title: RelativeLayout inside Navigation Drawer
body: <p>i'm implementing <code>Navigation Drawer</code>, it works ok , but i want to position a custom EditText inside of a RelativeLayout , but some <code>RelativeLayout</code> attributes like <code>layout_centerInParent</code> are missing and i can't assign those to my custom EditText :</p>
  
  <pre><code>&lt;android.support.v4.widget.DrawerLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/drawer_layout"
  android:layout_width="match_parent"
  android:layout_height="match_parent" &gt;
  
  &lt;FrameLayout
      android:id="@+id/search_frame"
      android:layout_width="match_parent"
      android:layout_height="match_parent" 
      android:background="@string/activity_search_color"&gt;
  
      &lt;RelativeLayout
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:orientation="vertical"
          android:background="@string/bg_color" &gt;
  
          &lt;com.xxx.xxx.Buttons.CustomEditText 
              xmlns:custom="http://schemas.android.com/apk/res/com.xxx.xxx"
              android:id="@+id/edt_box"
              android:gravity="center|center_vertical"
              custom:typeface="bold"
              style="@style/edtstyle"
          /&gt;
  
  
      &lt;/RelativeLayout&gt;
  
  &lt;/FrameLayout&gt;
  
  &lt;ListView android:id="@+id/left_drawer"
      android:layout_width="@dimen/nav_width"
      android:layout_height="match_parent"
      android:layout_gravity="right"
      android:choiceMode="singleChoice"
      android:divider="@android:color/black"
      android:dividerHeight="0.0dp"
      android:listSelector="@drawable/selector_nav"
      android:drawSelectorOnTop="true"/&gt;
  </code></pre>
  
  <p></p>
  
  <p>where is my mistake? Thanks in Advance</p>