Odtnhj

When I start my activity by the first time everything is fine I can navigate normally but after rotating the screen the fragmentMananger appears to bug, and after every change of fragment it loads a blank fragment if I rotate the screen and the activity is recreated the correct fragment appears but the bug persists.

when I quit the app and back to use it the error persists and only disappears after clear the user data, I try to recreate the activity after every fragment change but it only turn things worst.

the one thing solve the problem is to clear user data after every app finalization but it erases important data managed by the app at runtime that need persist via file for the next execution.

I use a companion object for manage fragment names:

companion object 
 val TAG = this::class.java.canonicalName!!
 const val MAIN_FRAGMENT = "MainFragment"
 const val SECOND_FRAGMENT = "SecondFragment"
 const val THIRD_FRAGMENT = "ThirdFragment"
 const val FOURTH_FRAGMENT = "FourthFragment"
 const val FIFTH_FRAGMENT = "FifthFragment"

functions for manage fragments:

fun callFragment(s: String? = null) 
 validateFrag(s ?: MAIN_FRAGMENT, ::setFragment)


fun updateFragment() 
 Control.logData("updating fragment $fragment_state")
 validateFrag(fragment_state, ::setFragment)


private fun validateFrag(s: String, f: (String) -> Unit) 
 when (s) 
 SECOND_FRAGMENT -> f(s)
 THIRD_FRAGMENT -> f(s)
 FOURTH_FRAGMENT -> f(s)
 FIFTH_FRAGMENT -> f(s)
 else -> f(MAIN_FRAGMENT)
 


private fun createFrag(id: String): Fragment = when (id) 
 SECOND_FRAGMENT -> SecondFragment.newInstance()
 THIRD_FRAGMENT -> ThirdFragment.newInstance()
 FOURTH_FRAGMENT -> FourthFragment.newInstance()
 FIFTH_FRAGMENT -> FifthFragment.newInstance(this)
 else -> MainFragment.newInstance()


private fun setFragment(id: String) 
 val userAuth = userAuth
 userAuth ?: return
 Control.logData("loading fragment $id")
 val frame = R.id.app_frame
 val fragment = (fragmentManager.findFragmentByTag(id) ?: createFrag(id))
 currentFragment = fragment as MyAppFragment
 fragment_state = id

 when
 fragmentManager.fragments.size == 0 -> 
 fragmentManager.beginTransaction()
 .add(frame, createFrag(MAIN_FRAGMENT), MAIN_FRAGMENT)
 .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
 .commitNowAllowingStateLoss()
 
 !fragmentManager.fragments.contains(fragment as Fragment) -> 
 fragmentManager.beginTransaction()
 .add(frame, fragment, id)
 .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
 .commitNowAllowingStateLoss()
 
 else ->
 with(fragmentManager.beginTransaction()) 
 replace(frame, fragment, id)
 setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
 commitNowAllowingStateLoss()
 
 
 

for the commits I try Commit(), CommitNow() too

my fragment implementation:

package com.domain.app.fragments

import android.content.Context
import android.support.v4.app.Fragment
import android.os.Bundle
import android.support.v7.widget.LinearLayoutManager
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageButton
import android.widget.ScrollView
import com.reactivex.disposables.Disposable
import com.domain.app.Control
import com.domain.app.R
import com.domain.app.AppApplicatcomn
import com.domain.app.activities.appActivity
import com.domain.app.dagger.services.IRXService
import com.domain.app.recycler.adapter.DataListAdapter
import kotlinx.android.synthetic.main.fragment_main.*
import javax.inject.Inject

class MainFragment : Fragment(), AppFragment 

// instanciate data

compancomn object 
 fun newInstance(): MainFragment
 return MainFragment()
 


override fun onAttach(context: Context?) 
 super.onAttach(context)
 activity?.let act ->
 //subscribe RX
 


override fun onDetach() 
 super.onDetach()
 //disposeRX


override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
 savedInstanceState: Bundle?): View? 
 return inflater.inflate(R.layout.fragment_main, container, false)


override fun onViewCreated(view: View, savedInstanceState: Bundle?) 
 super.onViewCreated(view, savedInstanceState)
 dockInit()
 recyclerInit()
 if(Control.index.isEmpty())
 noDataScreen()
 
 else
 Control.putOnScreen()
 


override fun noDataScreen() 
 activity?.runOnUiThread 
 main_noDataQrButton?.visibility = View.VISIBLE
 main_noDataText?.visibility = View.VISIBLE
 Control.loadingDataStream.onNext(false)
 isInit = false
 


override fun notifyRecycler() 
 activity?.runOnUiThread
 if(::list.isInitialized)
 mAdapter.update()
 list.adapter?.notifyDataSetChanged()
 
