Drawing on top of a component

Hi there.
if I have JPanel that contains a JLabel that contains is a 600x800 image, how can i draw a shape like circle on top of the image? I would like to be able to see the image with the circle on it. How can i make this possible?
Right now i can draw the circle on its own JPanel, but that is not what i want.
Thanks

Notably, that you have a inner class referencing
image variables defined in the class it's nested in.Inner classes can access all members of the declaring class,
even private members. In fact, the inner class itself is said to be
a member of the class; therefore, following the rules of
object-oriented engineering, it should have access to all
members of the class.
The inner class does nothing to set it's own size,
, since as far as that JLabel instance knows, it
contains nothing.
But this is not corrected, it's
only relying on the BorderLayout to fill the frame
with the label.
While your sample works fine as is, it's not very
portable. As the OP posted after, he attempted to
use your code adding a JPanel in between the content
pane and the label, and it wouldn't work because of
the layout issues. To solve that, one might tend
towards defining a null layout and setting the bounds
explicitly, or one might add a setMinimumSize or
setPreferredSize call to get a size.
But that's adding more code to fix a problem that has
a much simpler solution. Which is to just give the
label the image directly, let the label size itself
automatically based on that image, let the label draw
the image itself and only override paint to get the
custom drawing done on top.
Myself, I understand what you were saying in your
code. But clearly the OP did not, and I suspect was
heading to starting patching what wasn't working by
applying more code when one could more cleanly use
less code and take advantage of what JLabel will
already do for you.Agreed. But this problem can also be easily solved with "setPreferredSize(new Dimension(200,200));" in the constructor of "Picture".

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int xPos, yPos;
Image img;
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THANKS!!

Notably, that you have a inner class referencing
image variables defined in the class it's nested in.Inner classes can access all members of the declaring class,
even private members. In fact, the inner class itself is said to be
a member of the class; therefore, following the rules of
object-oriented engineering, it should have access to all
members of the class.
The inner class does nothing to set it's own size,
, since as far as that JLabel instance knows, it
contains nothing.
But this is not corrected, it's
only relying on the BorderLayout to fill the frame
with the label.
While your sample works fine as is, it's not very
portable. As the OP posted after, he attempted to
use your code adding a JPanel in between the content
pane and the label, and it wouldn't work because of
the layout issues. To solve that, one might tend
towards defining a null layout and setting the bounds
explicitly, or one might add a setMinimumSize or
setPreferredSize call to get a size.
But that's adding more code to fix a problem that has
a much simpler solution. Which is to just give the
label the image directly, let the label size itself
automatically based on that image, let the label draw
the image itself and only override paint to get the
custom drawing done on top.
Myself, I understand what you were saying in your
code. But clearly the OP did not, and I suspect was
heading to starting patching what wasn't working by
applying more code when one could more cleanly use
less code and take advantage of what JLabel will
already do for you.Agreed. But this problem can also be easily solved with "setPreferredSize(new Dimension(200,200));" in the constructor of "Picture".

