In addition to my question How can I more quickly render my array?, I made the following class to make a JFrame:
package myprojects;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
class BackgroundImageJFrame extends JFrame {
public BackgroundImageJFrame(BufferedImage img) {
setTitle("Background Color for JFrame");
int h = img.getHeight();
int w = img.getWidth();
setSize(w, h);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
setLayout(new BorderLayout());
setContentPane(new JLabel(new ImageIcon(img)));
setLayout(new FlowLayout());
// Just for refresh :) Not optional!
setSize(w-1, h-1);
setSize(w, h);
}
}
which I call with new BackgroundImageJFrame(img);. As I want to refresh the contents of this JFrame, this doesn't work optimally, since this creates a new JFrame everytime.
How could I alter this to just have the JFrame refreshed?
You can pretty simply do this by storing the JLabel control, and then setting the image with a method. Make sure you set the image on the Event Dispatch Thread!
I have revised the code to do this in a more stable way based on #MadProgrammer's excellent comments.
Brief summary of the issues addressed between this and the previous version:
You don't want the contentPane to be a JLabel, as it makes it more difficult to add other controls later and doesn't have a layout manager. I've added a JPanel in between, and given it BorderLayout.
The caller should be responsible for thread safety. I didn't do it this way originally because you didn't provide any calling code, but here, I do the Event Dispatch Thread delegation. Make sure you switch to the Event Dispatch Thread using EventQueue.invokeLater as I do here in main before calling setBackgroundImage().
I'm using setSize and setPreferredSize on the JLabel so that the layout managers can properly choose good sizes for the controls, and so that frame.pack works as expected.
I create the controls in the initComponents method, outside of the constructor, to make the code easier to follow and to make it easy to add more constructors later if necessary.
Here's the code:
public class NonogramSolutionJFrame extends JFrame {
private final JLabel label;
private final JPanel panel;
public NonogramSolutionJFrame(BufferedImage img) {
panel = new JPanel();
label = new JLabel();
initComponents(img);
}
private final void initComponents(BufferedImage img) {
setTitle("Background Color for JFrame");
setBackgroundImage(img);
setContentPane(panel);
panel.setLayout(new BorderLayout());
panel.add(label, BorderLayout.CENTER);
setLocationRelativeTo(null);
pack();
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public void setBackgroundImage(final BufferedImage img) {
label.setIcon(new ImageIcon(img));
label.setPreferredSize(new Dimension(img.getWidth(), img.getHeight()));
}
public static void main(String... args) throws Exception {
BufferedImage img = ImageIO.read(NonogramSolutionJFrame.class.getResource("/nonogram.png"));
NonogramSolutionJFrame frame = new NonogramSolutionJFrame(img);
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
frame.setVisible(true);
}
});
}
}
Using the image from your other answer, this code produces the following (on Linux):
Related
I'm making some test code to practice OOP, and I want to append a JTextArea from the "writeToArea" to the "initialize" method where the JTextArea is defined and initialized. I already tried to directly call the "output" variable, but this returns an "output cannot be resolved" error. I want so that whenever I call the "writeToArea" method in the main class, I'll be able to add lines to the "output" JTextArea in the "initialize" method.
Here's the main class:
public class Pangea {
public static void main(String[] args) {
UI.initialize();
UI.writeToArea();
}
}
Here's the initialize class:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class UI {
static void initialize() {
System.out.println("Initializing GUI.");
JFrame frame = new JFrame();
Font myFont = new Font("Courier", Font.BOLD, 14);
JTextField input = new JTextField("");
JTextArea output = new JTextArea("Initiated Succesfully.");
output.setWrapStyleWord(true);
output.setLineWrap(true);
input.setFont(myFont);
output.setFont(myFont);
input.setForeground(Color.WHITE);
output.setForeground(Color.WHITE);
input.setBackground(Color.BLACK);
input.setCaretColor(Color.WHITE);
output.setBackground(Color.BLACK);
output.setEditable(false);
JScrollPane jp = new JScrollPane(output);
frame.setTitle("PANGEA RPG [0.01 ALPHA][WIP]");
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(input, BorderLayout.SOUTH);
frame.add(jp, BorderLayout.CENTER);
frame.pack();
frame.setSize(800, 500);
frame.setVisible(true);
System.out.println("GUI Initialized.");
}
static void writeToArea() {
System.out.println("\"writeToArea\" running.");
output.append("Hello!");
System.out.println("\"writeToArea\" finished.");
}
}
I've tried to do something similar to this: Updating jtextarea from another class but it didn't work. If anyone has any suggestions I'd be very thankful.
