I'm having trouble getting an image to show on a JFrame.
The frame is completely black upon running. Here's my code:
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
public class JFrameTesting extends JFrame {
BufferedImage test = null;
public static void main(String[] args) throws URISyntaxException {
new JFrameTesting();
}
public JFrameTesting() throws URISyntaxException {
JFrame frame = new JFrame("My first JFrame!");
frame.setSize(400, 400);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
test = ImageIO.read(new File(getClass().getResource("test.png").toURI()));
} catch (IOException ex) {
Logger.getLogger(JFrameTesting.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void paint(Graphics g) {
super.paint(g);
g.drawImage(test, 200, 200, null);
}
}
I'm not sure if I'm nessecarily doing anything wrong. I have no errors at all when running.
Thanks in advance!
you can try, with this code.
you need to load a JLabel on Jframe when you add a image.
BufferedImage test = null;
public static void main(String[] args) throws URISyntaxException {
new JFrameTesting();
}
public JFrameTesting() throws URISyntaxException {
JFrame frame = new JFrame("My first JFrame!");
JLabel label = new JLabel();
frame.setSize(800, 800);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
test = ImageIO.read(new File(getClass().getResource("test.png").toURI()));
frame.add( new JLabel(new ImageIcon(test)),BorderLayout.CENTER);
frame.setIconImage(test);
frame.setVisible(true);
label.setVisible(true);
} catch (IOException ex) {
Logger.getLogger(JFrameTesting.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void paint(Graphics g) {
super.paint(g);
g.drawImage(test, 200, 200, null);
}
}
You haven't actually added your image to the JFrame yet. To have the image appear you need to add the BufferedImage onto a component then draw that. You can do that using a JLabel and an ImageIcon.
public class JFrameTesting extends JFrame {
BufferedImage test = null;
ImageIcon image = new ImageIcon();
public static void main(String[] args) throws URISyntaxException {
new JFrameTesting();
}
public JFrameTesting() throws URISyntaxException {
JFrame frame = new JFrame("My first JFrame!");
try {
test = ImageIO.read(new File(getClass().getResource("test.png").toURI()));
image.setImage(test);
} catch (IOException ex) {
Logger.getLogger(JFrameTesting.class.getName()).log(Level.SEVERE, null, ex);
}
JLabel label = new JLabel();
label.setIcon(image);
frame.add(label);
frame.setSize(400, 400);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
Alternatively you can skip the Label and draw onto a component if you want. In which case you you'll have to override the draw method of a JPanel.
JPanel pane = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 200, 200, null);
}
};
frame.add(pane);
Another note is that you're extending JFrame but also making a new JFrame inside of the class. You can remove the extra JFrame and all the "frame." The class itself is a JFrame so you don't need an extra one.
//set the title using the setTitle method
setTitle("My first JFrame!");
add(label);
setSize(400, 400);
setVisible(true);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)
Also, I believe the ImageIO.read(...) method can take a URI as a parameter so you shouldn't have to create a File from it.
My code draws image, but need repaint. For this you need for example to change size of frame using you mouse.
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
public class JFrameTesting extends JFrame {
BufferedImage test = null;
public static void main(String[] args) throws URISyntaxException {
new JFrameTesting();
}
public JFrameTesting() throws URISyntaxException {
JFrame frame = new JFrame("My first JFrame!");
frame.setSize(400, 400);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
System.out.println("init");
test = ImageIO.read(new File(getClass().getResource("test.png").toURI()));
System.out.println(test);
} catch (IOException ex) {
Logger.getLogger(JFrameTesting.class.getName()).log(Level.SEVERE, null, ex);
}
final JPanel pane = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
System.out.println("paint");
super.paintComponent(g);
g.drawImage(test, 0, 0, null);
}
};
frame.add(pane);
frame.repaint();
}
#Override
public void paint(Graphics g) {
super.paint(g);
System.out.println("paint");
g.drawImage(test, 200, 200, null);
}
}
Related
Some of the lines I'm drawing with Java Swing are changing thickness in the middle and I'm not sure why.
