Android Animate view from off screen not working

I have a view that is positioned totally off screen and I am trying to animate it onto the screen.

When I call:

view.startAnimation(tA);

nothing happens, tA.initialize and tA.applyTransformation never get called.

If I move the view so that any part of it is visible before I start the animation, then the animation works correctly.

What is preventing a view from being animated when it is positioned off the parent View?