I have an app am working on, the app is using leak canary to detect possible memory leaks. The app seems to be fine except for my extended floating action button, according to leak canary the button is leaking, I do not have an idea on how to rectify this.
Below is my XML
<?xml version="1.0" encoding="utf-8"?>
<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:id="#+id/coordinator"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".fragments.store.StoreFragment">
<com.google.android.material.card.MaterialCardView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="#dimen/small_margin"
app:cardElevation="#dimen/normal_elevation"
app:shapeAppearanceOverlay="#style/ShapeAppearanceOverlayLargeCutLeftTopCorner">
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:id="#+id/swipeToRefresh"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<androidx.core.widget.NestedScrollView
android:id="#+id/nestScrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fadingEdge="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ViewStub
android:id="#+id/layoutCategories"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inflatedId="#+id/panel_layoutCategories"
android:layout="#layout/store_layout_categories" />
<ViewStub
android:id="#+id/layoutDeals"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inflatedId="#+id/panel_layoutDeals"
android:layout="#layout/store_layout_deals" />
<ViewStub
android:id="#+id/layoutCollections"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inflatedId="#+id/panel_layoutCollections"
android:layout="#layout/store_layout_collections" />
</LinearLayout>
</androidx.core.widget.NestedScrollView>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</com.google.android.material.card.MaterialCardView>
<com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
android:id="#+id/btnGoToCart"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:text="#string/cart"
android:textColor="#android:color/white"
android:textStyle="bold"
app:backgroundTint="#color/colorAccent"
app:elevation="#dimen/large_elevation"
app:icon="#drawable/ic_shopping_cart_24px"
app:iconTint="#android:color/white"
app:layout_anchor="#id/nestScrollView"
app:layout_anchorGravity="bottom|end"
app:shapeAppearanceOverlay="#style/ShapeAppearanceOverlayLargeCutLeftTopCorner" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
And my Java code
public class StoreFragment extends Fragment implements View.OnClickListener {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_store, container, false);
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
ButterKnife.bind(this, view);
btnGoToCart.setOnClickListener(this);
}
#Override
public void onClick(View v) {
switch (v.getId()) {
....
case R.id.btnGoToCart:
Navigation.findNavController(v).navigate(R.id.cartFragment);
break;
....
}
}
}
Below is a snippet from leak canary. At first the leak was pointing to the ID of the coordinator layout, I removed it, now it is pointing to the Extended floating action button.
Instead of having the Fragment implement OnClickListener why not just create a new OnClickListner inner class? From what I see you ar passing the fragment as the OnClickListener and the view later holds a reference to your fragment and that's probably the cause of the leak. Just do (new OnClickListener () {}); instead of implementing OnClickListener.
EDIT:
I've just noticed that you are using ButterKnife in a Fragment.
If your using ButterKnife in a Fragment you should use:
private Unbinder unbinder;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fancy_fragment, container, false);
unbinder = ButterKnife.bind(this, view);
// TODO Use fields...
return view;
}
#Override public void onDestroyView() {
super.onDestroyView();
unbinder.unbind();
}
BINDING RESET Fragments have a different view lifecycle than
activities. When binding a fragment in onCreateView, set the views to
null in onDestroyView. Butter Knife returns an Unbinder instance when
you call bind to do this for you. Call its unbind method in the
appropriate lifecycle callback.
I was trying to migrate from ButterKnife to Android data binding.
When using ButterKnife (which is working perfectly fine):
// Called after a network call
public void updateView(MyAdapter adapter, String title) {
toolbar.setTitle(title);
recyclerView.setHasFixedSize(true);
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(adapter);
}
Using Android data binding:
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
binding = MyFragmentBinding.inflate(inflater, container, false);
binding.toolbar.setTitle(R.string.app_name); // this works
return binding.getRoot();
}
// Called after a network call
public void updateView(MyAdapter adapter, String title) {
binding.toolbar.setTitle(title);
binding.recyclerView.setHasFixedSize(true);
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
binding.recyclerView.setLayoutManager(layoutManager);
binding.recyclerView.setAdapter(adapter);
}
After calling updateView on the later code, the screen goes blank.
I debugged to find out that view remains attached to the Fragment.
