objective-ccocoa

Copy NSView in cocoa / objective-c

I can't see any way to copy an NSView and create an identical NSView object. I see google hits about "use an NSData" but I don't understand that.

Solution

  • To straight up "copy" an NSView, the view has to implement the NSCopying protocol. Unfortunately, NSView does not.

    Fortunately, it does implement the NSCoding protocol, which means we can still duplicate a view like:

    NSData * archivedView = [NSKeyedArchiver archivedDataWithRootObject:myView];
NSView * myViewCopy = [NSKeyedUnarchiver unarchiveObjectWithData:archivedView];

    And voilá! You now have a duplicate of myView.

    Edit: (Swift version)

    let archivedView = NSKeyedArchiver.archivedData(withRootObject: myView)
let myViewCopy = NSKeyedUnarchiver.unarchiveObject(with: archivedView)

    (archivedView is of type Data, not NSData)