android, how to place a scroll view in the middle of the screen: - scrollview

Question

I'm trying to create a a screen layout of the following though:
A line with some TextView in it
A scroll view where the user actions will add or remove View from
A buttons line.
I have no problem with 1. or 3. But 2. gives me troubles. My scheme is:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/mainX"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/labels"
android:layout_weight="1">
<!--Some text view of various sizes -->
</LinearLayout>
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/dataScroll">
<LinearLayout
android:id="#+id/dataShow"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</LinearLayout>
</ScrollView>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/buttons"
android:layout_weight="1">
<!--some buttons-->
</LinearLayout>
</LinearLayout>
When I run the program, the buttons line is in the middle of the screen and When I add element to the screen (using the addView on the dataShow layout), the frist one is added without a problem but after that I can't tell what is happening.
Thanks

Answer 1

I'm not exactly sure what you are trying to do.
It seems like you want to dynamically add items to the dataShow layout. Instead of using a ScrollView containing a LinearLayout, you should be using a ListView (vertical scrolling) or Gallery (horizontal scrolling) for your dataShow layout. This will provide the scroll functionality and allow you to add items dynamically to the list/gallery.

Answer 2

Try using a RelativeLayout, then align the header at the top, and the footer at the bottom. Set the ScrollView paddingBottom.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/header"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/colorPrimary"
android:paddingBottom="10dp"
android:paddingTop="10dp"
android:text="text"
android:textAlignment="center"
android:layout_centerHorizontal="true"
android:layout_alignParentTop="true"/>
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_below="#+id/header"
android:layout_above="#+id/footer"
android:paddingBottom="100dp">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="center main content"
android:textAlignment="center"
android:layout_centerHorizontal="true"
android:layout_alignParentTop="true"/>
</ScrollView>
<RelativeLayout
android:id="#+id/footer"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="#color/colorPrimary"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="text"
android:textAlignment="center"
android:layout_centerHorizontal="true"
android:layout_alignParentTop="true"/>
</RelativeLayout>
</RelativeLayout>