Develop Reference

Recylerview appends the old result on back pressed

I'm trying to create a application with bottom navigation view, But it looks like it is stacking up the fragments. Let me show you the picture to be clear.
[![Blank screen when back button is clicked again][3]][3]
Here is the code:
Home.xml
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="#+id/bottomfrag"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
/>
<com.google.android.material.bottomappbar.BottomAppBar
android:id="#+id/bottom_app_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:contentInsetStart="0dp"
app:fabAlignmentMode="center">
<com.rawat.soccermatch.CustomBottomNav
android:id="#+id/bottomNavigationView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:itemRippleColor="#android:color/transparent"
app:labelVisibilityMode="labeled"
app:itemIconTint="#color/enable_disable"
app:itemTextColor="#color/enable_disable"
app:menu="#menu/bottom_nav_menu"
app:layout_behavior="#string/hide_bottom_view_on_scroll_behavior" />
</com.google.android.material.bottomappbar.BottomAppBar>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:backgroundTint="#FF9800"
android:contentDescription="#string/title_create"
android:src="#drawable/ic_plusn"
app:tint="#fff"
app:layout_anchor="#id/bottom_app_bar" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Home.java
bt = findViewById(R.id.bottomNavigationView);
loadFragment(new HomeFrag()); // at first home fragment will be loaded
bt.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment mfragment;
int item_id=item.getItemId();
if(item_id==R.id.navigation_home){
mfragment = new HomeFrag();
loadFragment(mfragment);
}
else if(item_id==R.id.navigation_feed){
mfragment = new Feed();
loadFragment(mfragment);
}
else if(item_id==R.id.navigation_create){
mfragment = new creatematch();
loadFragment(mfragment);
}
else if (item_id==R.id.navigation_following){
mfragment = new Following();
loadFragment(mfragment);
}
else {
mfragment = new Account();
loadFragment(mfragment);
}
return true;
}
});
ft = findViewById(R.id.fab);
ft.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
ft.setBackgroundTintList(ColorStateList.valueOf(Color.GREEN));
ft.setRippleColor(Color.GREEN);
Fragment fragment = new creatematch();
bt.getMenu().findItem(R.id.navigation_create).setChecked(true);
loadFragment(fragment);
}
});
}
private void loadFragment(Fragment fragment) {
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.bottomfrag, fragment);
transaction.addToBackStack(null);
transaction.commit();
}
Should I post HomFrag Code too?
I have edited the question now the problem which I understand is when clicking back my Home Fragment is resuming from where it was left but the recylerview values are resetting and appends the new results with old. Also the ripple color is not changing from following to home.

Try to use this function instead of yours
public void loadFragment(Fragment fragment) {
try {
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction ft = manager.beginTransaction();
manager.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
ft.addToBackStack(null);
ft.replace(R.id.bottomfrag, fragment);
ft.commit();
} catch (Exception e) {
e.printStackTrace();
}
}

you are adding that fragment to backstack so when you click back detach it, you need to make sure that your fragment is not added to backstack

Override onBackPressed() method. Inside it you can check what section is opened at the current moment and what you want to do in this case (nothing/close the app/navigate to another section).

in the bottom navigation activity you have to set default fragment is select which fragment you want for eg in common Home fragment always show as a default fragment so set homefragment as default.
set these code on create
bottomNavigationView.setSelectedItemId(R.id.nav_home);
checkon backpress
#Override
public void onBackPressed() {
if (getSupportFragmentManager().getBackStackEntryCount() == 1) {
finish();
} else {
super.onBackPressed();
}
}

