Replace fragmentA with fragmentB issue

Question

I have a image in the main activity and when this image is clicked i want to show the fragmentA that has a list view.

When a item of this listView is clicked i want to replace the fragmentA by the fragmentB that has a textview, and I want to show in this textview the text associated to the clicked list item.

So in main activity I have this:

public class MainActivity extends AppCompatActivity implements  Listener{
    private ImageView img;
    private String text;
    FragmentManager fragmentManager;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        fragmentManager = getFragmentManager();
        img = (ImageView) findViewById(R.id.imageView);
    }
    public void AddFragmentA(View view) {
        FragmentA fragmentA = new FragmentA();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.add(R.id.containerFragmentA, new FragmentA(), "fragA");
        transaction.commit();
    }
    public void AddFragmentB() {
        FragmentB fragment = new FragmentB();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.add(R.id.containerFragmentB, new FragmentA(), "fragB");
        transaction.commit();
    }
    @Override
    public void addText(String text) {
        this.text = text;
        Toast.makeText(this, "Text received in Activity:" +text, Toast.LENGTH_SHORT).show();
        sendDataToFragmentB();
    }

 public void sendDataToFragmentB(){

            FragmentB fragmentB = (FragmentB) fragmentManager.findFragmentByTag("fragB");
            fragmentB.addText(text);
        }
}

Note: The toast in addText() appears with the correct text at this point, so the text of the list view is received in Activity with success.

Question: Now how to replace fragmentA with fragmentB and show the textview with the received text in the activity instead of showing the listview of the fragmentA?

Below is all the complete example.

FragmentA class:

public class FragmentA extends Fragment{
    private ListView listItems;
    private String[] items = {
            "item1",
            "item2",
            "item3",
            "item4"
    };
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment, container, false);
        return view;
    }
    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        listItems = (ListView) getView().findViewById(R.id.listviewInFragment);

        ArrayAdapter<String> adapter =
                new ArrayAdapter<String>(getActivity().getApplicationContext(),
                        android.R.layout.simple_list_item_1, android.R.id.text1, items);

        listItems.setAdapter(adapter);
        listItems.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                int positionCode = i;

                String clickedValue = (String) adapterView.getItemAtPosition(i);
                Listener listener = (Listener) getActivity();
                listener.addText(clickedValue);
            }
        });
    }

}

FramentB:

public class FragmentB extends Fragment {
    private TextView tv;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_b, container, false);
        tv = (TextView) getView().findViewById(R.id.textView);
        return view;
    }
    public void addText(String text) {
        String result = text;
        tv.setText(result);
    }
}

main activity xml:

<?xml version="1.0" encoding="utf-8"?>
<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">
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:srcCompat="@drawable/image"
        android:onClick="AddFragmentA"
        tools:layout_editor_absoluteX="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp" />
    <FrameLayout
        android:id="@+id/containerFragmentA"
        android:layout_width="0dp"
        android:layout_height="300dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        tools:layout_editor_absoluteY="1dp">
    </FrameLayout>

    <FrameLayout
        android:id="@+id/containerFragmentB"
        android:layout_width="0dp"
        android:layout_height="300dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        tools:layout_editor_absoluteY="1dp">
    </FrameLayout>
</android.support.constraint.ConstraintLayout>

fragment a xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#0ff">

    <ListView
        android:layout_width="368dp"
        android:layout_height="495dp"
        android:layout_marginLeft="8dp"
        android:layout_marginStart="16dp"
        android:id="@+id/listviewInFragment"/>

</android.support.constraint.ConstraintLayout>

fragment b xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ff0">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="300dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
         />
</android.support.constraint.ConstraintLayout>

Answer 1

you are placing fragment A in below function instead of fragment B

 public void AddFragmentB() {
        FragmentB fragment = new FragmentB();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.add(R.id.containerFragmentB, new FragmentA(), "fragB");
        transaction.commit();
    }

it should be

public void AddFragmentB() {
        FragmentB fragment = new FragmentB();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.containerFragmentB, new FragmentB(), "fragB");
        transaction.commit();
    }

if you want to replace a fragment with another just use the same container don't create separate (R.id.containerFragmentB, R.id.containerFragmentA) container.

