yep, it’s been done before.
i’d probably set it up with a slider to control the completion (to make it more like the type-on preset).
to set that up, create your text layer, make it right justified and then add a slider expression control effect.
then copy/paste this expression to the source text property of the text layer:
completion = effect(“Slider Control”)(“Slider”);
txt = value;
n = Math.round(linear(completion, 0, 100, 0, txt.length));
(txt).substr(0,n)
as you change the slider value, the text should type on, and if you have the justification set to right, it will type out to the left.
Kevin Camp
Art Director
KCPQ, KZJO & KRCW