How to calculate a length of text field in scriptlet

[aniri.g]

I am looking for a scriptlet example to know overflow of a text field.

I'd like to pass a font, font size and a string from a text field and find out if the string does not fit to the length of the textfield.

If yes, I am going to show a box with a smaller font size, if no, a box with a default font size.

Ideally, it should be something like 'fit to the box', providing a size of the box and textfield.

In this solution, the font size is not changing, just horizontal character spacing is changing