The main error in your code is the lack of OOP design. Making all static is poor design.
Also swing is event based, so you should append text to the textArea when an event happens. See the example i write for you.
public class UI {
private JPanel panel;
private JTextArea output;
public UI(){
initialize();
}
private void initialize() {
panel = new JPanel();
Font myFont = new Font("Courier", Font.BOLD, 14);
final JTextField input = new JTextField(""); // must be declared final cause you use it in anonymous class, you can make it instance variable if you want to as textArea
//add an actionListener then when you press enter this will write to textArea
input.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent evt){
writeToArea(input.getText());
}
});
output = new JTextArea("Initiated Succesfully",50,100);// let the component determinate its preferred size.
output.setWrapStyleWord(true);
output.setLineWrap(true);
input.setFont(myFont);
output.setFont(myFont);
input.setForeground(Color.WHITE);
output.setForeground(Color.WHITE);
input.setBackground(Color.BLACK);
input.setCaretColor(Color.WHITE);
output.setBackground(Color.BLACK);
output.setEditable(false);
JScrollPane jp = new JScrollPane(output);
panel.setLayout(new BorderLayout());
panel.add(input, BorderLayout.SOUTH);
panel.add(jp, BorderLayout.CENTER);
}
private void writeToArea(String something) {
System.out.println("\"writeToArea\" running.");
output.append(something);
System.out.println("\"writeToArea\" finished.");
}
public JPanel getPanel(){
return panel;
}
}
And in your client code
public class Pangea {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
#Override
public void run(){
createAndShowGUI();
}
});
}
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event dispatch thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
System.out.println("Initializing GUI.");
JFrame frame = new JFrame();
frame.setTitle("PANGEA RPG [0.01 ALPHA][WIP]");
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Add contents to the window.
frame.add(new UI().getPanel());
frame.pack();//sizes the frame
frame.setVisible(true);
System.out.println("GUI Initialized.");
}
}
Here you have a tutorial with better examples than this How to Use Text Areas
I remove your setSize and use pack()
The pack method sizes the frame so that all its contents are at or
above their preferred sizes. An alternative to pack is
to establish a frame size explicitly by calling setSize or setBounds
(which also sets the frame location). In general, using pack is
preferable to calling setSize, since pack leaves the frame layout
manager in charge of the frame size, and layout managers are good at
adjusting to platform dependencies and other factors that affect
component size.
Read the section from the Swing tutorial on How to Use Text Areas. It will show you how to better structure your code so that you don't use static methods and variables everywhere.
Once you have a panel that has a reference to the text area you can add methods that allow you to update the text area on the panel.
JButton and JLabel disappears when adding custom background. I don't see any problems in my program, but maybe you guys find an solution! I think it's only a little thing I forgot, but I can't figure it out.
Here's the code:
GameWindow.java:
setContentPane(new StartImagePanel(RollrackLogo));
out.println("adding JLWelcome");
JLWelcome.setText("Welcome to Rollrack, " + namewindow.name);
add(JLWelcome);
JLWelcome.setVisible(true);
out.println("JLWelcome added");
out.println("adding JBRandom");
JBRandom.setText("Random");
add(JBRandom);
JBRandom.setVisible(true);
out.println("added JBRandom");
The background appears perfect, but not the JButton and JLabel!
Code to the StartImagePanel.java:
public class StartImagePanel extends JComponent{
private Image image;
public StartImagePanel(Image image) {
this.image = image;
}
#Override
protected void paintComponent(Graphics g) {
g.drawImage(image, 0, 0, null);
}
}
Your button and label are added to your GameWindow frame while they should be added to its contentPane, setContentPane(new StartImagePanel(RollrackLogo)); instead. That's why they are not showing, they are added to the frame.
Make a variable of the StartImagePanel and add the button and label to it and they should show up.
StartImagePanel contentPanel = new StartImagePanel(RollrackLogo);
setContentPane(contentPanel);
...
out.println("adding JLWelcome");
JLWelcome.setText("Welcome to Rollrack, " + namewindow.name);
contentPanel.add(JLWelcome);
JLWelcome.setVisible(true);
out.println("JLWelcome added");
out.println("adding JBRandom");
JBRandom.setText("Random");
contentPanel.add(JBRandom);
JBRandom.setVisible(true);
out.println("added JBRandom");
Answer dispute
The claims in the first paragraph are plain wrong. Here is source that proves it.
