Help with AnimationDrawable

Ravenize · by **Ravenize** » Thu Jan 22, 2009 9:55 am

Hey all.

So I seem to be incapable of getting AnimationDrawable to work at all. It's really frustrating and has eaten up a lot of my time, so I figure I need some other people's eyes on this to tell me what I'm doing wrong. I tried getting the Google Group's help on this, but nobody has bothered to respond, so I'm hoping for more over here.

First, we have the regular simple app:

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public class Example extends Activity {
 
   /** Called when the activity is first created. */
 
   @Override
 
   public void onCreate(Bundle savedInstanceState) {
 
       super.onCreate(savedInstanceState);
 
       setContentView(new ExampleView(this));
 
   }
 
}
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And the view class this uses:

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class ExampleView extends View {
 
    private Bitmap image1;
 
    private Bitmap image2;
 
    private BitmapDrawable frame1;
 
    private BitmapDrawable frame2;
 
    private AnimationDrawable anim;
 
    public ExampleView(Context context) {
 
        super(context);
 
        Resources res = context.getResources();
 
        anim = new AnimationDrawable();
 
        image1 = BitmapFactory.decodeResource(res, R.drawable.image1);
 
        image2 = BitmapFactory.decodeResource(res, R.drawable.image2);
 
        frame1 = new BitmapDrawable(image1);
 
        frame2 = new BitmapDrawable(image2);
 
        anim.addFrame(frame1, 50);
 
        anim.addFrame(frame2, 50);
 
        anim.setOneShot(Boolean.FALSE); // make it loop
 
    }
 
    @Override
 
    protected void onDraw(Canvas canvas) {
 
       // draw a bunch of other stuff
 
        anim.setBounds(0, 0, 50, 50);
 
        anim.draw(canvas);
 
        invalidate();
 
    }
 
    // fix for bug where .start() doesn't work within context of activity starting
 
    @Override
 
    public void onWindowFocusChanged(boolean has_focus) {
 
        if (has_focus) {
 
            anim.start();
 
        } else {
 
            anim.stop();
 
        }
 
    }
 
}
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I have verified that the animation is indeed running, and that there are multiple frames, but for some reason I can still only see the first frame (i.e. it never actually animates). I've tried attaching the AnimationDrawable to an ImageView as the background drawable and drawing the ImageView to the canvas, but that didn't seem to help at all. I've also messed around with where .start() is called a lot to no avail. Today I even tried using XML instead of using code but its always the same problem: it shows up on the screen exactly where I expect, but only the first frame ever appears.

Any insight into why I am only seeing the first frame and can't get this to animate would be greatly appreciated.

Ravenize · by **Ravenize** » Sat Feb 07, 2009 9:35 pm

If anyone else is still looking at this I finally figured it out. The trick is to use a ViewGroup as the parent class and then use addView to attach something like an ImageView that has the AnimationDrawable set as its background. It might seem clunky at first, but this gives you the ability to add as many Views / Animations as you want and each one controls its own drawing.

Help with AnimationDrawable

Help with AnimationDrawable

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