main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <fragment class="com.coreno.testfragment.SelectorFragment"
        android:id="@+id/select"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        />

    <fragment class="com.coreno.testfragment.DetailsFragment"
        android:id="@+id/detail_holder"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="2"
        />
    <!--
    <FrameLayout
        android:id="@+id/detail_holder"
        android:layout_width="0px"
        android:layout_height="match_parent"
        android:layout_weight="2"
        />
 -->
</LinearLayout>