Develop Reference

BottomNavigationView - How to avoid recreation of Fragments and reuse them

I would like to make a bottom navigation bar in my project. Every view has it's own fragment. The problem is that every time i click on the button to change the view for example from recents to favorites it creates new fragment with completely new states(e.g. scroll position, text changed whatever my fragment contains). I know that in official Android documentation there was written that bottom navigation bar should reset the task states, but i think it is too uncomfortable for users.
I would like to have kind of similar functionality like instagram that you change from feed to explore and back to feed the scroll position the image caches everything remains saved. I tried almost every way to solve this problem the only thing that worked is by setting visibility GONE and setting visibility VISIBLE according to situation but i understand that it is not RIGHT way there should be better way of doing this and i am not talking about manually saving needed instances. I followed almost every tutorial about bottom nav fragments but the interesting thing is that no one is interested to make it use without calling new every time.
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.frameLayout, FirstFragment.newInstance());
fragmentTransaction.commit();
bottomNavigationView = (BottomNavigationView) findViewById(R.id.navigation);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment = null;
switch (item.getItemId()) {
case R.id.menu_dialer:
fragment = FirstFragment.newInstance();
break;
case R.id.menu_email:
fragment = SecondFragment.newInstance();
break;
case R.id.menu_map:
fragment = ThirdFragment.newInstance();
break;
}
if (fragment != null) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.frameLayout, fragment);
fragmentTransaction.commit();
}
return true;
}
});
I also tried the onAttach and Deattach solutions but again no success.
VIDEO LINK : new i tried Nino Handler version it only works when i tap on the same fragment button
Maybe it is connected that i am using canary version or something wrong in my gradle dependencies?
NEW UPDATES:
public class MainActivity extends AppCompatActivity {
private TextView mTextMessage;
private static final String TAG_FRAGMENT_ONE = "fragment_one";
private static final String TAG_FRAGMENT_TWO = "fragment_two";
private FragmentManager fragmentManager;
private Fragment currentFragment;
String TAG = "babken";
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
Fragment fragment = null;
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_home:
fragment = fragmentManager.findFragmentByTag(TAG_FRAGMENT_ONE);
if (fragment == null) {
fragment = FragmentFirst.newInstance();
}
replaceFragment(fragment, TAG_FRAGMENT_ONE);
break;
case R.id.navigation_dashboard:
fragment = fragmentManager.findFragmentByTag(TAG_FRAGMENT_TWO);
if (fragment == null) {
fragment = FragmentSecond.newInstance();
}
replaceFragment(fragment, TAG_FRAGMENT_TWO);
break;
}
return true;
}
};
private void replaceFragment(#NonNull Fragment fragment, #NonNull String tag) {
if (!fragment.equals(currentFragment)) {
fragmentManager
.beginTransaction()
.replace(R.id.armen, fragment, tag)
.commit();
currentFragment = fragment;
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentManager = getSupportFragmentManager();
Fragment fragment = fragmentManager.findFragmentByTag(TAG_FRAGMENT_ONE);
if (fragment == null) {
fragment = FragmentFirst.newInstance();
}
replaceFragment(fragment, TAG_FRAGMENT_ONE);
BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
}
}

I had similar issue, but this code solved my problem.
public class MainActivity extends AppCompatActivity {
boolean doubleBackToExitPressedOnce = false;
final Fragment fragment1 = new HomeFragment();
final Fragment fragment2 = new DashboardFragment();
final Fragment fragment3 = new NotificationsFragment();
final FragmentManager fm = getSupportFragmentManager();
Fragment active = fragment1;
BottomNavigationView navigation;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
setFragment(fragment1, "1", 0);
}
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_home:
setFragment(fragment1, "1", 0);
return true;
case R.id.navigation_dashboard:
setFragment(fragment2, "2", 1);
return true;
case R.id.navigation_notifications:
setFragment(fragment3, "3", 2);
return true;
}
return false;
}
};
public void setFragment(Fragment fragment, String tag, int position) {
if (fragment.isAdded()) {
fm.beginTransaction().hide(active).show(fragment).commit();
} else {
fm.beginTransaction().add(R.id.main_container, fragment, tag).commit();
}
navigation.getMenu().getItem(position).setChecked(true);
active = fragment;
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main_menu, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
startActivity(new Intent(MainActivity.this, SettingsActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onBackPressed() {
if (active == fragment1) {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();
} else {
setFragment(fragment1, "1", 0);
}
}
}