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Drawing on top of an image

Hello!
I am trying to create a Panel on which I can draw stuff using the mouse. I have managed to get it working, apart from one small part. I want to have an image (jpg) as a background, and as soon as I try to add an image either the image does not show or the drawing stuff stops working.
Here is my working drawing code (i.e. without image):
public void paintComponent(Graphics g) {
         super.paintComponent(g);
         if (image == null || image.getWidth(null) != getWidth()
               || image.getHeight(null) != getHeight()) {
            image = (BufferedImage) createImage(getWidth(), getHeight());
            graph = (Graphics2D) image.getGraphics();
            graph.fillRect(0, 0, getWidth(), getHeight());
            graph.setColor( Color.white );
            graph.setStroke(new BasicStroke(3));
            graph.addRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING,
                  RenderingHints.VALUE_ANTIALIAS_ON));
         Rectangle r = g.getClipBounds();
         g.drawImage(image, r.x, r.y, r.x + r.width, r.y + r.height, r.x, r.y,
               r.x + r.width, r.y + r.height, null);
         if (endPoint != null) {
            g.setColor(currentColor);
            if (shapeType == 0)
               g.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y);
            if (shapeType == 1)
               g.drawOval(pn.x, pn.y, pn.width, pn.height);
            if (shapeType == 2)
               g.drawRect(pn.x, pn.y, pn.width, pn.height);
         public void mouseDragged( MouseEvent m ) {
            if (shapeType > 3 && shapeType != 8)
               return;
            if (endPoint == null)
               endPoint = new Point();
            repaint(pn.x, pn.y, pn.width + 1, pn.height + 1);
            pn.x = Math.min(startPoint.x, m.getX());
            pn.y = Math.min(startPoint.y, m.getY());
            pn.width = Math.abs(m.getX() - startPoint.x);
            pn.height = Math.abs(m.getY() - startPoint.y);
            if (shapeType == 0) {
               endPoint.setLocation(m.getPoint().getLocation());
            if (shapeType == 3) {
               graph.setColor(currentColor);
               graph.drawLine(startPoint.x, startPoint.y, m.getX(), m.getY());
               startPoint = m.getPoint();
            repaint(pn.x, pn.y, pn.width + 1, pn.height + 1);
         public void mouseReleased(MouseEvent m) {
            if (endPoint != null)
               draw();
            endPoint = null;
         public void mousePressed(MouseEvent m) {
            startPoint = m.getPoint();
         public void draw() {
            graph.setColor(currentColor);
            if (shapeType == 0)
               graph.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y);
            if (shapeType == 1)
               graph.drawOval(pn.x, pn.y, pn.width, pn.height);
            if (shapeType == 2)
               graph.draw(pn);
            repaint(pn.x, pn.y, pn.width + 1, pn.height + 1);
         }To me it seemed logical to add:
graph.drawImage(my_gif, 0, 0, this);at the end of the if statement, but that did not work.
Where and how should I add the image?
Thanks!

