Develop Reference

Go back from a fragment to main fragment

This is my main activity where I am calling my fragments:
public class what extends AppCompatActivity {
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mToggle;
private ListView mDrawerList;
private ArrayAdapter<String> mAdapter;
private FragmentTransaction fragmentTransaction;
NavigationView navigationView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_what);
mDrawerLayout=(DrawerLayout)findViewById(R.id.drawer_layout);
mToggle=new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);
mDrawerLayout.addDrawerListener(mToggle);
mToggle.syncState();
fragmentTransaction= getSupportFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.main_content,new mainfrag());
fragmentTransaction.commit();
ActionBar actionBar= getSupportActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
navigationView=(NavigationView)findViewById(R.id.nav_view);
navigationView.getMenu().getItem(1).setChecked(false);
navigationView.getMenu().getItem(0).setChecked(true);
navigationView.getMenu().getItem(2).setChecked(false);
navigationView.getMenu().getItem(3).setChecked(false);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.nav_main:
navigationView.getMenu().getItem(1).setChecked(false);
navigationView.getMenu().getItem(2).setChecked(false);
navigationView.getMenu().getItem(3).setChecked(false);
navigationView.setCheckedItem(R.id.nav_main);
mDrawerLayout.closeDrawers();
fragmentTransaction=getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.main_content, new mainfrag());
fragmentTransaction.commit();
getSupportActionBar().setTitle(("SGPA and CGPA Calculator"));
item.setChecked(true);
break;
case R.id.nav_savedcal:
navigationView.getMenu().getItem(0).setChecked(false);
navigationView.getMenu().getItem(2).setChecked(false);
navigationView.getMenu().getItem(3).setChecked(false);
navigationView.setCheckedItem(R.id.nav_savedcal);
mDrawerLayout.closeDrawers();
fragmentTransaction=getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.main_content, new savedFragment());
fragmentTransaction.commit();
getSupportActionBar().setTitle(("Saved Calculations"));
item.setChecked(true);
break;
case R.id.nav_upldoc:
navigationView.getMenu().getItem(0).setChecked(false);
navigationView.getMenu().getItem(1).setChecked(false);
navigationView.getMenu().getItem(3).setChecked(false);
navigationView.setCheckedItem(R.id.nav_upldoc);
mDrawerLayout.closeDrawers();
fragmentTransaction=getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.main_content, new uploadedfragment());
fragmentTransaction.commit();
getSupportActionBar().setTitle(("Uploaded documents"));
item.setChecked(true);
break;
case R.id.nav_site:
navigationView.getMenu().getItem(0).setChecked(false);
navigationView.getMenu().getItem(1).setChecked(false);
navigationView.getMenu().getItem(2).setChecked(false);
navigationView.setCheckedItem(R.id.nav_site);
mDrawerLayout.closeDrawers();
fragmentTransaction=getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.main_content, new resultsite());
fragmentTransaction.commit();
getSupportActionBar().setTitle(("VTU Results"));
item.setChecked(true);
break;
}
return false;
}
});
}
public boolean onOptionsItemSelected(MenuItem item ){
if(mToggle.onOptionsItemSelected(item)){
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onBackPressed() {
DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case DialogInterface.BUTTON_POSITIVE: {
finish();
}
break;
case DialogInterface.BUTTON_NEGATIVE:
break;
}
}
};
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Are you sure you want to exit?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
return;
}
}
This is my default fragment :
public class mainfrag extends Fragment {
private View view;
private AdView adView;
private Button button10;
private Button button11;
public mainfrag() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_mainfrag, container, false);
adView = view.findViewById(R.id.adView);
button10 = (Button) view.findViewById(R.id.button10);
button10.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openmainactivity();
}
});
button11 = (Button) view.findViewById(R.id.button11);
button11.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openscheme();
}
});
return view;
}
public void openmainactivity() {
Intent intent = new Intent(getContext(), MainActivity.class);
startActivity(intent);
}
public void openscheme(){
Intent intent=new Intent(getContext(), scheme.class);
startActivity(intent);
}
}
This is one of the other fragments:
public class savedFragment extends Fragment {
RecyclerView recyclerview;
adapter_sgpa recyclerAdapter;
ArrayList<POJO> sgpaArrayList;
public savedFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FragmentTransaction tx = getChildFragmentManager().beginTransaction();
tx.replace(R.id.container, new sgpa_frag());
tx.commit();
}
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
int id = item.getItemId();
Fragment fragment = null;
switch (id) {
case R.id.navigation_sgpa:
sgpa_frag sf = new sgpa_frag();
FragmentManager fragmentManager = getChildFragmentManager();
fragmentManager.beginTransaction().replace(R.id.container, sf).commit();
return true;
case R.id.navigation_cgpa:
cgpa_frag cf = new cgpa_frag();
fragmentManager = getChildFragmentManager();
fragmentManager.beginTransaction().replace(R.id.container, cf).commit();
return true;
}
return false;
}
};
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_saved, container, false);
BottomNavigationView nav = (BottomNavigationView) v.findViewById(R.id.bottom_navigation);
nav.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
return v;
}
}
What changes should I make in this code so that I am able to move back from the other fragments to the main fragment on pressing back button ?

