Made the popover detachable

Sources/CustomizablePopoverSegue.swift

@@ -15,12 +15,13 @@ class CustomizablePopoverSegue: NSStoryboardSegue {
     var preferredEdge: NSRectEdge = NSMinXEdge
     
     var appearance: NSAppearance? {
-        get {
-            return popover.appearance
-        }
-        set {
-            popover.appearance = newValue
-        }
+        get { return popover.appearance }
+        set { popover.appearance = newValue }
+    }
+    
+    var popoverDelegate: NSPopoverDelegate? {
+        get { return popover.delegate }
+        set { popover.delegate = newValue }
     }
     
     private let popover = NSPopover()

Sources/MainViewController.swift

@@ -8,11 +8,13 @@
 
 import AppKit
 
-class MainViewController: NSViewController {
+class MainViewController: NSViewController, NSPopoverDelegate {
     
     @IBOutlet weak var appearanceSelection: NSMatrix!
     @IBOutlet weak var positionSelection: NSMatrix!
     
+    // MARK: - Storyboard Segue
+    
     override func prepareForSegue(segue: NSStoryboardSegue, sender: AnyObject?) {
         if segue.identifier == "DetachablePopover" {
             let popoverSegue = segue as CustomizablePopoverSegue
@@ -21,9 +23,18 @@ class MainViewController: NSViewController {
             popoverSegue.positioningView = button
             popoverSegue.appearance = appearanceForSelectedRadioButton(appearanceSelection.selectedRow)
             popoverSegue.preferredEdge = preferredEdgeForSelectedRadioButton(positionSelection.selectedRow)
+            popoverSegue.popoverDelegate = self
         }
     }
     
+    // MARK: - Popover Delegate
+    
+    func popoverShouldDetach(popover: NSPopover) -> Bool {
+        return true
+    }
+    
+    // MARK: - Helper Methods
+    
     private func appearanceForSelectedRadioButton(radioButton: Int) -> NSAppearance {
         switch radioButton {
         case 0: return NSAppearance(named: NSAppearanceNameAqua)!