I wouldn't keep the fragment instances globally.
Instead add a tag to the fragment when creating them
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.container, new PlaceholderFragment(), TAG_PLACEHOLDER)
.commit();
Then you can always retrieve it like this:
Fragment fragment = getSupportFragmentManager().findFragmentByTag(TAG_PLACEHOLDER);
if (fragment == null) {
fragment = new PlaceholderFragment();
}
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.container, fragment, TAG_PLACEHOLDER)
.commit();
UPDATE: I updated my answer and to provide a complete solution:
private static final String TAG_FRAGMENT_ONE = "fragment_one";
private static final String TAG_FRAGMENT_TWO = "fragment_two";
private static final String TAG_FRAGMENT_THREE = "fragment_three";
private FragmentManager fragmentManager;
private Fragment currentFragment;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// instantiate the fragment manager
fragmentManager = getSupportFragmentManager();
Fragment fragment = fragmentManager.findFragmentByTag(TAG_FRAGMENT_ONE);
if (fragment == null) {
fragment = FirstFragment.newInstance();
}
replaceFragment(fragment, TAG_FRAGMENT_ONE);
bottomNavigationView = (BottomNavigationView) findViewById(R.id.navigation);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment = null;
switch (item.getItemId()) {
case R.id.menu_dialer:
// I'm aware that this code can be optimized by a method which accepts a class definition and returns the proper fragment
Fragment fragment = fragmentManager.findFragmentByTag(TAG_FRAGMENT_ONE);
if (fragment == null) {
fragment = FirstFragment.newInstance();
}
replaceFragment(fragment, TAG_FRAGMENT_ONE);
break;
case R.id.menu_email:
Fragment fragment = fragmentManager.findFragmentByTag(TAG_FRAGMENT_TWO);
if (fragment == null) {
fragment = SecondFragment.newInstance();
}
replaceFragment(fragment, TAG_FRAGMENT_TWO);
break;
case R.id.menu_map:
Fragment fragment = fragmentManager.findFragmentByTag(TAG_FRAGMENT_THREE);
if (fragment == null) {
fragment = ThirdFragment.newInstance();
}
replaceFragment(fragment, TAG_FRAGMENT_THREE);
break;
}
return true;
}
});
}
private void replaceFragment(#NonNull Fragment fragment, #NonNull String tag) {
if (!fragment.equals(currentFragment)) {
fragmentManager
.beginTransaction()
.replace(R.id.frameLayout, fragment, tag)
.commit();
currentFragment = fragment;
}
}
ADDITIONAL INFO: If you want to be sure that the fragment states don't change and if you also want to be able to swipe the fragments you should consider using a ViewPager with a FragmentStatePagerAdapter and change the current fragment in the adapter with every click event

I wrote a Kotlin Extension function for FragmentManager class
fun FragmentManager.switch(containerId: Int, newFrag: Fragment, tag: String) {
var current = findFragmentByTag(tag)
beginTransaction()
.apply {
//Hide the current fragment
primaryNavigationFragment?.let { hide(it) }
//Check if current fragment exists in fragmentManager
if (current == null) {
current = newFrag
add(containerId, current!!, tag)
} else {
show(current!!)
}
}
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
.setPrimaryNavigationFragment(current)
.setReorderingAllowed(true)
.commitNowAllowingStateLoss()
}
This can be called by supportFragmentManager.swtich(R.id.container,newFrag,newFrag.TAG) from onNavigationItemSelected

All the previous answers are using fragmentTransaction.replace(...). This will replace the current fragment by destroying it (which is causing the problem). Therefore all those solutions won't actually work.
This is the closest thing I could get to as a solution for this problem:
private void selectContentFragment(Fragment fragmentToSelect)
{
FragmentTransaction fragmentTransaction = this.getSupportFragmentManager().beginTransaction();
if (this.getSupportFragmentManager().getFragments().contains(fragmentToSelect)) {
// Iterate through all cached fragments.
for (Fragment cachedFragment : this.getSupportFragmentManager().getFragments()) {
if (cachedFragment != fragmentToSelect) {
// Hide the fragments that are not the one being selected.
fragmentTransaction.hide(cachedFragment);
}
}
// Show the fragment that we want to be selected.
fragmentTransaction.show(fragmentToSelect);
} else {
// The fragment to be selected does not (yet) exist in the fragment manager, add it.
fragmentTransaction.add(R.id.fragment_container, fragmentToSelect);
}
fragmentTransaction.commit();
}
To make this work, you should keep track of the fragments in an array (or in separate variables) in your Activity. I for reference pre-instantiated all fragments in a SparseArray.