Maintain one boolean variable to check current fragment is MainFragment or not.
if its not MainFragment -> replace MainFragment
Else -> super.onBackPressed()
ex:
private boolean isMainFragment=true; //make it false when move to other fragment
#Override
public void onBackPressed() {
if(!isMainFragment){
isMainFragment=true;
//replace your MainFragment
}
else{
//your logic show dialog or super.onBackPressed()
}
}

Ithink I know what you need. have a look at the last part of this documentation
"You can add a fragment transaction to the back stack. The back stack keeps track of actions in your app which can be backtracked when the user clicks Android's standard "back" button on the device. If you add a fragment transaction to the back stack then the transaction can be backtracked (reversed) with a click on the back button on the device" quotet from Jenkov
simply do fragmentTransaction.addToBackStack(null) on your main activity before you do the commit this will allow you to travel back using the back button
if you always want to travel back to the main fragment then you want to only add the main fragment to the backstack that way on pressing the back button you will always land there
in this part of your oncreate:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_what);
mDrawerLayout=(DrawerLayout)findViewById(R.id.drawer_layout);
mToggle=new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);
mDrawerLayout.addDrawerListener(mToggle);
mToggle.syncState();
fragmentTransaction= getSupportFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.main_content,new mainfrag());
//HERE YOU PUT THE CODE V
fragmentTransaction.addToBackStack(null);
//HERE YOU PUT THE CODE ^
fragmentTransaction.commit();
ActionBar actionBar= getSupportActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
// ALL THE OTHER STUFF COMMING AFTER

Want to move from navigation drawer activity to another screen using fragments to show drawer across all screens

I'm trying for last two days to add fragment next to my drawer activity to get navigation drawer visible across the whole application. I have tried several ways from stackoverflow and many others but still no success. and after that i have to move to 2nd fragment from 1st fragment and so on till the need for navigation drawer.
I want to replace entire view except drawer when i move from from my activity to any fragment. Each fragment have its own layout.xml like an activity(Linear/Relative layouts as parent in them).
Drawer avtivity:
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
Button btnfragOne = (Button) findViewById(R.id.btnfrag_one);
btnfragOne.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
FragOne fragment = new FragOne();
getSupportFragmentManager().beginTransaction()
.replace(R.id.frag2, fragment, fragment.getClass().getSimpleName()).addToBackStack(null).commit();
}
});
}
1st Fragment class:
public class FragOne extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.frag_one, container, false);
}
// 2nd Fragment class:
public class FragTwo extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.frag_two, container, false);
}

Simply for this task you have to override onNavigationItemSelected method in your Activity, which return id of selected fragment on NavigationDrawer.
Try this,
#Override
public boolean onNavigationItemSelected(MenuItem item) {
//calling the method displayselectedscreen and passing the id of selected menu
displaySelectedFragment(item.getItemId());
return true;
}
Now displaySelectedFragment,
private void displaySelectedScreen(int itemId) {
//creating fragment object
Fragment fragment = null;
//initializing the fragment object which is selected
switch (itemId) {
case R.id.your_fragment_one_id:
fragment = new FragOne();
break;
case R.id.your_fragment_two_id:
fragment = new FragTwo();
break;
}
//replacing the fragment
if (fragment != null) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.main_layout_id_which_is_to_be_replace, fragment);
ft.commit();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.your_drawer_layout_id);
drawer.closeDrawer(GravityCompat.START);
}
Edit -- If you want navigate from FragOne to FragTwo. Try this,
Create a method in your Activity,
public void showFragTwo(){
FragmentManager manager = getSupportFragmentManager();
FragTwo frag = new FragTwo();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.your_layout_id_which_is_to_be_replace, frag);
transaction.commit();
}
Then in your FragOne when you want to start FragTwo, call startFragTwo method from Activity as,
((YourActivity) getActivity()).showFragTwo();

