Self-maintained passcode lock

- No cancel button anywhere in the passcode lock yet
- Poor UI

passKit/Controllers/PasscodeLockPresenter.swift

@@ -0,0 +1,59 @@
+//
+//  PasscodeLockPresenter.swift
+//  PasscodeLock
+//
+//  Created by Yanko Dimitrov on 8/29/15.
+//  Copyright © 2015 Yanko Dimitrov. All rights reserved.
+//
+
+import UIKit
+
+open class PasscodeLockPresenter {
+    
+    fileprivate var mainWindow: UIWindow?
+    
+    fileprivate lazy var passcodeLockWindow = UIWindow(frame: UIScreen.main.bounds)
+        
+    open var isPasscodePresented = false
+    open let passcodeLockVC: PasscodeLockViewController
+    
+    public init(mainWindow window: UIWindow?, viewController: PasscodeLockViewController) {
+        mainWindow = window
+        passcodeLockVC = viewController
+    }
+
+    public convenience init(mainWindow window: UIWindow?) {
+        let passcodeLockVC = PasscodeLockViewController()
+        self.init(mainWindow: window, viewController: passcodeLockVC)
+    }
+    
+    open func present(windowLevel: CGFloat?) {
+        guard PasscodeLock.shared.hasPasscode else { return }
+        guard !isPasscodePresented else { return }
+        
+        isPasscodePresented = true
+
+        mainWindow?.endEditing(true)
+        moveWindowsToFront(windowLevel: windowLevel)
+        passcodeLockWindow.isHidden = false
+
+        let userDismissCompletionCallback = passcodeLockVC.dismissCompletionCallback
+        passcodeLockVC.dismissCompletionCallback = { [weak self] in
+            userDismissCompletionCallback?()
+            self?.dismiss()
+        }
+        passcodeLockWindow.rootViewController = passcodeLockVC
+    }
+
+    open func dismiss() {
+        isPasscodePresented = false
+        passcodeLockWindow.isHidden = true
+        passcodeLockWindow.rootViewController = nil
+    }
+
+    fileprivate func moveWindowsToFront(windowLevel: CGFloat?) {
+        let windowLevel = windowLevel ?? UIWindowLevelNormal
+        let maxWinLevel = max(windowLevel, UIWindowLevelNormal)
+        passcodeLockWindow.windowLevel =  maxWinLevel + 1
+    }
+}