You can use attach() and detach() methods:
private FirstFragment firstFragment = FirstFragment.newInstance();
private SecondFragment secondFragment= SecondFragment.newInstance();
private ThirdFragment thirdFragment = ThirdFragment.newInstance();
navigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_dialer:
changeFragment(firstFragment, "firstFragment");
return true;
case R.id.menu_email:
changeFragment(secondFragment, "secondFragment");
return true;
case R.id.menu_map:
changeFragment(thirdFragment, "thirdFragment");
return true;
}
return false;
}
});
public void changeFragment(Fragment fragment, String tagFragmentName) {
FragmentManager mFragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
Fragment currentFragment = mFragmentManager.getPrimaryNavigationFragment();
if (currentFragment != null) {
fragmentTransaction.detach(currentFragment);
}
Fragment fragmentTemp = mFragmentManager.findFragmentByTag(tagFragmentName);
if (fragmentTemp == null) {
fragmentTemp = fragment;
fragmentTransaction.add(R.id.content, fragmentTemp, tagFragmentName);
} else {
fragmentTransaction.attach(fragmentTemp);
}
fragmentTransaction.setPrimaryNavigationFragment(fragmentTemp);
fragmentTransaction.setReorderingAllowed(true);
fragmentTransaction.commitNowAllowingStateLoss();
}

So I have been researching for this for a long time and figured out that there is no way to reuse fragment with AUTOMATICALLY saved states you have to save your needed states manually then retrieve them whenever a new fragment is created but what about scroll position it is too hard and even in some cases it is impossible to save scroll view position state(e.g. recycler view). So i used the concept called VISIBILITY when i click on the button that fragment becomes visible others hide automatically.

How about that.
You declare the fragments in the class.
Fragment firstFragment,secondFragment,thirdFragment;
then in the switch-case you can code as that:
switch (item.getItemId()) {
case R.id.menu_dialer:
if(firstFragment != null) {
fragment = firstFragment;
}else{
fragment = FirstFragment.newInstance();
}
break;
case R.id.menu_email:
// the same ...
break;
case R.id.menu_map:
//the same ...
break;
}

Thomas's answer nearly helped me but had an issue that whenever I open new fragments the very first time, they overlapped but doesn't get overlapped once I open them again by pressing the menu buttons.
So I modified his code and obtained the solution using the following code:
private fun selectContentFragment(fragmentToSelect: Fragment) {
val fragmentTransaction = fragmentManager?.beginTransaction()
if (fragmentManager?.fragments?.contains(fragmentToSelect)!!) {
// Show the fragment that we want to be selected.
fragmentTransaction?.show(fragmentToSelect)
} else {
// The fragment to be selected does not (yet) exist in the fragment manager, add it.
fragmentTransaction?.add(R.id.container, fragmentToSelect)
}
// Iterate through all cached fragments.
for (cachedFragment in fragmentManager?.fragments!!) {
if (cachedFragment !== fragmentToSelect) {
// Hide the fragments that are not the one being selected.
// Uncomment following line and change the name of the fragment if your host isn't an activity and a fragment otherwise whole view will get hidden.
// if (!cachedFragment.toString().contains("HomeContainerFragment"))
fragmentTransaction?.hide(cachedFragment)
}
}
fragmentTransaction?.commit()
}
Make sure you're not passing the fragment's new instance every time.
This will work:
selectContentFragment(
when (item.itemId) {
R.id.home -> frag1
R.id.photoGallery -> frag2
else -> Home()
}
)
where frag1 and frag2 are global variables defined as:
val frag1 = Home()
val frag2 = PhotoGallery()
This will not work:
selectContentFragment(
when (item.itemId) {
R.id.home -> Home()
R.id.photoGallery -> PhotoGallery()
else -> Home()
}
)
It wasted my several hours. Hope it helps others!

