Develop Reference

Calling Graphics.drawImage in the contructor of a JFrame Java [duplicate]

I'm new on working with Java and Netbeans. In many others languages, it's a simple stuff to do. But after broke my brain thinking, I couldn't. My doubt is simple to explain.
How can I show bitmaps (stored on Hard Drive) in runtime, in a commom JFrame, using java2D? What I need to edit, and or create? Is it simple to do?
Thanks in advance...

The basic process is use Graphics#drawImage to render an image you have previously loaded.
There are a number of things you need in order to achieve this...
An image to paint
A surface to paint on
Luckily, both these are relatively easy to achieve in Swing
See ImageIO for reading images, Reading/Loading an Image
See Performing Custom Painting for more details about how to perform painting in Swing...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
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.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ShowMyImage {
public static void main(String[] args) {
new ShowMyImage();
}
public ShowMyImage() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
ImagePane pane = new ImagePane();
try {
pane.setImg(ImageIO.read(new File("C:\\hold\\thumbnails\\_MTCGAC__Pulling_Cords_by_Dispozition.png")));
} catch (IOException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(pane);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ImagePane extends JPanel {
private BufferedImage img;
public ImagePane() {
}
public void setImg(BufferedImage value) {
if (img != value) {
img = value;
repaint();
}
}
public BufferedImage getImg() {
return img;
}
#Override
public Dimension getPreferredSize() {
BufferedImage img = getImg();
return img == null ? new Dimension(200, 200) : new Dimension(img.getWidth(), img.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
BufferedImage img = getImg();
if (img != null) {
int x = (getWidth() - img.getWidth()) / 2;
int y = (getHeight()- img.getHeight()) / 2;
g2d.drawImage(img, x, y, this);
}
g2d.dispose();
}
}
}

You need, as was told below to extend JPanel class and override paintComponent method in it.
public class DrawImageClass extends JPanel {
private static final long serialVersionUID = 1L;
private Image image;
public DrawImageClass(Image image) throws HeadlessException {
super();
this.image = image;
}
#Override
protected void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D)g;
g2d.drawImage(image, null, null);
}
}
And then create JFrame and add this class to it.
public class App {
private static final int WIDTH=480, HEIGHT = 640;
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(new Dimension(HEIGHT, WIDTH));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
DrawImageClass panel = new DrawImageClass(ImageIO.read(new File(App.class.getResource("/1.png").getPath())));
panel.setPreferredSize(new Dimension(HEIGHT, WIDTH));
frame.add(panel);
frame.setVisible(true);
} catch (Exception e) {
System.out.println("wrong path or smth other");
}
}
}
Example for picture which is in resource folder in project

You can do this with the basic AWT package in java. You will need to extend the JFrame class and override its paintComponent method to display an image there. i.e.
public class MyFrame extends JFrame {
private java.awt.Image bitmap = ImageIO.read(new File("myBitmap.bmp"));
#Override
public void paintComponent(java.awt.Graphics graphics) {
int x = 0;
int y = 0;
int w = bitmap.getWidth(null);
int h = bitmap.getHeight(null);
graphics.drawImage(bitmap, x, y, w, h, this);
}
}
You can simply instantiate it then
MyFrame myFrame = new MyFrame();
myFrame.setPreferredSize(new Dimension(100, 100));
myFrame.setVisible(true);
This is a basic example of course.

Placing JButton on image

Aim: to place JButton on a top of an image that is loaded from a different class.
Problem: only JButton or image can be displayed
//main class
JPanel mPanel.add(new JButton("ddd") );
mPanel.add(drawbg);
class DrawBg extends JPanel {
public Dimension getPreferredSize() {
return new Dimension(1280, 720);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
// background
Image img = new ImageIcon(getClass().getResource("/images/test_bg.jpg")).getImage();
int imgX = img.getWidth(null);
int imgY = img.getHeight(null);
g.drawImage(img, (getWidth() - imgX), (getHeight() - imgY), imgX, imgY, null);
}