Also, if I am updating something inside onCreateView then that works.
Is there anything am I doing wrong?
Layout:
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_alignParentTop="true"
android:background="?attr/colorPrimary"
android:elevation="#dimen/_6sdp"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:navigationIcon="#drawable/default_nav_icon_back"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light" />
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize" />
</android.support.design.widget.CoordinatorLayout>
</layout>
How to handle empty data View in a RecyclerView ,I have tried so many ways from internet but none seems to work. I am also using realm database so I don't know if this is the right way to check if it is empty or not.
this is my Fragment xml where the RecyclerView is located
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/tv_no_data"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/holo_green_dark"
android:gravity="center"
android:text="emptty"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#android:color/white"
android:visibility="invisible" />
<android.support.v7.widget.RecyclerView
android:id="#+id/rv_favorite"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorPrimaryDark">
</android.support.v7.widget.RecyclerView>
</FrameLayout>
and this is my fragment class
public class FavouriteFragment extends Fragment {
RecyclerView mRecyclerView;
FavouriteAdapter adapter;
Realm mRealm;
int positions;
TextView emptyText;
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.favourite_fragment,container,false);
mRealm=Realm.getDefaultInstance();
RealmQuery<news> quotesRealmQuery = mRealm.where(News.class).equalTo("favourite",true);
RealmResults<News> mResults = newsRealmQuery.findAll();
emptyText= (TextView) view.findViewById(R.id.tv_no_data);
//adapter=new FavouriteAdapter(getActivity(),mResults,mRealm);
mRecyclerView= (RecyclerView) view.findViewById(R.id.rv_favorite);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
if (!mResults.isEmpty()) {
//if data is available, don't show the empty text
emptyText.setVisibility(View.INVISIBLE);
adapter=new FavouriteAdapter(getActivity(),mResults,mRealm,pos,single);
mRecyclerView.setAdapter(adapter);
mRealm.addChangeListener(new RealmChangeListener<Realm>() {
#Override
public void onChange(Realm element) {
adapter.notifyItemRemoved(positions);
}
});
} else
emptyText.setVisibility(View.VISIBLE);
return view;
}
Your RecyclerView is not transparent so you should remember to hide it when is empty:
if (!mResults.isEmpty()) {
//if data is available, don't show the empty text
emptyText.setVisibility(View.INVISIBLE);
mRecyclerView.setVisibility(View.VISIBLE);
} else {
emptyText.setVisibility(View.VISIBLE);
mRecyclerView.setVisibility(View.GONE);
}
I'm trying to adapt the strategy for hiding / showing a toolbar (or any visual element) from the well explained and great article:
http://mzgreen.github.io/2015/02/15/How-to-hideshow-Toolbar-when-list-is-scroling%28part1%29/
But in my case I'm using a Fragment to hold the recycleview instead of the activity. My problem is that the padding is not being applied so the first element is under the toolbar, and I have also another strange behavior, as the toolbar is also under the statusbar. I don't know what is happening here.
The following are my "moving pieces":
BasicActivity.java: based on the one given on the previous post, but moving away the recycleview part as is going to be on the Fragment piece. Also it exposes the show and hide methods to allow the fragment to access it:
public class BasicActivity extends ActionBarActivity {
private Toolbar mToolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_basic);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container,new RecycleFragment())
.commit();
overridePendingTransition(0, 0);
initToolbar();
}
private void initToolbar() {
mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);
setTitle(getString(R.string.app_name));
mToolbar.setTitleTextColor(getResources().getColor(android.R.color.white));
}
public void hideViews() {
mToolbar.animate().translationY(-mToolbar.getHeight()).setInterpolator(new AccelerateInterpolator(2));
}
public void showViews() {
mToolbar.animate().translationY(0).setInterpolator(new DecelerateInterpolator(2));
}
}
My activiy_basic.xml is the following:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
<include layout="#layout/toolbar_actionbar" />
</FrameLayout>
The layout toolbar_actionbar.xml
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:clipToPadding="false"/>
The Fragment RecycleFragment.java:
public class RecycleFragment extends Fragment {
#Override public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_recycler, container, false);
return view;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
initRecyclerView(view);
}
private void initRecyclerView(View view) {
RecyclerView recyclerView = (RecyclerView)view.findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
RecyclerAdapter recyclerAdapter = new RecyclerAdapter(createItemList());
recyclerView.setAdapter(recyclerAdapter);
recyclerView.setOnScrollListener(new HidingScrollListener() {
#Override
public void onHide() {
((BasicActivity)getActivity()).hideViews();
}
#Override
public void onShow() {
((BasicActivity)getActivity()).showViews();
}
});
}
private List<String> createItemList() {
List<String> itemList = new ArrayList<>();
for(int i=0;i<20;i++) {
itemList.add("Item "+i);
}
return itemList;
}
}
And the layout for the fragment is just a recyclerview fragment_recycler.xml:
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
The adapter and the viewholder for the recycler are the same as the article, and they doesn't affect the behavior.
