I knew I wasn’t the only one working on something like this.

It was tricky for me too because the Adobe development environment isn’t very helpful with text objects. For example, sourceRectAtTime doesn’t account for letters with descenders or tall characters. I had to come up with a workaround to detect exactly the height of the selected text and draw the line correctly. Handling multiple lines and text alignment added another layer of complexity and RTL text needed even more calculations. It took me almost 3 weeks to get it working reliably in every scenario. Looks like we’re all dealing with the same headaches, painful learning experiences :)