Bottom Navigation View gets Shrink Down

I have made an app with bottom navigation view with Promo, Store, Reward, Coupon and Account tabs when I am changing from Coupon fragment to any other fragment, the bottom navigation view gets shrunk down as shown in the image, I tried changing layout width, height and converting coordinator layout to linear layout but it didn't help. The problem is occurring when I'm switching from home to any other tab only.
Layout File activity_main.xml
<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/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activity.MainActivity">
<FrameLayout
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="56dp"
android:text="#string/title_home"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.design.widget.BottomNavigationView
android:id="#+id/navigation"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginEnd="0dp"
android:layout_marginStart="0dp"
android:background="#color/white"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:itemTextColor="#color/selector_bottom_navigation"
app:itemIconTint="#color/selector_bottom_navigation"
app:menu="#menu/navigation" />
Java File MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//loading the default fragment
loadFragment(new PromoFragment());
//getting bottom navigation view and attaching the listener
BottomNavigationView navigation = findViewById(R.id.navigation);
BottomNavigationViewUtils.disableShiftMode(navigation);
navigation.setOnNavigationItemSelectedListener(this);
}
#Override
public boolean onCreatePanelMenu(int featureId, Menu menu) {
getMenuInflater().inflate(R.menu.menu_wallet, menu);
return super.onCreatePanelMenu(featureId, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.menu_wallet1:
return true;
case R.id.menu_qrcode:
Intent intent = new Intent(this, ScannerActivity.class);
startActivity(intent);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment fragment = null;
switch (item.getItemId()) {
case R.id.navigation_promo:
fragment = new PromoFragment();
break;
case R.id.navigation_store:
fragment = new StoreFragment();
break;
case R.id.navigation_reward:
fragment = new RewardFragment();
break;
case R.id.navigation_coupon:
fragment = new CouponFragment();
break;
case R.id.navigation_account:
fragment = new AccountFragment();
break;
}
return loadFragment(fragment);
}
private boolean loadFragment(Fragment fragment) {
if (fragment != null) {
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.fragment_container, fragment)
.commit();
return true;
}
return false;
}
This is the picture I meant:
I previously added SearchView to the coupon fragment and fragment store

It turns out that if you are using a coordinator layout and viewpager inside a fragment, you will notice that the viewpager extends the screen a bit. Just disable the scroll features of the coordinator layout inside the fragment and you will notice the bottom bar doesn't get shrunk. Weird I know, but it works.

I add android:fitsSystemWindows="false" in CoordinatorLayout and it worked

Find android:fitsSystemWindows="true" in your fragment xml and remove this line
or change it to android:fitsSystemWindows="false". Your problem will be solved.

Replacing fragments dynamically?

Now I know this is a very simple question and was asked many times, but non of the solutions provided previously has worked for me.
I have an activity with a FrameLayout as follows:
<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"
tools:context=".MainActivity">
<FrameLayout
android:id="#+id/replace_me"
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.constraint.ConstraintLayout>
And in my MainActivity class I have the following:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
replaceFragment(new ChooseLevelFragment(), false);
}
}
public void replaceFragment(Fragment fragment, boolean addToBackStack) {
FragmentTransaction replace = getSupportFragmentManager().beginTransaction().replace(R.id.replace_me, fragment);
if (addToBackStack) {
replace.addToBackStack(null);
}
replace.commit();
Log.d(TAG, "Fragment replaced!");
}
The first fragment is being shown correctly. However, when the user clicks on an item from the menu and logs in, the app should replace the current fragment with the new one
private void showAuthenticationDialog() {
FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
Fragment fragmentByTag = getSupportFragmentManager().findFragmentByTag(AuthenticationDialogFragment.TAG);
if (fragmentByTag != null) {
fragmentTransaction.remove(fragmentByTag);
}
fragmentTransaction.addToBackStack(null);
AuthenticationDialogFragment authenticationDialogFragment = AuthenticationDialogFragment.newInstance(() -> {
replaceFragment(new ParentControlPanelFragment(), true);
});
authenticationDialogFragment.show(fragmentTransaction, AuthenticationDialogFragment.TAG);
}
The new fragment is not being replaced even after the commit. I can see my log message but not the new fragment. I'm not quite sure where the problem is.

The problem was that I was trying to replace the fragment before I dismiss the dialog.
The correct approach is to dismiss the dialog first then try to replace the fragment.

FragmentManager replace not working?

