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One part of Fragment layout is not showing in Activity

I have 2 fragments in Main Activity when I click on first fragment's FAB it will be replaced with the second fragment, when I pressed back button in Fragment 2nd it will back on Fragment 1st, but it not show one big part of the layout, look this images to understand the problem:
1: When the app launched
2: when I pressed back button in 2nd fragment and cames back to 1st fragment
In 1st fragment xml I have 3 part main Item:
<androidx.coordinatorlayout.widget.CoordinatorLayout
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"/>
<com.google.android.material.appbar.AppBarLayout>
...
</com.google.android.material.appbar.AppBarLayout>
<androidx.core.widget.NestedScrollView>
...
</androidx.core.widget.NestedScrollView>
<com.google.android.material.floatingactionbutton.FloatingActionButton/>
</androidx.coordinatorlayout.widget.CoordinatorLayout >
actually, NestedScrollview and its subItems Not show when I came back from 2nd fragment to 1st fragment.
In Fragment 1st I start Fragment 2nd with these codes:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_first, container, false);
FloatingActionButton fab = view.findViewById(R.id.fabAddWord);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
getFragmentManager()
.beginTransaction()
.addToBackStack(TAG)
.replace(R.id.fragment_container, SecondFragment.newInstance(),
WordSearchFragment.class.getSimpleName())
.commit();
}
});
return view;
}

you should override the onBackPressed and show the first fragment when the back button pressed
#Override
public void onBackPressed() {
if (getFragmentManager().getBackStackEntryCount() > 1)
getFragmentManager().popBackStack();
else
super.onBackPressed();
}

After 2 days I solved the problem, The problem Was for FrameLayout That I used as Fragment Container. I learned Use FrameLayout as Container and see in everywhere that people use Framelayout, but in fact, FrameLayot not adapted for complex Layout Fragments.
So in MainActivity.xml, I changed FrameLayout To ConstraintLayout and worked!

Interacting with hidden fragment - Android

I'm adding fragments to my activity in way that I first hide current fragment and then add new one. My problem is that when I show my new fragment and start interacting with him, it also interacts with previous one.
The code which I use to add new and hide current fragment is:
public void add(int containerViewId, Fragment fragment, boolean addToBackStack){
FragmentTransaction ft = fragmentManager.beginTransaction().hide(currentFragment).add(containerViewId, fragment);
if (addToBackStack){
ft.addToBackStack(null);
}
ft.commit();
currentFragment = fragment;
backStackCount++;
}
What is going on, and how to hide fragment so I can interact only with the last one added? replace is not an option because I don't want to remove current fragment.

I also had similar problem. I don't know what possibly is creating this issue but what I did to resolve it is that I set an onclick listener to the outermost layout of my fragment.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/top_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
android:clickable="false"
android:orientation="vertical"
tools:context=".Fragments.TopicsFragment">
...other components
</LinearLayout>
In fragment:
LinearLayout topLayout = (LinearLayout) fragmentView.findViewById(R.id.top_layout);
topLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//do nothing
}
});
Also you might see I have added a background #FFFFFF to this outermost layout, because in mycase the content of previous fragment was also visible behind the new one. So this solved that problem too.

ViewPager Fragments are not recreated after FragmentTransaction.replace() followed by back button