import javax.swing.*;
import java.awt.*;
public class Main extends Canvas {
public static void main(String[] args) {
try {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Main canvas = new Main();
canvas.setSize(900, 700);
frame.add(canvas);
frame.pack();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
public void paint(Graphics g) {
g.setColor(Color.BLACK);
g.drawLine(450, 0, 900, 450);
}
}
Image of the line drawn by this program:
What I'm trying to do is to create a desktop application using Swing. I need to add a background image to my frame and also add some buttons on some specific locations which should NOT have their content area filled. So, here is what I've done so far;
public class MainGUI extends JFrame {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MainGUI window = new MainGUI();
window.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public MainGUI() {
setUndecorated(true);
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
this.setSize(screenSize);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initialize();
}
private void initialize() {
JPanel mainPanel = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
try {
g.drawImage(new ImageIcon(ImageIO.read(new File("a.png"))).getImage(), 0, 0, null);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
mainPanel.setLayout(new BorderLayout());
JButton btn1 = new JButton();
btn1 .setAlignmentX(Component.CENTER_ALIGNMENT);
btn1 .setContentAreaFilled(false);
btn1 .setBorder(new EmptyBorder(0, 0, 0, 0));
btn1 .setIcon(new ImageIcon("btn1.png"));
JPanel rightButtonPanel = new JPanel();
rightButtonPanel.setLayout(new BoxLayout(rightButtonPanel, BoxLayout.Y_AXIS));
rightButtonPanel.add(btn1);
mainPanel.add(rightButtonPanel, BorderLayout.EAST);
this.setContentPane(mainPanel);
}
}
When I do this, setContentAreaFilled(false) feature does not work. I suppose it's related to the painting but I'm not sure. Can anyone help me with this please?
So I took your code and modified it.
Primarily:
Added btn1.setOpaque(false);
And added rightButtonPanel.setBackground(Color.GREEN);
Example
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
public class MainGUI extends JFrame {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MainGUI window = new MainGUI();
window.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public MainGUI() {
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initialize();
pack();
}
private void initialize() {
JPanel mainPanel = new JPanel() {
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
}
};
mainPanel.setBackground(Color.RED);
mainPanel.setLayout(new BorderLayout());
JButton btn1 = new JButton();
btn1.setAlignmentX(Component.CENTER_ALIGNMENT);
btn1.setContentAreaFilled(false);
btn1.setOpaque(false);
btn1.setBorder(new EmptyBorder(0, 0, 0, 0));
btn1.setText("This is a test");
JPanel rightButtonPanel = new JPanel();
rightButtonPanel.setBackground(Color.GREEN);
rightButtonPanel.setLayout(new BoxLayout(rightButtonPanel, BoxLayout.Y_AXIS));
rightButtonPanel.add(btn1);
mainPanel.add(rightButtonPanel, BorderLayout.EAST);
this.setContentPane(mainPanel);
}
}
This produced
So, it's not the buttons (at least at this point) which are at fault.
So, I changed rightButtonPanel.setBackground(Color.GREEN); to rightButtonPanel.setOpaque(false); and it produced
I wrote JPanel class where I load image. I'm trying to add a scrolls to this panel, but it didn't work. Can someone help me? Sorry for my bad language.