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class AddToCustomContentPane {
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
// the GUI as seen by the user (without frame)
JPanel gui = new JPanel(new FlowLayout());
gui.setBorder(new EmptyBorder(2, 3, 2, 3));
gui.setBackground(Color.RED);
JFrame f = new JFrame("Demo");
f.setContentPane(gui);
// Acid test. Can we add buttons direct to the frame?
f.add(new JButton("Button 1"));
f.add(new JButton("Button 2"));
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See http://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
Edit after the custom panel code was given
Here's a snippet that works to show both button and label on a black image background, I removed that was not needed (listeners).
public static void main(String[] v) {
class StartImagePanel extends JPanel {
private Image image;
public StartImagePanel(Image image) {
this.image = image;
}
#Override
protected void paintComponent(Graphics g) {
g.drawImage(image, 0, 0, null);
}
}
class GameWindow extends JFrame{
public GameWindow() {
BufferedImage RollrackLogo;
RollrackLogo = new BufferedImage(400,200,BufferedImage.TYPE_INT_RGB);
final JButton JBRandom = new JButton();
final JLabel JLWelcome = new JLabel();
setDefaultCloseOperation(EXIT_ON_CLOSE);
StartImagePanel panel = new StartImagePanel(RollrackLogo);
setContentPane(panel);
setExtendedState(MAXIMIZED_BOTH);
setVisible(true);
JLWelcome.setText("Welcome to Rollrack");
panel.add(JLWelcome);
JLWelcome.setVisible(true);
JBRandom.setText("Random");
panel.add(JBRandom);
JBRandom.setVisible(true);
}
}
GameWindow window = new GameWindow();
window.pack();
window.setVisible(true);
}
I rather use an instance of a JFrame, instead of extending it, as #Andrew Thompson suggested in another question.
However, if you're extending it, it might be a good practice to call super() in the constructor.
Additionally, we may need to know what is going on in your StartImagePanel.
It seems, to me, to be the problem.
Ensure both your GameWindow and StartImagePanel extend properly their superclasses (call super();).
Ensure your StartImagePanel has a proper Layout.
Add your components before you set your frame visible. This also means you won't need JLWelcome.setVisible(true);.
Ensure that your code is executed in the EDT (Event-Dispatch Thread).
Example:
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class GameWindow extends JFrame{
BufferedImage rollrackLogo;
JButton jbRandom;
JLabel jlWelcome;
public GameWindow() {
super();
jbRandom = new JButton("Random");
jlWelcome = new JLabel("Welcome to Rollrack, " +
namewindow.name);
rollrackLogo = new BufferedImage(400, 200,
BufferedImage.TYPE_INT_RGB);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setContentPane(new StartImagePanel(rollrackLogo));
// Add your components.
add(jlWelcome);
add(jbRandom);
addKeyListener(new KeyListener() {
#SuppressWarnings("static-access")
#Override
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == e.VK_ESCAPE){
System.exit(7);
}
}
#Override
public void keyReleased(KeyEvent arg0) {}
#Override
public void keyTyped(KeyEvent arg0) {}
});
// Pack, or otherwise set fullscreen.
pack();
// Now, set frame visible.
setVisible(true);
}
}
Edit: Now that you've posted the code for your StartImagePanel, I see that you're extending JComponent. Follow my previous advice, (call super), set a Layout, and extend JPanel instead.
I just can't get past square one on JLayeredPanes. (See my original question of yesterday. I have been studying the JLayeredPane tutorial and API. These tutorials are geared somewhat differently to what I am ultimately trying to produce.
Going back to square one, I took Oracle's JFrame Example and modified it to include Layered panes.
Here is the code:
package components;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/* FrameDemo.java requires no other files. */
public class FrameDemo {
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("FrameDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel mainLayer = new JPanel(new BorderLayout());
mainLayer.setPreferredSize(new Dimension(640, 480));
frame.setContentPane(mainLayer);
frame.getLayeredPane().add(mainLayer, JLayeredPane.DEFAULT_LAYER, 0);
JLabel emptyLabel = new JLabel("LABEL");
emptyLabel.setPreferredSize(new Dimension(320, 240));
mainLayer.add(emptyLabel, BorderLayout.NORTH);
JPanel subLayer = new JPanel(new BorderLayout());
JLabel subLabel = new JLabel("SUBLABEL");
subLabel.setPreferredSize(new Dimension( 200, 100));
subLabel.setBackground(Color.YELLOW);
subLayer.add(subLabel, BorderLayout.SOUTH);
subLayer.setVisible(true);
subLabel.setVisible(true);
frame.getLayeredPane().add(subLayer, JLayeredPane.PALETTE_LAYER, 0);
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
Why doesn't it work? IOW, why doesn't the sublabel show up? It's at a higher level than the main layer.
