Support Comb-Style forms

[maribox]

There are a lot of institutions using comb-style Forms where each letter has a specific spacing with a vertical line between each character.
That can look like this

It would be cool if these were properly supported, which is possible thanks to the "comb" option:

comb: (Boolean; only for type=textfield; PDF 1.5) If true and the multiline, fileselect, and password op-
tions are false, and the maxchar option has been supplied with an integer value, the field will be divided
into a number of equidistant subfields (according to the maxchar option) for individual characters. De-
fault: false

Source: pdflib reference

Here's an example file with those comb forms:

comb_example.pdf

I know this would be a big issue to solve, but if it were solved, I think a PDF Editor with this library would change a lot how we deal with forms by the tax agency etc.

[jbarrow]

I'll take a look, though this might require a modeling change.

[bendersej]

Hey @maribox!

If you've not solved it yet, have a look at SimplePDF, we've solved it for our customers.

Under the hood we use CommonForms and have augmented it with custom heuristics at the glyph level (we did not refine the model as we needed speed on large documents), namely for comb fields and other form fields.

You can try it on your existing form here: comb_example.pdf, just click the "detect fields" button

Disclosure: I'm the founder of SimplePDF