What is wrong with the code?
UPDATE:
A Michał Z. below pointed out. What was missing is the paddingTop and clipptoPadding on the Recyclerview view
So the final xml should be:
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="?attr/actionBarSize"
android:clipToPadding="false"/>
And to solve the statusbar overlapping problem, it is needed to add a "fitsystemwindows" = "true" element on the activity layout. So it must be as the following:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<FrameLayout android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
<include layout="#layout/toolbar_actionbar" />
</FrameLayout>
UPDATE2
The fitSystemWindows is only needed if the theme is setting the statusbar as translucent
Your fragment_recycler.xml file is missing paddingTop and clipToPadding attributes.
It should look like this:
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="?attr/actionBarSize"
android:clipToPadding="false"/>
And also remove clipToPadding from your toolbar_actionbar.xml.
I need help regarding working on fragment inside fragment, actually I
am facing a problem on pressing back button. Application Main screen
has buttons and pressing on each button view replace with new
fragment(and that fragment contain inside another fragment),
dynamically adding/replacing fragment is working fine, by pressing
button1 fragment replaced, same happens when pressing button, but if
I press the button again, got an exception:
"Duplicate id 0x7f05000a, tag null, or parent id 0x7f050009 with
another fragment for com........ fragmentname"
means fragment or inner fragments are already added and I am trying
to add them again, anybody has idea how to work with fragment inside
fragment and moving back and forth without any problem, thanks for the
support.
MainActivity, where fragments are dynamical added and
replaced.
public class FragmentInsideFragmentTestActivity extends Activity {
private Button button1;
private Button button2;
private Button button3;
private Button button4;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button1 =(Button) this.findViewById(R.id.button1);
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
onButtonClick(view);
}
});
button2 =(Button) this.findViewById(R.id.button2);
button2.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
onButtonClick(view);
}
});
button3 =(Button) this.findViewById(R.id.button3);
button3.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
onButtonClick(view);
}
});
button4 =(Button) this.findViewById(R.id.button4);
button4.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
onButtonClick(view);
}
});
}
public void onButtonClick(View v) {
Fragment fg;
switch (v.getId()) {
case R.id.button1:
fg=FirstFragment.newInstance();
replaceFragment(fg);
break;
case R.id.button2:
fg=SecondFragment.newInstance();
replaceFragment(fg);
break;
case R.id.button3:
fg=FirstFragment.newInstance();
replaceFragment(fg);
break;
case R.id.button4:
fg=SecondFragment.newInstance();
replaceFragment(fg);
break;
}
}
private void replaceFragment(Fragment newFragment) {
FragmentTransaction trasection = getFragmentManager().beginTransaction();
if(!newFragment.isAdded()) {
try {
//FragmentTransaction trasection =
getFragmentManager().beginTransaction();
trasection.replace(R.id.linearLayout2, newFragment);
trasection.addToBackStack(null);
trasection.commit();
} catch (Exception e) {
// TODO: handle exception
// AppConstants.printLog(e.getMessage());
} else {
trasection.show(newFragment);
}
}
}
Here is Layout: main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button1" />
<Button
android:id="#+id/button2"
android:text="Button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="#+id/button3"
android:text="Button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="#+id/button4"
android:text="Button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" />
</LinearLayout>
Hope I tried to clear my problem.
AFAIK, fragments cannot hold other fragments.