One thought is why am I adding mainLayer to both the Content Pane and the Layered Pane? If I don't do that, nothing shows up. I.e, by commenting out this line, I just get a blank frame.
// frame.setContentPane(mainLayer);
Obviously, I'm not understanding something. But what is it?
I should add that obviously, this simple demo can be done without Layered Panes. But my ultimate goal is to have a layer that can be turned on and off programatically. But I can't even get this simple case to work. If I can get over this hump, I think the rest will be easier.
ADDENDUM:
What I want to acheive is illustrated by the following Code, which is very similar to what TrashGod set up below and it works. There is a JLayeredPane with a constant layer (layered at Integer(0)) and a floating layer layered initially at Integer(-1) but togglable by the F7 and F8 keystrokes between the Integer(-1) layer and the Integer(1) layer, thereby allowing it to float above or below the constant layer.
package components;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/* MyLayeredPaneDemo.java requires no other files. */
public class MyLayeredPaneDemo {
private JFrame frame;
private JLayeredPane mainPanel;
private JPanel constantLayer;
private JPanel floatingLayer;
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private MyLayeredPaneDemo() {}
private void createAndShowGUI() {
//Create and set up the window.
this.frame = new JFrame("MyLayeredPaneDemo");
this.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.frame.setPreferredSize(new Dimension(640, 480));
mainPanel = new JLayeredPane();
constantLayer = new JPanel(new BorderLayout(0,0));
floatingLayer = new JPanel(new BorderLayout(0,0));
// constantLayer.setPreferredSize();
constantLayer.setOpaque(true);
constantLayer.setBackground(Color.BLUE);
JLabel constantLabel = new JLabel("MAIN LAYER");
constantLayer.setPreferredSize(new Dimension(640, 480));
constantLayer.add(constantLabel, BorderLayout.CENTER);
JLabel subLabel = new JLabel("SUB LAYER");
floatingLayer.setBackground(Color.YELLOW);
floatingLayer.add(subLabel, BorderLayout.SOUTH);
floatingLayer.setOpaque(true);
floatingLayer.setVisible(true);
floatingLayer.setVisible(true);
subLabel.setBackground(Color.YELLOW);
mainPanel.add(constantLayer, new Integer(0), 0);
constantLayer.setBounds(0,0,640,480);
mainPanel.add(floatingLayer, new Integer(-1), 0);
floatingLayer.setBounds(100, 360, 300, 90 );
frame.add(mainPanel, BorderLayout.CENTER);
//Display the window.
mapKeyToAction(frame.getRootPane(),
JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT,
KeyStroke.getKeyStroke(KeyEvent.VK_F7, 0),
"Hide Layer",
new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("F7 pressed");
mainPanel.setLayer(floatingLayer, new Integer(-1));
}
});
mapKeyToAction(frame.getRootPane(),
JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT,
KeyStroke.getKeyStroke(KeyEvent.VK_F8, 0),
"Show Layer",
new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("F8 pressed");
mainPanel.setLayer(floatingLayer, new Integer(1));
}
});
frame.pack();
frame.setVisible(true);
frame.getRootPane().setFocusable(true);
boolean ok = frame.getRootPane().requestFocusInWindow();
System.out.println("focus ok: " + ok);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
new MyLayeredPaneDemo().createAndShowGUI();
}
});
}
private static void mapKeyToAction(JComponent component,
int whichMap, KeyStroke keystroke,String key, Action action) {
component.getInputMap(whichMap).put(keystroke, key);
component.getActionMap().put(key, action);
}
}
However, I am having trouble getting this to work in my real case. The difference between the two is that here, my JLayeredPane is owned by the Frame, whereas in my real application, I want the JLayeredPane to be owned by a JPanel is that some levels down in the containment hierarchy from the Frame, and whose size is set by a GridBagLoyout in its parent, and the size is therefore unknowable at the time its constructor is called, making it difficult to call setBounds() which I need to do on a child of a JLayeredPane.