I am having a hard time figuring out why my FragmentManager isn't working.
I'm using an Android studio template for nav drawer activity. The most confusing thing is, I have the exact same code in another app and it works just fine.
Here is the code:
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
int id = item.getItemId();
Fragment fragment = null;
switch (id) {
case R.id.nav_camera:
fragment = new MyFragment();
Log.i("ID", String.valueOf(id));
break;
case R.id.nav_gallery:
break;
}
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.content_main, fragment)
.commit();
DrawerLayout drawer = findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
Now, when I click on the nav_camera it logs the click just fine, but nothing else happens, the fragment doesn't get replaced. No errors, no exceptions, just the same screen over and over.
Fragment code, nothing here just testing:
public class MyFragment extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_list, container, false);
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
}
Fragment layout, just a blank:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
The rest of the code is auto generated by andorid studio.
Here is content_main, which I am trying to replace with fm:
<LinearLayout 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:id="#+id/content_main"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="com.example.goran.mymoviedb.movies.MainActivity"
tools:showIn="#layout/app_bar_main">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
It should replace the layout with a blank one whan nav_camera is clicked but nothing happens, even though correct click is registered.

Actually your code is working but the issue is that you have blank layout and because background of fragment layout is by default transparent you can not see the change. Put background color on your root layout of fragment (LinearLayout) for example: android:background="#android:color/white"
and you will see fragement replacement.

Drawing fragment over main activity

I am new to developing android applications, so please pardon any stupid mistakes that I may have made. On to the question:
I am making an application which has its main activity layout screen containing some stuff and have a navigation drawer wired in. Now I am trying to use the entries in the navigation drawer to call up various fragments and display them over my main activity. However when I run my piece of code, I am getting an Activity Destroyed error I have attached my code below for reference. I think the problem is with what I have done with the container. To make the fragment cover the whole screen of my main activity, I gave the fragment container as the root layout as I was unsure how to go about this.
Code which handles item clicks from navigation drawer
class DrawerItemClickListener extends FragmentActivity implements ListView.OnItemClickListener {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
private void selectItem(int position) {
Fragment mFragment = null;
switch(position) {
case 0:
mFragment = new AnnouncementFragment();
Bundle args = new Bundle();
args.putInt(null, position);
break;
case 1:
break;
case 2:
break;
case 3:
break;
default:
break;
}
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction().replace(R.id.drawer_layout, mFragment);
transaction.commit();
transaction.addToBackStack(null);
}
Code for fragment
public class AnnouncementFragment extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_announcement, container, false);
}
XML layout of main activity
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:id = "#+id/main_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/screen_login"
android:gravity="center"
android:textColor="#android:color/holo_blue_light"
android:id="#+id/login_tv"
android:layout_alignParentTop="true"
android:layout_marginTop="105dp"
android:layout_alignParentEnd="true"
android:layout_alignParentStart="true"
android:textSize="40sp" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/username_et"
android:layout_below="#id/login_tv"
android:layout_alignParentStart="true"
android:layout_marginTop="45dp"
android:layout_alignParentEnd="true"
android:hint="#string/username"/>
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:ems="10"
android:id="#+id/editText2"
android:layout_below="#id/username_et"
android:layout_alignParentStart="true"
android:layout_marginTop="30dp"
android:layout_alignParentEnd="true"
android:hint="#string/password" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/login"
android:id="#+id/login_btn"
android:layout_below="#+id/editText2"
android:layout_centerHorizontal="true"
android:layout_marginTop="25dp" />
</RelativeLayout>
<ListView
android:id="#+id/drawer_list"
android:layout_width="200dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#ffeeeeee"/>
Error
java.lang.IllegalStateException: Activity has been destroyed
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1399)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:637)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:616)
at com.it.learnera.DrawerItemClickListener.selectItem(DrawerItemClickListener.java:40)
at com.it.learnera.DrawerItemClickListener.onItemClick(DrawerItemClickListener.java:19)
I am wondering how I can make the fragment draw over the main activity layout without causing a mess
Cheers and Thanks in advance

