PPF-1134: Can't remove radio button border

[flywire]

Version

PyPDFForm=3.3.2

Issue Description

Can't remove radio button border (shown in black).

Two other niggles:

1. I'd expect white fill but it has a slight blue hue
2. Once a radio button is selected can't unselect all buttons

Code Snippet

from PyPDFForm import PdfWrapper
# from PyPDFForm import FormWrapper


new_form = PdfWrapper("Capital-gains-tax-schedule-2022.pdf").create_widget(
"radio", "7A", 3, [313,447,555], [759,759,759], size=11, button_style="cross", shape="square", bg_color=(0, 0, 0, 0), border_color=(0, 0, 0), border_width=0
)

with open("sample.pdf", "wb+") as output:
    output.write(new_form.read())


"""
filled = FormWrapper("sample.pdf").fill(
    {
        "Date": "22052025",
    },
)

with open("output.pdf", "wb+") as output:
    output.write(filled.read())
"""

PDF Form Template

Capital-gains-tax-schedule-2022.pdf

Screenshots (if applicable)

[chinapandaman]

I will make sure this is documented in the next release, but specifying alpha band for border_color worked for me.

border_color=(0, 0, 0, 0)

I'd expect white fill but it has a slight blue hue

This is just the behavior of PDF form fields. If you flatten it it will look white.

Once a radio button is selected can't unselect all buttons

Again, just behavior of any PDF forms.

[flywire]

specifying alpha band for border_color worked for me.

It's inconsistent, it's not required for text boxes (both with border_width=0). I suspect it's a bug with border_width=0.

[chinapandaman]

It probably is a bug, but I suspect a bug from PDF spec itself.

Border width is defined by the widget's BS -> W property (see Table 166 in the PDF standard). I tried setting the value to 0 through both the upstream dependency (which is the current implementation) and manually myself. While the value will be set to 0 successfully, the PDF output will still display a border that, seems to me have a width of 1. And yes it doesn't occur on text fields and it seems to only be a problem when setting border width to 0 (setting it to any non-zero value will adjust the border width to that appropriate width).

So short answer, I don't have a fix for this, nor would I image the upstream dependency (reportlab, and it does exactly what I described above) will have a fix for this either, as this seems more like a bug on PDF itself.

[flywire]

Thank you.

I will make sure this is documented in the next release

It would be worth noting in documentation border_width=0 does not remove the border from radio button (and ??). This appears to be a bug in the pdf specification. Specifying alpha band for border_color eg border_color=(0, 0, 0, 0) works.