Back button from activity is removing fragment

I am trying to retain the state of Fragment. I have MotherActivity in which I have FragmentOne,FragmentTwo,FragmentThree and inside from FragmentTwo I am calling another activity ChildActivity. Problem is that When I am pressing back button in ChildActivity it is refreshing MotherActivity and not keeping the state of my FragmentTwo instead it is showing me FragmentOne which come first time.
I only want when I am pressing BackButton from ChildActivity, on container FragmentTwo should be there:
MainAcitivity:
public class MotherActivity extends FragmentActivity {
AHBottomNavigation bottomNavigation;
Fragment selectedFragment = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bottomNavigation = (AHBottomNavigation) findViewById(R.id.navigation);
bottomNavigation.addItem(item1);
bottomNavigation.addItem(item2);
bottomNavigation.addItem(item3);
bottomNavigation.setOnTabSelectedListener(new AHBottomNavigation.OnTabSelectedListener() {
#Override
public boolean onTabSelected(int position, boolean wasSelected) {
if (position == 0) {
selectedFragment = FragmentOne.newInstance(bottomNavigation);
} else if (position == 1) {
selectedFragment = FragmentTwo.newInstance(bottomNavigation);
} else if (position == 2) {
selectedFragment = FragmentThree.newInstance(bottomNavigation);
}
android.app.FragmentManager fragmentManager = getFragmentManager();
android.app.FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.frame_layout,selectedFragment);
fragmentTransaction.commit();
return true;
}
});
}
#Override
protected void onStart() {
super.onStart();
android.app.FragmentManager fragmentManager = getFragmentManager();
android.app.FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.frame_layout, FragmentOne.newInstance(bottomNavigation));
fragmentTransaction.commit();
}
public void setNotification(){
bottomNavigation.setNotification("1", 1);
}
#Override
protected void onSaveInstanceState(Bundle outState) {
//No call for super().
}
#Override
public void onBackPressed() {
Intent intent = new Intent();
setResult(113, intent);
finish();
return;
}
}
FragmentTwo from where I am calling childActivity:
public class FragmentTwo extends Fragment {
public static AHBottomNavigation bottomNavigation1;
Card_detail_Adapter_Footer searchabledapter;
public static boolean showAddress = false;
Fragment selectedFragment;
public static FragmentTwo newInstance(AHBottomNavigation bottomNavigation) {
FragmentTwo fragment = new FragmentTwo();
bottomNavigation1 = bottomNavigation;
showNotificationCounter(3);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_cart, container, false);
if(showAddress == true){
showAddress = false;
// From here I am calling ChildActivity
Intent intent = new Intent(getActivity(), ChildActivity.class);
startActivity(intent);
}
return view;
}
}
In ChildActivity simply calling onBackPressed()

The problem is with the onStart() method of your MotherActivity.java because when you open another activity from FragmentTwo, your MotherActivity onStop() gets called. When you press back button from ChildActivity onStart() of MotherActivity called which is replacing FragmentTwo from FragmentOne by committing transaction.
Please have a look at https://developer.android.com/guide/components/activities/activity-lifecycle.html

Put code from onStart() method into onCreate() method and check if configuration been changed:
if (savedInstanceState == null) {
android.app.FragmentManager fragmentManager = getFragmentManager();
android.app.FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.frame_layout, FragmentOne.newInstance(bottomNavigation));
fragmentTransaction.commit();
}

