Develop Reference

How do I add a Picture to a JFrame by adding a JLabel?

I have a problem with my code here. I want to set the Background of a JFrame by adding a JLabel which I drew the image on.
But its not showing the img, btw the Image is read correctly(No Exception).
I'm working with multiple classes: Var.java, Label.java, Gui.java -> All are in the same package
public class Main {
public static void main(String[] args) {
new Gui();
new Label();
new Var();
new KeyHandler();
}
}
import java.awt.Color;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Gui {
public Gui() {
Var.jf1 = new JFrame();
Var.jf1.setSize(Var.breite, Var.höhe);
Var.jf1.setLocationRelativeTo(null);
Var.jf1.setLayout(null);
Var.jf1.setTitle("Meriadoc Brandybock");
Var.jf1.setResizable(false);
Var.jf1.requestFocus();
Var.jf1.addKeyListener((KeyListener) new KeyHandler());
Var.jf1.setVisible(true);
Var.lbl1 = new Label();
Var.lbl1.setBounds(0, 0, Var.breite, Var.höhe);
Var.lbl1.setVisible(true);
Var.jf1.add(Var.lbl1);
}
}
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JLabel;
public class Label extends JLabel{
protected void paintcomponent(Graphics g){
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.drawImage(Var.b1, 0, 0, 1000, 600, null);
repaint();
}
}
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
public class Var {
static JFrame jf1;
static Label lbl1;
static int breite = 1000;
static int höhe = 600;
static boolean moveUP = false;
static boolean moveDOWN = false;
static boolean moveRIGHT = false;
static boolean moveLEFT = false;
static BufferedImage b1;
public Var() {
try {
Var.b1 = ImageIO.read(new File("rsc/b1.png"));
} catch(IOException e){
e.printStackTrace();
System.out.println("Background konnte nicht geladen werden");
}
}
}
Thank you very much in advance for your answers!

JPanel created on click not appearing

The below code is not my actual code but a concise, runnable remake of what I am trying to achieve. I want the JPanel CP, an instance of clickPanel, to appear when the user clicks on the image in JPanel hasAnImage. I can see in the Netbeans console that the is executing because of the Sys.out.print, but nothing appears on the screen. I have tried setting visible to false then true again and revalidate() in the mousePressed event; the image moves to the left, but nothing appears on the screen. The goal is for CP to appear. What am I missing? Hope my question is clear.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Testo extends JFrame{
public Testo(){
BufferedImage image = null;
try {
image = ImageIO.read(new File("C:\\Users\\someimage.jpg"));
} catch (IOException ex) {
ex.printStackTrace();
}
;
final JLabel label = new JLabel(new ImageIcon(image));
JPanel hasAnImage = new JPanel();
hasAnImage.addMouseListener(new MouseAdapter(){
#Override //I override only one method for presentation
public void mousePressed(MouseEvent e) {
clickPanel CP = new clickPanel();
hasAnImage.add(CP);
revalidate();
//setVisible(false);
//setVisible(true);
}
});
hasAnImage.add(label);
add(hasAnImage);
setVisible(true);
}
public static void main(String[] args) {
Testo frame = new Testo();
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.getContentPane().setBackground(Color.WHITE);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public class clickPanel extends JPanel{
public clickPanel() {
setPreferredSize(new Dimension(100,60));
setMaximumSize(new Dimension(100,60));
setBackground(new Color(1.0f,1.0f,1.0f,0.1f));
setBorder(BorderFactory.createMatteBorder(2,2,2,2,Color.GREEN));
System.out.println("This is being executed...");
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setFont(new Font("Arial", Font.PLAIN, 12));
g.setColor(Color.GREEN);
g.drawString("CLICK", 2, 2);
}
}
}

Beyond revalidate();ing the pane, you also need to repaint(); it. Thus your mousePressed method should become:
public void mousePressed(MouseEvent e) {
clickPanel CP = new clickPanel();
hasAnImage.add(CP);
revalidate();
repaint();
}
For further reading: http://docs.oracle.com/javase/7/docs/api/java/awt/Component.html#repaint()

Jbutton acction listener

I am trying to create a form. there is a button that when clicking the button, a photo which is specified would appear. my problem is, when I click the button, the picture pops up and if the cursor passes the form boundary, the image disappears. here is my code:
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import static java.lang.Math.abs;
import static java.lang.Math.min;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
public class SeamCarving extends JFrame
{
public static void main(String[] args) throws IOException {
final BufferedImage input = ImageIO.read(new File("path"));
final BufferedImage[] toPaint = new BufferedImage[]{input};
final Frame frame = new Frame("Seams") {
#Override
public void update(Graphics g) {
final BufferedImage im = toPaint[0];
if (im != null) {
g.clearRect(0, 0, getWidth(), getHeight());
g.drawImage(im, 0, 0, this);
}
}
};
frame.setSize(input.getWidth(), input.getHeight());
frame.setVisible(true);
frame.add(startButton);
startButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
BufferedImage out = input;
out = deleteVerticalSeam(out);
toPaint[0] = out;
frame.repaint();
System.out.println("Do Something Clicked");
}
});
}
}

