title: Set roughike bottombar drawable background
body: <p>I am using roughike bottombar to navigate through fragments in my project, I am trying to set a drawable background to my bottombar but is having difficulty doing so. The example in the official guide <a href="https://github.com/roughike/BottomBar" rel="nofollow noreferrer">https://github.com/roughike/BottomBar</a> only shows how to change the color of the bar. Is there any possible way to do so?</p>
  
  <pre><code>    resId = R.drawable.footer_bg_02;
      bottomBar = BottomBar.attach(this, savedInstanceState);
      if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.JELLY_BEAN) {
          bottomBar.setBackground(resId);
      }
      bottomBar.setFragmentItems(getSupportFragmentManager(), R.id.fragmentContainer,
              new BottomBarFragment(StoreList.newInstance("Content for fragment 1."), R.drawable.ic_01, "fragment 1"),
              new BottomBarFragment(QRscanner.newInstance("Content for fragment 2."), R.drawable.ic_02, "fragment 2"),
              new BottomBarFragment(MyBooking.newInstance("Content for fragment 3."), R.drawable.ic_03, "fragment 3"),
      );
  
      bottomBar.setOnItemSelectedListener(new OnTabSelectedListener() {
          @Override
          public void onItemSelected(int position) {
              switch (position) {
                  case 0:
                      getSupportActionBar();
                      //return;
                  case 1:
                      //getSupportActionBar().hide();
                  case 2:
                      //return;
                  case 3:
                      //getSupportActionBar().hide();
                  case 4:
                      //return;
                      // Item 1 Selected
              }
          }
      });
  </code></pre>
  
  <p>I am trying to use setBackground but cannot get any luck.</p>