**This code very helpful for me. Just like youtube. **
private Deque<Integer> fragmentIds = new ArrayDeque<>(3);
int itemId;
private HomeFragment homeFragment = new HomeFragment();
private FavouriteFragment favouriteFragment = new FavouriteFragment();
private NearmeFragment nearmeFragment = new NearmeFragment();
BottomNavigationView bottomNavigationView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentIds.push(R.id.action_home);
showTabWithoutAddingToBackStack(homeFragment);
bottomNavigationView = findViewById(R.id.bottom_navigation);
bottomNavigationView.setOnNavigationItemSelectedListener(onNavigationItemClicked);
}
private BottomNavigationView.OnNavigationItemSelectedListener onNavigationItemClicked = new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
itemId= item.getItemId();
if(fragmentIds.contains(itemId)){
fragmentIds.remove(itemId);
}
fragmentIds.push(itemId);
showTabWithoutAddingToBackStack(getFragment(item.getItemId()));
return true;
}
};
private Fragment getFragment(int fragmentId) {
switch (fragmentId) {
case R.id.action_home:
return homeFragment;
case R.id.action_favorites:
return favouriteFragment;
case R.id.action_nearme:
return nearmeFragment;
}
return homeFragment;
}
private void showTabWithoutAddingToBackStack(Fragment fragment) {
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, fragment, fragment.getClass().getSimpleName()).commit();
}
#Override
public void onBackPressed() {
if(fragmentIds.getLast() != R.id.action_home){
fragmentIds.addLast(R.id.action_home);
}
fragmentIds.pop();
bottomNavigationView.getMenu().getItem(fragmentIds.size()-1).setChecked(true);
if (!fragmentIds.isEmpty()) {
showTabWithoutAddingToBackStack(getFragment(fragmentIds.peek()));
} else {
finish();
}
}

For Kotlin user may help this code :
First create a FragmentManager extension class
fun FragmentManager.replace(containerId: Int, fragment: Fragment, tag: String) {
var current = findFragmentByTag(tag)
beginTransaction()
.apply {
//Hide the current fragment
primaryNavigationFragment?.let { hide(it) }
//Check if current fragment exists in fragmentManager
if (current == null) {
current = fragment
add(containerId, current!!, tag)
} else {
show(current!!)
}
}
.setTransition(FragmentTransaction.TRANSIT_ENTER_MASK)
.setPrimaryNavigationFragment(current)
.setReorderingAllowed(true)
.commitNowAllowingStateLoss()
}
Now simply call it on your
onNavigationItemSelected
supportFragmentManager.replace(R.id.fragment_id,YourFragmentClass,yourFragment.TAG)

I had the same issue but I resolved it by creating multiple fragment hosts then I added fragments in fragmentHost. And when bottom nav itemSelected I just make the required host fragment visible and other host fragmentsHost to visibility gone.
This method may be wrong but it works perfectly for me.
And we don't have to manually handle the states of fragment only we need to handle backpress of activity.
But this method does not pause the fragments.
And I don't know how to handle the pauses and resumes of fragments so please reply to me.
Maybe This will help you.
This is my fragmentHosts Home Activity:
<androidx.fragment.app.FragmentContainerView
android:id="#+id/homeFragmentHost"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/bottom_NavBar"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:visibility="gone"/>
<androidx.fragment.app.FragmentContainerView
android:id="#+id/libraryFragmentHost"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/bottom_NavBar"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:visibility="gone"/>
<androidx.fragment.app.FragmentContainerView
android:id="#+id/myStuffFragmentHost"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/bottom_NavBar"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:visibility="gone"/>
<androidx.fragment.app.FragmentContainerView
android:id="#+id/moreFragmentHost"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="#+id/bottom_NavBar"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:visibility="gone"/>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/bottom_NavBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:menu="#menu/app_bottom_nav_menu"
tools:ignore="BottomAppBar" />
Home Activity onCreate:
supportFragmentManager.beginTransaction().replace(R.id.homeFragmentHost,HomeFragment()).commitNow()
supportFragmentManager.beginTransaction().replace(R.id.libraryFragmentHost,LibraryFragment()).commitNow()
supportFragmentManager.beginTransaction().replace(R.id.myStuffFragmentHost,MyStuffFragment()).commitNow()
supportFragmentManager.beginTransaction().replace(R.id.moreFragmentHost,MoreFragment()).commitNow()
homeFragmentHost.visibility = View.VISIBLE
Bottom nav Item Selected listener
override fun onNavigationItemSelected(item: MenuItem): Boolean {
return when(item.itemId){
R.id.homeFragment -> loadFragmentHost(homeFragmentHost)
R.id.libraryFragment -> loadFragmentHost(libraryFragmentHost)
R.id.myStuffFragment -> loadFragmentHost(myStuffFragmentHost)
R.id.moreFragment -> loadFragmentHost(moreFragmentHost)
else -> false
}
loadFragmentHost function
private fun loadFragmentHost(view:FragmentContainerView): Boolean {
val list = arrayListOf(homeFragmentHost,libraryFragmentHost,myStuffFragmentHost,moreFragmentHost)
list.remove(view)
view.visibility = View.VISIBLE
list.forEach {
it.visibility = View.GONE
}
return true
}

