Created attachment 93390 [details]
Allow properly identifying grouping elements
The StructElement class, used for exposing Tagged-PDF information,
does not provide a way of identifying which elements are grouping
elements. According to section 18.104.22.168 of the PDF standard (titled
“Grouping elements”, those shall not be considered as block elements,
nor as inline elements. Provided that there are already methods
StructElement::isInline() and StructElement::isBlock(), it would
be reasonable to expected that a StructElement::isGrouping() existed.
Last, but not least, some actual applications may need to know when
an element is used to group other elements. One example usage would
be being able to collapse text content of all elements in a grouping
element to perform text reflowing, presenting the text as a single
entity to accessibility technologies, etc.