title: Get preferred screen brightness in Android
body: <p>How do you get the preferred screen brightness in Android?</p>
  
  <p>To change the screen brightness I use <a href="http://developer.android.com/reference/android/view/WindowManager.LayoutParams.html#screenBrightness" rel="noreferrer">WindowManager.LayoutParams.screenBrightness</a>. According to the documentation:</p>
  
  <blockquote>
    <p>This can be used to override the
    user's preferred brightness of the
    screen. A value of less than 0, the
    default, means to use the preferred
    screen brightness. 0 to 1 adjusts the
    brightness from dark to full bright.</p>
  </blockquote>
  
  <p>When <code>screenBrightness</code> is less than 0 I would like to start with the preferred screen brightness. How can I get this value?</p>