gistfile1.txt

//from your application class, call 
//    new NavigationLogger().start(this);

//logs activity and fragment lifecycle events. 
class NavigationLogger {
    val logger = PVLog("Navigation")
    
    fun start(app: Application) {
        app.registerActivityLifecycleCallbacks(object: Application.ActivityLifecycleCallbacks {
            override fun onActivityCreated(p0: Activity, p1: Bundle?) {
                logger.log("Activity Created: ${p0.javaClass.simpleName}")
                if(p0 is FragmentActivity) {
                    p0.supportFragmentManager.registerFragmentLifecycleCallbacks(object: FragmentManager.FragmentLifecycleCallbacks() {
                        override fun onFragmentStarted(fm: FragmentManager, f: Fragment) {
                            logger.log("Fragment Started: ${f.javaClass.simpleName}")
                        }

                        override fun onFragmentAttached(fm: FragmentManager, f: Fragment, context: Context) {
                            logger.log("Fragment Attached: ${f.javaClass.simpleName} to ${context.javaClass.simpleName}")
                        }
                    }, true)
                }
            }

            override fun onActivityStarted(p0: Activity) {
                logger.log("Activity Started: ${p0.javaClass.simpleName}")
            }

            override fun onActivityResumed(p0: Activity) {
                logger.log("Activity Resumed: ${p0.javaClass.simpleName}")
            }

            override fun onActivityPaused(p0: Activity) {
                logger.log("Activity Paused: ${p0.javaClass.simpleName}")
            }

            override fun onActivityStopped(p0: Activity) {
                logger.log("Activity Stopped: ${p0.javaClass.simpleName}")
            }

            override fun onActivitySaveInstanceState(p0: Activity, p1: Bundle) {
                //do nothing
            }

            override fun onActivityDestroyed(p0: Activity) {
                logger.log("Activity Destroyed: ${p0.javaClass.simpleName}")
            }
        })
    }
}