Just an idea, why don’t you declare first in the xml layout the textview on the right and set its width as wrap content, android:layout_alignParentRight="true" and android:gravity="right". Then declare the textview on the left, set its width as fill parent, android:layout__toLeftOf={the id of the textview on the right} having RelativeView as the root view.
By declaring first the right textview, its required width will be computed first and occupy the view while the textview on the left will occupy the remaining space of the view.
I still have not tried this though it might give you some idea.
[Update]
I tried creating an xml resource layout… and it somehow works…
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<TextView
android:id="@+id/right"
android:layout_alignParentRight="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="right"
android:text="right"
>
</TextView>
<TextView
android:id="@+id/left"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@id/right"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:ellipsize="end"
android:lines="1"
android:singleLine="true"
android:maxLines="1"
android:text="too looooooooooong ofskgjo sdogj sdkogjdfgds dskjgdsko jgleft"
>
</TextView>
</RelativeLayout>