public void adjustAddViewAlpha(Rect panelRect){
  if (mAddView != null) {
    mAddView.getHitRect(mAddRect);
    int difference=panelRect.top - mAddRect.top;
    boolean setAlpha=false;
    if (difference < 0) {
      mAddView.setAlpha(0.0f);
    }
 else {
      mAddView.setAlpha(Math.min(((float)difference) / mAddRect.height(),1.0f));
    }
  }
}

public void adjustAddViewAlpha ( Rect panelRect ) { if ( mAddView != null ) { mAddView . getHitRect ( mAddRect ) ; int difference = panelRect . top - mAddRect . top ; boolean setAlpha = false ; if ( difference < 0 ) { mAddView . setAlpha ( 0.0f ) ; } else { mAddView . setAlpha ( Math . min ( ( ( float ) difference ) / mAddRect . height ( ) , 1.0f ) ) ; } } }
adjusts the alpha of the add button based on the bottom panel ( which houses the axis ) . the button is completely hidden when it ' s below the panel ' s bottom , but fades in as it intersects and moves above the panel .