FURTHER ADDENDUM. I know that the Oracle Tutorials mention a case where Layouts rather than absolute positioning is used with a JLayeredPane. The difference between this case and mine is that in my case the layers occupy the same horizontal space on different layers, whereas in this case, the components on different layrers occupy different horizontal spaces. It's almost as if we need a 3D Layout Manager!
"By default, a layered pane has no layout manager."—How to Use Layered Panes
Addendum: I need to avoid using the Frame's layered pane and instead add a layered pane to the window.
Yes, The Root Pane is an instance of JRootPane, which contains a JLayeredPane. In particular, "The layered pane contains the menu bar and content pane, and enables Z-ordering of other components."
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class FrameDemo {
private static void createAndShowGUI() {
JFrame frame = new JFrame("FrameDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLayeredPane mainLayer = new JLayeredPane();
frame.add(mainLayer, BorderLayout.CENTER);
JLabel label = new JLabel("LABEL", JLabel.CENTER);
label.setBounds(100, 100, 200, 100);
label.setOpaque(true);
label.setBackground(Color.cyan);
mainLayer.add(label, 1);
JPanel subLayer = new JPanel(new BorderLayout());
JLabel subLabel = new JLabel("SUBLABEL", JLabel.CENTER);
subLabel.setBounds(20, 20, 200, 100);
subLabel.setOpaque(true);
subLabel.setBackground(Color.yellow);
subLayer.add(subLabel, BorderLayout.SOUTH);
mainLayer.add(subLabel, 2);
frame.pack();
frame.setSize(320, 240);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
}
}
The solution I came up and thanks to trashgod which I expect is good advice too is to implement ComponentListener and capture the component resize event. At that point you can get the actual bounds of the container and use it to set the actual bounds of the layer JPanels which are always in some fixed relation to the bounds of the component that contains them. It works.
Trashgod's solution would also work I believe but I have not tried it.
Good day!
Is it possible to add a JPanel on top of a JLabel?
I would like my JFrame to have a background image and in order to this, i used this code (based from past stackoverflow answers):
setLocation(150,50);
setSize(700,650);
setVisible(true);
JLabel contentPane = new JLabel();
contentPane.setIcon(new ImageIcon("pics/b1.jpg"));
contentPane.setLayout( new BorderLayout());
setContentPane( contentPane );
Now my problem is, I cannot put a panel on my JFrame because of the JLabel background.
Please help.
Thanks.
To create a background image for a JFrame, I recommend that you draw the image in the paintComponent method of a JPanel, and then add this JPanel to the contentPane BorderLayout.CENTER which has it fill the contentPane. You may even want to set the JPanel's preferredSize to be that of the Image. Then you can add any components you'd like to the image panel, and don't have to worry about trying to add comopnents to a JLabel which seems bass ackwards to me.
For example here's a program that does this but slightly different. It creates an ImagePanel object, a JPanel that draws an image and sizes itself to the image and then places it in a JScrollPane which is then added to the contentPane, but you can just get rid of the JScrollPane and put your image JPanel directly in the contentPane instead:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
public class BigDukeImage {
public static final String IMAGE_PATH = "http://" + "duke.kenai.com/nyanya/NyaNya.jpg";
private static final Dimension SCROLLPANE_SIZE = new Dimension(900, 700);
private static void createAndShowUI() {
Image image = null;
try {
URL url = new URL(IMAGE_PATH);
image = ImageIO.read(url);
// JLabel label = new JLabel(new ImageIcon(image));
ImagePanelA imagePanel = new ImagePanelA(image);
JScrollPane scrollpane = new JScrollPane();
// scrollpane.getViewport().add(label);
scrollpane.getViewport().add(imagePanel);
scrollpane.setPreferredSize(SCROLLPANE_SIZE);
JFrame frame = new JFrame("Big Duke Image");
frame.getContentPane().add(scrollpane);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
JScrollBar vertSBar = scrollpane.getVerticalScrollBar();
JScrollBar horzSBar = scrollpane.getHorizontalScrollBar();
vertSBar.setValue((vertSBar.getMaximum() - vertSBar.getVisibleAmount()) / 2);
horzSBar.setValue((horzSBar.getMaximum() - horzSBar.getVisibleAmount()) / 2);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
#SuppressWarnings("serial")
class ImagePanelA extends JPanel {
private Image image;
public ImagePanelA(Image image) {
this.image = image;
setPreferredSize(new Dimension(image.getWidth(null), image.getHeight(null)));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null) {
g.drawImage(image, 0, 0, null);
}
}
}
You could use a JLayeredPane. This lets you add components to different layers and have them ontop of one another.