 


private fun recyclerInit()
 mAdapter = DataListAdapter(activity as appActivity)
 mAdapter.setHasStableIds(true)
 list = view!!.findViewById<RecyclerView>(R.id.main_listDataListRecycler).apply 
 setHasFixedSize(true)
 setItemViewCacheSize(8)
 layoutManager = LinearLayoutManager(context)
 adapter = mAdapter
 

my manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.domain.app">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.VIBRATE" />

<application
 android:name=".AppApplication"
 android:allowBackup="true"
 android:icon="@drawable/app"
 android:label="@string/app_name"
 android:roundIcon="@drawable/app_round"
 android:supportsRtl="true"
 android:theme="@style/AppTheme.NoActionBar"
 android:allowClearUserData="true"
 android:fullBackupContent="@xml/backup_descriptor">

 <!-- android:theme="@style/AppTheme" -->

 <activity
 android:name=".activities.AppActivity"
 android:screenOrientation="portrait"
 android:label="@string/app_name"
 android:theme="@style/AppTheme.NoActionBar">
 <intent-filter>

 <!-- para ser aberto com action APP -->
 <action android:name="android.intent.action.APP" />
 <action android:name="android.intent.action.MAIN" />
 <action android:name="io.ubivis.digitalmobility.action.CONSUME_APP_NOTIFICATION" />

 <category android:name="android.intent.category.DEFAULT" />
 </intent-filter>
 <intent-filter>
 <action android:name="android.intent.action.VIEW" />

 <category android:name="android.intent.category.DEFAULT" />
 <category android:name="android.intent.category.BROWSABLE" />

 <data
 android:host="app.domain.io"
 android:scheme="https" />
 </intent-filter>
 </activity>

 <service android:name=".services.FirebaseMessageService">
 <intent-filter>
 <action android:name="com.google.firebase.MESSAGING_EVENT" />
 </intent-filter>
 </service>
 <service android:name=".services.FirebaseTokenService">
 <intent-filter>
 <action android:name="com.google.firebase.INSTANCE_ID_EVENT" />
 </intent-filter>
 </service>

 <meta-data
 android:name="com.google.firebase.messaging.default_notification_icon"
 android:resource="@drawable/ic_logo_app_60dp" />
 <meta-data
 android:name="com.google.firebase.messaging.default_notification_color"
 android:resource="@color/colorPrimary" />

 <!-- Para Android 8 - Necessário um canal para notificações -->
 <!-- <meta-data -->
 <!-- android:name="com.google.firebase.messaging.default_notification_channel_id" -->
 <!-- android:value="@string/default_notification_channel_id"/> -->
</application>

my activity xml is:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.v7.widget.CardView
 android:id="@+id/app_connectionCard"
 android:layout_width="match_parent"
 android:layout_height="40dp"
 android:visibility="gone"
 app:cardBackgroundColor="@android:color/holo_red_dark"
 app:layout_constraintEnd_toEndOf="parent"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toBottomOf="@+id/app_toolbar">

 <android.support.constraint.ConstraintLayout
 android:layout_width="match_parent"
 android:layout_height="match_parent">

 <TextView
 android:id="@+id/textView2"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="@string/connectionFail"
 android:textColor="@color/cardview_light_background"
 android:textSize="24sp"
 android:textStyle="bold"
 app:layout_constraintBottom_toBottomOf="parent"
 app:layout_constraintEnd_toEndOf="parent"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toTopOf="parent" />
 </android.support.constraint.ConstraintLayout>
</android.support.v7.widget.CardView>

<android.support.v7.widget.Toolbar
 android:id="@+id/app_toolbar"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:background="@color/ubivis_background_blue"
 android:theme="@style/ThemeOverlay.AppCompat.Dark"
 app:layout_constraintEnd_toEndOf="parent"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toTopOf="parent" />

<android.support.v4.widget.DrawerLayout
 android:id="@+id/app_drawer"
 android:layout_width="0dp"
 android:layout_height="0dp"
 app:layout_constraintBottom_toBottomOf="parent"
 app:layout_constraintEnd_toEndOf="parent"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toBottomOf="@+id/app_connectionCard"
 tools:openDrawer="start">

 <FrameLayout
 android:id="@+id/app_frame"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 app:layout_constraintBottom_toBottomOf="parent"
 app:layout_constraintEnd_toEndOf="parent"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toTopOf="parent">
 </FrameLayout>

