Spinning progress bar in every listview item

Question

I\'ve been scratching my head over this for a long time now and searched for an answer without any luck! It seems to be trivial, but as far as I know, it isn\'t.

I use a

Answer 1

Here's how to make it work. Use just one AnimationDrawable, multiplex the callback. ProgressBar doesn't really add anything, you might as well stick with View. Make a subclass of View that bypasses the Drawable management.

public class Whirly extends View
{
   Drawable image = null;

   public Whirly(Context context, AttributeSet attr)
   {
      super(context, attr);
   }

   @Override
   public void draw(Canvas canvas)
   {
      if (image!=null)
         image.draw(canvas);
   }

   public void setImageDrawable(Drawable image)
   {
      this.image = image;
      invalidate();
   }
}

Then make your activity keep track of all the whirlies somehow.

public class Demo extends Activity implements Drawable.Callback
{
   private Handler h;
   private AnimationDrawable a;

   private Whirly w0;
   private Whirly w1;
   private Whirly w2;
   private Whirly w3;

   public void onCreate(Bundle bundle)
   {
      ...

      h = new Handler();

      a = (AnimationDrawable) getResources().getDrawable(R.drawable.mywhirly);
      int width = a.getIntrinsicWidth();
      int height = a.getIntrinsicHeight();
      a.setBounds(0, 0, width, height);

      w0 = (Whirly) findViewById(R.id.whirly0);
      w1 = (Whirly) findViewById(R.id.whirly1);
      w2 = (Whirly) findViewById(R.id.whirly2);
      w3 = (Whirly) findViewById(R.id.whirly3);

      w0.setImageDrawable(a);
      w1.setImageDrawable(a);
      w2.setImageDrawable(a);
      w3.setImageDrawable(a);

      a.setCallback(this);
      a.start();
   }

   public void invalidateDrawable (Drawable who)
   {
      w0.invalidate();
      w1.invalidate();
      w2.invalidate();
      w3.invalidate();
   }

   public void scheduleDrawable (Drawable who, Runnable what, long when)
   {
      h.postAtTime(what, who, when);
   }

   public void unscheduleDrawable (Drawable who, Runnable what)
   {
      h.removeCallbacks(what, who);
   }
}