Toggle details view in NavigationView

I'm trying to build an macOS App that has a MainView (containing a list of selectable items) and an InspectorView (to get more info about the selected item) on the right. I would like to have:
  1. The InspectorView should be "togglable" (in best case using animations), i.e. there is a "hide/show inspector" toggle button, that should expand/collapse the InspectorView (this resizes the window).

  2. If the InspectorView is shown, there should be a divider between the two views to resize the views (-> split view)

  3. If the InspectorView is shown, resizing the window should first resize the InspectorView (up to a minimal width) (-> .layoutPriority)

I thought I could make it work by using a NavigationView. But I failed with 1.

Is there a way to get 1. with a NavigationView as well, or should I use different views?
(I couldn't get it to work with a HSplitView either.)

Note: The window is created in an NSApplicationDelegate.
Toggle details view in NavigationView
 
 
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