Thanks for answering!
Here is the entire code:
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import javax.swing.JApplet;
import javax.swing.JLabel;
import javax.swing.JPanel;
@SuppressWarnings("serial")
public class ImageExample extends JApplet {
   private static final Dimension DRAWING_AREA_SIZE = new Dimension(300,300);
   private static final Point DRAWING_AREA_UPPER_LEFT = new Point(100,50);
   private static final Color BACKGROUND_COLOR = Color.black;
   private Image my_gif;
   private Color currentColor = Color.white;
   private JLabel currentColorIndicator;
   private JPanel pane = new JPanel(null);
   Point startPoint, endPoint;
   Rectangle pn = new Rectangle();
   BufferedImage image;
   Graphics2D graph;
   int shapeType = 3;
   public void init() {
      setContentPane(pane);
      my_gif = getImage( getDocumentBase(), "fractal.gif" );
      pane.setOpaque(true);
      pane.setBackground(BACKGROUND_COLOR);
      createColorMap();
      DrawingPanel drawingPanel = new DrawingPanel();
      drawingPanel.setBounds(DRAWING_AREA_UPPER_LEFT.x, DRAWING_AREA_UPPER_LEFT.y, DRAWING_AREA_SIZE.width,
            DRAWING_AREA_SIZE.height);
      pane.add(drawingPanel);
   // Private methods
   private void createColorMap() {
      ColorPickerListener listener = new ColorPickerListener();
      JLabel colorText = new JLabel("Color");
      colorText.setBounds(10, DRAWING_AREA_UPPER_LEFT.y-20, 50, 25);
      colorText.setForeground(Color.white);
      pane.add(colorText);
      JLabel redColor = new JLabel("");
      redColor.addMouseListener(listener);
      redColor.setBackground(Color.RED);
      redColor.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+10, 50, 30);
      redColor.setOpaque(true);
      pane.add(redColor);
      JLabel blueColor = new JLabel("");
      blueColor.addMouseListener(listener);
      blueColor.setBackground(Color.blue);
      blueColor.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+40, 50, 30);
      blueColor.setOpaque(true);
      pane.add(blueColor);
      JLabel whiteColor = new JLabel("");
      whiteColor.addMouseListener(listener);
      whiteColor.setBackground(Color.white);
      whiteColor.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+70, 50, 30);
      whiteColor.setOpaque(true);
      pane.add(whiteColor);
      JLabel greenColor = new JLabel("");
      greenColor.addMouseListener(listener);
      greenColor.setBackground(Color.green);
      greenColor.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+100, 50, 30);
      greenColor.setOpaque(true);
      pane.add(greenColor);
      JLabel blackColor = new JLabel("");
      blackColor.addMouseListener(listener);
      blackColor.setBackground(Color.black);
      blackColor.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+130, 50, 30);
      blackColor.setOpaque(true);
      pane.add(blackColor);
      JLabel grayColor = new JLabel("");
      grayColor.addMouseListener(listener);
      grayColor.setBackground(Color.gray);
      grayColor.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+160, 50, 30);
      grayColor.setOpaque(true);
      pane.add(grayColor);
      JLabel yellowColor = new JLabel("");
      yellowColor.addMouseListener(listener);
      yellowColor.setBackground(Color.yellow);
      yellowColor.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+190, 50, 30);
      yellowColor.setOpaque(true);
      pane.add(yellowColor);
      // Display currently chosen color
      JLabel currentColorText = new JLabel("Current");
      currentColorText.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+230, 50, 25);
      currentColorText.setForeground(Color.white);
      pane.add(currentColorText);
      currentColorIndicator = new JLabel("");
      currentColorIndicator.setBounds(10, DRAWING_AREA_UPPER_LEFT.y+260, 50, 30);
      updateCurrentColorLabel();
      currentColorIndicator.setOpaque(true);
      pane.add(currentColorIndicator);
   private void updateCurrentColorLabel() {
      currentColorIndicator.setBackground(currentColor);
      currentColorIndicator.setForeground(new Color(255 - currentColor.getRed(), 255 - currentColor.getGreen(),
            255 - currentColor.getBlue()));
   // Private classes
   private class DrawingPanel extends JPanel implements MouseListener, MouseMotionListener {
      BufferedImage image;
      public DrawingPanel() {
         addMouseMotionListener(this);
         addMouseListener(this);
      public void paintComponent(Graphics g) {
         super.paintComponent(g);
         if (image == null || image.getWidth(null) != getWidth()
               || image.getHeight(null) != getHeight()) {
            image = (BufferedImage) createImage(getWidth(), getHeight());
            graph = (Graphics2D) image.getGraphics();
            graph.fillRect(0, 0, getWidth(), getHeight());
            graph.setColor( Color.white );
            graph.setStroke(new BasicStroke(3));
            graph.addRenderingHints(new RenderingHints(RenderingHints.KEY_ANTIALIASING,
                  RenderingHints.VALUE_ANTIALIAS_ON));
            graph.drawImage(my_gif, 0, 0, this);
            System.out.println(my_gif + " <- my_gif");
            System.out.println(my_gif.getWidth(this) + " <- my_gif.getWidth(this)");
            System.out.println(my_gif.getHeight(this) + " <- my_gif.getheight(this)");
         Rectangle r = g.getClipBounds();
         g.drawImage(image, r.x, r.y, r.x + r.width, r.y + r.height, r.x, r.y,
               r.x + r.width, r.y + r.height, null);
         if (endPoint != null) {
            g.setColor(currentColor);
            if (shapeType == 0)
               g.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y);
            if (shapeType == 1)
               g.drawOval(pn.x, pn.y, pn.width, pn.height);
            if (shapeType == 2)
               g.drawRect(pn.x, pn.y, pn.width, pn.height);
         public void mouseDragged( MouseEvent m ) {
            if (shapeType > 3 && shapeType != 8)
               return;
            if (endPoint == null)
               endPoint = new Point();
            repaint(pn.x, pn.y, pn.width + 1, pn.height + 1);
            pn.x = Math.min(startPoint.x, m.getX());
            pn.y = Math.min(startPoint.y, m.getY());
            pn.width = Math.abs(m.getX() - startPoint.x);
            pn.height = Math.abs(m.getY() - startPoint.y);
            if (shapeType == 0) {
               endPoint.setLocation(m.getPoint().getLocation());
            if (shapeType == 3) {
               graph.setColor(currentColor);
               graph.drawLine(startPoint.x, startPoint.y, m.getX(), m.getY());
               startPoint = m.getPoint();
            repaint(pn.x, pn.y, pn.width + 1, pn.height + 1);
         public void mouseReleased(MouseEvent m) {
            if (endPoint != null)
               draw();
            endPoint = null;
         public void mousePressed(MouseEvent m) {
            startPoint = m.getPoint();
         public void draw() {
            graph.setColor(currentColor);
            if (shapeType == 0)
               graph.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y);
            if (shapeType == 1)
               graph.drawOval(pn.x, pn.y, pn.width, pn.height);
            if (shapeType == 2)
               graph.draw(pn);
            repaint(pn.x, pn.y, pn.width + 1, pn.height + 1);
         public void mouseClicked(MouseEvent arg0) {}
         public void mouseEntered(MouseEvent arg0) {         }
         public void mouseExited(MouseEvent arg0) {         }
         public void mouseMoved(MouseEvent arg0) {         }
   //Listeners
   private class ColorPickerListener extends MouseAdapter {
      public void mouseClicked(MouseEvent e) {
         JLabel color = (JLabel) e.getSource();
         currentColor = color.getBackground();
         updateCurrentColorLabel();
}So the problem might be that the system.outs in there put out:
sun.awt.image.ToolkitImage@1a0c10f <- my_gif
-1 <- my_gif.getWidth(this)
-1 <- my_gif.getheight(this)I don't know how to fix so that the height and width are set. Isn't it enough to do the:
      my_gif = getImage( getDocumentBase(), "fractal.gif" );before initializing the drawing panel?
Thanks again!

