ScrollView doesn't show top part

Question

Problem : ScrollView hides top part of its child view when it grows beyond certain height.

I have following layout defined in XML

<?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" >

    <LinearLayout
        android:id="@+id/commandPanel"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:paddingLeft="5dip"
        android:paddingRight="5dip" >

        <Button
            android:id="@+id/button1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="OK" />

        <Button
            android:id="@+id/button2"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Back" />
    </LinearLayout>

    <RelativeLayout
        android:id="@+id/mainContentPanel"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_above="@id/commandPanel"
        android:background="@android:color/white" >

        <ScrollView
            android:id="@+id/formScrollView"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_gravity="center"
            android:layout_marginTop="5dip"
            android:layout_weight="1"
            android:background="@android:color/darker_gray"
            android:fillViewport="false"
            android:paddingBottom="5dip"
            android:scrollbarStyle="insideOverlay" >

            <LinearLayout
                android:id="@+id/formContentLayout"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:layout_gravity="center"
                android:layout_marginTop="20dip"
                android:background="@android:color/black"
                android:gravity="center_horizontal|top"
                android:orientation="vertical"
                android:paddingLeft="5dip"
                android:paddingRight="5dip"
                android:paddingTop="20dip" >

                <LinearLayout
                    android:id="@+id/tr"
                    android:layout_width="fill_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="10dip"
                    android:orientation="horizontal" >

                    <TextView
                        android:id="@+id/title"
                        android:layout_width="fill_parent"
                        android:layout_height="wrap_content"
                        android:layout_weight="1"
                        android:text="sample title" />

                    <TextView
                        android:id="@+id/value"
                        android:layout_width="fill_parent"
                        android:layout_height="wrap_content"
                        android:layout_weight="1"
                        android:text="sample value ......." />
                </LinearLayout>
            </LinearLayout>
        </ScrollView>
    </RelativeLayout>

</RelativeLayout>

---------- code ------

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.scrollview);
    updateUi();
}

//add few more rows here
void updateUi() {
    LinearLayout sampletr = (LinearLayout) findViewById(R.id.tr);
    LinearLayout contentPane = (LinearLayout) findViewById(R.id.formContentLayout);
    TextView title = (TextView) findViewById(R.id.title);
    TextView value = (TextView) findViewById(R.id.value);
    for (int i = 0; i < 25; i++) {
        LinearLayout tr = new LinearLayout(this);
        TextView t = new TextView(this);
        t.setText("Sample title : " + i);
        TextView v = new TextView(this);
        v.setText("Sample value : " + i);

        tr.addView(t, title.getLayoutParams());
        tr.addView(v, value.getLayoutParams());
        contentPane.addView(tr, sampletr.getLayoutParams());
    }
}

Here top rows in LinearLayout (ScrollView's immediate child) start disappearing from top if no. of rows grows more than 15! Moreover I can not even scroll up manually to view them, Any pointer please, what's wrong with this layout?

Answer 1

ok, I've solved it by removing following line from LinearLayout (Immediate child of ScrollView)

android:layout_gravity="center"

ScrollView works perfectly now. Thanks everyone for suggestions.