Android Fragment (Weird) behaviour on rotation change -

backstory: i'm building app school project. works api json , convert , show user.

note: (players people in world of tanks, i'm using api)

my current structure: home -> navigation drawer -> players -> select player -> details of player

my problem: when in detail view of player opens perfectly. when change orientation horizontal screen goes "back" search view.

when go nav drawer detail of player (using hardcoded player) , change screen horizontal nothing happens.

i'm totally clueless causes this.

finally code: (please not school project , i'm new android)

i chose dev api 21+

xml search

<?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent" android:layout_height="match_parent"     android:id="@+id/someid">       <edittext         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:id="@+id/search_query"         android:hint="@string/search_hint"         android:layout_alignbottom="@+id/search_button"         android:layout_alignparentstart="true"         android:maxlines="1"         android:layout_tostartof="@+id/search_button" />      <button         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="@string/search_button"         android:onclick="getplayers"         android:id="@+id/search_button"         android:layout_alignparenttop="true"         android:layout_alignparentend="true" />      <listview         android:layout_width="wrap_content"         android:layout_height="wrap_content"           android:id="@id/android:list"         android:layout_below="@+id/search_query"         android:layout_alignparentstart="true" />    </relativelayout> 

xml detail

<relativelayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:id="@+id/player_detail_fragment"     tools:context="com.jdkmedia.vh8.fragment.playerdetailfragment">      <textview         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:textappearance="?android:attr/textappearancelarge"         android:id="@+id/playername"         android:layout_alignparenttop="true"         android:layout_centerhorizontal="true"         android:layout_margintop="24dp"/>       <android.support.v7.widget.recyclerview         android:id="@+id/tank_list"         android:layout_width="match_parent"         android:layout_height="match_parent"         android:scrollbars="vertical"         android:layout_below="@+id/playername"         android:layout_alignparentstart="true"         android:layout_margintop="40dp" />  </relativelayout> 

mainactivity navigation drawer

 @override     public void onnavigationdraweritemselected(int position) {         // update main content replacing fragments         fragment fragment = null;          switch (position) {             case 0:                 fragment = mainactivityfragment.newinstance(accesstoken);                 log.i(app + " class: " + tag, "main activity fragment selected");                 break;             case 1:                 fragment = playersearchmainfragment.newinstance();                 log.i(app + " class: " + tag, "player search activity fragment selected");                 break;             case 2: //                fragment = new tankcomparetopfragment();                 player player = new player(314134134,"stack overflow");                 onplayerselected(player);                 break;             default:                 fragment = mainactivityfragment.newinstance(accesstoken);                 log.i(app + " class: " + tag, " default fragment selected");                 break;         }          if(fragment != null){             log.i(app + " class: " + tag, "fragment not null - transaction");             fragmentmanager fragmentmanager = getfragmentmanager();             fragmentmanager.begintransaction(   )                     .replace(r.id.container, fragment, fragment.getclass().getname()).addtobackstack(fragment.getclass().getname()).commit();         }     } 

any other code files can posted when needed.

1. device rotated. fragmentmanager saves state fragments, frees them.
2. new activity. new fragments instantiated, states restored.
3. fragments moved oncreate.
4. oncreate of navigationdrawerfragment triggers replace transaction.
5. the replace transaction removes restored placeholderfragment new one, has no saved state. credit chiu-ki chan taken here