Null Pointer Exception in an Android Table Layout

Question

I created an xml file using Eclipse for an Android app that I was creating. After finishing all the layouts, and doing some coding and such, I found out that the final product needed to be on an earlier API level (10 to be exact). So I began the process of rolling back the code and the xml files, but have run into a problem that I can't solve, and doesn't seem to have any documentation. I created a table layout, and have many table rows. When I try to run the program on the virtual device, I'm given a Null Pointer Exception with regards to the TableRow.measureNullChild(int) function, the code of which is:

@Override
int measureNullChild(int childIndex) {
return mConstrainedColumnWidths[childIndex];
}

Obviously the problem is in there somewhere, but I'm not sure of the exact specifics, and was wondering if anybody else has had this problem. I'll now post the xml file that causes the crash:

<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/livelayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

<TableRow
    android:id="@+id/tableRow8"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingTop="5dp" >

     <RelativeLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:background="@drawable/hope" >

    </RelativeLayout>
</TableRow>

<TableRow
    android:id="@+id/tableRow7"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="30dp"
        android:layout_gravity="center_vertical"
        android:layout_margin="0dp"
        android:gravity="center"
        android:paddingLeft="0dp"
        android:paddingTop="0dp"
        android:text="@string/us"
        android:textSize="28dp"
        android:textColor="#CC7F32" />

    <FrameLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <TextView
            android:id="@+id/TextView01"
            android:layout_width="70dp"
            android:layout_height="30dp"
            android:layout_margin="0dp"
            android:gravity="center"
            android:paddingLeft="0dp"
            android:paddingTop="0dp"
            android:text="@string/them"
            android:textSize="26dp"
            android:textColor="#CC7F32" />

    </FrameLayout>

</TableRow>

<TableRow
    android:id="@+id/tableRow2"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_vertical"
    android:visibility="visible" >

    <Button
        android:id="@+id/us2"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us2" />

    <Button
        android:id="@+id/us2made"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us2m" />

    <Button
        android:id="@+id/button3"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/them2" />

    <Button
        android:id="@+id/button4"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/them2m" />

</TableRow>

<TableRow
    android:id="@+id/tableRow1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical" >

    <Button
        android:id="@+id/button5"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us1" />

    <Button
        android:id="@+id/button6"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us1m" />

    <Button
        android:id="@+id/button7"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/them1" />

    <Button
        android:id="@+id/button8"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/them1m" />
</TableRow>

<TableRow
    android:id="@+id/tableRow3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical" >

    <Button
        android:id="@+id/button9"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us3" />

    <Button
        android:id="@+id/button10"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us3m" />

    <Button
        android:id="@+id/button11"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/them3" />

    <Button
        android:id="@+id/button12"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/them3m" />

</TableRow>

<TableRow
    android:id="@+id/tableRow4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical" >

    <Button
        android:id="@+id/button13"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/usOreb" />

    <Button
        android:id="@+id/button14"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/usXreb" />

    <Button
        android:id="@+id/button15"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/themOreb" />

    <Button
        android:id="@+id/button16"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/themXreb" />

</TableRow>

<TableRow
    android:id="@+id/tableRow5"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical" >

    <Button
        android:id="@+id/button17"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us2f" />

    <Button
        android:id="@+id/button18"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:text="@string/us2fm" />

    <Button
        android:id="@+id/button19"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:padding="5dp"
        android:text="@string/them2f" />

    <Button
        android:id="@+id/button20"
        android:layout_width="70dp"
        android:layout_height="50dp"
        android:padding="5dp"
        android:text="@string/them2fm" />

</TableRow>

<TableRow
    android:id="@+id/tableRow6"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingTop="30dp" >
</TableRow>

<FrameLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingLeft="60dp"
    android:paddingRight="60dp" >

    <Button
        android:id="@+id/button21"
        android:layout_width="201dp"
        android:layout_height="match_parent"
        android:text="Button" />

</FrameLayout>

<FrameLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingLeft="60dp"
    android:paddingRight="60dp"
    android:paddingTop = "15dp" >

    <Button
        android:id="@+id/Button01"
        android:layout_width="201dp"
        android:layout_height="match_parent"
        android:text="Button" />

</FrameLayout>


</TableLayout>

Any help would be absolutely fantastic, as I've been stuck here for like two days, and haven't been able to figure out what's wrong. I'll be sure to post here if I do though so that googlers can find the answer if this happens to them. Thanks in advance

EDIT: After removing all rows but one, that contains content, I get the same error in the same spot

And mConstrainedColumnWidths is ...? And initialized when/how? — K-ballo
– K-ballo, Commented Jun 8, 2012 at 3:20
If the exception is in the code you posted, then the only explanation is that mConstrainedColumnWidths is null when the method is called. — Ted Hopp
– Ted Hopp, Commented Jun 8, 2012 at 3:22
The only way I see that happening is if layout is called before measure. Are you calling layout (or onLayout) for the table or any of its rows explicitly? — Ted Hopp
– Ted Hopp, Commented Jun 8, 2012 at 3:28
The code at the top isn't my own, it's copied from the source code for the Android layout stuff. I could post the entire thing, but I feel that'd be a bit ridiculous. mConstrainedColumnWidths is an array that's declared but not specifically initialized at the beginning of the class file, that's initialized using the int childIndex. Also, I'm not calling onLayout specifically no — Jamie E
– Jamie E, Commented Jun 8, 2012 at 3:39

Jamie E · Accepted Answer · 2012-06-08 22:58:07Z

1

But of course it was something too simple to think of. I forgot to swap the Gingerbread layout ID for the Ice Cream Sandwich one, so it was trying to load the API 15 layout in a level 10 environment. Swapping the ID's solved that problem entirely.

answered Jun 8, 2012 at 22:58

Jamie E

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