sheetParent
The window to which the sheet is attached.
Declaration
var sheetParent: NSWindow? { get }Discussion
The value of this property is nil if the receiver is not a sheet or has no sheet parent.
The window object in this property refers to the window to which the sheet is logically attached, regardless of appearance. The parent window–sheet relationship begins with the beginning of the sheet (for example, through beginSheet(_:completionHandler:)) and ends with the sheet’s dismissal (for example, through endSheet(_:)).