[poppler] Radio buttons and NoToggleToOff

[Jason Crain]

On 2016-01-14, Albert Astals Cid <aacid at kde.org> wrote:
> Hi guys, I was having a look at the radio buttons spec/implementation and 
> found the NoToggleToOff flag.
> 
> Spec says " If set, exactly one radio button shall be selected at
> all times; selecting the currently selected button has no effect. If clear,
> clicking the selected button deselects it, leaving no button selected."
> 
> Which i understand that if the bit is not set means that you can end up having 
> a group of radio buttons with none selected when clicking on the selected one.
> 
> I modified the attached file so that the vertical radio (Alta/modifcacion/
> baja) does not have the NoToggleToOff flag set i.e. /Ff 32768
> 
> When loading the file into Adobe Reader it seems it doesn't let me uncheck the 
> radio.
> 
> Am I reading the spec wrong? Or maybe this this is a bug in Adobe Reader?
> 
> Anything else i may have missed?

I don't think you've missed anything.  According to the spec, it looks like you
should be able to uncheck the boxes.  I've also found various forum and mailing
list posts complaining about that feature not working in Adobe Reader, or only
working in certain versions.  It looks like the only way to get that behavour
is to remove the radio flag, so they're check boxes instead.