title: How to change background of ExpandableListView's items
body: <p>I have an ExpandableListView.
  When a child is expanded it should be considered "selected". When a child is selected both the child and the child's children should display a different background (to show the user which is the current selected item).</p>
  
  <p>Right now this is what I have:</p>
  
  <p><strong>XML</strong></p>
  
  <pre><code>    &lt;ExpandableListView
          android:id="@+id/listViewAccepted"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:choiceMode="singleChoice"
          android:listSelector="@drawable/custom_selector" &gt;
      &lt;/ExpandableListView&gt;
  </code></pre>
  
  <p><strong>The ListView</strong>  </p>
  
  <pre><code>        setOnGroupClickListener(new OnGroupClickListener() {
  
              @Override
              public boolean onGroupClick(ExpandableListView parent, View view,int groupPosition, long id) {
                  view.setSelected(true);
                  parent.setItemChecked(groupPosition, true);
                  return false;
              }
          });
  </code></pre>
  
  <p><strong>The Selector</strong></p>
  
  <pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;item android:state_pressed="true"&gt;
          &lt;shape&gt;
              &lt;solid android:color="@color/holo_blue_light" /&gt;
          &lt;/shape&gt;
      &lt;/item&gt;
      &lt;item android:state_selected="true"&gt;
          &lt;shape&gt;
              &lt;solid android:color="@color/green" /&gt;
          &lt;/shape&gt;
      &lt;/item&gt;
      &lt;item android:state_checked="true"&gt;
          &lt;shape&gt;
              &lt;solid android:color="@color/green" /&gt;
          &lt;/shape&gt;
      &lt;/item&gt;
      &lt;item android:state_focused="true"&gt;
          &lt;shape&gt;
              &lt;solid android:color="@color/green" /&gt;
          &lt;/shape&gt;
      &lt;/item&gt;
      &lt;item android:state_activated="true"&gt;
          &lt;shape&gt;
              &lt;solid android:color="@color/green" /&gt;
          &lt;/shape&gt;
      &lt;/item&gt;
      &lt;item&gt;
          &lt;shape&gt;
              &lt;solid android:color="@color/transparent" /&gt;
          &lt;/shape&gt;
      &lt;/item&gt;
  &lt;/selector&gt;
  </code></pre>