Restore Window Size on MacCatalyst Apps

Sometimes its easier to just enable MacCatalyst on an iOS app to bring it to the Mac than to fiddle around with a dedicated Mac target or using the Mac version of SwiftUI. The drawback is that you don’t have access to AppKit but have to stick with UIKit / SwiftUI. So some quite useful features of AppKit are not available in MacCatalyst.

E.g. there is this nice AppKit construct to save and restore the window size and position between app launches:

But there is no equivalent in MacCatalyst since iOS apps don’t mess around with windows. In this post I’ll show how to achieve a similar behaviour in MacCatalyst.

An improved version of OutlinePicker

I’ve promised to present an improved version of the OutlinePicker shown in this post and here it is. What did I do?

  1. The parameter list changed a little bit. Now there’s a special title for „No Selection“ and we do not need the isExpanded parameter anymore since we want to expand the nodes automatically according to the selection.
  2. I’ve introduced the new array nodesToExpand. I’ll come back to that a little bit later.
  3. Instead of a sheet the selection view is presented as a popover (WithPopover from this post). Using that we do not need a close button anymore.
  4. The NodeOutlineGroup from this post is used to accept the array of expanded nodes.
  5. Instead of a Form I use a List here with a plain listStyle. That looks better in the popover view.
  6. The „No Selection“ section is now separated from the list in a similar manner as a Divider would do it in a Picker view.


An improved version of NodeOutlineGroup

This is the second post of my little series about a fine-tuned version of my OutlinePicker. Today, I’d like to propose an improved version of the already presented NodeOutlineGroup. As stated here the NodeOutlineGroup gives you control whether the disclosure group should be collapsed or expanded on show up of the outline group. I want to use that for my hierarchical picker. But on start of my picker the pre-selected node might be deep in the tree instead of being one of the root nodes.

So, if I set up the picker with all nodes collapsed the pre-selected node would not be visible immediately and the user might search for it for quite a long time. On the other hand, if I expand all nodes it might be quite a big tree to display on startup. The ideal solution would be that all nodes are collapsed except to those ones which have the selected node as a child or grand child.



In this last post I‘ve proposed an OutlinePicker for SwiftUI. But, to be honest, I am not quite satisfied with this solution. The selection view appears as a sheet in contrast to the standard picker and its layout deserves some more fine tuning.

The problem with the standard popover modifier in SwiftUI is that it’s mutated to a sheet presentation on iPhones. I know, there is this new modifier presentationCompactAdaptation(horizontal:vertical:) but that’s only available since iOS16.4. In addition, I want to use a List in the popover and that’s collapsed to a tiny square if you do not specify a frame size. To make a long explanation short: I prefer to use the nice utility view „WithPopover“ for the presentation of my picker selection.


An Outline Picker for SwiftUI

If you want to display an outline in SwiftUI you may use the framework supplied OutlineGroup construct. That’s based on a nested tree of DisclosureGroup and is quite nice. But on appearance of the OutlineGroup all outlines are collapsed. Well, in one of my projects I wanted to display the outline all expanded on show up. No way to do that with OutlineGroup as far as I know. But then I found this nice variant ( with a control of expansion: