We Keep Coding

ImageIcon is displayed as a small square

where is the problem. It does not show image properly.
default.png = *********
what i see = *********
I dont think there is a problem with png. It is also in my src and I refreshed it on eclipse.
codes:
import java.awt.*;
import javax.swing.*;
public class Main {
public static void main(String[] args) {
JFrame jf = new JFrame();
jf.setTitle( "test");
jf.setLayout( new FlowLayout());
jf.setSize(350, 450);
jf.setVisible(true);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.add(new Panel());
}
}
panel:
import java.awt.Graphics;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
public class Panel extends JPanel {
// PROPERTIES
public ImageIcon icon;
// CONSTRUCTORS
public Panel() {
icon = new ImageIcon(this.getClass().getResource("default.png"));
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(icon.getImage(), 0, 0, null);
}
}

This answer addresses my criticism of the answer by the OP. The example incorporates the advice added in various comments.
import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.border.LineBorder;
public class Main {
public static void main(String[] args) throws Exception {
URL url = new URL("http://i.imgur.com/o0E0aGD.png");
BufferedImage bi = ImageIO.read(url);
JFrame jf = new JFrame();
jf.setTitle("test");
jf.setLayout(new FlowLayout());
//jf.setSize(350, 450); just pack()
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.add(new BackgroundImagePanel(bi));
jf.pack();
jf.setMinimumSize(jf.getSize());
jf.setVisible(true);
}
}
class BackgroundImagePanel extends JPanel {
public Image img;
// CONSTRUCTOR
public BackgroundImagePanel(Image img) {
this.img = img;
this.setBorder(new LineBorder(Color.RED, 2));
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 0, 0, this);
// g.drawImage(img, 0, 0, getWidth(), getHeight(), this); // Better!
}
#Override
public Dimension getPreferredSize() {
Dimension d = super.getPreferredSize();
int w = d.width>img.getWidth(this) ? d.width : img.getWidth(this);
int h = d.height>img.getHeight(this) ? d.height : img.getHeight(this);
return new Dimension(w, h);
}
}

I solved this by adding at Panel class constructor:
setPreferredSize(new Dimension( 500, 500 ));

move image from one panel to another

I have Code where I can move image.
Everything works well.
here I have only one ImagePanel (children of JPanel) on the frame.
Questions:
I need to drag and drop image from one JPanel to another JPanel.
Then I need to move dragged image to current panel.
Can you give me an example code, please?
class ImagePanel extends JPanel {
int x, y;
BufferedImage image;
ImagePanel() {
setBackground(Color.white);
setSize(450, 400);
addMouseMotionListener(new MouseMotionHandler());
Image img = getToolkit().getImage("C:\\2.png");
MediaTracker mt = new MediaTracker(this);
mt.addImage(img, 1);
try {
mt.waitForAll();
} catch (Exception e) {
System.out.println("Image not found.");
}
image = new BufferedImage(img.getWidth(this), img.getHeight(this),BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = image.createGraphics();
g2.drawImage(img, 0, 0, this);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2D = (Graphics2D) g;
g2D.drawImage(image, x, y, this);
}
class MouseMotionHandler extends MouseMotionAdapter {
public void mouseDragged(MouseEvent e) {
x = e.getX();
y = e.getY();
repaint();
}
public void mouseMoved(MouseEvent e) {
}
}
}
I need to do that code, with this following design. I need to add image with some layout (I don't need to done this with Point pixels). or how to add image with some layout? for example Grid bag layout. I don't need Points (x,y). because I need to add another components too.
public class DragAndDrop {
private JFrame frame;
/* .. another component here .. */
private JPanel leftPanel; // here is my image
public JPanel rightContentPanel; // destination of dragable image
public static void main(String[] args) {
DragAndDrop window = new DragAndDrop();
}
public DragAndDrop() {
initialize();
}
private void initialize() {
frame = new JFrame();
frame.getContentPane().setLayout(new BorderLayout(0, 0));
leftPanel = new leftPanel();
/* add components to left panel */
rightContentPanel = new rightPanel();
/* add component to right panel */
frame.getContentPane().add(rightContentPanel, BorderLayout.CENTER);
frame.getContentPane().add(leftPanel, BorderLayout.WEST);
frame.setVisible(true);
frame.setResizable(false);
}
}
class leftPanel extends JPanel {
/ ... /
}
class rightPanel extends JPanel{
/ ... /
}