Don't override update, this isn't how painting is achieved in Swing. Attempting to paint directly to a top level container like JFrame is problematic at best.
Instead, start with a JPanel and use it's paintComponent method instead. Make sure you call super.paintComponent as well.
In fact, you could probably just use a JLabel to display the image instead.
Take a look at;
Performing Custom Painting
How to use labels
For more details
Updated with example
I still think a JLabel would be simpler solution, but what do I know.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class SeamCarving {
public static void main(String[] args) {
new SeamCarving();
}
public SeamCarving() {
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.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage input;
private BufferedImage[] toPaint;
public TestPane() {
try {
input = ImageIO.read(new File("C:\\hold\\thumbnails\\2005-09-29-3957.jpeg"));
toPaint = new BufferedImage[1];
} catch (IOException ex) {
ex.printStackTrace();
}
setLayout(new GridBagLayout());
JButton startButton = new JButton("Start");
startButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
BufferedImage out = input;
out = input; //deleteVerticalSeam(out);
toPaint[0] = out;
repaint();
System.out.println("Do Something Clicked");
}
});
add(startButton);
}
#Override
public Dimension getPreferredSize() {
return input == null ? new Dimension(400, 400) : new Dimension(input.getWidth(), input.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (toPaint[0] != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(input, 0, 0, this);
g2d.dispose();
}
}
}
}
The problem with overriding update is the paint subsystem can choose to avoid calling and end up calling paint directly, circumventing your painting.
Painting also involves painting child components (like your button) and borders, which you've conveniently discarded by not calling super.update.

JAVA Showing Image -GUI

I'm trying to make a simple GUI using JAVA
no image is shown
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.swing.*;
import javax.imageio.*;
public class EmiloLadderSnack {
public JFrame frame=new JFrame("EmiloLadderSnack");
public Image img;
public Graphics g;
public EmiloLadderSnack()
{
frame.setBounds(0, 0, Toolkit.getDefaultToolkit().getScreenSize().width, Toolkit.getDefaultToolkit().getScreenSize().height);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
try
{
img= ImageIO.read(new File("/media/01CCE00FA6888D80/Achieve/Eclipse/EmiloLadderSnack/src/photo.jpg"));
g.drawImage(img, 50, 50, null);
}
catch(Exception e)
{
System.out.println(e.toString());
}
}
public static void main(String args[])
{
new EmiloLadderSnack();
}
}
please help me to show an image in my simple GUI using JAVA
I'm using Eclipse

Hovercraft Full Of Eels is right, as he/she usually is. It really did not look like you tried.
Look at the tutorials, but I do believe when Hovercraft Full Of Eels says the correct way, hover means as follows.
Let me explain what I did below. First I created a new class that extended the JFrame. The JFrame is what is suppose to hold all of the components in a window. Then draw on the JPanel so that all of your drawings are contained in a lightweight container. I set the layout with a new layout I just discovered due to StackOverflow which I am very thankful for. The layout is called the MigLayout and it is a third party resource. You have to download it and import it. Please note that you do not have to have the MigLayout, but it is preferable to use due to its ease of use. After I set the Layout Constraint to fill and docked the JPanel in the center I created a new class which extended the JPanel so that I could change the paint method. The #Override lets you, in a way, re create the method for that extended class. As you can see once draw to that one graphics class then you are all set. There is a lot more you should read up on. Read the comments below your post, they suggest fairly good material.
Anything I get wrong Hovercraft will say below in the comments. So look for that as well.
Hovers corrections:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class GraphicExample extends JPanel {
private static final String IMG_FILE_PATH = "/media/01CCE00FA6888D80/" +
"Achieve/Eclipse/EmiloLadderSnack/src/photo.jpg";
private BufferedImage img;
public GraphicExample(BufferedImage img) {
this.img = img;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
g.drawImage(img, 0, 0, this);
}
}
#Override
public Dimension getPreferredSize() {
if (img != null) {
return new Dimension(img.getWidth(), img.getHeight());
}
return super.getPreferredSize();
}
private static void createAndShowGui() {
try {
BufferedImage img = ImageIO.read(new File(IMG_FILE_PATH));
JFrame frame = new JFrame("GraphicExample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new GraphicExample(img));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
// the easy way to display an image -- in a JLabel:
ImageIcon icon = new ImageIcon(img);
JLabel label = new JLabel(icon);
JOptionPane.showMessageDialog(frame, label);
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
My initial recommendations:
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import net.miginfocom.swing.MigLayout;
public class DrawCircle extends JFrame {
JPanel panel;
public DrawCircle(String title, int width, int height) {
this.setTitle(title);
this.setSize(width, height);
this.setLocationRelativeTo(null); // Center JFrame
this.setLayout(new MigLayout("fill")); // Download external jar
this.panel = new DrawOval();
this.add(panel, "dock center"); // Link: http://www.miglayout.com/
this.setVisible(true);
}
public class DrawOval extends JPanel {
Color color = new Color(1, 1, 1);
public DrawOval() {
}
#Override
public void paint(Graphics g) {
g.setColor(color.RED);
g.fillOval(0, 0, this.getWidth(), this.getHeight());
}
}
}

I can't imagine that this is compiling. There must be a NullPointerException.
When you want to draw something you usually subclass JPanel and do the drawing in the paintComponent() method, like this:
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 50, 50, null);
}

How to save window contents as an image

I want to capture the contents of a JPanel as an image so that I can store it exactly as the user sees it. Is there a relatively simple way to do this with swing?

From here http://forums.oracle.com/forums/thread.jspa?threadID=2156176&tstart=0
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class SavePaint extends JPanel
{
public SavePaint()
{
JFrame frame = new JFrame("TheFrame");
frame.add(this);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400,400);
frame.setVisible(true);
try
{
BufferedImage image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = image.createGraphics();
frame.paint(graphics2D);
ImageIO.write(image,"jpeg", new File("/home/deniz/Desktop/jmemPractice.jpeg"));
}
catch(Exception exception)
{
//code
}
}
protected void paintComponent(Graphics g)
{
g.drawRect(50,50,50,50);
}
public static void main(String[] args)
{
new SavePaint();
}
}

Use Robot and public BufferedImage createScreenCapture(Rectangle screenRect). and here is the link how to use it

use new java.awt.Robot().createScreenCapture(screenRect)