this it to avoid abusing the primitive to create inverted text
(for secure UI elements only). It does degrade from the aesthetics
of a busy bar but it is a computationally efficient way to patch
around the concern.
This is just the TextView primitive with a "state" variable added
that controls how far the strips should march across the screen.
Users can specify with or without a bounding box.
The exact location of the text within the bar depends on the
BoundingBox option picked.
The primitive computes the total region to animate based upon
the typesetting engine's output. Thus it is not recommended
to "compress" the amount of whitespace allocated to the animation,
because it can cause the animation to have artifacts due to
whitespace overflow of typesetting.