I am trying to implement saving and restoring state, but I am running into problems when replacing the main Fragment with a PreferenceFragment and then hitting the back button. My main Fragment consists of a ViewPager with a FragmentPagerAdapter with 3 Fragments to swipe through. None of the Fragment.onCreateView() callbacks for my 3 Fragments are invoked after hitting the back button. I have tried all the solutions I have come over here on SO, but I have not been able to resolve the issue.
Another possibly important thing to note is that the data for my 3 ViewPager Fragments are stored in separate classes which are instanced and accessible through the Activity. The 3 Fragments all contain RecyclerViews for listing a fair amount of data. This is done for cleanliness, but also so that these data persist in the Activity. This is probably not an issue, since it works fine when starting the app, but also since the main issue is that my Fragments are not recreated.
Unexpected behavior:
On application creation, everything works fine, but when I replace my main Fragment (containing a ViewPager with a FragmentPagerAdapter) with another one and then pressing the back button, the Fragments in the ViewPager are not recreated. The onCreateView() of my main Fragment is called.
Questions:
What am I missing? Is there some other callbacks that should be created? Where and how should I recreate the Fragments?
What have I tried:
Changed the FragmentAdapter in use, but I should really use getSupportFragmentManager() as was the solution here.
EDIT: Use of erroneous FragmentManager actually was the source of my troubles. See my answer below.
Add
#Override public int getItemPosition(Object object) {return POSITION_NONE;} to the FragmentPagerAdapter, as suggested here.
Change from FragmentPagerAdapter to FragmentStatePagerAdapter which should not matter here, as far as I understand. The internals of FragmentStatePagerAdapter actually keeps the Fragments, but they are not rendered anew.
Add the main Fragment back using a FragmentTransaction when its onCreateView() is called and in several of the other callbacks of that Fragment, see MMMainFragment below.
Various other things.
My MainFragment class with corresponding XML layout
public class MMMainFragment extends Fragment
{
private MMViewPager mMMViewPager = null;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Note that this method IS called when the back button is pressed.
// I have tried setting the content back to this instance in several places.
View view = inflater.inflate(R.layout.mm_main_fragment, container, false);
// Setup ViewPager.
mMMViewPager = (MMViewPager) view.findViewById(R.id.mm_pager);
TabLayout tabLayout = (TabLayout) view.findViewById(R.id.mm_tablayout);
tabLayout.setupWithViewPager(mMMViewPager);
return view;
}
public MMViewPager getMMViewPager()
{
return mMMViewPager;
}
}
mm_main_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.design.widget.TabLayout
android:id="#+id/mm_tablayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="scrollable" />
<com.mycompany.myapp.gui.mmpager.MMViewPager
android:id="#+id/mm_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1" />
</LinearLayout>
Then, in Activity.onCreate() i simply do:
// Insert Main Fragment.
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.mm_content_frame, new MMMainFragment())
.commit();
where mm_content_frame is a FrameLayout where I replace and remove Fragments. Then, when a button to view the preferences are pushed, I run the following snippet below in the Activity. I add this Fragment to the backstack to be able to use the back button.
public void showSettingsFragment()
{
getSupportActionBar().setTitle(getString(R.string.mm_drawer_settings));
getSupportFragmentManager().beginTransaction()
.replace(R.id.mm_content_frame, new MMPreferencesFragment(), FragmentConstants.SETTINGS_FRAGMENT_TAG)
.addToBackStack(null)
.commit();
}
The MMViewPager clas:
public class MMViewPager extends ViewPager
{
private MMActivity mMMActivity;
private MMPagerAdapter mMMPagerAdapter;
public MMViewPager(Context context, AttributeSet attrs)
{
super(context, attrs);
mMMActivity = (MMActivity) context;
mMMPagerAdapter = new MMPagerAdapter(mMMActivity.getSupportFragmentManager(), mMMActivity);
this.setOffscreenPageLimit(PagerConstants.OFFSCREEN_PAGE_LIMIT);
this.setAdapter(mMMMPagerAdapter);
this.setCurrentItem(PagerConstants.PAGE_FILTER_RECIPES);
}
}
The MMPagerAdapter class, currently a FragmentStatePagerAdapter:
public class MMPagerAdapter extends FragmentStatePagerAdapter
{
private MMActivity mMMActivity;
public MMPagerAdapter(FragmentManager fragmentManager, MMActivity mmActivity)
{
super(fragmentManager);
mMMActivity = mmActivity;
}
#Override
public Fragment getItem(int position)
{
switch (position)
{
case PagerConstants.PAGE_FILTER_RECIPES:
return new FilteredRecipesFragment();
case PagerConstants.PAGE_SELECTED_RECIPES:
return new SelectedRecipesFragment();
case PagerConstants.PAGE_SHOPPING_LIST:
return new ShoppingListFragment();
default:
return null;
}
}
#Override
public int getCount()
{
return PagerConstants.NUMBER_OF_PAGES; // 3
}
#Override
public CharSequence getPageTitle(int position)
{
switch (position)
{
case PagerConstants.PAGE_FILTER_RECIPES:
return mMMActivity.getResources().getString(R.string.mm_title_recipe_filter_fragment);
case PagerConstants.PAGE_SELECTED_RECIPES:
return mMMActivity.getResources().getString(R.string.mm_title_selected_recipes_fragment);
case PagerConstants.PAGE_SHOPPING_LIST:
return mMMActivity.getResources().getString(R.string.mm_title_shopping_list_fragment);
default:
return "Tab";
}
}
}
For reference, here is also the main layout of the Activity:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/mm_drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- Source: http://developer.android.com/training/implementing-navigation/nav-drawer.html -->
<!-- The main content view -->
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- Source: http://android-developers.blogspot.in/2014/10/appcompat-v21-material-design-for-pre.html -->
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/mm_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?attr/actionBarSize"
android:layout_alignParentTop="true"
style="#style/MMActionBar"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light" />
<!-- The FrameLayout where I replace Fragments -->
<FrameLayout
android:id="#+id/mm_content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/mm_toolbar"/>
</RelativeLayout>
<ListView
android:id="#+id/mm_drawer_listview"
android:layout_width="260dp"
android:layout_height="match_parent"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingStart="16dp"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp"
android:background="#color/mm_white" />
</android.support.v4.widget.DrawerLayout>

