This is my Activity.xml file.

          ' <?xml version="1.0" encoding="utf-8"?>
<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnCount="2"
    android:rowCount="2"
    android:layout_margin="10sp"
    tools:context=".MainActivity"
    android:id="@+id/gridView">


    <fragment
        android:id="@+id/frag1"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:name="com.example.drag.Fragment1"
        android:layout_row="0"
        android:layout_column="0"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:layout_gravity="fill"
        android:layout_margin="20sp"
        android:background="@color/teal_200"
        >

    </fragment>

    <fragment
        android:id="@+id/frag2"
        android:name="com.example.drag.Fragment2"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_row="0"
        android:layout_column="1"
        android:layout_gravity="fill"
        android:background="@color/teal_200"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:layout_margin="20sp">

    </fragment>

    <fragment
        android:id="@+id/frag3"
        android:name="com.example.drag.Fragment3"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_row="1"
        android:layout_column="0"
        android:layout_gravity="fill"
        android:background="@color/teal_200"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:layout_margin="20sp">

    </fragment>

    <fragment
        android:id="@+id/frag4"
        android:name="com.example.drag.Fragment4"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_row="1"
        android:layout_column="1"
        android:layout_gravity="fill"
        android:background="@color/teal_200"
        android:layout_columnWeight="1"
        android:layout_rowWeight="1"
        android:layout_margin="20sp">

    </fragment>


    </GridLayout>'

This is my MainActivity.java file

           `package com.example.drag;

import androidx.appcompat.app.AppCompatActivity;
import androidx.constraintlayout.widget.ConstraintLayout;
import androidx.fragment.app.Fragment;

import android.app.Activity;
import android.app.FragmentTransaction;
import android.content.ClipData;
import android.content.ClipDescription;
import android.graphics.Color;
import android.icu.text.Transliterator;
import android.os.Bundle;
import android.view.DragEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.GridLayout;
import android.widget.GridView;
import android.widget.LinearLayout;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        (findViewById(R.id.frag1)).setOnDragListener(new MyDragListener());
        (findViewById(R.id.frag2)).setOnDragListener(new MyDragListener());
        (findViewById(R.id.frag3)).setOnDragListener(new MyDragListener());
        (findViewById(R.id.frag4)).setOnDragListener(new MyDragListener());

        MyDragListener myDragListener = null;

        myDragListener = new MyDragListener();
        (findViewById(R.id.frag1)).setOnDragListener(myDragListener);
        (findViewById(R.id.frag2)).setOnDragListener(myDragListener);
        (findViewById(R.id.frag3)).setOnDragListener(myDragListener);
        (findViewById(R.id.frag4)).setOnDragListener(myDragListener);


        (findViewById(R.id.frag1)).setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                ClipData.Item item = new ClipData.Item((CharSequence) v.getTag());
                ClipData dragData = new ClipData(
                        (CharSequence) v.getTag(),
                        new String[]{ClipDescription.MIMETYPE_TEXT_PLAIN},
                        item);
                View.DragShadowBuilder myShadow = new MyDragShadowBuilder((findViewById(R.id.frag1)));
                v.startDrag(dragData, myShadow, v, 0);
                return true;
            }
        });

        (findViewById(R.id.frag2)).setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                ClipData.Item item = new ClipData.Item((CharSequence) v.getTag());
                ClipData dragData = new ClipData(
                        (CharSequence) v.getTag(),
                        new String[]{ClipDescription.MIMETYPE_TEXT_PLAIN},
                        item);
                View.DragShadowBuilder myShadow = new MyDragShadowBuilder((findViewById(R.id.frag2)));
                v.startDrag(dragData, myShadow,v, 0);
                return true;
            }
        });

        (findViewById(R.id.frag3)).setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                ClipData.Item item = new ClipData.Item((CharSequence) v.getTag());
                ClipData dragData = new ClipData(
                        (CharSequence) v.getTag(),
                        new String[]{ClipDescription.MIMETYPE_TEXT_PLAIN},
                        item);
                View.DragShadowBuilder myShadow = new MyDragShadowBuilder((findViewById(R.id.frag3)));
                v.startDrag(dragData, myShadow, v, 0);
                return true;
            }
        });

        (findViewById(R.id.frag4)).setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                ClipData.Item item = new ClipData.Item((CharSequence) v.getTag());
                ClipData dragData = new ClipData(
                        (CharSequence) v.getTag(),
                        new String[]{ClipDescription.MIMETYPE_TEXT_PLAIN},
                        item);
                View.DragShadowBuilder myShadow = new MyDragShadowBuilder((findViewById(R.id.frag4)));
                v.startDrag(dragData, myShadow, v, 0);
                return true;
            }
        });
    }
    class MyDragListener implements View.OnDragListener{

        @Override
        public boolean onDrag(View v, DragEvent event) {
            final int action = event.getAction();
            final FragmentTransaction ft = getFragmentManager().beginTransaction();
            switch (action){
                case DragEvent.ACTION_DRAG_STARTED:
                    if(event.getClipDescription().hasMimeType(ClipDescription.MIMETYPE_TEXT_PLAIN)){
                        v.setBackgroundColor(Color.BLUE);

                        return true;
                    }
                    return false;
                case DragEvent.ACTION_DRAG_ENTERED:
                    v.setBackgroundColor(Color.GREEN);
                    return true;

                case DragEvent.ACTION_DRAG_LOCATION:
                    return true;

                case DragEvent.ACTION_DRAG_EXITED:
                    v.setBackgroundColor(Color.BLUE);
                    return true;

                case DragEvent.ACTION_DROP:

                    ClipData.Item item = event.getClipData().getItemAt(0);
                    CharSequence dragData = item.getText();
                   View view = (View) event.getLocalState();
                    ViewGroup owner = (ViewGroup) view.getParent();
                    owner.removeView(view);
                    LinearLayout container1 = (LinearLayout) v;
                    view.setVisibility(View.VISIBLE);


                    break;


                case DragEvent.ACTION_DRAG_ENDED:

                    return true;
            }
            return false;
        }
    }

}`

Each fragments xml like this

         `<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/purple_200"
    tools:context=".Fragment1"
    >

    <TextView
        android:id="@+id/firstFragment"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Slide 1"
        android:textSize="30dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

    </TextView>



</LinearLayout>`

When i tried to run it and start my dragging of fragments. the fragments start adding in the size of container rather than swapping between them. it supposedly work like when i drag one fragment and drop it to the other fragments. the fragments should swap their places.