLayout());
forgroundPanel.setOpaque(false);
JLabel fooLabel = new JLabel("Foo");
fooLabel.setFont(fooLabel.getFont().deriveFont(Font.BOLD, 32));
fooLabel.setForeground(Color.cyan);
forgroundPanel.add(fooLabel);
forgroundPanel.add(Box.createRigidArea(new Dimension(50, 50)));
forgroundPanel.add(new JButton("bar"));
forgroundPanel.add(Box.createRigidArea(new Dimension(50, 50)));
forgroundPanel.add(new JTextField(10));
forgroundPanel.setSize(backgrndLabel.getPreferredSize());
JLayeredPane layeredPane = new JLayeredPane();
layeredPane.setPreferredSize(backgrndLabel.getPreferredSize());
layeredPane.add(backgrndLabel, JLayeredPane.DEFAULT_LAYER);
layeredPane.add(forgroundPanel, JLayeredPane.PALETTE_LAYER);
setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
add(new JScrollPane(new JTextArea("Output", 10, 40)));
add(layeredPane);
} catch (MalformedURLException e) {
e.printStackTrace();
System.exit(1);
} catch (IOException e) {
e.printStackTrace();
System.exit(1);
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("LayeredPaneFun");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new LayeredPaneFun());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}