Automatic displaying Titel Save Area in a MOGERT

[Screener]

Hi Community, I am looking for a way to display a red titel save boarder in a mogert. If users enter text which is to narrow to one side of the screen, the red border should show that your in the illegal area. Any Ideo how to solve that via expressions?

Thanks for help.

[ShiveringCactus]

You'll need to use sourceRecAtTime() on the opacity property to get the width of the text layer, something like:

txtWidth = thisComp.layer("Text").sourceRectAtTime().width;
if (txtWidth > 500) {
    100
} else {
    0
}