Where do I find them?

Hello Everyone,

I've new to the whole SU API and am finding it difficult to find some seemingly simple direction. What I'm trying to do is dynamically update a text box based on component attributes. Like so:

Then when the user edits the component and push/pulls the surface:

So far I've got the code to create the initial flat component and the text and leader to it, it's the dynamic updating and getting the new height of the component through an observer that I'm having trouble with. (If that's even the correct way to do it!)

How would you all go about this?