Question

I have a strange problem…

I have a JFrame and added two JInternalFrame

I have added a JPanel to one of the internal frames.

I used a mouse listener to the jpanel and wrote a code ‘like placing a device object(a class extendng jpanel ) when i release the mouse.

The device image does display, but only after i move d internal frame or maximize it.. why is tat?

The following code is the JPanel which is added to one of the Internal Frames…

public class Board extends JPanel implements MouseListener{
Device[] devices=new Device[10];

int X,Y,i=0;
int j=10;

Point p1,p2;

ImageIcon icon;
public Board()
{
    setBackground(Color.WHITE);
    this.addMouseListener(this);
    setLayout(null);


}

public void mouseClicked(MouseEvent me){

}
public void mouseExited(MouseEvent me){
}
public void mouseEntered(MouseEvent me){

}
public void mousePressed(MouseEvent me){
}

public void mouseReleased(MouseEvent me){

    X=me.getX();
    Y=me.getY();

    icon=new ImageIcon("E:\\java\\ecadpb\\src\\ecadpb\\device"+Layout1.clicked+".png");

    devices[i].setBounds(X,Y,icon.getIconWidth(),icon.getIconHeight()+20);
    devices[i].setVisible(true);
    this.add(devices[i]);
    this.repaint(X,Y,icon.getIconWidth(),icon.getIconHeight()+20);
    i++;
    }

}

}

The following is the Device class..

public Device(Point pos,JLabel label,Rectangle r,int input,int output){
    setVisible(true);
    setBackground(Color.BLACK);
    deviceNo=dno;
    position=pos;
    inputs=input;
    outputs=output;
    this.r=r;

    label.setLayout(null);
    setOpaque(false);
    this.add(label);
    label.addMouseListener(this);
    dno++;


}

}

Answer 1

Swing has to lay out the new component hierarchy. Take a look at JComponent.revalidate() and its related methods.