code: public void hide() {
  
          // animate with a fade
          ObjectAnimator animator = ObjectAnimator.ofFloat(this, View.ALPHA, 1.0f, 0.0f);
          animator.addListener(new AnimatorEndListener() {
              @Override
              public void onAnimationEnd(Animator animator) {
                  // remove the view from the screen
                  androidContentView.removeView(PeekView.this);
  
                  if (callbacks != null) {
                      callbacks.dismissed();
                  }
              }
          });
          animator.setDuration(options.useFadeAnimation() ? ANIMATION_TIME : 0);
          animator.setInterpolator(INTERPOLATOR);
          animator.start();
  
          Blurry.delete((ViewGroup) androidContentView.getRootView());
      }
docs: Hide the PeekView and remove it from the android.R.id.content FrameLayout.