There's probably any number of ways to achieve what you want. You could use the glass pane or JXLayer or you could stop treating the two panels as separate elements and more like they were just windows into a large virtual space.
This example basically treats the parent component as the "virtual space" into which the two image panes are windows.
They both share the same image and image location details. They, individual, convert the image location (which is in virtual coordinates) to local coordinates and draw as much of the image as would appear on them...
Mouse control is maintained by the parent. This greatly simplifies the process, as it can notify both the panels simultaneously
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
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.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;
public class CrossImage {
public static void main(String[] args) {
new CrossImage();
}
public CrossImage() {
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 img;
private ImagePane left;
private ImagePane right;
private Point imagePoint;
public TestPane() {
setBorder(new EmptyBorder(10, 10, 10, 10));
setLayout(new GridLayout(0, 2, 10, 10));
left = new ImagePane();
right = new ImagePane();
imagePoint = new Point(10, 10);
left.setImageLocation(imagePoint);
right.setImageLocation(imagePoint);
try {
img = ImageIO.read(new File("Background.jpg"));
left.setImage(img);
right.setImage(img);
} catch (IOException ex) {
ex.printStackTrace();
}
add(left);
add(right);
MouseAdapter mouseHandler = new MouseAdapter() {
private Point delta;
#Override
public void mousePressed(MouseEvent e) {
Point origin = e.getPoint();
Rectangle bounds = new Rectangle(imagePoint, new Dimension(img.getWidth(), img.getHeight()));
if (bounds.contains(origin)) {
delta = new Point(origin.x - imagePoint.x, origin.y - imagePoint.y);
}
}
#Override
public void mouseDragged(MouseEvent e) {
if (delta != null) {
imagePoint = e.getPoint();
imagePoint.translate(-delta.x, -delta.y);
left.setImageLocation(imagePoint);
right.setImageLocation(imagePoint);
}
}
#Override
public void mouseReleased(MouseEvent e) {
delta = null;
}
};
addMouseListener(mouseHandler);
addMouseMotionListener(mouseHandler);
}
}
public class ImagePane extends JPanel {
private Image image;
private Point imageLocation;
public ImagePane() {
setBorder(new LineBorder(Color.DARK_GRAY));
}
#Override
public Dimension getPreferredSize() {
return image == null ? super.getPreferredSize() : new Dimension(image.getWidth(this), image.getHeight(this));
}
public void setImage(Image image) {
this.image = image;
repaint();
}
public void setImageLocation(Point imageLocation) {
this.imageLocation = imageLocation;
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null && imageLocation != null) {
Point p = SwingUtilities.convertPoint(getParent(), imageLocation, this);
g.drawImage(image, p.x, p.y, this);
}
}
}
}

JPanel with a background image which has some part transparent

My image is like a frame which is transparent in the middle. I want to make it as background image of a JPanel. I have done this but for the transparent part of image, white color is coming. I want to remove this white color so that the components below this Jpanel become visible.
My code for custom JPanel is
public class JPanelWithBackground extends JPanel {
private static final long serialVersionUID = 1L;
Image imageOrg = null;
Image image = null;
{
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
int w = JPanelWithBackground.this.getWidth();
int h = JPanelWithBackground.this.getHeight();
image = w>0&&h>0?imageOrg.getScaledInstance(w,h,
java.awt.Image.SCALE_SMOOTH):imageOrg;
JPanelWithBackground.this.repaint();
});
}
public JPanelWithBackground(Image image2) {
imageOrg=image2;
image=image2;
setOpaque(false);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (image!=null)
g.drawImage(image, 0, 0, null);
}
}

I don't have any particular problem with your code. The problem is probably that your image is not transparent as you expect.
Here is an example that seems to work perfectly (I only took the liberty to fix minor issues in your code):
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class JPanelWithBackground extends JPanel {
private static final long serialVersionUID = 1L;
Image imageOrg = null;
public JPanelWithBackground(Image image2) {
imageOrg = image2;
setOpaque(false);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(imageOrg.getWidth(this), imageOrg.getHeight(this));
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (imageOrg != null) {
System.err.println("painting");
g.drawImage(imageOrg, 0, 0, getWidth(), getHeight(), this);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
try {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanelWithBackground panel = new JPanelWithBackground(new ImageIcon(new URL(
"http://www.lemondedemario.fr/images/dossier/bowser/bowser.png")).getImage());
JPanel greenPanel = new JPanel(new BorderLayout());
greenPanel.setBackground(Color.GREEN);
greenPanel.add(panel);
frame.add(greenPanel);
frame.pack();
frame.setVisible(true);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
}

paint method draws outside jFrame if first coord 0,0

First coord in this case should be 0,0 and not 8,30. What am i doing wrong(i am using NetBeans)
import java.awt.Color;
import java.awt.Graphics;
public class TEST extends javax.swing.JFrame {
#Override
public void paint(Graphics g){
super.paint(g);
g.setColor(Color.blue);
g.drawRect(8, 30, 200, 200);
repaint();
}}

Add a JPanel to the frame and paint in that. The frame's coordinates include the decorations (title bar, borders, etc.). It would look something like this:
public class Test extends JFrame {
public static void main(String[] args) {
new Test();
}
private Test() {
add(new MyPanel());
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(600, 600);
setVisible(true);
}
private class MyPanel extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.blue);
g.drawRect(8, 30, 200, 200);
}
}
}
Also, don't call repaint(); in paint();. That will cause an infinite loop and will freeze the entire program.