public class MainActivity extends AppCompatActivity {
boolean doubleBackToExitPressedOnce = false;
final Fragment fragment1 = new HomeFragment();
final Fragment fragment2 = new DashboardFragment();
final Fragment fragment3 = new NotificationsFragment();
final FragmentManager fm = getSupportFragmentManager();
Fragment active = fragment1;
BottomNavigationView navigation;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
setFragment(fragment1, "1", 0);
}
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_home:
setFragment(fragment1, "1", 0);
return true;
case R.id.navigation_dashboard:
setFragment(fragment2, "2", 1);
return true;
case R.id.navigation_notifications:
setFragment(fragment3, "3", 2);
return true;
}
return false;
}
};
public void setFragment(Fragment fragment, String tag, int position) {
if (fragment.isAdded()) {
fm.beginTransaction().hide(active).show(fragment).commit();
} else {
fm.beginTransaction().add(R.id.main_container, fragment, tag).commit();
}
navigation.getMenu().getItem(position).setChecked(true);
active = fragment;
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main_menu, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
startActivity(new Intent(MainActivity.this, SettingsActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onBackPressed() {
if (active == fragment1) {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();
} else {
setFragment(fragment1, "1", 0);
}
}
}
Maintain Bottom sheet fragment Reusable
BackPress Maintain
double back press to exit

public class MainActivity extends AppCompatActivity {
BottomNavigationView bottomNavigationView;
Toaster toaster;
private final Fragment androidFragment = new AndroidFragment();
private final Fragment settingsFragment = new SettingsFragment();
Fragment active;
String TAG = MainActivity.class.getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toaster = new Toaster(this);
bottomNavigationView = findViewById(R.id.bottom_navigation);
renderFragment(androidFragment, "android");
active = androidFragment;
bottomNavigationView.setOnItemSelectedListener(
item -> {
Log.e(TAG, "onCreate: " + active );
if(item.getItemId() == R.id.action_android){
renderFragment(androidFragment, "android");
return true;
}
else if(item.getItemId() == R.id.action_settings){
renderFragment(settingsFragment, "settings");
return true;
}
return false;
}
);
}
private void renderFragment(Fragment fragment, String tag){
FragmentManager fragmentManager = getSupportFragmentManager();
if(fragment.isAdded()){
fragmentManager.beginTransaction().hide(active).show(fragment)
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN).commit();
}
else {
if(active != null){
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container_view, fragment, tag)
.hide(active)
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN).commit();
}
else {
getSupportFragmentManager().beginTransaction()
.add(R.id.fragment_container_view, fragment, tag)
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN).commit();
}
}
active = fragment;
}
}
This worked for me Guys.

Create the three fragments as members of the class and reuse them.
public class MainActivity extends AppCompatActivity {
private final Fragment mFirstFragment = new FirstFragment();
private final Fragment mSecondFragment = new SecondFragment();
private final Fragment mThirdFragment = new ThirdFragment();
#Override
protected void onCreate(Bundle savedInstanceState) {
......
......
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.frameLayout, mFirstFragment);
fragmentTransaction.commit();
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
if (bottomNavigationView.getSelectedItemId() != item.getItemId()) {
switch (item.getItemId()) {
R.id.menu_dialer:
replaceFragment(mFirstFragment);
break;
case R.id.menu_email:
replaceFragment(mSecondFragment);
break;
case R.id.menu_map:
replaceFragment(mThirdFragment);
break;
}
}
return true;
}
});
}
private void replaceFragment(Fragment fragment) {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.frameLayout, fragment);
fragmentTransaction.commit();
}
}

How to open Fragments and Activities in the same function (with drawer layout)?

