SourceRectAtTime() Revisited - Adobe After Effects tutorial

This is the tutorial project file for SourceRectAtTime() Revisited - Adobe After Effects tutorial available here: https://youtu.be/In4miXUdxko

We take another closer look at the SourceRectAtTime expression. Usually used to make boxes the same size as text layers, many of you asked for more control over what kind of text alignment could be used. Well, this is the long answer I couldn't just type at you in the comments. This tutorial uses MATH and EXPRESSIONS. You have been warned.

This project requires Adobe After Effects CC 13.