XML : Android – How can I Move a Layout Partially Offscreen?

I am trying to make a sliding menu in an android application I am building for my school, and whenever I open the menu, the menu button, in addition to the other views I've tried, are scaled to fit in the remaining 25% of the layout still on the screen. So my question is, how can I disable this scaling so views can be moved offscreen along with their parent layout?

This is the XML file of the layout I am trying to move. It contains the misbehaving button:

  <?xml version="1.0" encoding="utf-8"?>    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"      android:layout_width="fill_parent"      android:layout_height="fill_parent">    <ImageView       android:layout_width="fill_parent"      android:layout_height="fill_parent"      android:src="@drawable/background_color"/>    <ImageButton      android:id="@+id/menu_button"      android:layout_width="56dp"      android:layout_height="35dp"      android:layout_alignParentRight="true"      android:background="@drawable/menu_button"/>    </RelativeLayout>    

This is what the menu looks like closed:

This is how it looks when opened:

And this is how I want it to be when opened. Notice the menu button has moved offscreen.

Any help is appreciated.