So experimenting with UISplitViewController on Mac Catalyst. I have a triple split. The primary view controller is a sidebar. I have the default sidebar button showing in the toolbar and that collapsed/expands the sidebar fine. But when I drag to try to collapse the split (as is typical on macOS) the sidebar doesn't collapse. It clamps to the min. size. Is there anyway to enable this? I tried passing 0 to -setMinimumPrimaryColumnWidth: but that didn't work.
UISplitViewController on Mac Catalyst Collapse the Primary (Sidebar) View Controller by Dragging the Split macOS Style?
Maybe it's not possible? I just tried to do it in the "Developer" app which I believe is a Catalyst app and it won't collapse the sidebar via drag. Notes, Mail, Xcode, Finder, etc. all allow you to collapse the sidebar by dragging the split.
I duped this thread in a feedback: FB11689969
Still doesn't appear to be supported on Sonoma. Oh well.