What is up with FormattedHeight?

[Howard Bornstein]

I need to find the smallest rectangle that will enclose a line of text of
arbitrary text size in a field. I thought I could use formattedheight and
formattedwidth to do this but it doesn't seem to be working.

The dictionary says about FormattedHeight:

Use the *formattedHeight* property to determine how much vertical space an
object needs.

The *formattedHeight* of a chunk in a field is the amount of vertical space
that portion of the field's text requires


 That's not what I get. If you'd like to follow along at home, here are
some simple steps to show what I mean:


 Create a field in LC.
set the showborder to true
Set the border to 1 (this is only to show what LC thinks is the boundary of
the field)
Set the 3D to false
set the margins to 0,0,0,0
Set the fixedlineheight to off
Set the textfont to Helvetica
 Set the textsize to 100
Type in the following into the field "1234"
Go to the "size and positioning" tab of the object inspector and click both
Fit Content buttons for width and height.

I would have expected the border to tighten down to include the text and no
more. But instead, look at all that space at the top—and a fair amount of
space at the bottom. Why is that space considered part of the height of the
text?

I can gain what I want by manually adjusting a number of properties.

If I use the fixed line height property, I get a little more control,
although, as far as I can tell, formattedheight should work without it, but
it doesn't.

If I turn on the fixed line height (i.e. the textheight property) in the
inspector (with the configuration I described above), it is automatically
set to a text height of 93 and the text jumps up to the top of the bounding
box (I've got nice screen shots of all this but I seem to remember that
we're not supposed to use attachments or images on this list).

If I click "Fit Content" for height at this point, the box closes down and
gets rid of some, but not all, of the space at the bottom.

If I adjust the field height value to 73, I can finally get the bounding
box to match the height of the text.

This is what I am looking for. I am trying to figure out the relationship
of settings which will always produce a bounding box with this level of
tightness for any size text (I am ignoring the extra space on the left of
the field for now). I need to be able to do this under script control.

If I go through the same exercise but set the text size to 200 points, I
can again adjust things so that the bounding box only encloses the text
with no additional space, but I can't find any clear relationship between
the settings for 100 points and 200 points.

So my questions are these:

Why doesn't the formattedHeight of a field just do this automatically? Why
does it include extra space at the top and bottom of the field?
What are the relationships among text size, text height, and field height
that will allow the field to adjust to exactly the size of the text
regardless of the text size.

Please let me know if I'm totally missing the point about formattedHeight
or if there is something else obvious that has eluded me.

-- 
Regards,

Howard Bornstein
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