outlineView(_:shouldShowOutlineCellForItem:)
Returns whether the specified item should display the outline cell (the disclosure triangle).
Declaration
@MainActor optional func outlineView(_ outlineView: NSOutlineView, shouldShowOutlineCellForItem item: Any) -> BoolParameters
- outlineView:
The outline view that sent the message.
- item:
An item in the outline view.
Return Value
true if the outline cell should be displayed, otherwise false.
Discussion
Returning false causes frameOfOutlineCell(atRow:) to return NSZeroRect, hiding the cell. In addition, the row will not be collapsible by keyboard shortcuts.
This method is called only for expandable rows.