Drawing a rectanlge and moving it around

Hi,
I have a JTable in which I do drag and drop. To visually support this, I draw a marker in the JTable, when the cursor is over a valid drop position, to indicate where the object will be inserted. I do this by drawing a rectangle between two tables.
        Rectangle rect= tt1.getCellRect(row, col, true);
        Rectangle2D marker= new Rectangle2D.Double(rect.getX()-1, rect.getY(), 2, rect.getHeight());
        if (marker.equals(lastMarker)){
            return lastMarker;
        }else{
            //Line2D line= new Line2D.Double( rect.getX()-1, rect.getY()+rect.getHeight());
            tt1.repaint();
            Graphics2D g2= (Graphics2D) tt1.getGraphics();
            g2.fill(marker);
            return marker;
        }(the lastMarker is used to avoid redrawing it, if would be on the same position.)
Now my problem is the tt1.repaint(). (tt1 is the JTable)
This repaint always deletes my rectangle. I think, this is because the actual redraw is done after the marker is drawn. Therefore the rectangle is shown for some milliseconds and then disappears. But how can I avoid this? Any ideas?

Don't use getGraphics for this. Trying to draw from event code doesn't work because system
repaint events work independently of your event code, ie, system repaints call the paint
methods of the components in the component hierarchy which have no idea that you are
drawing markers from event code. Override the paint method (which will draw on top of the
component) in your JTable to draw your drop marker. This way it will always be called
during both event-initiated and system repaints.

Drawing on top of a component

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