Android Timeout Passcode (PasscodeManager : https://components.xamarin.com/view/Passcode)

TimeOutPassCodeActivityCallBacks.cs

// usage : in your Android Application OnCreate() :
// this.RegisterActivityLifecycleCallbacks(new TimeOutPassCodeActivityCallBacks("1234"));

class TimeOutPassCodeActivityCallBacks : Java.Lang.Object, Android.App.Application.IActivityLifecycleCallbacks
{
	DateTime? loggedInTime = null;

	readonly string passcode;
	readonly int timeoutInSeconds;

	readonly PasscodeManager passcodeManager;


	public TimeOutPassCodeActivityCallBacks (string passcode, int timeoutInSeconds = 30)
	{
		this.passcode = passcode;
		this.timeoutInSeconds = timeoutInSeconds;

		passcodeManager = new PasscodeManager();
		passcodeManager.PasscodeLength = passcode.Length;
		passcodeManager.PasscodeEntered += (sender, e) => OnPasswordCorrect (CheckPassword (e.GetPasscodeAsString ()));
	}


	protected virtual void OnPasswordCorrect (bool isCorrect)
	{
		if (isCorrect) {
			resetTimer ();
			passcodeManager.Dismiss ();
		} else {
			passcodeManager.WrongPasscode();
		}
	}

	protected virtual bool CheckPassword (string passwordToCheck)
	{
		return passwordToCheck == this.passcode;
	}

	#region IActivityLifecycleCallbacks

	public void OnActivityCreated (Activity activity, Android.OS.Bundle savedInstanceState) { }

	public void OnActivityDestroyed (Activity activity) { }

	public void OnActivityPaused (Activity activity)
	{
		resetTimer ();
	}

	public void OnActivityResumed (Activity activity)
	{
		CheckLoggedIn (activity);
	}

	public void OnActivitySaveInstanceState (Activity activity, Android.OS.Bundle outState) { }

	public void OnActivityStarted (Activity activity) { }

	public void OnActivityStopped (Activity activity) { }

	#endregion IActivityLifecycleCallbacks

	void resetTimer ()
	{
		loggedInTime = DateTime.Now;
	}

	public bool IsLoggedIn {
		get { return loggedInTime.HasValue; }
	}

	public bool CheckLoggedIn (Activity activity)
	{
		if (!IsLoggedIn ||
			(DateTime.Now - loggedInTime.Value) > TimeSpan.FromSeconds (timeoutInSeconds)
		) {
			loggedInTime = null;
			passcodeManager.Show (activity);
			return false;
		}

		resetTimer ();

		return true;
	}
}