After struggling with this for a few days I realized that the problem actually was that I passed the wrong FragmentManager to the ViewPager. It is indeed the FragmentManager returned by Fragment.getChildFragmentManager() that should be used. This makes sense, since it is the Fragment itself that stores the state of the child Fragments in the ViewPager. I am not sure why I couldn't make that work before, but now the LifeCycle of the app works fine with the following setup in my main Fragment's onCreate() method:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.mm_main_fragment, container, false);
mMMActivity = (MMActivity) container.getContext();
mMMActivity.getSupportActionBar().setTitle(getString(R.string.mm_toolbar_title_main_fragment));
// Setup ViewPager.
mViewPager = (ViewPager) view.findViewById(R.id.mm_pager);
mAdapter = new MMPagerAdapter(getChildFragmentManager(), mMMActivity); // <-- This is the key
mViewPager.setAdapter(mAdapter);
mViewPager.setOffscreenPageLimit(PagerConstants.OFFSCREEN_PAGE_LIMIT);
mViewPager.setCurrentItem(PagerConstants.PAGE_FILTER_RECIPES);
// Setup TabLayout.
TabLayout tabLayout = (TabLayout) view.findViewById(R.id.mm_tablayout);
tabLayout.setupWithViewPager(mViewPager);
return view;
}
This was also the solution of another question. As a side note, I use this solution to get the Fragments in my ViewPager and it works just fine with the LifeCycle.
Test Application:
In the research of this issue I created a test application for this. The ones interested can clone it from here. It has ugly colors.

As far as, I understand you have solved your problem. I have faced a quite similar issue in the past. Maybe this help others trying something similar.
The thing that helped me in order to retain my fragment state was to replace the
#Override
public Fragment getItem(int position)
{
switch (position)
{
case PagerConstants.PAGE_FILTER_RECIPES:
return new FilteredRecipesFragment();
case PagerConstants.PAGE_SELECTED_RECIPES:
return new SelectedRecipesFragment();
case PagerConstants.PAGE_SHOPPING_LIST:
return new ShoppingListFragment();
default:
return null;
}
}
method of my adapter.
I change the Adapter so as to keep a HashMap of Fragment. This way the fragments are created once and then retrieved from the HashMap. Depending on your structure you can use an ArrayList instead of the HashMap.
This is done in an efficient and "smart" way of implementing getItemPosition(Object object) to return POSITION_NONE; or the proper position of the item.
I don't really remember if I had the getChildFragmentManager in the adapter or not.
I guess that I could dig into my filesystem if you need further information :)