Edit Ah yes, as ControlAltDel points out, you're not adding your JButton to your drawing JPanel instance. Just do that, and your problem is solved.
I don't see the bug in your code, so it might lie in code not shown. I do see a problem in that you're reading the image in, inside of paintComponent, something that should never be done as it will slow down painting and thus slow down the perceived responsiveness of your program. Also, why re-read in the image with each paint. Instead read it in once.
For example:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
public class ButtonOnImg extends JPanel {
public static final String IMG_PATH = "https://duke.kenai.com/gun/Gun.jpg";
private BufferedImage img;
public ButtonOnImg() throws IOException {
URL url = new URL(IMG_PATH);
img = ImageIO.read(url);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
g.drawImage(img, 0, 0, null);
}
}
#Override
public Dimension getPreferredSize() {
if (img == null) {
return super.getPreferredSize();
} else {
int w = img.getWidth();
int h = img.getHeight();
return new Dimension(w, h);
}
}
private static void createAndShowGui() {
try {
ButtonOnImg mainPanel = new ButtonOnImg();
mainPanel.add(new JButton("Button!"));
JFrame frame = new JFrame("ButtonOnImg");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Which displays as:

Java Swing Graphical Glitches Dealing with Transparency and Images

So I have this login form and I have a "user photo." I'm trying to make it so that when you hover the mouse over the photo area, a transparent label with a colored background will appear (to give the effect of "selecting the photo"). It looks like this:
And once you move your mouse off it, it goes back to being "deselected."
Now my problem is, if you hover your mouse over the login button first then move your mouse over the photo, a "ghost login button" appears. It looks like this:
I don't know why this is happening. Can someone help? Here is the relevant code:
package com.stats;
public class Stats extends JFrame implements Serializable {
private JLabel fader;
public Stats() {
try {
Image image = ImageIO.read(new File(System.getenv("APPDATA")
+ "\\Stats\\Renekton_Cleave.png"));
JLabel labelUserPhoto = new JLabel(new ImageIcon(image));
fader = new JLabel();
fader.setBounds(97, 44, 100, 100);
fader.setOpaque(true);
fader.setBackground(new Color(0, 0, 0, 0));
labelUserPhoto.setBounds(97, 44, 100, 100);
PicHandler ph = new PicHandler();
contentPane.add(fader);
contentPane.add(labelUserPhoto);
fader.addMouseMotionListener(ph);
} catch(Exception e) {
e.printStackTrace();
}
}
private class PicHandler implements MouseMotionListener {
public void mouseDragged(MouseEvent e) { }
public void mouseMoved(MouseEvent e) {
int x = e.getX();
int y = e.getY();
System.out.println("x: " + x + ", y: " + y);
if ((x > 16 && x < 80) && (y > 16 && y < 80)) {
if (!fader.isOpaque()) {
fader.setOpaque(true);
fader.setBackground(new Color(0, 0, 0, 40));
fader.repaint();
}
} else {
if (fader.isOpaque()) {
fader.setOpaque(false);
fader.repaint();
}
}
}
}

I can see a number of issues with your example, but the most significant is the use of a color with an alpha value.
fader.setBackground(new Color(0, 0, 0, 40));
Swing doesn't render components with alpha based colors well (within this context). By making component opaque and then setting the background color to use an alpha value, you are telling Swing that it doesn't need to worry about painting what's underneath your component, which isn't true...
The Graphics context is also a shared resource, meaning that anything that was painted before your component is still "painted", you need to clear the Graphics context before painting.
This example uses a rather nasty trick to get it's work done. Because all the painting occurs within the UI delegate, if we were simply to allow the default paint chain to continue, we wouldn't be able to render underneath the icon. Instead, we take over control of the "dirty" details and paint the background on the behalf the parent.
This would be simpler to achieve if we simple extended from something like JPanel and painted the image ourselves
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
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.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class FadingIcon {
public static void main(String[] args) {
new FadingIcon();
}
public FadingIcon() {
startUI();
}
public void startUI() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
BufferedImage img = null;
try {
img = ImageIO.read(new File("C:\\Users\\swhitehead\\Documents\\My Dropbox\\Ponies\\SmallPony.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setLayout(new GridBagLayout());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new FadingLabel(new ImageIcon(img)));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class FadingLabel extends JLabel {
private boolean mouseIn = false;
private MouseHandler mouseHandler;
public FadingLabel(Icon icon) {
super(icon);
setBackground(Color.RED);
super.setOpaque(false)(
}
#Override
public void setOpaque(boolean opaque) {
}
#Override
public final boolean isOpaque() {
return false;
}
protected MouseHandler getMouseHandler() {
if (mouseHandler == null) {
mouseHandler = new MouseHandler();
}
return mouseHandler;
}
#Override
public void addNotify() {
super.addNotify();
addMouseListener(getMouseHandler());
}
#Override
public void removeNotify() {
removeMouseListener(getMouseHandler());
super.removeNotify();
}
#Override
protected void paintComponent(Graphics g) {
if (mouseIn) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
g2d.setColor(getBackground());
g2d.fillRect(0, 0, getWidth(), getHeight());
g2d.dispose();
}
getUI().paint(g, this);
}
public class MouseHandler extends MouseAdapter {
#Override
public void mouseEntered(MouseEvent e) {
mouseIn = true;
repaint();
}
#Override
public void mouseExited(MouseEvent e) {
mouseIn = false;
repaint();
}
}
}
}
I would also recommend that you take the time to learn how to use appropriate layout managers, they will save you a lot of hair pulling later
Check out A Visual Guide to Layout Managers and Laying Out Components Within a Container