SO I had this code that allowed me to open fragments through the navigation drawer, but it doesn't allow to open activities:
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
Fragment fragment = null;
Class fragmentClass = null;
if (id == R.id.nav_home) {
Intent homeIntent = new Intent(this, MainActivity.class);
startActivity(homeIntent); //Doesn't Work
} else if (id == R.id.nav_contacts) {
fragmentClass = Contactos.class; //Works
} else if (id == R.id.nav_about) {
fragmentClass = Sobre.class; /Works
} else if (id == R.id.nav_settings){
Intent settingIntent = new Intent(this, SettingsActivity.class); //Doesn't Work
startActivity(settingIntent);
}
try {
fragment = (Fragment) fragmentClass.newInstance();
} catch (Exception e) {
e.printStackTrace();
}
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
DrawerLayout drawer = (DrawerLayout) findViewById(drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
So i searched the web for some other solution, and with this new one I can open activities but can't open fragments :|
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
Fragment fragment = null;
Class fragmentClass = null;
switch (id) {
case R.id.nav_home:
Intent homeIntent = new Intent(this, MainActivity.class); //Works
startActivity(homeIntent);
break;
case R.id.nav_contacts:
fragmentClass = Contactos.class; //Doesn't Work
break;
case R.id.nav_about:
fragmentClass = Sobre.class; //Doesn't Work
break;
case R.id.nav_settings:
Intent settingsIntent = new Intent(this, SettingsActivity.class); //Works
startActivity(settingsIntent);
break;
}
return false;
}
How can I open both things?
Appreciate any help :)

1) You are not replacing your fragmment in your second snippet.
2) You are returning false for onNavigationItemSelected() method. That's why it doesn't work.
#SuppressWarnings("StatementWithEmptyBody")
#Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
FragmentManager fm = getSupportFragmentManager();
switch (id) {
case R.id.nav_home:
Intent homeIntent = new Intent(this, MainActivity.class);
startActivity(homeIntent);
break;
case R.id.nav_contacts:
fm.beginTransaction().replace(R.id.fl_content, new Contactos(), "Tag").commit();
break;
case R.id.nav_about:
fm.beginTransaction().replace(R.id.fl_content, new Sobre(), "Tag").commit();
break;
case R.id.nav_settings:
Intent settingsIntent = new Intent(this, SettingsActivity.class); //Works
startActivity(settingsIntent);
break;
}
DrawerLayout drawer = (DrawerLayout) findViewById(drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
If you are going to the MainActivity, make sure you also have a fl_content Layout in MainActivity.

How to pass data to navigation drawer item?

I am using a nav drawer with three items(Time sheet, claims, project) and I would like to pass ab to claims. In time sheet I have 3 activities, the ab is in the work_details activity.How can I do to achieve this?
TimeSheet has 3 activities (Information(extend to fragment),work force,work details)
Claims has 2 activities(claims(extend to fragment), cameraMain).
WorkDetails.java
Button btn1 = (Button) findViewById(R.id.button2);
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
AlertDialog.Builder builder = new AlertDialog.Builder(WorkDetailsTable.this);
builder.setTitle("Data Saved");
builder.setMessage("Are you sure you want to save?");
builder.setIcon(android.R.drawable.ic_dialog_alert);
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int ii) {
long ab = ts.insertTimeSheet(name, weather, date, status,b,i);
Bundle bundle =new Bundle();
bundle.putString("ab","ab");
Claims o=new Claims();
o.setArguments(bundle);
}
Claims.java
final Long fk=this.getArguments().getLong("ab");
Button button = (Button) claims.findViewById(R.id.button8);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
Intent intent = new Intent(getActivity().getApplicationContext(), CameraMain.class);
Toast.makeText(getActivity().getApplicationContext(), fk+"", Toast.LENGTH_LONG).show();
startActivity(intent);
}
});
return claims;
}
I refer from Send data from activity to fragment in android but the app crashed when I select claims item.
11-02 09:25:55.910 6116-6116/com.example.project.project
E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.project.project, PID: 6116
java.lang.NullPointerException
at com.example.project.project.Claims.onCreateView(Claims.java:59)
at android.app.Fragment.performCreateView(Fragment.java:1700)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:890)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
at android.app.BackStackRecord.run(BackStackRecord.java:684)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1453)
I think the NullPointException is came from here
fk=data.getLong("ab");
Do I need to add the parameter in MainActivity?
MainActivity.java
Some part of code snippet in mainActivity
private void selectItem(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment=new Information();
break;
case 1:
fragment=new Claims();
break;
case 2:
fragment=new Project();
case 3:
fragment=new Report();
case 4:
fragment=new ViewView();
default:
break;
}
if (fragment != null) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
setTitle(mNavigationDrawerItemTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
} else {
Log.e("MainActivity", "Error in creating fragment");
}
EDITED
Button btn1 = (Button) findViewById(R.id.button2);
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
AlertDialog.Builder builder = new AlertDialog.Builder(WorkDetailsTable.this);
builder.setTitle("Data Saved");
builder.setMessage("Are you sure you want to save?");
builder.setIcon(android.R.drawable.ic_dialog_alert);
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int ii) {
long ab = ts.insertTimeSheet(name, weather, date, status,b,i);
Bundle bundle =new Bundle();
bundle.putLong("ab",ab);
Claims o=new Claims();
o.setArguments(bundle);
}
Claims.java
Bundle bundle=this.getArguments();
fk=bundle.getLong("ab");
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getActivity().getApplicationContext(), fk+"", Toast.LENGTH_LONG).show();
AlertDialogRadio(a1);
}
});
MainActivity
private void selectItem(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment=new Information();
break;
case 1:
fragment=new Claims();
break;
case 2:
fragment=new Project();
break;
case 3:
fragment=new Report();
break;
case 4:
fragment=new ViewView();
default:
break;
}
if (fragment != null) {
FragmentManager fragmentManager = getFragmentManager();
if(fragment instanceof Claims)
{
Bundle bundle=new Bundle();
bundle.putString("ab","ab");
fragment.setArguments(bundle);
fragment.setArguments(bundle);
}
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
setTitle(mNavigationDrawerItemTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
} else {
Log.e("MainActivity", "Error in creating fragment");
}
}
}

