Injector.kt

object Injector {

    fun init(application: MvvmTestingApplication) {
        application.registerActivityLifecycleCallbacks(object : Application.ActivityLifecycleCallbacks {
            override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
                if (activity is HasSupportFragmentInjector && activity is Injectable) {
                    AndroidInjection.inject(activity)
                }
                if (activity is FragmentActivity) {
                    activity.supportFragmentManager.registerFragmentLifecycleCallbacks(
                            object : FragmentManager.FragmentLifecycleCallbacks() {
                                override fun onFragmentPreAttached(fm: FragmentManager, f: Fragment, context: Context) {
                                    if (f is Injectable) {
                                        AndroidSupportInjection.inject(f)
                                    }
                                }
                            }, true)
                }
            }
            
            override fun onActivityStarted(activity: Activity) {
            }
            
            override fun onActivityResumed(activity: Activity) {
            }
            
            override fun onActivityPaused(activity: Activity) {
            }
            
            override fun onActivityStopped(activity: Activity) {
            }
            
            override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle) {
            }

            override fun onActivityDestroyed(activity: Activity) {
            }
        })
    }
}