code: package io.virtualapp.widgets;
  
  import android.animation.ValueAnimator;
  import android.graphics.Canvas;
  import android.graphics.Paint;
  
  import java.util.ArrayList;
  
  public class BallGridBeatIndicator extends Indicator {
  
      private static final int ALPHA = 255;
  
      private static final int[] ALPHAS = new int[]{ALPHA,
              ALPHA,
              ALPHA,
              ALPHA,
              ALPHA,
              ALPHA,
              ALPHA,
              ALPHA,
              ALPHA};
  
      @Override
      public void draw(Canvas canvas, Paint paint) {
          float circleSpacing = 4;
          float radius = (getWidth() - circleSpacing * 4) / 6;
          float x = getWidth() / 2 - (radius * 2 + circleSpacing);
          float y = getWidth() / 2 - (radius * 2 + circleSpacing);
  
          for (int i = 0; i < 3; i++) {
              for (int j = 0; j < 3; j++) {
                  canvas.save();
                  float translateX = x + (radius * 2) * j + circleSpacing * j;
                  float translateY = y + (radius * 2) * i + circleSpacing * i;
                  canvas.translate(translateX, translateY);
                  paint.setAlpha(ALPHAS[3 * i + j]);
                  canvas.drawCircle(0, 0, radius, paint);
                  canvas.restore();
              }
          }
      }
  
      @Override
      public ArrayList<ValueAnimator> onCreateAnimators() {
          ArrayList<ValueAnimator> animators = new ArrayList<>();
  
          int[] durations = {960, 930, 1190, 1130, 1340, 940, 1200, 820, 1190};
          int[] delays = {360, 400, 680, 410, 710, -150, -120, 10, 320};
  
          for (int i = 0; i < 9; i++) {
              final int index = i;
              ValueAnimator alphaAnim = ValueAnimator.ofInt(255, 168, 255);
              alphaAnim.setDuration(durations[i]);
              alphaAnim.setRepeatCount(-1);
              alphaAnim.setStartDelay(delays[i]);
              addUpdateListener(alphaAnim, animation -> {
                  ALPHAS[index] = (int) animation.getAnimatedValue();
                  postInvalidate();
              });
              animators.add(alphaAnim);
          }
          return animators;
      }
  
  
  }