FragmentTransaction transaction = getSupportFragmentManager()
.beginTransaction()
.replace(R.id.drawer_layout, mFragment); // < - first problem ( see ad. 1)
.commit() // <- third problem (see ad. 3)
// second problem ( see ad. 2)
mFragment = new AnnouncementFragment();
Bundle args = new Bundle();
args.putInt(null, position);
ad 1. You replacing DrawerLayout instead of its container
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- The main content view -->
<FrameLayout
android:id="#+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<!-- The navigation drawer -->
<ListView android:id="#+id/left_drawer"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp"
android:background="#111"/>
drawer_layou - this is a view which holds:
FrameLayout / with id - >content_frame
( container capable to hold "only" one element: fragment / view)
ListView / with id - > left_drawer
( list view for example with menu entries )
so you need replace content_frame
ps to better see purpose of transaction you should call it in one statement - in "chain / sequence "
FragmentTransaction transaction = getSupportFragmentManager()
.beginTransaction()
.replace(R.id.frame_layout, mFragment)
.addToBackStack(null) // add to manager " will remember this fragment - for navigation purpose"
.commit() // commit mean do everything from top to bottom on next pass
ad 2. you need also put args in fragment:
mFragment = new AnnouncementFragment();
Bundle args = new Bundle();
args.putInt(null, position);
mFragment.setArguments(args)
ad 3. You calling commit when activity is after onSaveInstanceState
Note:
A fragment transaction can only be created/committed prior to an activity saving its state.
If you try to commit a transaction after:
Activity.onSaveInstanceState()
and prior to a following
Activity.onStart()
Activity.onResume()
you will get an error. This is because the framework takes care of saving your current fragments in the state, and if changes are made after the state is saved then they will be lost.
After FragmentTransaction is committed with FragmentTransaction.commit() is scheduled to be executed asynchronously on the process's main thread.
If you want to immediately executing any such pending operations, you can call this function (only from the main thread) to do so. Note that all callbacks and other related behavior will be done from within this call, so be careful about where this is called from.
boolean executePendingTransactions();
which return true if there were any pending transactions to be executed.
btw look at this docs which refers to extending an FragmentActivity:
https://developer.android.com/reference/android/support/v4/app/FragmentActivity.html
i don't know which api you target but you may also check this bug:
http://johnfeng.github.io/blog/2015/05/31/fragment-activity-has-been-destoryed-problem/
( problem with child fragment which state is not being reset )
Hi, appreciate the detailed explanation but it doesnt work – Prejith P
and this article about state loss which is i think related to your problem
http://www.androiddesignpatterns.com/2013/08/fragment-transaction-commit-state-loss.html
so you can try call instead of commit() (but this is not solution):
commitAllowingStateLoss()
Hi, I fixed it myself just now. I changed the implementation of my navigation drawer a bit and it just started working. I have no idea how it got fixed, which is why I haven't posted an answer here – Prejith P
YES - the problem was your implementation you have tried to call commit() after an activity instance was destroyed what is indicating by stack trace
java.lang.IllegalStateException: Activity has been destroyed
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1399)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:637)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:616)
at com.it.learnera.DrawerItemClickListener.selectItem(DrawerItemClickListener.java:40)
at com.it.learnera.DrawerItemClickListener.onItemClick(DrawerItemClickListener.java:19)
`
when You call commit() you should ensure that:
activity is attached
activity is visible ( before onSaveInstanceState )

The problem is that you're calling transaction.addToBackStack(null); after you commit the replacement. I suggest you to do as follow:
getSupportFragmentManager().beginTransaction()
.replace(R.id.drawer_layout, mFragment).addToBackStack(null).apply();

u need a fragment to fragment communication
class DetailActivity extends
AppCompatActivity implements BioDetailClickView {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setNavigationIcon(R.drawable.navigation);
setSupportActionBar(toolbar);
FragmentManager fm = getSupportFragmentManager();
Fragment fragment = fm.findFragmentById(R.id.fragment_container);
if (fragment == null) {
fragment = new Fragment1();
fm.beginTransaction()
.add(R.id.fragment_container, fragment)
.commit();
}
}
public void fragment_transaction(Fragment fragment){
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
#Override
public void onClickFragmentQuick() {
Fragment frag= new Fragment1();
fragment_transaction(frag);
}
#Override
public void onClickFragment2() {
Fragment fragment =new Fragment2();
fragment_transaction(fragment);
}
#Override
public void onClickFragment3() {
Fragment fragment =new Fragment3();
fragment_transaction(fragment);
}
public interface BioDetailClickView {
void onClickFragment1();
void onClickFragment2();
void onClickFragment3();
}