MainActivity
private void selectItem(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment=new Information();
break;
case 1:
fragment=new Claims();
Bundle bundle=new Bundle();
bundle.putLong("ab",WorkDetails.ab);
fragment.setArguments(bundle);
break;
case 2:
fragment=new Project();
break;
case 3:
fragment=new Report();
break;
case 4:
fragment=new ViewView();
default:
break;
}
if (fragment != null) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
mDrawerList.setItemChecked(position, true);
mDrawerList.setSelection(position);
setTitle(mNavigationDrawerItemTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
} else {
Log.e("MainActivity", "Error in creating fragment");
}
}
}
WorkDetails
public static long ab=-1;//this is flied ,don't put in the method
Button btn1 = (Button) findViewById(R.id.button2);
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
AlertDialog.Builder builder = new AlertDialog.Builder(WorkDetailsTable.this);
builder.setTitle("Data Saved");
builder.setMessage("Are you sure you want to save?");
builder.setIcon(android.R.drawable.ic_dialog_alert);
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int ii) {
ab = ts.insertTimeSheet(name, weather, date, status,b,i);
}

What you can just do is to place this data in your activity where fragment is placed. example is.
in your activity
long ab = 12.4;
in your fragment
long data = ((YourActivity)getActivity()).ab;
"OR"
make ab like
static long ab = value; // your Details activity
in your details activity and get the value of this
with details activity name like
long data = Details.ab //in your claims activity.

When you are instantiating your Claim Fragment , instantiate a bundle object and assign whatever data that you need to be passed in bundle and set it as argument to the fragment.
Bundle bundle = new Bundle();
bundle.putLong("ab",10L);
new Claims().setargument(bundle);
Then in your Claim fragment's onCreateView() you can access this bundle data as
Bundle bundle = getArguments();
long ab = bundle.getLong("ab");

Parsing string during fragment creation

in an application , I wish I would pass a string fragment and display it in a toast.
The problem is with my code, the creation of the fragment I have a toast that appears, but empty ...
I do not understand where did my problem ( it's the first time I try to do that )
My code :
MainActivity :
public class MainActivity extends ActionBarActivity
implements NavigationDrawerCallbacks {
private NavigationDrawerFragment mNavigationDrawerFragment;
private Toolbar mToolbar;
private CharSequence mUrl;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
setSupportActionBar(mToolbar);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getFragmentManager().findFragmentById(R.id.fragment_drawer);
// Set up the drawer.
mNavigationDrawerFragment.setup(R.id.fragment_drawer, (DrawerLayout) findViewById(R.id.drawer), mToolbar);
}
#Override
public void onNavigationDrawerItemSelected(int position) {
Fragment objFragment = null;
switch (position) {
case 0:
Intent intent = new Intent(MainActivity.this, fragment_test.class);
intent.putExtra("message", "test");
objFragment = new fragment_test();
break;
case 1:
objFragment = new menu2_Fragment();
break;
case 2:
objFragment = new menu3_Fragment();
break;
case 3:
objFragment = new menu4_Fragment();
break;
case 4:
objFragment = new menu5_Fragment();
break;
case 5:
objFragment = new menu6_Fragment();
break;
case 6:
objFragment = new menu8_Fragment();
break;
case 7:
objFragment = new menu9_Fragment();
break;
case 8:
objFragment = new menu7_Fragment();
break;
}
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container, objFragment)
.commit();
}
#Override
public void onBackPressed() {
if (mNavigationDrawerFragment.isDrawerOpen())
mNavigationDrawerFragment.closeDrawer();
else
super.onBackPressed();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
if (!mNavigationDrawerFragment.isDrawerOpen()) {
// Only show items in the action bar relevant to this screen
// if the drawer is not showing. Otherwise, let the drawer
// decide what to show in the action bar.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
return super.onCreateOptionsMenu(menu);
}
/*#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
return super.onOptionsItemSelected(item);
}*/}
Fragment_test :
public class fragment_test extends Fragment {
View rootview;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
rootview = inflater.inflate(R.layout.xml1, container, false);
Intent intent = getActivity().getIntent();
String message = intent.getStringExtra("message");
Toast toast = Toast.makeText(getActivity(), message, Toast.LENGTH_LONG);
toast.show();
return rootview;
}}
thx in advance
ps : sorry for my english french

