如何使用动画 gif 作为 JFrame 标题栏图标

Question

Is it possible to use an animated.gif image as the icon of a JFrame?

example:

public class myFrame extends JFrame
{
    java.net.URL imgURL = getCLass().getResource("/icons/AnimatedGif.gif");
    ImageIcon icon = new ImageIcon(imgURL);

    this.setIconImage(icon.getImage());
    icon.setImageObserver(this);

    ...
}

This method has not worked for me. The application hangs prior to making the JFrame visible. Everything works fine though with a regular.gif icon.

Answer 1

I tried a while back to have the icon of my JFrame animated just by setting the icon image to an animated gif. I could never get that to work. I have come up with a work around though. No guarantees about correctness or thread safety.

The basic idea is to have a separate thread that handles the icon animation. This thread's job is to constantly set the frame's icon image.

This is a demo frame:

import java.awt.EventQueue;
import javax.swing.JFrame;

public class FrameWithAnimatedIcon extends JFrame
{
public static void main(String[] args)
{
    final FrameWithAnimatedIcon frame = new FrameWithAnimatedIcon();
    EventQueue.invokeLater(new Runnable()
    {
        public void run()
        {
            try
            {
                frame.setVisible(true);
            } catch(Exception e)
            {
                e.printStackTrace();
            }
        }
    });

    IconAnimator animator = new IconAnimator(frame, Images.images, 250);
    animator.run();
}

public FrameWithAnimatedIcon()
{
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 450, 300);

}
}

This is the icon animator class:

import java.awt.Image;
import java.util.ArrayList;
import javax.swing.JFrame;

public class IconAnimator
{

JFrame           frame = null;
ArrayList<Image> images;
long             msBetweenImages;

public IconAnimator(JFrame frame, ArrayList<Image> images, long msBetweenImages)
{
    this.frame = frame;
    this.images = images;
    this.msBetweenImages = msBetweenImages;
}

public void run()
{
    while(true)
    {
        for(Image image : images)
        {
            try
            {
                frame.setIconImage(image);

                Thread.sleep(msBetweenImages);

            } catch(InterruptedException e)
            {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            if(frame == null)
            {
                return;
            }
        }
    }
}
}    

With this IconAnimator class, I can give it the target frame, a list of images, and the time between images, and it will animate the JFrame icon. I imagine this code is probably not "best practices" material, however, it works. A side note on implementation, I made a separate class called Images that just loads my images into an ArrayList. Each image is 16x16. The list declaration of that class looks like this:

public static ArrayList<Image> images = new ArrayList<Image>(){{
   add(Toolkit.getDefaultToolkit().getImage(
       Images.class.getResource("/toolbarButtonGraphics/development/Bean16.gif")));

   add(Toolkit.getDefaultToolkit().getImage(
           Images.class.getResource   ("/toolbarButtonGraphics/development/Application16.gif"))); 

   add(Toolkit.getDefaultToolkit().getImage(
           Images.class.getResource("/toolbarButtonGraphics/development/Applet16.gif"))); 

   add(Toolkit.getDefaultToolkit().getImage(
           Images.class.getResource("/toolbarButtonGraphics/development/WebComponent16.gif"))); 
}};