From fragment to another fragment

For the first second I making a Android App where students can rent a room. Now I work on the login en register pages.
I have a problem with the register page. In my app there can two types of users register they are called "Student" and "Verhuurder". In the account fragment there are two buttons for the register pages. I can't get it working to the two pages..
I had so much trouble with activity and fragments...
Can anyone help me?
My code :
Account Fragment
public class AccountFragment extends Fragment implements View.OnClickListener{
public AccountFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (MainActivity.loginId == "")
{
return inflater.inflate(R.layout.fragment_account, container, false);
}
else
{
return inflater.inflate(R.layout.inlog_account, container, false);
}
}
// BUTTON
Button btnStudent = (Button) view.findViewById(R.id.btnRegisterStudent);
btnStudent.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btnStudent:
//what to put here
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.fragment_container, new AccountFragmentStudent());
ft.commit();
break;
}
}
});
}
XML Account fragment
<Button
android:id="#+id/btnRegisterStudent"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#FFFFFF"
android:text="Student op zoek naar een kamer"
android:background="#color/colorPrimary"
android:onClick="StudentRegister"/>
MainActivity
public class MainActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener, Callback<LoginResults> {
private EditText emailInput;
private EditText passwordInput;
private HomeFragment fragment;
public static String loginId = "";
public static String loginSecret = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
HomeFragment fragment = new HomeFragment();
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.fragment_container, fragment);
fragmentTransaction.commit();
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
}
#Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
public void Login(View v) {
emailInput = (EditText) findViewById(R.id.email);
passwordInput = (EditText) findViewById(R.id.password);
String email = emailInput.getText().toString();
String password = passwordInput.getText().toString();
doLogin(email, password);
}
public void onResponse(Response<LoginResults> response) {
if (response.isSuccess() && response.body() != null) {
loginId = response.body().clientId;
loginSecret = response.body().clientSecret;
fragment.setLoginToken1(loginId);
fragment.setLoginToken2(loginSecret);
new AlertDialog.Builder(MainActivity.this)
.setTitle("Gelukt")
.setMessage("U bent ingelogd")
.setCancelable(false)
.setPositiveButton("oke", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
}).create().show();
// Create fragment and give it an argument specifying the article it should show
InlogAccountFragment newFragment = new InlogAccountFragment();
Bundle args = new Bundle();
newFragment.setArguments(args);
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
transaction.commit();
}
else
new AlertDialog.Builder(MainActivity.this)
.setTitle("Mislukt")
.setMessage("Uw inloggegevens zijn incorrect")
.setCancelable(false)
.setPositiveButton("oke", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
}).create().show();
{
}
}
public void onFailure(Throwable t) {
new AlertDialog.Builder(MainActivity.this)
.setTitle("Er is iets fouts gegaan")
.setMessage("Probeer opnieuw")
.setCancelable(false)
.setPositiveButton("oke", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
}).create().show();
}
public void doLogin(String email, String password){
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("BLABLA")
.addConverterFactory(GsonConverterFactory.create())
.build();
Login service = retrofit.create(Login.class);
service.loginResults(
email,
password
).enqueue(this);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_home) {
HomeFragment fragment = new HomeFragment();
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.commit();
} else if (id == R.id.nav_favorieten) {
FavoriteFragment fragment = new FavoriteFragment();
android.support.v4.app.FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.commit();
} else if (id == R.id.nav_berichtenbox) {
MessageFragment fragment = new MessageFragment();
android.support.v4.app.FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.commit();
} else if (id == R.id.nav_account) {
AccountFragment fragment = new AccountFragment();
android.support.v4.app.FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.commit();
} else if (id == R.id.nav_instellingen) {
SettingsFragment fragment = new SettingsFragment();
android.support.v4.app.FragmentTransaction fragmentTransaction =
getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.commit();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}

I generally try to keep my fragments light and decoupled, and delegate heavy lifting (particularly interaction with other fragments) to the activity which is using them. You might like to try the following approach:
Try adding a listener interface to your AccountFragment - something like this:
public interface Listener {
void onStudentRegistrationSelected();
void onVerhuurderRegistrationSelected();
}
You'll also need to add:
// Member declaration at the top of the fragment class
private Listener mListener;
#Override public void onAttach(Context context) {
super.onAttach(context);
try {
mListener = (Listener) context;
} catch (ClassCastException e) {
throw new ClassCastException(context.toString() + " must implement " +
Listener.class.getSimpleName() + ".");
}
}
This will set the activity which is using the fragment as the listener.
Then, set up the on click handler of the appropriate buttons in AccountFragment to call the appropriate method on the listener. Something like this:
view.findViewById(R.id.btnRegisterStudent).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mListener.onStudentRegistrationSelected();
}
}
Back in MainActivity, implement the AccountFragment.Listener interface, override the methods of the listener, and create and commit the appropriate registration fragment in each of the listener method overrides - for example, onStudentRegistrationSelected() would display the AccountFragmentStudent fragment. Also, if you add this to the fragment backstack, then the user will be returned to the AccountFragment if they hit the back button while on the AccountFragmentStudent, which is a nice piece of UX.
Hope that helps!