 <android.support.design.widget.NavigationView
 android:id="@+id/app_navigation"
 android:layout_width="wrap_content"
 android:layout_height="match_parent"
 android:layout_gravity="start"
 android:background="@color/colorPrimaryDark"
 android:fitsSystemWindows="true"
 android:theme="@style/UbivisDrawerTheme"
 app:headerLayout="@layout/nav_header_app"
 app:itemIconTint="@color/ubivis_orange"
 app:menu="@menu/activity_app_drawer" />

</android.support.v4.widget.DrawerLayout>

fragment xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
android:theme="@style/AppTheme.NoActionBar"
tools:context=".fragments.MainFragment">

<ImageView
 android:id="@+id/imageView"
 android:layout_width="0dp"
 android:layout_height="0dp"
 android:adjustViewBounds="false"
 android:cropToPadding="false"
 android:scaleType="fitEnd"
 android:tint="@color/background"
 android:translationX="128dp"
 android:translationY="128dp"
 android:visibility="visible"
 app:layout_constraintBottom_toBottomOf="parent"
 app:layout_constraintEnd_toEndOf="parent"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toTopOf="parent"
 app:srcCompat="@drawable/logo_domain_vasado" />

<android.support.v7.widget.RecyclerView
 android:id="@+id/main_listDataListRecycler"
 android:layout_width="0dp"
 android:layout_height="0dp"
 app:layout_constraintBottom_toBottomOf="parent"
 app:layout_constraintEnd_toStartOf="@+id/main_dock"
 app:layout_constraintHorizontal_bias="0.0"
 app:layout_constraintStart_toStartOf="parent"
 app:layout_constraintTop_toTopOf="parent"
 app:layout_constraintVertical_bias="0.0">

</android.support.v7.widget.RecyclerView>

<TextView
 android:id="@+id/main_noDataText"
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 android:layout_marginBottom="8dp"
 android:layout_marginEnd="8dp"
 android:layout_marginStart="8dp"
 android:text="@string/noDataMessage"
 android:textAlignment="center"
 android:textSize="30sp"
 android:textStyle="bold"
 android:visibility="visible"
 app:layout_constraintBottom_toTopOf="@+id/main_noDataQrButton"
 app:layout_constraintEnd_toStartOf="@+id/main_dock"
 app:layout_constraintStart_toStartOf="parent" />

<Button
 android:id="@+id/main_noDataQrButton"
 android:layout_width="220dp"
 android:layout_height="220dp"
 android:layout_marginBottom="5dp"
 android:layout_marginEnd="8dp"
 android:layout_marginStart="8dp"
 android:layout_marginTop="30dp"
 android:background="@drawable/shape_qr_code_frame"
 android:elevation="16dp"
 android:onClick="qrScan"
 android:theme="@style/AppTheme"
 android:visibility="visible"
 app:layout_constraintBottom_toBottomOf="parent"
 app:layout_constraintEnd_toStartOf="@+id/main_dock"
 app:layout_constraintStart_toStartOf="@+id/main_listDataListRecycler"
 app:layout_constraintTop_toTopOf="parent"
 tools:ignore="OnClick" />

for the activity lifecycle:

override fun onCreate(savedInstanceState: Bundle?) 
 super.onCreate(savedInstanceState)
 Control.logData("creating activity")

 setContentView(R.layout.activity_app)
 // keep screen alive
 window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
 // set toolbar
 setSupportActionBar(findViewById(R.id.app_toolbar))
 supportActionBar?.title = getString(R.string.Datas)
 supportActionBar?.setDisplayHomeAsUpEnabled(true)
 supportActionBar?.setDisplayShowHomeEnabled(true)
 isWaitingResult = savedInstanceState?.getBoolean(isWaitingResultCode) ?: false
 savedInstanceState?.let
 fragment_state = savedInstanceState.getString(fragState) ?: fragment_state
 userAuth = savedInstanceState.getSerializable(userAuthCode) as? UserAuthentication?
 
 val DataMenu = findViewById<NavigationView>(R.id.app_navigation)
 .menu.findItem(R.id.DataButton)
 DataMenu?.isChecked = true
 if (!Control.filters) filterMenu?.icon = drawable(R.drawable.filter_inactive)
 //injection
 if (!isInjected) 
 onInject()
 


override fun onStop() 
 super.onStop()
 Control.logData("stopping activity")
 fragmentManager.executePendingTransactions()
 Control.mainRunning = false
 loop = false
 saveFav()


override fun onDestroy() 
 super.onDestroy()
 Control.logData("destroying activity")
 Control.rx.forEach it.dismiss() 
 Control.rx.clear()

Control is a object with some function and data commonly used across the App

in my case the blank screen was caused by the main thread blocked, after an api update some deprecated functions started to return null and block the main thread inside the fragments for solve the problem I used the new functions provided by the api to replace the deprecated ones