I cannot put a panel on my JFrame because of the JLabel background
Thats because a panel is opague so it paints over top of the label. You need to use:
panel.setOpaque( false );
sure..you can....Use NetBEans IDE to simplify tedious tasks like this by drag and drop and write the actual programming..
I have created one GUI using Swing of Java. I have to now set one sample.jpeg image as a background to the frame on which I have put my components.How to do that ?
There is no concept of a "background image" in a JPanel, so one would have to write their own way to implement such a feature.
One way to achieve this would be to override the paintComponent method to draw a background image on each time the JPanel is refreshed.
For example, one would subclass a JPanel, and add a field to hold the background image, and override the paintComponent method:
public class JPanelWithBackground extends JPanel {
private Image backgroundImage;
// Some code to initialize the background image.
// Here, we use the constructor to load the image. This
// can vary depending on the use case of the panel.
public JPanelWithBackground(String fileName) throws IOException {
backgroundImage = ImageIO.read(new File(fileName));
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
// Draw the background image.
g.drawImage(backgroundImage, 0, 0, this);
}
}
(Above code has not been tested.)
The following code could be used to add the JPanelWithBackground into a JFrame:
JFrame f = new JFrame();
f.getContentPane().add(new JPanelWithBackground("sample.jpeg"));
In this example, the ImageIO.read(File) method was used to read in the external JPEG file.
This is easily done by replacing the frame's content pane with a JPanel which draws your image:
try {
final Image backgroundImage = javax.imageio.ImageIO.read(new File(...));
setContentPane(new JPanel(new BorderLayout()) {
#Override public void paintComponent(Graphics g) {
g.drawImage(backgroundImage, 0, 0, null);
}
});
} catch (IOException e) {
throw new RuntimeException(e);
}
This example also sets the panel's layout to BorderLayout to match the default content pane layout.
(If you have any trouble seeing the image, you might need to call setOpaque(false) on some other components so that you can see through to the background.)
The Background Panel entry shows a couple of different ways depending on your requirements.
You can either make a subclass of the component
http://www.jguru.com/faq/view.jsp?EID=9691
Or fiddle with wrappers
http://www.java-tips.org/java-se-tips/javax.swing/wrap-a-swing-jcomponent-in-a-background-image.html
Perhaps the easiest way would be to add an image, scale it, and set it to the JFrame/JPanel (in my case JPanel) but remember to "add" it to the container only after you've added the other children components.
ImageIcon background=new ImageIcon("D:\\FeedbackSystem\\src\\images\\background.jpg");
Image img=background.getImage();
Image temp=img.getScaledInstance(500,600,Image.SCALE_SMOOTH);
background=new ImageIcon(temp);
JLabel back=new JLabel(background);
back.setLayout(null);
back.setBounds(0,0,500,600);
Here is another quick approach without using additional panel.
JFrame f = new JFrame("stackoverflow") {
private Image backgroundImage = ImageIO.read(new File("background.jpg"));
public void paint( Graphics g ) {
super.paint(g);
g.drawImage(backgroundImage, 0, 0, null);
}
};
if you are using netbeans you can add a jlabel to the frame and through properties change its icon to your image and remove the text. then move the jlabel to the bottom of the Jframe or any content pane through navigator
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class BackgroundImageJFrame extends JFrame
{
JButton b1;
JLabel l1;
public BackgroundImageJFrame()
{
setTitle("Background Color for JFrame");
setSize(400,400);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
/*
One way
-----------------*/
setLayout(new BorderLayout());
JLabel background=new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads\\colorful design.png"));
add(background);
background.setLayout(new FlowLayout());
l1=new JLabel("Here is a button");
b1=new JButton("I am a button");
background.add(l1);
background.add(b1);
// Another way
setLayout(new BorderLayout());
setContentPane(new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads \\colorful design.png")));
setLayout(new FlowLayout());
l1=new JLabel("Here is a button");
b1=new JButton("I am a button");
add(l1);
add(b1);
// Just for refresh :) Not optional!
setSize(399,399);
setSize(400,400);
}
public static void main(String args[])
{
new BackgroundImageJFrame();
}
}