title: Android keyboard open or closed listener event not work
body: <p>I am trying to do some operation on keyboard close on Android. For this, I have tried as below</p>
  
  <pre><code>@Override
  public void onConfigurationChanged(Configuration newConfig) {
      super.onConfigurationChanged(newConfig);
  
  
      // Checks whether a hardware keyboard is available
      if (newConfig.hardKeyboardHidden == Configuration.HARDKEYBOARDHIDDEN_NO) {
          Toast.makeText(this, "keyboard visible", Toast.LENGTH_SHORT).show();
      } else if (newConfig.hardKeyboardHidden == Configuration.HARDKEYBOARDHIDDEN_YES) {
          Toast.makeText(this, "keyboard hidden", Toast.LENGTH_SHORT).show();
      }
  }
  </code></pre>
  
  <p>but this <code>configurationNotChanged</code> is not triggered on my activity. What's wrong with it?</p>
  
  <h3>Do we have any other way to handling the keyboard open/close ?</h3>