The problem is your paint(..) method is not taking into account the JFrame Insets by calling getInsets which as docs state:
If a border has been set on this component, returns the border's
insets.
this code works fine:
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class Test {
public Test() {
createAndShowGui();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test();
}
});
}
private void createAndShowGui() {
JFrame frame = new JFrame() {
#Override
public void paint(Graphics g) {
super.paint(g);
g.setColor(Color.blue);
g.drawRect(0 + getInsets().left, 0 + getInsets().top, 200, 200);
}
};
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
however this is not best practice.
Rather add JPanel to JFrame and override paintComponent(Graphics g) of JPanel dont forget call to super.paintComponent(g) as first call in the overridden method and than draw there (dont forget to override getPreferredSize() and return correct Dimensions so the JPanel will fit its drawing/graphic content) this problem will no longer persist as JPanel is added at correct co-ordinates on contentPane like so:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Test {
public Test() {
createAndShowGui();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test();
}
});
}
private void createAndShowGui() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.addRenderingHints(new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY));
g2d.setColor(Color.blue);
g2d.drawRect(0, 0, 200, 200);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
};
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
}
The above includes Graphics2D and RenderingHints i.e anti-aliasing. Just for some better looking drawings :)

Im not sure how to get the data from my text field

My text field is local to main so I cannot access it from actionPerformed, I believe I need to make it a instance variable but I'm not sure how to because my frame is also in main so I'm not sure how I would then add it to the frame.
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;
import java.net.*;
import java.sql.*;
import java.lang.Object;
import java.awt.Graphics;
import java.awt.Graphics2D;
/**
* This class demonstrates how to load an Image from an external file
*/
public class Test extends JPanel {
int x=77, y=441, w=23, h=10;
BufferedImage img =
new BufferedImage(100, 50,
BufferedImage.TYPE_INT_ARGB);
// BufferedImage img;
public void paintComponent(Graphics g) {
g.drawImage(img, 0, 0, null);
// g.fillRect(10,10,10,10);
}
public Test() {
try {
img = ImageIO.read(new File("sales-goal.png"));
} catch (IOException e) {}
Graphics2D g = img.createGraphics();
Color myColor = Color.decode("#32004b");
g.setColor(myColor);
g.fillRect(x,y,w,h);
//77,441,23,10
}
public Dimension getPreferredSize() {
if (img == null) {
return new Dimension(100,100);
} else {
//return new Dimension(img.getWidth(null), img.getHeight(null));
return new Dimension(300,600);
}
}
public static void main(String[] args) {
JFrame f = new JFrame("Load Image Sample");
JTextField textField=new JTextField();
f.add(textField);
textField.setBounds(10,10,40,30);
textField.setVisible(true);
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
f.add(new Test());
f.pack();
f.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
//if (e.getSource() == textField) {}
}
}

I think that you should not set up your swing application this way. Instead of creating everything in the main method you should create a subclass of JFrame and do the initialization in its constructor (or something like that). This class can then hold references to the components it contains. Example:
public class TestFrame extends JFrame {
private JTextField textField;
public TestFrame() {
super("Load Image Sample");
textField = new JTextField();
this.add(textField);
textField.setBounds(10,10,40,30);
textField.setVisible(true);
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
this.add(new Test());
this.pack();
this.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == textField) {
// ...
}
}
}

create your frame and initialize it inside constructor.
public static void main(String[] args) {
new Test();
}

The event handling method actionPerformed must be registered by an ActionListener interface. As both textField and Test are components of the JFrame a logical place would be the JFrame, or a separate controller class that wires everything together.
I have rewritten your code with a more conventional approach on some details. For that I introduced a new class MyFrame.
public class MyFrame extends JFrame implements ActionListener {
JTextField textField = new JTextField();
public MyFrame(String title) {
super(title); // Or constructor without parameters and:
setTitle("Load Image Sample");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//setLayout(...); for instance with null for absolute positioning
add(textField);
textField.setBounds(10, 10, 40, 30);
textField.setVisible(true);
Test panel = new Test();
add(panel);
pack();
}
public static void main(String[] args) {
JFrame f = new MyFrame("Load Image Sample");
f.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Text: " + textField.getText());
}
}
And then your JPanel
import java.awt.Color;
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.JPanel;
/**
* This class demonstrates how to load an Image from an external file
*/
class Test extends JPanel {
int x = 77, y = 441, w = 23, h = 10;
BufferedImage img;
Color myColor = Color.decode("#32004b");
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(myColor);
g.fillRect(x, y, w, h);
g.drawImage(img, 0, 0, null);
// g.fillRect(10,10,10,10);
}
public Test() {
setBackground(Color.red);
try {
img = ImageIO.read(new File("sales-goal.png"));
} catch (IOException e) {
img = new BufferedImage(100, 50, BufferedImage.TYPE_INT_ARGB);
}
setPreferredSize(new Dimension(300, 600));
}
}