browser.setFileFilter(imgFilter); // ustawienie filtra
browser.setAcceptAllFileFilterUsed(false);
browser.setCurrentDirectory(new File("."));
int result = browser.showOpenDialog(imagePanel);
if (result == JFileChooser.APPROVE_OPTION) {
// tworzenie obrazu
imagePanel = new ImagePanel(browser.getSelectedFile());
JScrollPane scrollPane = new JScrollPane(imagePanel);
scrollPane.setSize(new Dimension(300, 400));
//add(imagePanel);
add(scrollPane);
//imagePanel.repaint();
scrollPane.repaint();
}
And this is my imagePanel class:
private class ImagePanel extends JPanel {
private Image img;
private File file;
public ImagePanel(File file) {
this.file = file;
setSize(SCREEN_HEIGHT / 2, SCREEN_WIDTH * 3/4);
try {
img = ImageIO.read(file);
}
catch(IOException e) {
System.out.println("Wystąpił błąd podczas wczytywanie obrazu.");
e.printStackTrace();
}
}
public void paintComponent(Graphics g) {
if(img == null) return;
g.drawImage(img, 0, 0, null);
}
}
You should be overriding the getPreferredSize() of the ImagePanel to give the panel a preferred size, which the scroll pane will use to determine whether or not to add scrolls. Generally, when doing custom painting, you always want to override the getPreferredSize of the drawing canvas panel, as the default is 0x0
Example:
public class Test {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run() {
// image is 256 x 256
Image image = new ImageIcon("stackoverflow.png").getImage();
JPanel imagePanel = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(image.getWidth(this),
image.getHeight(this));
}
};
JScrollPane pane = new JScrollPane(imagePanel);
pane.setPreferredSize(new Dimension(200, 200));
JOptionPane.showMessageDialog(null, pane);
}
});
}
}
With getPreferredSize
Without getPreferredSize
UPDATE
A couple thing I see wrong with your current code.
Creating a new ImagePanel when you want to set the image. Instead just have a method like setImage in the ImagePanel class where you can just set the image and repaint.
Trying to add(scrollPane); at runtime without revalidate().
See full example here.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.filechooser.FileNameExtensionFilter;
public class Test {
public Test() {
JFrame frame = new JFrame();
ImagePanel panel = new ImagePanel();
JScrollPane pane = new JScrollPane(panel);
pane.setPreferredSize(new Dimension(200, 200));
JButton button = createButton(panel, pane);
frame.add(pane);
frame.add(button, BorderLayout.PAGE_END);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private JButton createButton(ImagePanel panel, JScrollPane pane) {
JButton button = new JButton("Change image");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JFileChooser chooser = new JFileChooser();
FileNameExtensionFilter filter = new FileNameExtensionFilter(
"JPG & GIF Images", "jpg", "gif");
chooser.setFileFilter(filter);
int returnVal = chooser.showOpenDialog(null);
if (returnVal == JFileChooser.APPROVE_OPTION) {
Image image = new ImageIcon(
chooser.getSelectedFile().getAbsolutePath()).getImage();
panel.setImage(image);
pane.revalidate();
}
}
});
return button;
}
private class ImagePanel extends JPanel {
Image image;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null) {
g.drawImage(image, 0, 0, this);
}
}
#Override
public Dimension getPreferredSize() {
return image == null ? new Dimension(150, 150)
: new Dimension(image.getWidth(this),
image.getHeight(this));
}
public void setImage(Image img) {
this.image = img;
repaint();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Test();
}
});
}
}
Hi i want to convert panel which contains components like label and buttons to image file.
I have done the following code. The image was saved. but the content of the panel not visible or saved. Can anyone tell me how to save the panel with its components.
Code:
package PanelToImage;
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.*;
public class sample extends JPanel {
public JPanel firstpanel;
public JPanel secondpanel;
JLabel label1, label2;
JButton button1, button2;
public sample() {
firstpanel = new JPanel();
firstpanel.setSize(400,300);
firstpanel.setBackground(Color.RED);
secondpanel = new JPanel();
secondpanel.setBackground(Color.GREEN);
secondpanel.setSize(400,300);
label1 = new JLabel("label1");
label2 = new JLabel("label2");
button1 = new JButton("button1");
button2 = new JButton("button2");
firstpanel.add(label1);
firstpanel.add(button1);
secondpanel.add(label2);
secondpanel.add(button2);
saveImage(firstpanel);
add(firstpanel);
// add(secondpanel);
}
public static void main(String args[]) {
JFrame frame = new JFrame();
sample sam = new sample();
frame.setContentPane(sam);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 300);
}
private void saveImage(JPanel panel) {
BufferedImage img = new BufferedImage(panel.getWidth(), panel.getHeight(), BufferedImage.TYPE_INT_RGB);
panel.paint(img.getGraphics());
try {
ImageIO.write(img, "png", new File("E://Screen.png"));
System.out.println("panel saved as image");
} catch (Exception e) {
System.out.println("panel not saved" + e.getMessage());
}
}
}
Tthis code works for me (in the JFrame):
Container c = getContentPane();
BufferedImage im = new BufferedImage(c.getWidth(), c.getHeight(), BufferedImage.TYPE_INT_ARGB);
c.paint(im.getGraphics());
ImageIO.write(im, "PNG", new File("shot.png"));
Maybe you have used custom panels. If true, try to add super.paint(g) at the beginning of the paint methods of your panels.
