Android linearlayout on relativelayout makes relative disappear

Question

I have a linearlayout with a listview in a relativelayout. Listview is visible, but the parent 2 buttons and textview are not. I cannot figure out why. I tried setting the linearlayout to bottom with

android:layout_alignParentBottom="true"

but that did not work, can anyone tell me why I can only see my listview and nothing else.

<?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">
    <TextView
        android:id="@+id/date"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        />
    <Button
        android:id="@+id/exercise"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/date"
        android:text="@string/Exercise"
        android:onClick="toStat"
        />
    <Button
        android:id="@+id/summary"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/date"
        android:layout_toRightOf="@id/exercise"
        android:text="@string/Summary"
        android:onClick="toTraining"
        />
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/blue">

            <ListView
                android:id="@+id/listView"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_centerHorizontal="true"
                android:layout_marginTop="10dp"
                android:stretchMode="columnWidth"
                android:gravity="center"
                />

        </LinearLayout>
</RelativeLayout>

Answer 1

Its because you have not mentioned the linearlayout should be below the summary button. Hence its just overlapping the textview and buttons. Just add android:layout_below="@id/summary" in the LinearLayout. Also mention the linear layout height as wrap_content.

<LinearLayout 
        android:layout_below="@id/summary"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/blue">

        <ListView
            android:id="@+id/listView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="10dp"
            android:stretchMode="columnWidth"
            android:gravity="center"
            />

</LinearLayout>