I stumbled over the following PDF since my PDF library has problems with it. It contains what I would call a peculiar interpretation of the PDF specification thus the radiobutton is not working correctly in most viewers. However a standard could be interpreted in many ways so the question is:
Is this a valid radiobutton group?
I see the following points - please share your insights:
- It mimics a 'RadiosInUnison' behavior without using the actual flag (probably by referencing the same index in the
Optarray) - The option array does only contain 4 widget references instead of 6
- The intent of the 0 index element of the option array seems to be a "standby position" for the DV or the initial V (or maybe a
NoToggleToOffwas desired?) - Encoding of Bär?
- ...?
Here is the "code" (shortened)
51 0 obj
<</DV /0 /FT/Btn /Ff 32768 /Kids[ 55 0 R 58 0 R 61 0 R 73 0 R 77 0 R 81 0 R ] /Opt [ (B) (Bär) (Sieglinde) (Duck) ] /T (A) /V /0 >>
endobj
55 0 obj
<</Type /Annot /AP <</N <</1 36 0 R/Off 39 0 R>>>> /AS /Off /F 0 /Parent 51 0 R /Rect [ 255 387 301 447 ] /Subtype /Widget>>
endobj
58 0 obj
<</Type /Annot /AP <</N <</2 41 0 R /Off 43 0 R>>>> /AS /Off /F 0 /Parent 51 0 R /Rect [ 313 387 348 447 ] /Subtype /Widget>>
endobj
61 0 obj
<</Type /Annot /AP <</N <</3 45 0 R /Off 47 0 R>>>> /AS /Off /F 0 /Parent 51 0 R /Rect [ 360 387 417 447 ] /Subtype /Widget>>
endobj
73 0 obj
<</Type /Annot /AP 72 0 obj<</D <</1 66 0 R/Off 68 0 R>>/N <</1 62 0 R/Off 64 0 R>>>> /AS /Off /F 0 /Parent 51 0 R /Rect [ 272 367 284 379 ] /Subtype /Widget>>
endobj
77 0 obj
<</Type /Annot /AP <</D <</2 66 0 R/Off 68 0 R>>/N <</2 62 0 R /Off 64 0 R>>>> R /AS /Off /F 0 /Parent 51 0 R /Rect [ 325 367 336 379 ] /Subtype /Widget>>
endobj
81 0 obj
<</Type /Annot /AP <</D <</3 66 0 R/Off 68 0 R>>/N <</3 62 0 R/Off 64 0 R>>>> /AS /Off /F 0 /Parent 51 0 R /Rect [ 383 367 395 379 ] /Subtype /Widget>>
endobj
1. According to the PDF spec the Opt array is:
An array containing one entry for each widget annotation in the Kids array of the radio button [...]
2. And also
When this entry (=
Opt) is present, the names used to represent the on state in the AP dictionary of each annotation may use numerical position (starting with 0) of the annotation in the Kids array [...]
Which basically means that the indices must match, right?
/Kids[55 0 R 58 0 R 61 0 R 73 0 R 77 0 R 81 0 R ]
| | | | | |
/Opt [(B) (Bär) (Sieglinde) (Duck) ? ? ]
3.
For radio buttons, the same behaviour (several widgets are checked) shall occur only if the RadiosInUnison flag is set. If it is not set, at most one radio button in a field shall be set at a time.
=> to reach the result in the example PDF that two radiobutton widgets are checked the RadiosInUnison must be set
Any other violations? (Background: After everything is collected I'll inform the latex3 guys and hopefully we'll get this improved)
Radiosinunisonbehavior you need to set the flagOptarray be smaller than the number of elements in theKidsarray:This messes up your export values as shown in the following viewer:
There are several possibilities to correctly specify the scenario of your test document:
OR