code: public void onContentViewChanged(NotificationView view, View contentView, int layoutId) {
          if (DBG) Log.v(TAG, "onContentViewChanged");
  
          ChildViewManager mgr = view.getChildViewManager();
  
          if (layoutId == R.layout.notification_simple ||
              layoutId == R.layout.notification_large_icon ||
              layoutId == R.layout.notification_full) {
  
              view.setNotificationTransitionEnabled(false);
  
              mgr.setView(ICON, contentView.findViewById(R.id.switcher_icon));
              mgr.setView(TITLE, contentView.findViewById(R.id.switcher_title));
              mgr.setView(TEXT, contentView.findViewById(R.id.switcher_text));
              mgr.setView(WHEN, contentView.findViewById(R.id.switcher_when));
  
          } else if (layoutId == R.layout.notification_simple_2) {
  
              view.setNotificationTransitionEnabled(true);
  
              mgr.setView(ICON, contentView.findViewById(R.id.icon));
              mgr.setView(TITLE, contentView.findViewById(R.id.title));
              mgr.setView(TEXT, contentView.findViewById(R.id.text));
              mgr.setView(WHEN, contentView.findViewById(R.id.when));
          }
      }
docs: Called when content view is changed. All child-views were cleared due the
  change of content view. You need to re-setup the associated child-views.
  
  @param view
  @param contentView
  @param layoutId