HideOnScrollExample - HidingScrollListener class

HidingScrollListener.java

public abstract class HidingScrollListener extends RecyclerView.OnScrollListener {
  private static final int HIDE_THRESHOLD = 20;
  private int scrolledDistance = 0;
  private boolean controlsVisible = true;
  
  @Override
  public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
   
    if (scrolledDistance > HIDE_THRESHOLD && controlsVisible) {
      onHide();
      controlsVisible = false;
      scrolledDistance = 0;
    } else if (scrolledDistance < -HIDE_THRESHOLD && !controlsVisible) {
      onShow();
      controlsVisible = true;
      scrolledDistance = 0;
    }
    
    if((controlsVisible && dy>0) || (!controlsVisible && dy<0)) {
      scrolledDistance += dy;
    }
  }
  
  public abstract void onHide();
  public abstract void onShow();

}