Since I can't comment I have to put this as an answer:
As trashgod mentioned, this problem can be caused by a missing super.paintComponent(g) call however you don't seem to be overriding the paintComponent method at all (at least you didn't show it here). If you do override the paintComponent method of a JFrame or any JPanels, you need to have:
public void paintComponent(Graphics g) {
super.paintComponent(g);
//rest of your drawing code....
}
But if you haven't used one at all then the problem may be caused by something else.

Since jdk7 there a new mechanism to apply visual decorations (and listening to events for child components): that's the JLayer/LayerUI pair.
In your case a custom layerUI would
trigger a repaint on rollover
implement the paint to apply the transparent color
Below is an example, similar to the WallPaperUI in the tutorial:
// usage: create the component and decorate it with the custom ui
JLabel label = new JLabel(myIcon);
content.add(new JLayer(label, new RolloverUI()));
// custom layerUI
public static class RolloverUI extends LayerUI<JComponent> {
private Point lastMousePoint;
private JLayer layer;
/**
* Implemented to install the layer and enable mouse/motion events.
*/
#Override
public void installUI(JComponent c) {
super.installUI(c);
this.layer = (JLayer) c;
layer.setLayerEventMask(AWTEvent.MOUSE_MOTION_EVENT_MASK
| AWTEvent.MOUSE_EVENT_MASK);
}
#Override
protected void processMouseMotionEvent(MouseEvent e,
JLayer<? extends JComponent> l) {
updateLastMousePoint(e.getPoint());
}
#Override
protected void processMouseEvent(MouseEvent e,
JLayer<? extends JComponent> l) {
if (e.getID() == MouseEvent.MOUSE_EXITED) {
updateLastMousePoint(null);
} else if (e.getID() == MouseEvent.MOUSE_ENTERED) {
updateLastMousePoint(e.getPoint());
}
}
/**
* Updates the internals and calls repaint.
*/
protected void updateLastMousePoint(Point e) {
lastMousePoint = e;
layer.repaint();
}
/**
* Implemented to apply painting decoration below the component.
*/
#Override
public void paint(Graphics g, JComponent c) {
if (inside()) {
Graphics2D g2 = (Graphics2D) g.create();
int w = c.getWidth();
int h = c.getHeight();
g2.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, .5f));
g2.setPaint(new GradientPaint(0, 0, Color.yellow, 0, h,
Color.red));
g2.fillRect(0, 0, w, h);
g2.dispose();
}
super.paint(g, c);
}
protected boolean inside() {
if (lastMousePoint == null || lastMousePoint.x < 0
|| lastMousePoint.y < 0)
return false;
Rectangle r = layer.getView().getBounds();
r.grow(-r.width / 10, -r.height / 10);
return r.contains(lastMousePoint);
}
}

I had a similar problem with ghosted images after something moved or was resized.
#MadProgrammer has some really good points, but in the end, they didn't work for me (possibly because I had multiple layers using 0.0 alpha value colors, some of which also had images in them, so I couldn't set a composite value for the whole component). In the end, what fixed it was a simple call to
<contentpane>.repaint()
after all the draw commands were executed.

