Sets which page is visible when self is collapsed.
If set to TRUE, the content widget will be the visible page when
propertyNavigationSplitView:collapsed is TRUE; otherwise the sidebar
widget will be visible.
If the split view is already collapsed, the visible page changes immediately.
Sets which page is visible when self is collapsed.
If set to TRUE, the content widget will be the visible page when propertyNavigationSplitView:collapsed is TRUE; otherwise the sidebar widget will be visible.
If the split view is already collapsed, the visible page changes immediately.