Question

I want to overlap two image. For that, I use JLabel and set an ImageIcon to it. I also have a JPanel using a gridlayout containing my images (like a tile-based map). So far, no problem and it works great.

The problem I encounter, is when I tried to overlap two image. For that, I tried with a JLayeredPane in the gridlayout and put two images (JLabel) in a different level. This method throws me this exception:

Exception in thread “AWT-EventQueue-0” java.lang.IllegalArgumentException: Comparison method violates its general contract!

I made some research and tried to downgrade to jdk-6 instead of 7, cause it appears that in the jdk-7 it doesn’t work well. The exception has now disappeared, but nothing is drawn on the screen.

Then I tried a new method by creating a class that extends JComponent and I override the paintComponent() method. My class contain an arrayList of my images (JLabel) and in the paintComponent method, I iterate through the arrayList and call each label’s paintComponent method with the Graphics object of my own class. The same exception is raised.

Here’s a sample my paintComponent method:

@Override
public void paintComponent(Graphics g) {
    for(JLabel label : this.images) {
        label.paintComponents(g);
    }
}

Answer 1

you can to use

1. JLayer (Java7) based on JXLayer (Java6)

2. GlassPane

3. OverlayLayout

4. JLayeredPane

then you can (for example) moving or animate with Icons / ImageIcons placed in JLabel