title: MPAndroidChart-BarChart issue
body: <p>I am using the <a href="https://github.com/PhilJay/MPAndroidChart" rel="nofollow noreferrer">MPAndroidChart library</a>. I have some questions about BarChart.</p>
  
  <p>Here is my chart data.</p>
  
  <pre><code>ArrayList&lt;String&gt; xVals = new ArrayList&lt;String&gt;();
  xVals.add("AAA");
  xVals.add("BBB");
  xVals.add("Z1");
  xVals.add("CCC");
  xVals.add("DDD");
  xVals.add("Z2");
  xVals.add("EEE");
  xVals.add("FFF");
  xVals.add("Z3");
  </code></pre>
  
  <p>The BarChart data sets.</p>
  
  <pre><code>ArrayList&lt;BarEntry&gt; yVals = new ArrayList&lt;BarEntry&gt;();
  ArrayList&lt;BarEntry&gt; yValsSet = new ArrayList&lt;BarEntry&gt;();
  yVals.add(new BarEntry(42, 0));
  yVals.add(new BarEntry(15, 1));
  yValsSet.add(new BarEntry(57, 2));
  yVals.add(new BarEntry(35, 3));
  yVals.add(new BarEntry(14, 4));
  yValsSet.add(new BarEntry(49, 5));
  yVals.add(new BarEntry(7, 6));
  yVals.add(new BarEntry(21, 7));
  yValsSet.add(new BarEntry(28, 8));
  </code></pre>
  
  <p>And the chart.
  <img src="https://i.stack.imgur.com/5YRG6.jpg" alt="enter image description here"></p>
  
  <p>The "Z3" on x-axis didn't show.</p>
  
  <p>And chart isn't at correct position.</p>
  
  <p>The dark gray one is CCC's value, but it shows at Z1.</p>
  
  <p>How to fix it?</p>
  
  <hr>
  
  <p>UPDATE:
  If I use only one data set, it works great.</p>