Using desktop as a clear white board

Some software uses the monitor as a clear white board to draw. The white board is transparent, and you can see the desktop underneath the clear white board
So how this is possible?
I mean in Java is it like making the JFrame to screen size and making it transparent to draw or how is this being done?
We have a similar requirement so we're trying to understand how to do this?

Here is one way to do it: you create a transparent window on which you put a JLabel displaying a BufferedImage. As the users presses and drags the mouse, you draw on the BufferedImage and repaint the label to update the content.
Some example code to get started:
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class TestTransparentFrame extends JLabel {
private boolean drawing = false;
private Point lastPoint;
private BufferedImage image;
public TestTransparentFrame() {
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
updateImage();
}
});
MouseAdapter mouseAdapter = new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
drawing = true;
lastPoint = e.getPoint();
}
#Override
public void mouseReleased(MouseEvent e) {
drawing = false;
lastPoint = null;
}
#Override
public void mouseExited(MouseEvent e) {
drawing = false;
lastPoint = null;
}
#Override
public void mouseDragged(MouseEvent e) {
if (drawing && lastPoint != null) {
Graphics graphics = image.getGraphics();
graphics.setColor(Color.RED);
((Graphics2D) graphics).setStroke(new BasicStroke(5.0f));
graphics.drawLine(lastPoint.x, lastPoint.y, e.getX(), e.getY());
repaint();
lastPoint = e.getPoint();
}
}
};
addMouseListener(mouseAdapter);
addMouseMotionListener(mouseAdapter);
}
protected void updateImage() {
if (image == null || image.getWidth() < getWidth() || image.getHeight() < getHeight()) {
if (image == null) {
image = getGraphicsConfiguration().createCompatibleImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
} else {
BufferedImage newImage = getGraphicsConfiguration().createCompatibleImage(getWidth(), getHeight(),
BufferedImage.TYPE_INT_ARGB);
newImage.getGraphics().drawImage(image, 0, 0, null);
image = newImage;
}
} else {
image = image.getSubimage(0, 0, getWidth(), getHeight());
}
setIcon(new ImageIcon(image));
}
protected void initUI() {
JFrame frame = new JFrame(TestTransparentFrame.class.getSimpleName());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setUndecorated(true);
frame.setBackground(new Color(255, 255, 255, 1));
TestTransparentFrame comp = new TestTransparentFrame();
frame.setContentPane(comp);
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible(true);
}
/**
* #param args
*/
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new TestTransparentFrame().initUI();
}
});
}
}
And the result:

Adding mouseListener to my object in java

I'm trying to make an applet which I can simply drag an image. And I want image object to listen events. So here is the applet code which simple run in a thread:
import java.awt.*;
import java.net.URL;
import javax.swing.JApplet;
public class Client extends JApplet implements Runnable {
private static final long serialVersionUID = 1L;
MediaTracker mediaTracker;
Image [] imgArray;
Tas t1;
public void init()
{
mediaTracker = new MediaTracker(this);
imgArray = new Image[1];
URL base = getCodeBase();
imgArray[0] = getImage(base,"okey.png");
mediaTracker.addImage(imgArray[0],1);
try {
mediaTracker.waitForAll();
} catch (InterruptedException e) {
e.printStackTrace();
}
t1 = new Tas(this, new Rectangle(0, 0, imgArray[0].getWidth(this), imgArray[0].getHeight(this)), imgArray[0]);
Thread t = new Thread(this);
t.start();
}
public void paint(Graphics g)
{
t1.paint(g);
}
#Override
public void run() {
while(true){
//System.out.println("run");
repaint();
try {
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
And the class of object which holds image is:
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Movable extends JPanel implements MouseListener {
public Client mainObj;
public Rectangle rect;
public Image image;
public Movable(Client mainObj, Rectangle rect, Image image) {
this.mainObj = mainObj;
this.rect = rect;
this.image = image;
addMouseListener(this);
}
public void paint(Graphics g) {
g.drawImage(image, rect.x, rect.y, rect.width, rect.height, this);
}
#Override
public void mouseClicked(MouseEvent arg0) {
System.out.println("clicked");
}
#Override
public void mouseEntered(MouseEvent arg0) {
}
#Override
public void mouseExited(MouseEvent arg0) {
}
#Override
public void mousePressed(MouseEvent arg0) {
System.out.println("pressed");
}
#Override
public void mouseReleased(MouseEvent arg0) {
}
}
#SuppressWarnings("serial")
class Tas extends Movable{
public String name = "";
public Tas(Client mainObj, Rectangle rect, Image image) {
super(mainObj, rect, image);
}
}
I can see the image in my applet but nothing happens when I click in or out of the image. So what's wrong with this code.

