code: package io.virtualapp.widgets;
  
  import android.animation.ValueAnimator;
  import android.graphics.Canvas;
  import android.graphics.Paint;
  
  import java.util.ArrayList;
  
  public class BallPulseIndicator extends Indicator {
  
      public static final float SCALE = 1.0f;
  
      //scale x ,y
      private float[] scaleFloats = new float[]{SCALE,
              SCALE,
              SCALE};
  
  
      @Override
      public void draw(Canvas canvas, Paint paint) {
          float circleSpacing = 4;
          float radius = (Math.min(getWidth(), getHeight()) - circleSpacing * 2) / 6;
          float x = getWidth() / 2 - (radius * 2 + circleSpacing);
          float y = getHeight() / 2;
          for (int i = 0; i < 3; i++) {
              canvas.save();
              float translateX = x + (radius * 2) * i + circleSpacing * i;
              canvas.translate(translateX, y);
              canvas.scale(scaleFloats[i], scaleFloats[i]);
              canvas.drawCircle(0, 0, radius, paint);
              canvas.restore();
          }
      }
  
      @Override
      public ArrayList<ValueAnimator> onCreateAnimators() {
          ArrayList<ValueAnimator> animators = new ArrayList<>();
          int[] delays = new int[]{120, 240, 360};
          for (int i = 0; i < 3; i++) {
              final int index = i;
  
              ValueAnimator scaleAnim = ValueAnimator.ofFloat(1, 0.3f, 1);
  
              scaleAnim.setDuration(750);
              scaleAnim.setRepeatCount(-1);
              scaleAnim.setStartDelay(delays[i]);
  
              addUpdateListener(scaleAnim, animation -> {
                  scaleFloats[index] = (float) animation.getAnimatedValue();
                  postInvalidate();
              });
              animators.add(scaleAnim);
          }
          return animators;
      }
  
  
  }