Answer 2

You need to change your

 public void AddFragmentA(View view) {
    FragmentA fragmentA = new FragmentA();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.containerFragmentA, new FragmentA(), "fragA");
    transaction.commit();
}
public void AddFragmentB() {
    FragmentB fragment = new FragmentB();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.containerFragmentB, new FragmentA(), "fragB");
    transaction.commit();
}

to

 public void AddFragmentA(View view) {
    FragmentA fragmentA = new FragmentA();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.container, fragmentA , "fragA");
    transaction.commit();
}
public void AddFragmentB() {
    FragmentB fragment = new FragmentB();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.container, fragment, "fragB");
    transaction.commit();
}

and activity_main.xml should be

<?xml version="1.0" encoding="utf-8"?>
<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">
    <ImageView
        android:id="@+id/imageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:srcCompat="@drawable/image"
        android:onClick="AddFragmentList"
        tools:layout_editor_absoluteX="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp" />
    <FrameLayout
        android:id="@+id/container"
        android:layout_width="0dp"
        android:layout_height="300dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        tools:layout_editor_absoluteY="1dp">
    </FrameLayout>


</android.support.constraint.ConstraintLayout>

EDIT

 listItems.setAdapter(adapter);
    listItems.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            int positionCode = i;

            String clickedValue = (String) adapterView.getItemAtPosition(i);
            Listener listener = (Listener) getActivity();
            listener.addText(clickedValue);
        }
    });

Listener

public interface IScanner {

void addText(String Text);

}

MainActivity

public class MainActivity extends AppCompatActivity implements  Listener{
private ImageView img;
private String text;
FragmentManager fragmentManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    fragmentManager = getFragmentManager();
    img = (ImageView) findViewById(R.id.imageView);
}
public void AddFragmentA(View view) {
    FragmentA fragmentA = new FragmentA();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.containerFragmentA, new FragmentA(), "fragA");
    transaction.commit();
}

@Override
public void addText(String text) {
    this.text = text;
    Toast.makeText(this, "Text received in Activity:" +text, Toast.LENGTH_SHORT).show();
    sendDataToFragmentB(text);
}

 public void sendDataToFragmentB(String clickedValue){
    Bundle b = new Bundle();
    b.putString("clickedValue", clickedValue);

    FragmentB fragment = new FragmentB();
    fragment.setArguments(b);
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.containerFragmentB, new FragmentA(), "fragB");
    transaction.commit();
    }
 }

FragmentB

public class FragmentB extends Fragment {
private TextView tv;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_b, container, false);
    tv = (TextView) getView().findViewById(R.id.textView);
    return view;
}
Bundle bundle = this.getArguments();
if (bundle != null) {
        String text = bundle.getString("clickedValue", "");
}
}

This will solve your problem

Answer 3

This is how you will achieve the required task. make chnages to your class accordingly below. MainActivity.java

public class MainActivity extends AppCompatActivity implements FragmentA.ClickListener{
    private Button button;
    public static String EXTRA_STRING = "extraString";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button = (Button)findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                AddFragment(FragmentA.getInstance());
            }
        });
    }
    public void AddFragment(Fragment fragment) {
        getSupportFragmentManager().beginTransaction().replace(R.id.containerFragmentA, fragment).commit();
    }

    @Override
    public void onClick(String data) {
        AddFragment(FragmentB.getInstance(data));
    }
} 

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/containerFragmentA"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        tools:layout_editor_absoluteY="1dp"/>

    <Button
        android:id="@+id/button"
        style="@style/Widget.AppCompat.Button.Colored"
        android:layout_margin="8dp"
        android:layout_alignParentBottom="true"
        android:text="Add Fragment B"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</RelativeLayout>

FragmentA.java

public class FragmentA extends Fragment {
private ListView listItems;
private String[] items = {"item1", "item2", "item3", "item4"};
private ClickListener clickListener;

public static FragmentA getInstance() {
    return new FragmentA();
}

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    clickListener = (ClickListener)context;
}

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_a, container, false);
    return view;
}

@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    listItems = (ListView) getView().findViewById(R.id.listviewInFragment);
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(),android.R.layout.simple_list_item_1, items);
    listItems.setAdapter(adapter);
    listItems.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            String clickedValue = items[i];
            clickListener.onClick(clickedValue);
        }
    });
}

public interface ClickListener{
    void onClick(String data);
}

}

fragment_a.xml

    <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ListView
        android:layout_width="368dp"
        android:layout_height="495dp"
        android:layout_marginLeft="8dp"
        android:layout_marginStart="16dp"
        android:id="@+id/listviewInFragment"/>

</android.support.constraint.ConstraintLayout>

FragmentB.java

public class FragmentB extends Fragment {
    private TextView tv;
    private String data;

    public static FragmentB getInstance(String data){
        Bundle bundle = new Bundle();
        bundle.putString(MainActivity.EXTRA_STRING,data);
        FragmentB fragmentB = new FragmentB();
        fragmentB.setArguments(bundle);
        return fragmentB;
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_b, container, false);
        tv = view.findViewById(R.id.textView);
        data = getArguments().getString(MainActivity.EXTRA_STRING);
        addText(data);
        return view;
    }
    public void addText(String text) {
        String result = text;
        tv.setText(result);
    }
}

fragment_b.xml

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_gravity="center"
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:gravity="center"
        android:textSize="24dp"
android:textAppearance="@style/TextAppearance.AppCompat.Widget.PopupMenu.Header"
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>