what to recast as an NSSplitViewItem - swift

Question

I am trying to self-learn OSX application development so I can make up all of my own bad habits 8).
Probably extraneous information
I have a trial app that works successfully - it resizes itself based on input from the user via a slider.
The key piece of code that does this is in one View controller ...
class JunkViewController2: NSViewController {
var myY: CGFloat!
#IBOutlet weak var mySlider: NSSlider!
#IBOutlet weak var myView: NSView!
override func viewDidLoad() {
super.viewDidLoad()
// Do view setup here.
self.preferredContentSize = NSMakeSize(self.view.frame.width, 83)
}
#IBAction func mySlider(sender: NSSlider) {
let mySplitViewController = self.childViewControllers[0] as! JunkSplitViewController
switch mySlider.intValue {
case 3:
myY = 140.0
mySplitViewController.splitViewItems[2].collapsed = false
mySplitViewController.splitViewItems[1].collapsed = false
mySplitViewController.showSubview(2)
mySplitViewController.showSubview(1)
mySplitViewController.showSubview(0)
case 2:
myY = 110.0
mySplitViewController.splitViewItems[2].collapsed = true
mySplitViewController.splitViewItems[1].collapsed = false
mySplitViewController.hideSubview(2)
mySplitViewController.showSubview(1)
mySplitViewController.showSubview(0)
default:
myY = 80.0
mySplitViewController.splitViewItems[2].collapsed = true
mySplitViewController.splitViewItems[1].collapsed = true
mySplitViewController.hideSubview(2)
mySplitViewController.hideSubview(1)
mySplitViewController.showSubview(0)
}
mySplitViewController.preferredContentSize = NSMakeSize(self.view.frame.width, myY - 50 + 3)
self.preferredContentSize = NSMakeSize(self.view.frame.width, myY + 3)
}
}
More pertinent information
In what is working, above, on the story board I have three duplicate ViewControllers connected to a SplitView controller. I do a bunch of what feels like belts and suspenders work to make sure that everything gets resized properly - but the key part (I think) is the .collapsed property.
I am now trying to accomplish the same thing, using a completely different method - dynamically adding / removing split view items. This should allow me to have only one of the small ViewControllers on my story board, and then instantiate it as needed.
Following that idea, here is my SplitViewController ...
class JunkSplitViewController: NSSplitViewController {
#IBOutlet weak var mySplitView: NSSplitView!
override func viewDidLoad() {
super.viewDidLoad()
// Do view setup here.
//mySplitView.adjustSubviews()
}
func makeChild() -> SmallViewController {
let mySmallGroup = NSStoryboard(name: "Main", bundle: nil).instantiateControllerWithIdentifier("smallVwCtl")
self.addSplitViewItem(mySmallGroup as! NSSplitViewItem)
return mySmallGroup as! SmallViewController
}
}
The main view controller invokes the makeChild function.
class JunkViewController: NSViewController {
#IBOutlet weak var mySlider: NSSlider!
#IBOutlet weak var myView: NSView!
override func viewDidLoad() {
super.viewDidLoad()
// Do view setup here.
self.preferredContentSize = NSMakeSize(self.view.frame.width, 83)
}
#IBAction func mySlider(sender: NSSlider) {
let mySplitViewController = self.childViewControllers[0] as! JunkSplitViewController
while mySlider.intValue.toIntMax() > mySplitViewController.splitViewItems.count.toIntMax() {
mySplitViewController.makeChild()
}
while mySlider.intValue.toIntMax() < mySplitViewController.splitViewItems.count.toIntMax(){
mySplitViewController.splitViewItems.removeLast()
}
}
}
I get an error at the self.addSplitViewItem(mySmallGroup as! NSSplitViewItem) line of JunkSplitViewController ... "Could not cast value of type Scratch2.SmallViewController to NSSplitViewItem"
I've tried a handful of combinations (forcing mySmallGroup, 'self.addSplitViewItem(mySmallGroup as! SmallViewController)`, etc.) Everything leads to a similar error, either at compile or run time.
I cannot find any documentation on SplitViewItem.
So the question - what will work as input to addSplitViewItem and still successfully connect a new instance of SmallViewController?
And gratefully accept any comments/feedback on the methodology

Answer 1

I hate it when I find my answer minutes after posting a question ...
Based on info I found here ...
func makeChild() -> SmallViewController {
let mySmallGroup = NSStoryboard(name: "Main", bundle: nil).instantiateControllerWithIdentifier("smallVwCtl") as! SmallViewController
self.addSplitViewItem(NSSplitViewItem(viewController: mySmallGroup))
return mySmallGroup
}
... but I'd still like to hear any feedback on methodology. Thanks.