UPDATE
With current versions of the Android Support package -- or native fragments on API Level 17 and higher -- you can nest fragments, by means of getChildFragmentManager(). Note that this means that you need to use the Android Support package version of fragments on API Levels 11-16, because even though there is a native version of fragments on those devices, that version does not have getChildFragmentManager().
I needed some more context, so I made an example to show how this is done. The most helpful thing I read while preparing was this:
Creating and Using Fragments
Activity
activity_main.xml
Add a FrameLayout to your activity to hold the parent fragment.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Activity"/>
<FrameLayout
android:id="#+id/parent_fragment_container"
android:layout_width="match_parent"
android:layout_height="200dp"/>
</LinearLayout>
MainActivity.java
Load the parent fragment and implement the fragment listeners. (See fragment communication.)
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity implements ParentFragment.OnFragmentInteractionListener, ChildFragment.OnFragmentInteractionListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Begin the transaction
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.parent_fragment_container, new ParentFragment());
ft.commit();
}
#Override
public void messageFromParentFragment(Uri uri) {
Log.i("TAG", "received communication from parent fragment");
}
#Override
public void messageFromChildFragment(Uri uri) {
Log.i("TAG", "received communication from child fragment");
}
}
Parent Fragment
fragment_parent.xml
Add another FrameLayout container for the child fragment.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="20dp"
android:background="#91d0c2">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Parent fragment"/>
<FrameLayout
android:id="#+id/child_fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
</LinearLayout>
ParentFragment.java
Use getChildFragmentManager in onViewCreated to set up the child fragment.
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
public class ParentFragment extends Fragment {
private OnFragmentInteractionListener mListener;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_parent, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
Fragment childFragment = new ChildFragment();
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.replace(R.id.child_fragment_container, childFragment).commit();
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void messageFromParentFragment(Uri uri);
}
}
Child Fragment
fragment_child.xml
There is nothing special here.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="20dp"
android:background="#f1ff91">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Child fragment"/>
</LinearLayout>
ChildFragment.java
There is nothing too special here, either.
import android.support.v4.app.Fragment;
public class ChildFragment extends Fragment {
private OnFragmentInteractionListener mListener;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_child, container, false);
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void messageFromChildFragment(Uri uri);
}
}
Notes
The support library is being used so that nested fragments can be used before Android 4.2.
Since Android 4.2 (API 17) nested fragments become available http://developer.android.com/about/versions/android-4.2.html#NestedFragments
To place fragment inside other fragment use getChildFragmentManager()
It also available in support library!
you can use getChildFragmentManager() function.
example:
Parent fragment :
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.parent_fragment, container,
false);
}
//child fragment
FragmentManager childFragMan = getChildFragmentManager();
FragmentTransaction childFragTrans = childFragMan.beginTransaction();
ChildFragment fragB = new ChildFragment ();
childFragTrans.add(R.id.FRAGMENT_PLACEHOLDER, fragB);
childFragTrans.addToBackStack("B");
childFragTrans.commit();
return rootView;
}
Parent layout (parent_fragment.xml):
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white">
<FrameLayout
android:id="#+id/FRAGMENT_PLACEHOLDER"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
Child Fragment:
public class ChildFragment extends Fragment implements View.OnClickListener{
View v ;
#Override
public View onCreateView(LayoutInflater inflater,
#Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
// TODO Auto-generated method stub
View rootView = inflater.inflate(R.layout.child_fragment, container, false);
v = rootView;
return rootView;
}
#Override
public void onClick(View view) {
}
}
Fragments can be added inside other fragments but then you will need to remove it from parent Fragment each time when onDestroyView() method of parent fragment is called. And again add it in Parent Fragment's onCreateView() method.
Just do like this :
#Override
public void onDestroyView()
{
FragmentManager mFragmentMgr= getFragmentManager();
FragmentTransaction mTransaction = mFragmentMgr.beginTransaction();
Fragment childFragment =mFragmentMgr.findFragmentByTag("qa_fragment")
mTransaction.remove(childFragment);
mTransaction.commit();
super.onDestroyView();
}
I solved this problem. You can use Support library and ViewPager. If you don't need swiping by gesture you can disable swiping. So here is some code to improve my solution:
public class TestFragment extends Fragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.frag, container, false);
final ArrayList<Fragment> list = new ArrayList<Fragment>();
list.add(new TrFrag());
list.add(new TrFrag());
list.add(new TrFrag());
ViewPager pager = (ViewPager) v.findViewById(R.id.pager);
pager.setAdapter(new FragmentPagerAdapter(getChildFragmentManager()) {
#Override
public Fragment getItem(int i) {
return list.get(i);
}
#Override
public int getCount() {
return list.size();
}
});
return v;
}
}
P.S.It is ugly code for test, but it improves that it is possible.
