Expand/Collapse All - New feature request

[kostaa]

First of all thanks you for this library. I have been waiting for one of these for quite some time :-)

One thing I think would be very useful is to the ability to expand/collapse all sections at the same time so the user does not have to do it one by one which is quite tedious especially for longer lists.

[tp7309]

I'm also glad you used this library ^_^
Expand state is stored in section model, so just update all section expand state.

  setState(() {
    sectionList.forEach(
        (section) => section.setSectionExpanded(!section.isSectionExpanded()));
  });

Is this what you need?

[kostaa]

Yes thanks that is exactly what I need.