Android home button with drawer navigation stops to work with rotation screen

I have a main activity with navigation drawer and a button to load fragment.
When the main ativity is launched I load the MainFragment.
In this moment all works well. The hamburger icon is showing and my Main fragment was loaded.
Next, I click a button and load a secondFragment. After I load the second fragment, I can use the backbutton and homebutton to come back to main activity without problems.
When I am with second fragment loaded and I make a rotation screen, the back button continues to work well, but the home button disappears and hamburger icon appears.
What am i doing wrong?
public class MainActivity extends AppCompatActivity {
private ActionBarDrawerToggle actionBarDrawerToggle;
private DrawerLayout drawerLayout;
private Toolbar toolbar;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String mSubTitle;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
initNavigationDrawer();
if (savedInstanceState != null) {
return;
}
MainActivityFragment mainFragment = new MainActivityFragment();
firstFragment.setArguments(getIntent().getExtras());
// Add the fragment to the 'fragment_container' FrameLayout
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
//transaction.replace(R.id.fragment_container, firstFragment);
transaction.replace(R.id.fragment_container, mainFragment, "princ");
transaction.commit();
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Only handle with DrawerToggle if the drawer indicator is enabled.
if (actionBarDrawerToggle.isDrawerIndicatorEnabled() &&
actionBarDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle your other action bar items...
return super.onOptionsItemSelected(item);
}
}
public Fragment getCurrentFragment(){
FragmentManager frgmgr = getSupportFragmentManager();
return frgmgr.findFragmentById(R.id.fragment_container);
}
#Override
public void onBackPressed() {
if (drawerLayout != null) {
if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
drawerLayout.closeDrawer(GravityCompat.START);
return;
}
}
if ((getCurrentFragment() instanceof MainFragment)) {
finish();
} else if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
getSupportFragmentManager().popBackStack();
} else super.onBackPressed();
}
public void initNavigationDrawer() {
NavigationView navigationView = (NavigationView) findViewById(R.id.navigation_view);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
FragmentManager frgmgr = getSupportFragmentManager();
FragmentTransaction transaction = frgmgr.beginTransaction();
Fragment cur_frag;
// Handle navigation view item clicks here.
int id = menuItem.getItemId();
switch (id) {
case R.id.home:
cur_frag = frgmgr.findFragmentById(R.id.fragment_container);
if (!(cur_frag instanceof MainActivityFragment)) {
MainActivityFragment frag = new MainActivityFragment();
transaction.setCustomAnimations(R.anim.enter_from_left, R.anim.exit_to_right, R.anim.enter_from_right, R.anim.exit_to_left);
transaction.replace(R.id.fragment_container, frag);
transaction.commit();
break;
}
drawerLayout.closeDrawers();
break;
case R.id.logout_drw:
finish();
}
drawerLayout.closeDrawer(GravityCompat.START);
return true;
}
});
View header = navigationView.getHeaderView(0);
TextView tv_email = (TextView) header.findViewById(R.id.tv_email);
tv_email.setText("Agendamento");
drawerLayout = (DrawerLayout) findViewById(R.id.drawer);
mTitle = mDrawerTitle = getTitle();
actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
#Override
public void onDrawerClosed(View v) {
super.onDrawerClosed(v);
}
#Override
public void onDrawerOpened(View v) {
super.onDrawerOpened(v);
}
};
drawerLayout.addDrawerListener(actionBarDrawerToggle);
actionBarDrawerToggle.syncState();
if (toolbar != null) {
getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
#Override
public void onBackStackChanged() {
int i=getSupportFragmentManager().getBackStackEntryCount();
if ((i > 0) || (!(getCurrentFragment() instanceof MainActivityFragment))) {
getSupportActionBar().setDisplayHomeAsUpEnabled(true); // show back button
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onBackPressed();
}
});
} else {
getSupportActionBar().setDisplayHomeAsUpEnabled(false);
actionBarDrawerToggle.syncState();
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
drawerLayout.openDrawer(GravityCompat.START);
}
});
}
}
});
}
}
}
Main Fragment:
public class MainFragment extends Fragment {
public MainFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.fragment_main, container, false);
Button butCons= (Button) view.findViewById(R.id.butcons);
butCons.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
SecundaryFrag frag = new SecundaryFragFrag();
// Add the fragment to the 'fragment_container' FrameLayout
FragmentTransaction transaction=getFragmentManager().beginTransaction();
transaction.setCustomAnimations(R.anim.enter_from_left, R.anim.exit_to_right, R.anim.enter_from_right, R.anim.exit_to_left);
transaction.replace(R.id.fragment_container, frag);
transaction.addToBackStack(null);
transaction.commit();
}
});
return view;
}
}
Secondary Fragment:
public class SecundaryFrag extends Fragment{
public SecundaryFrag() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.fragment_consulta_ag, container, false);
return view;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
((MainActivity)getActivity()).onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
After Rotation:
Main activty with main fragment:
Before Rotation:

I believe it is related to the fact that the view is recreated after the orientation change. I would take a closer look to the onCreate() from the MainActivity in particular when the
if (savedInstanceState != null) {
return;
}
is triggered.
One option is to retain the fragments and restoring them onCreate. Also you could turn off the recreation by catching the orientation and handle it yourself in the application, you can see here both options explained developer.android.com/guide/topics/resources/