EDIT: You have to call saveImage after display the frame:
public static void main(String args[]) {
...
frame.setSize(400, 300);
sam.saveImage(sam.firstpanel);
}
EDIT 2: This is the saved image (is little because the layout, but is the proof that it should work):
I called the saveImage as last call in the main, and used a file in the user dir (new File("Screen.png")) as nIcE cOw said.
Here try this example program, instead of using getGraphics() seems like you have to use createGraphics() for the BufferedImage you are about to make.
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.*;
public class SnapshotExample
{
private JPanel contentPane;
private void displayGUI()
{
JFrame frame = new JFrame("Snapshot Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
contentPane = new JPanel();
contentPane.setOpaque(true);
contentPane.setBackground(Color.WHITE);
JLabel label = new JLabel("This JLabel will display"
+ " itself on the SNAPSHOT", JLabel.CENTER);
contentPane.add(label);
frame.setContentPane(contentPane);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
makePanelImage(contentPane);
}
private void makePanelImage(Component panel)
{
Dimension size = panel.getSize();
BufferedImage image = new BufferedImage(
size.width, size.height
, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = image.createGraphics();
panel.paint(g2);
try
{
ImageIO.write(image, "png", new File("snapshot.png"));
System.out.println("Panel saved as Image.");
}
catch(Exception e)
{
e.printStackTrace();
}
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new SnapshotExample().displayGUI();
}
});
}
}
I think I'm being a bit of an idiot, given that I haven't done Swing programming in a while, but I'm trying to draw a simple image to screen, and I'm not getting what I expected
public class ImageApp {
public static void main(String[] args) throws MalformedURLException, IOException {
final Image image = ImageIO.read(new File("/Library/WebServer/Documents/image.gif"));
final JPanel component = new JPanel(){
public void paint(final Graphics g) {
System.out.println("Drawing image "+image.getWidth(null)+" "+image.getHeight(null));
g.drawString("hello", 0,0);
g.drawImage(image,this.getWidth()/2,this.getHeight()/2, 100, 100, Color.blue,this);
super.paint(g);
}
};
final JFrame frame = new JFrame();
frame.add(component);
frame.setSize(100, 100);
frame.pack();
frame.setVisible(true);
}
}
This renders a blank window which doesn't seem to be sized to 100,100. Is there some other step I need to perform to get the graphics to appear on screen, or the size to be respected?
I'm using JDK6 on OSX 10.6
In Swing, you should override paintComponent(), not paint().
Addendum: e.g., see below. In a comment, #eugener raises an excellent point about using a JLabel as an alternative image container.
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Image;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ImageApp {
public static void main(String[] args) throws IOException {
final Image image = ImageIO.read(new File("image.jpg"));
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
final JPanel component = new JPanel() {
#Override
public void paintComponent(final Graphics g) {
g.drawImage(image, 0, 0, null);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(
image.getWidth(this), image.getHeight(this));
}
};
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(component);
frame.pack();
frame.setVisible(true);
}
});
}
}
Try this:
public class ImageApp {
public static void main(String[] args) throws MalformedURLException, IOException {
final Image image = ImageIO.read(new File("/Library/WebServer/Documents/image.gif"));
final JPanel component = new JPanel() {
#Override
public void paintComponent(final Graphics g) {
super.paintComponent(g);
System.out.println("Drawing image " + image.getWidth(null) + " " + image.getHeight(null));
g.drawString("hello", 0,10);
g.drawImage(image, this.getWidth() / 2, this.getHeight() / 2, 100, 100, Color.blue, this);
}
};
final JFrame frame = new JFrame();
frame.add(component);
frame.setSize(100, 100);
frame.setVisible(true);
}
}