Help moving a watermark

Question

Hello to everyone, i have a picture and i wanted to be able to add a watermark. I succesfully made the code to do excactly that and know i want to take another step forward and be able to drag the watermark with the mouse where i want on top of the picture. Is this posible? and if yes can anybody help and most important explain to me?
note i also draw a rectangle over the picture wich i control with the mouse.
my code is:
//this is the class i draw the picture, rectangle and watermark
public class ScrollablePicture extends JLabel
        implements Scrollable,
        MouseMotionListener, MouseListener {
//////...... a lot of code
public void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2 = (Graphics2D) g;
            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                    RenderingHints.VALUE_ANTIALIAS_ON);
            g2.setPaint(Color.blue);
            if (!missingPicture) {
                  g2.draw(r);
                  g2.draw(centerRect);
//i use mouse clicked and note moved for simplicity
//if there is any syggestions to which mouse method excactly to use
//please tell
  public void mouseClicked(MouseEvent e) {
            Point p = e.getPoint();
            BufferedImage waterMarked = ScrollablePicture.graphicsConfiguration.createCompatibleImage(imageManager.getCurrentImage().getWidth(), imageManager.getCurrentImage().getHeight());
            final Graphics2D imageG = waterMarked.createGraphics();
            BufferedImage test = imageManager.getWatermark();
            // draw original image.
            imageG.drawImage(imageManager.getCurrentImage(), null, 0, 0);
            imageG.dispose();
            final Graphics2D g = waterMarked.createGraphics();
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.3f)); // 30% transparency
            //draw watermark.
            g.drawImage(test, (int)p.getX(), (int)p.getY(),null);
            g.dispose();
            imageManager.setCurrentImage(waterMarked);
      }i am expecting the watermark to be drawn when i press the mouse over the picture and at the excact location wich simply doesn't happen.
please excuse my poor english.
thanks in advance

Answer 1

You'll have to decide how you want the user to choose between dragging the rectangle and dragging the watermark image. You could provide components that allow for the selection of one or the other or you might try to do it with custom Keystrokes or special MouseEvents.
The class with the JFrame could host the View and any user–selection components.
public class View extends JPanel {
    protected void paintComponent(Graphics g) {
        draw background image
        if user wants to see rectangle
            draw rectangle
        if user wants to see watermark
            draw watermark image
public class Controller extends MouseInputAdapter {
    // mousePressed is better for low-level work like this.
    public void mousePressed(MouseEvent e) {
        Point p = e.getPoint();
        if dragging rect
            save p in member variable (savedPt)
            enable dragging
        else if user is dragging watermark
            make Rectangle r with location and size of wmImage
            if r contains p
                save difference between p and location of r
                enable dragging
    public void mouseReleased(MouseEvent e) {
        disable dragging
    public void mouseDragged(MouseEvent e) {
        if dragging enabled
            p = e.getPoint
            if dragging rect
                set rect with (savedPt, p) in component.
            else if dragging watermark
                calculate new origin (w/savedPt & p) for wmImage
                set new origin of watermark in view
}