Android: how to add another fragment to the main activity

I asked a question about how to add a Fragment that contained something drawn using OpenGL ES
here. Someone was kind enough to answer that for me, but unfortunately today I encountered another problem. As I mentioned in my other question, my purpose is to add other Fragments next to the one that contains OpenGL and because I am a beginner in Android development I don't seem to understand how this is done.
Here's what I want: right now, my code is exactly the one from my other question. I also have this Fragment:
public class TextFragment extends Fragment
{
private TextView textview;
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.text_fragment,
container, false);
textview = (TextView) view.findViewById(R.id.textView1);
return view;
}
}
together with its layout:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/frag2">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="Fragment Two"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
and I want to add this to my main activity, where right now I only have the OpenGL Fragment. Here's my main activity:
public class FragmentExampleActivity extends FragmentActivity implements ToolbarFragment.ToolbarListener
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener()
{
public void onBackStackChanged()
{
int backCount = getSupportFragmentManager().getBackStackEntryCount();
if (backCount == 0)
{
finish();
}
}
});
if (savedInstanceState == null)
{
getSupportFragmentManager()
.beginTransaction()
.add(R.id.main_container, new OpenGLES20ActivityFrag())
.addToBackStack(null)
.commit();
}
}
}
and the Fragment that has OpenGL in it and that I have already added to the main activity:
public class OpenGLES20ActivityFrag extends Fragment
{
private GLSurfaceView mGLView;
public OpenGLES20ActivityFrag()
{
super();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
mGLView = new MyGLSurfaceView(this.getActivity());
return mGLView;
}
}
What I tried and failed: using another call to the .add method inside getSupportFragmentManager() or adapting this bit of code for my second Fragment
getSupportFragmentManager()
.beginTransaction()
.add(R.id.frag2, TextFragment)
.addToBackStack(null)
.commit();
that gave me an 'expression expected' error in the add method. I tried adding this constructor to my second Fragment
public TextFragment()
{
super();
}
and then inside the add method I put .add(R.id.frag2, new TextFragment())
which still didn't work.

In order to dynamically add a Fragment to a layout, what you need is a container (like in your case, it was R.id.main_container). Thus, if you want to add multiple fragments, what you need is multiple containers, like so:
<LinearLayout android:orientation="vertical" android:layout_height="fill_parent" android:layout_width="fill_parent">
<FrameLayout android:id="#+id/main_container_1" android:layout_weight="1" android:layout_height="fill_parent" android:layout_width="fill_parent"/>
<FrameLayout android:id="#+id/main_container_2" android:layout_weight="1" android:layout_height="fill_parent" android:layout_width="fill_parent"/>
</LinearLayout>
(this snippet is from How to split the screen with two equal LinearLayouts? )
And then you would need to add the two Fragments:
if (savedInstanceState == null)
{
getSupportFragmentManager()
.beginTransaction()
.add(R.id.main_container_1, new OpenGLES20ActivityFrag())
.commit();
getSupportFragmentManager()
.beginTransaction()
.add(R.id.main_container_2, new TextFragment())
.commit();
}
Please note that with multiple Fragments on a single Activity, it's better not to add them to the backstack, because then you'd have to press Back as many times as there are Fragments, and in this case it's more reasonable to navigate between the "views" or states of the application with Activities, and not by replacing the Fragments.
(considering the backstack doesn't change, I don't think the backstack listener needs to be removed, but that's done so that if you press Back, you don't end the Activity, but the Fragments within it first if you have them added to the backstack. But the Activity doesn't end when it contains no fragments, and you'd have an "empty view", hence why that was added.)
Please also check if the rotation works and data is maintained even after the activity reconstruction, because there's a chance you need to set the retain instance state to true explicitly on the Fragments for that to work.

