Moving images in a layered pane

Question

Hi people. I've made a layeredpane which i have filled with images, one of which is a cloud. I'm trying to get the cloud to move across the screen, but am having trouble. My code compiles and looks fine to me, i have only started working with GUI's in the last few days and all is quite new to me. The thread part in the main class isn't done properly, but should still make the image move in some way.
import java.awt.* ;
import javax.swing.* ;
import java.applet.* ;
import java.net.* ;
public class Graphic extends JFrame
    private JLayeredPane layeredPane ;
    private BackgroundImage background ;
    private Cloud cloud1, cloud2 ;
    private Man man ;
    private Image logo ;
    public static void main( String[] args ) throws Exception
        Graphic program = new Graphic() ;
        program.run() ;
    void run() throws Exception
        JFrame window = new JFrame() ;
        layeredPane = new JLayeredPane() ;
        layeredPane.setPreferredSize( new Dimension( 500, 250 ) ) ;
        background = new BackgroundImage() ;
        man = new Man() ;
        cloud1 = new Cloud() ;
        cloud2 = new Cloud() ;
        layeredPane.add( background.getBackgroundImage(), 2 ) ;
        layeredPane.add( man.getMan(), 0 ) ;
        layeredPane.add( cloud1.getCloud( 400, 30 ), 1 ) ;
        layeredPane.add( cloud2.getCloud( 25, 55 ),  1 ) ;
        window.setLocationRelativeTo( null ) ;
        window.setTitle( "Mon Café De Poires" ) ;
        logo = Toolkit.getDefaultToolkit().getImage( "pear.png" ) ;
        window.setIconImage( logo ) ;
        window.setDefaultCloseOperation( window.EXIT_ON_CLOSE ) ;
        window.add( layeredPane ) ;
        window.pack() ;
        window.setVisible( true ) ;
        window.setResizable ( false ) ;
        for ( int i = 0 ; i < 100 ; i++ )
            Thread.sleep( 500 ) ;
            cloud1.update( i, i) ;
import java.awt.* ;
import javax.swing.* ;
public class Cloud extends JPanel
    private Image image ;
    private ImageIcon icon ;
    private int xtrans = 0, ytrans = 0 ;
    public Cloud()
        icon = new ImageIcon( "cloud.png" ) ;
        image = icon.getImage() ;
        setPreferredSize( new Dimension( 80, 32 ) ) ;
    public JLabel getCloud( int x, int y )
        JLabel cloud = new JLabel( icon ) ;
        cloud.setBounds( x, y, icon.getIconWidth(), icon.getIconHeight() ) ;
        return cloud ;
    void update( int x, int y )
        xtrans = xtrans + x ;
        ytrans = ytrans + y ;
        repaint() ;
    // Draw image on the panel
    public void paint( Graphics g )
        super.paintComponent( g ) ;
        Graphics2D g2 = ( Graphics2D ) g ;
        g2.drawImage( image, xtrans, ytrans, this ) ;
}

Answer 1

Let's analyze this.
layeredPane.add( background.getBackgroundImage(), 2 ) ;
layeredPane.add( man.getMan(), 0 ) ;
layeredPane.add( cloud1.getCloud( 400, 30 ), 1 ) ;
layeredPane.add( cloud2.getCloud( 25, 55 ),  1 ) ;You have a layered pane. A layered pane dosen't contain a layout manager so all the components in it have to have their bounds explicitly set by the user. It looks like you have two JLabels, a man (?), and a panel in this layered pane. The two JLabel's have there bounds set, so that's good. Hopefully the man and the background image also have their bounds set.
Now, take particular notice of this line since it's the source of your problems
layeredPane.add( cloud1.getCloud( 400, 30 ), 1 ) ;cloud1 is a subclass of JPanel. However, cloud1 isn't actually added to the layered pane. Instead the JLabel returned by getCloud(...) is added to the layered pane. As a result when you get to this part
for ( int i = 0 ; i < 100 ; i++ )
     Thread.sleep( 500 ) ;
      cloud1.update( i, i) ;
}cloud1 is indeed updated, but since it's not added to anything it's not like you can see the result. Instead, all you should see is a static cloud from the JLabel that was added to the layered pane instead of cloud1.