Your code
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.container, objFragment).commit();
Replace with
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.container, objFragment).commit();
Bundle bundle = new Bundle();
bundle.putString(key, value);
objFragment.setArguments(bundle);
Write below code in your another activity
if (getArguments() != null)
{
m_searchText = getArguments().getString(Key);
}

Listview inside Navigational Drawer Not responding to item click android

I am using DrawerLayout which has Listview
When I click on the Listview item , it does not responds to the click ( not launching another activity )
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
//requestWindowFeature(Window.FEATURE_NO_TITLE);
final ActionBar actionBar=getActionBar();
actionBar.setIcon(null);
actionBar.setTitle("");
setContentView(R.layout.main_activity);
// Custom ActionBar initializations.
getActionBar().setCustomView(R.layout.action_bar_custom);
getActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM | ActionBar.DISPLAY_SHOW_CUSTOM | ActionBar.DISPLAY_HOME_AS_UP);
getActionBar().setDisplayUseLogoEnabled(true);
getActionBar().setDisplayShowHomeEnabled(true);
getActionBar().setDisplayShowCustomEnabled(true);
//getActionBar().setIcon(R.drawable.ic_drawer);
// Remember me.
sharedPref=getSharedPreferences("myPref", MODE_PRIVATE);
editor=sharedPref.edit();
//Listview
mDrwawerList=(ListView)findViewById(R.id.list_slidermenu);
listDataHeader = new ArrayList<HashMap<String,String>>();
listDataHeader_temp = new ArrayList<String>();
navigational_adapter=new NavigationListAdapter(MainActivity.this, new ArrayList<HashMap<String,String>>());
mDrawerLayout=(DrawerLayout)findViewById(R.id.drawer_layout);
mDrawerToggle=new ActionBarDrawerToggle(this, mDrawerLayout, R.drawable.nav_btn,0, 0){
public void onDrawerClosed(View drawerView){
getActionBar().setTitle(mTitle);
invalidateOptionsMenu();
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
invalidateOptionsMenu();
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
mDrwawerList.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
TextView txtCategoryName=(TextView)view.findViewById(R.id.txt_category);
String category_name=txtCategoryName.getText().toString();
Log.e("category_name", "karjeevcategory_name "+category_name);
if (category_name.equals("Home")) {
}
else if (category_name.equals("Diamond of the Week")) {
}
else if (category_name.equals("About Us")) {
}
else if (category_name.equals("FAQ")) {
Intent intent=new Intent(MainActivity.this,FAQActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
else if (category_name.equals("Press & Download")) {
}
else if (category_name.equals("Contact Us")) {
}
}
});
new PerformGetCategory().execute();
}

Replace your existing code with this,and create a Intent inside particular position case of listview, if FAQ item is at 5th position, create Intent inside case 4:
mDrawerList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
displayView(position);
}
});
And inside displayView(int position) keep this:
private void displayView(int position) {
switch (position) {
case 0:
break;
case 1:
break;
case 2:
break;
case 3:
break;
case 4:
Intent intent=new Intent(MainActivity.this,FAQActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
break;
case 5:
break;
case 6:
break;
default:
break;
}
}
Hope this solves your problem.

I solved my problem from my end ...
There was layout issues , due to which the listview was not able to handle the click ..
I pasted my litsview code to bottom of the other layout code which was inside DrawerLayout