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
+    }
+}

passKit/Controllers/PasscodeLockViewController.swift

@@ -0,0 +1,125 @@
+//
+//  PasscodeLockViewController.swift
+//  PasscodeLock
+//
+//  Created by Yanko Dimitrov on 8/28/15.
+//  Copyright © 2015 Yanko Dimitrov. All rights reserved.
+//
+
+import UIKit
+import LocalAuthentication
+
+open class PasscodeLockViewController: UIViewController {
+    
+    open var dismissCompletionCallback: (()->Void)?
+    open var successCallback: (()->Void)?
+    open var cancelCallback: (()->Void)?
+    lazy var enterPasscodeAlert: UIAlertController = {
+        let enterPasscodeAlert = UIAlertController(title: "Authenticate Pass", message: "Unlock with passcode for Pass", preferredStyle: .alert)
+
+        enterPasscodeAlert.addTextField(configurationHandler: {(_ textField: UITextField) -> Void in
+            textField.placeholder = "passcode"
+            textField.isSecureTextEntry = true
+            textField.addTarget(self, action: #selector(self.passcodeTextFieldDidChange(_:)), for: UIControlEvents.editingChanged)
+            textField.clearButtonMode = UITextFieldViewMode.whileEditing
+            textField.becomeFirstResponder()
+        })
+        
+        let myContext = LAContext()
+        var authError: NSError?
+        if #available(iOS 8.0, macOS 10.12.1, *) {
+            if myContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &authError) {
+                var biometryType = "Touch ID"
+                if #available(iOS 11.0, *) {
+                    if myContext.biometryType == LABiometryType.faceID {
+                        biometryType = "Face ID"
+                    }
+                }
+                let bioAction = UIAlertAction(title: "Use " + biometryType, style: .default) { (action:UIAlertAction) -> Void in
+                    self.authenticate()
+                }
+                enterPasscodeAlert.addAction(bioAction)
+            }
+        }
+        
+        return enterPasscodeAlert
+    }()
+    
+    open override func viewDidLoad() {
+        super.viewDidLoad()
+        self.view.backgroundColor = UIColor.white
+    }
+    
+    open override func viewDidAppear(_ animated: Bool) {
+        super.viewDidAppear(animated)
+        authenticate()
+    }
+
+    internal func dismissPasscodeLock(completionHandler: (() -> Void)? = nil) {
+        // clean up the textfield
+        enterPasscodeAlert.textFields?[0].text = ""
+        if presentingViewController?.presentedViewController == self {
+            // if presented as modal
+            dismiss(animated: true, completion: { [weak self] in
+                self?.dismissCompletionCallback?()
+                completionHandler?()
+            })
+        // if pushed in a navigation controller
+        } else {
+            _ = navigationController?.popViewController(animated: true)
+            dismissCompletionCallback?()
+            completionHandler?()
+        }
+    }
+
+    // MARK: - PasscodeLockDelegate
+
+    open func passcodeLockDidSucceed() {
+        dismissPasscodeLock(completionHandler: successCallback)
+    }
+    
+    open func passcodeLockDidCancel() {
+        dismissPasscodeLock(completionHandler: cancelCallback)
+    }
+    
+    public func authenticate() {
+        print(enterPasscodeAlert.isBeingPresented)
+        
+        let myContext = LAContext()
+        let myLocalizedReasonString = "Authentication is needed to access Pass."
+        var authError: NSError?
+        
+        if #available(iOS 8.0, *) {
+            if myContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &authError) {
+                myContext.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: myLocalizedReasonString) { success, evaluateError in
+                    if success {
+                        DispatchQueue.main.async {
+                            // user authenticated successfully, take appropriate action
+                            self.passcodeLockDidSucceed()
+                        }
+                    } else {
+                        // User did not authenticate successfully
+                        self.showPasswordAlert()
+                    }
+                }
+            } else {
+                // could not evaluate policy; look at authError and present an appropriate message to user
+                self.showPasswordAlert()
+            }
+        } else {
+            // fallback on earlier versions
+            self.showPasswordAlert()
+        }
+    }
+    
+    @objc func passcodeTextFieldDidChange(_ sender: UITextField) {
+        // check whether the passcode is correct
+        if PasscodeLock.shared.check(passcode: sender.text ?? "") {
+            self.passcodeLockDidSucceed()
+        }
+    }
+    
+    func showPasswordAlert() {
+        self.present(enterPasscodeAlert, animated: true, completion: nil)
+    }
+}