Previous fragment visible under the new fragment

I have a tab + ViewPager layout and in one of these tabs I have a list view. When I replace that list fragment upon the onclick I can still see the old fragment under the new fragment. See:
Code:
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction transaction = fragmentManager.beginTransaction();
HallsInStateFragment hallsForState = new HallsInStateFragment();
transaction.replace(R.id.container, hallsForState);
transaction.addToBackStack(null);
transaction.commit();
where the R.id.container is the FrameLayout in the view.

when need to remove all views from the parent view you need to call removeAllViews() at container in your onCreateView() method of your fragment.
Here is the code:
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
container.removeAllViews(); // Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_example, container, false);
}

Instead of R.id.container put id of fragment like this: ((ViewGroup)getView().getParent()).getId(). Actually it is not replacing the fragment but the previous layout i.e FrameLayout. It works for me and i hope it will work in your case also.

Add this to both fragment parent layout
android:background="#android:color/white".
The one which you are replacing and one which you will replace.

The fragment's UI is a part of the activity view hierarchy. So if you created your views in onCreateView() method then you inflate your layout using the ViewGroup container. This container keeps references to your fragment views. Try to override onDestroyView() method of your fragment and remove all the views from the parent:
#Override
public void onDestroyView() {
//mContainer.removeAllViews();
ViewGroup mContainer = (ViewGroup) getActivity().findViewById(R.id.container);
mContainer.removeAllViews();
super.onDestroyView();
}

Your fragments should be loaded in FrameLayout like this
<FrameLayout
android:id="#+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="?android:windowBackground" />
And your fragments should be added/loaded in this frameLayout by this function
private fun switchFragment(
fragment: Fragment,
addToBackstack: Boolean
) {
//check new fragment is alredy loaded currently, then return
val myFragment =
supportFragmentManager.fragments.lastOrNull()//return current visible fragment or null
if (myFragment != null && fragment::class == myFragment::class) {
return
}
val fragmentManager = supportFragmentManager
val transaction = fragmentManager.beginTransaction()
//transaction.add(R.id.frameLayout, fragment, fragment.javaClass.name)
transaction.replace(
R.id.frameLayout,
fragment,
fragment.javaClass.name
)//using replace will make sure that the previous fragment won't be visible from new fragment
if (addToBackstack) {
transaction.addToBackStack(fragment.javaClass.name)
}
transaction.commit()
}
So initially, your first fragment should be loaded like this,
switchFragment(HomeFragment(), false)
and then other fragments when you select from bottom navigation view or navigation drawer, call this function like this
switchFragment(MyProfileFragment(), true)

In My Case , This was happening because I was using the static fragment as
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<fragment
android:name="com.example.android.FooFragment"
android:id="#+id/fooFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
where foofragment is the initial fragment , Then Trying to replace the fragment using with other fragment , so that both fragment overlaps.
Instead , Problem is solved , when I used dynamic Linkage , in place of fragment in the xml , we need to use framelayout as
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout
android:id="#+id/your_placeholder"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</LinearLayout>
Then dynamically adding the fragment-1 and replacing with the fragment-2 , is working fine for me.
I did not find answer earlier, hence posting this solution.

In the root view add clickable = true and add a background color(both in the xml) of the fragment replacing the current fragment .
Its just a fix for workaround

Best code for it. clearly and not used another ram of device.
on you Activity onCreate or before adding fragments add this code:
for (Fragment fragment : getSupportFragmentManager().getFragments()) {
if (fragment instanceof NavigationDrawerFragment) {
continue;
}
else if (fragment != null) {
getSupportFragmentManager().beginTransaction().remove(fragment).commit();
}
}
Happy coding :)