public void setMinR(float minR) {
    this.minR = minR;
  }

  public void setMaxR(float maxR) {
    this.maxR = maxR;
  }

  public void setBrokeDistance(float distance) {
    this.brokeDistance = distance;
  }

public Buble(Context context) {
    super(context);
    init();
  }

  public Buble(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    init();
  }

private void init() {
    paint = new Paint();
    paint.setStyle(Paint.Style.FILL);
    paint.setColor(Color.GREEN);
    paint.setAntiAlias(true);
  }

protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    drawOriginalCircle(canvas);
    if (!canBroke) {
      drawMoveCircle(canvas);
      drawBCurve(canvas);
    }
  }

 private void drawOriginalCircle(Canvas canvas) {
    canvas.drawCircle(getWidth() / 2, getHeight() / 2, minR, paint);
  }

  private void drawMoveCircle(Canvas canvas) {
    canvas.drawCircle(moveX, moveY, maxR, paint);
  }

  private void drawBCurve(Canvas canvas) {
    canvas.drawPath(path, paint);
  }

double angle = Math.atan((offsetX - minCircleX) / (offsetY - minCircleY));

private void setPath(float offsetX, float offsetY) {
    float minCircleX = (float) getWidth() / 2;
    float minCircleY = (float) getHeight() / 2;
    double angle = Math.atan((offsetX - minCircleX) / (offsetY - minCircleY));
    float x1 = (float) (minCircleX + Math.cos(angle) * minR);
    float y1 = (float) (minCircleY - Math.sin(angle) * minR);
    float x2 = (float) (offsetX + Math.cos(angle) * maxR);
    float y2 = (float) (offsetY - Math.sin(angle) * maxR);
    float x3 = (float) (offsetX - Math.cos(angle) * maxR);
    float y3 = (float) (offsetY + Math.sin(angle) * maxR);
    float x4 = (float) (minCircleX - Math.cos(angle) * minR);
    float y4 = (float) (minCircleY + Math.sin(angle) * minR);
    float centerX = minCircleX + (offsetX - minCircleX) / 2;
    float centerY = minCircleY + (offsetY - minCircleY) / 2;
    path.reset();
    path.moveTo(minCircleX, minCircleY);
    path.lineTo(x1, y1);
    path.quadTo(centerX, centerY, x2, y2);
    path.lineTo(x3, y3);
    path.quadTo(centerX, centerY, x4, y4);
    path.lineTo(minCircleX, minCircleY);
    path.close();
  }

 switch (event.getAction()) {
      case MotionEvent.ACTION_DOWN:
        this.canBroke = false;
        moveX = event.getX();
        moveY = event.getY();
        touchArea = !setCanBroke(moveX, moveY, maxR);
        break;
      case MotionEvent.ACTION_MOVE:
        if (touchArea) {
          moveX = event.getX();
          moveY = event.getY();
          if (setCanBroke(moveX, moveY, brokeDistance)) {
            touchArea = false;
            this.canBroke = true;
          } else {
            setPath(moveX, moveY);
          }
          invalidate();
        }
        break;
      case MotionEvent.ACTION_UP:
        Log.d("aaa", "actionUp" + touchArea);
        if (touchArea) {
          resetCircle(event.getX(), event.getY());
        }
        break;
    }
    return true;

 private boolean setCanBroke(float offsetX, float offsetY, float brokeDistance) {
    float minCircleX = (float) getWidth() / 2;
    float minCircleY = (float) getHeight() / 2;
    return (offsetX - minCircleX) * (offsetX - minCircleX) +
        (offsetY - minCircleY) * (offsetY - minCircleY) > brokeDistance * brokeDistance;
  }

private void resetCircle(float x, float y) {
    valueAnimatorX = ValueAnimator.ofFloat(x, (float) getWidth() / 2);
    valueAnimatorY = ValueAnimator.ofFloat(y, (float) getHeight() / 2);
    valueAnimatorX.removeAllUpdateListeners();
    valueAnimatorY.removeAllUpdateListeners();
    valueAnimatorX.setInterpolator(new BounceInterpolator());
    valueAnimatorY.setInterpolator(new BounceInterpolator());
    valueAnimatorX.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        tempX = (float) animation.getAnimatedValue();
        moveX = tempX;
      }
    });
    valueAnimatorY.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
      @Override
      public void onAnimationUpdate(ValueAnimator animation) {
        tempY = (float) animation.getAnimatedValue();
        moveY = tempY;
        setPath(tempX, tempY);
        postInvalidate();
      }
    });
    set.playTogether(valueAnimatorX, valueAnimatorY);
    set.start();
  }