Assuming that Tas in code #1 is Moveable in code #2...
You don't actually use the Moveable as a Component, but instead ask it to paint itself onto the Applet's graphics context, here:
public void paint(Graphics g)
{
t1.paint(g);
}
Instead you should add an instance of Moveable onto the Applet's container, wherein painting will become automatic, and it will start to receive mouse events. You can also remove that paint() method then too.

First of all you should never override the paint method of a top level container (JApplet, JFrame, JDialog).
Then to do custom painting on other Swing components you override the paintComponent() method of the component, NOT the paint() method. Read the Swing tutorial on Custom Painting. So first fix those problems.
I'm not sure what the point of the Thread is but remove it from your code until you solve your other problems. If you are trying to do animation, then you should be using a Swing Timer, not a Thread.
If you want to see some code for dragging components you can take a look at Moving Windows for some generic code.

This is a working solution. It is not an applet but you can easily convert that. Hope it helps :
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Point2D;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class ImagePanel extends JPanel {
Image image;
Point2D axis = new Point2D.Double();
boolean drag = false;
Point2D dragPoint = new Point2D.Double();
public ImagePanel(Image image) {
this.image = image;
setPreferredSize(new Dimension(300,300));
addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
drag = true;
dragPoint = e.getPoint();
}
#Override
public void mouseReleased(MouseEvent e) {
drag = false;
}
});
addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
if (drag) {
axis.setLocation(axis.getX()
+ (e.getPoint().x - dragPoint.getX()), axis.getY()
+ (e.getPoint().y - dragPoint.getY()));
dragPoint = e.getPoint();
repaint();
}
}
});
}
#Override
public void paintComponent(Graphics g) {
g.setColor(Color.white);
g.fillRect(0, 0, getWidth(), getHeight());
g.drawImage(image, (int) axis.getX(), (int) axis.getY(), null);
}
public static void main(String[] args) {
try {
JFrame f = new JFrame();
f.getContentPane().add(
new ImagePanel(ImageIO.read(new File("image.jpg"))));
f.pack();
f.setVisible(true);
} catch (IOException e) {
e.printStackTrace();
}
}
}

The simple answer is - you don't have code to do anything in mousePressed() or mouseReleased().
There are lots of other problems in the code though...
Simplest solution I could come up with -
public class Client extends JApplet {
private MouseInputAdapter myMouseListener = new MyMouseListener();
public void init() {
// usually a very bad idea, but needed here
// since you want to move things around manually
setLayout(null);
// assuming this will get used often, so making it a method.
addLabelForImage(getImage(getCodeBase(), "okay.png"));
}
private void addLabelForImage(Image image) {
ImageIcon icon = new ImageIcon(image);
JLabel l = new JLabel(icon);
add(l);
l.setSize(l.getPreferredSize());
// you'll probably want some way to calculate initial position
// of each label based on number of images, size of images,
// size of applet, etc. - just defaulting to 100,100 now.
l.setLocation(100, 100);
l.addMouseListener(myMouseListener);
l.addMouseMotionListener(myMouseListener);
}
// Made this a MouseInputAdapter because I assume you may want to handle
// other types of mouse events later...
private static class MyMouseListener extends MouseInputAdapter {
#Override
public void mouseDragged(MouseEvent e) {
// when the mouse is dragged over a the component this listener is
// attached to (ie - one of the labels) convert the point of the mouse
// event from the internal component coordinates (0,0 is upper right
// corner of each label), to it's parent's coordinates (0,0 is upper
// right corner of the applet), and set the components location to
// that point.
Component theLabel = e.getComponent();
Container theApplet = theLabel.getParent();
Point labelPoint = e.getPoint();
Point appletPoint = SwingUtilities.convertPoint(
theLabel, labelPoint, theApplet );
theLabel.setLocation(appletPoint);
}
}
}