I think most of customtoast xml-examples throughout the Internet are based on the same source.
The Android documentation, which is very outdated in my opinion. fill_parent should not be used any more. I prefer using wrap_content in combination with a xml.9.png. That way you can define the minimum size of toastbackground throughout the size of the provided source.
If more complex toasts are required, frame or relative layout should be used instead of LL.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/points_layout"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/background"
android:layout_gravity="center"
android:gravity="center" >
<TextView
android:id="@+id/points_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:gravity="center"
android:layout_margin="15dp"
android:text="@+string/points_text"
android:textColor="@color/Green" />
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<nine-patch
xmlns:android="http://schemas.android.com/apk/res/android"
android:src="@drawable/background_96"
android:dither="true"/>
background_96 is background_96.9.png.
This is not tested very well, and hints are appreciated :)