P.P.S Inside fragment ChildFragmentManager should be passed to ViewPagerAdapter
It's nothing complicated. We cannot use getFragmentManager() here. For using Fragments inside a Fragment, we use getChildFragmentManager(). Rest will be the same.
Use getChildFragmentManager(), follow the link :
Nested Fragment
You can add FrameLayout to the fragment and replace it with another fragment when it initializes.
This way , you could consider the other fragment to be inside the first fragment.
Curently in nested fragment, the nested one(s) are only supported if they are generated programmatically! So at this time no nested fragment layout are supported in xml layout scheme!
That may help those who works on Kotlin you can use extension function
so create a kotlin file let's say "util.kt" and add this piece of code
fun Fragment.addChildFragment(fragment: Fragment, frameId: Int) {
val transaction = childFragmentManager.beginTransaction()
transaction.replace(frameId, fragment).commit()
}
Let's say this is the class of the child
class InputFieldPresentation: Fragment()
{
var views: View? = null
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
views = inflater!!.inflate(R.layout.input_field_frag, container, false)
return views
}
override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
...
}
...
}
Now you can add the children to the father fragment like this
FatherPresentation:Fragment()
{
...
override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val fieldFragment= InputFieldPresentation()
addChildFragment(fieldFragment,R.id.fragmet_field)
}
...
}
where R.id.fragmet_field is the id of the layout which will contain the fragment.This lyout is inside the father fragment of course.
Here is an example
father_fragment.xml:
<LinearLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android"
>
...
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:id="#+id/fragmet_field"
android:orientation="vertical"
>
</LinearLayout>
...
</LinearLayout>
There is no support for MapFragment, Android team says is working on it since Android 3.0. Here more information about the issue But what you can do is by creating a Fragment that returns a MapActivity. Here is a code example. Thanks to inazaruk:
How it works:
MainFragmentActivity is the activity that extends FragmentActivity and hosts two MapFragments.
MyMapActivity extends MapActivity and has MapView.
LocalActivityManagerFragment hosts LocalActivityManager.
MyMapFragment extends LocalActivityManagerFragment and with help of TabHost creates internal instance of MyMapActivity.
If you have any doubt please let me know
Hi I solved this problem by putting per Fragment into distinct layout.And I made just related Layout visible and made the others visibilities gone.
I mean:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button android:layout_width="wrap_content"
android:id="#+id/button1"
android:layout_height="wrap_content"
android:text="Button1"></Button>
<Button android:text="Button2"
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></Button>
<Button android:text="Button3"
android:id="#+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></Button>
<Button android:text="Button4"
android:id="#+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></Button>
</LinearLayout>
<LinearLayout android:layout_width="full_screen"
android:layout_height="0dp"
android:layout_weight="1"
android:id="action_For_Button1"
android:visibility="visible">
<Fragment android:layout_width="full_screen"
android:layout_height="full_screen"
android:id="fragment1"
.
.
.
/ >
</LinearLayout>
<LinearLayout android:layout_width="full_screen"
android:layout_height="0dp"
android:id="action_For_Button1"
android:layout_weight="1"
android:visibility="gone">
<Fragment android:layout_width="full_screen"
android:layout_height="full_screen"
android:id="fragment2"
.
.
.
/ >
</LinearLayout>
.
.
.
</LinearLayout>
I assumed that you will open your page as button 1 is clicked.You can control your fragment's visibilities on click action.You can make related Layout visible and the others gone and by Fragment Manager you can take your fragment.This approach worked for me.And since view that has visibility:gone is invisible, and it doesn't take any space for layout purposes I think this approach does not cause any space problem.
P.S:I just tried to explain my solution code may have syntax mistakes or uncompleted structure.