How to Create Expandable Listview in Android Studio?

expandable_item.xml

        
        
        
        <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:id="@+id/motherLayout"
    android:layout_height="wrap_content">

    <RelativeLayout
        android:id="@+id/itemClicked"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:id="@+id/bookImg"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:layout_centerVertical="true"
            android:src="@drawable/ic_book" />

        <LinearLayout
            android:id="@+id/titleLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_marginStart="5dp"
            android:layout_marginEnd="5dp"
            android:layout_toStartOf="@id/arrowImg"
            android:layout_toEndOf="@+id/bookImg"
            android:orientation="vertical">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:padding="5dp"
                android:text="@string/title"
                android:textColor="@android:color/black"
                android:textSize="18sp"
                android:textStyle="bold" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:padding="5dp"
                android:text="Bangladesh"
                android:textColor="@android:color/black"
                android:textSize="15sp" />

        </LinearLayout>

        <ImageView
            android:id="@+id/arrowImg"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:layout_alignParentEnd="true"
            android:layout_centerVertical="true"
            android:src="@drawable/ic_down_arrow" />

    </RelativeLayout>

    <LinearLayout
        android:visibility="gone"
        android:id="@+id/discLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        >
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/dis"
            android:layout_marginTop="5dp"
            android:textColor="@android:color/black"
            android:fontFamily="serif"
            android:textAlignment="center"
            android:padding="5dp"
            android:textSize="16sp"
            />
    </LinearLayout>

</LinearLayout>
    
    
    
    
 

activity_main.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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />

</LinearLayout>  
    
    
    
    
 

MainActivity.java

      
      
      
      ListView listView;
      
      
          // OnCreate Method Start Here =============

      
       listView = findViewById(R.id.listView);
        MyAdapter myAdapter = new MyAdapter();
        listView.setAdapter(myAdapter);
    
    
    // OnCreate Method Close Here =============

    private class MyAdapter extends BaseAdapter{

        @Override
        public int getCount() {
            return 10;
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            LayoutInflater layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View myView = layoutInflater.inflate(R.layout.expandable_item, parent,false);

            LinearLayout motherLayout = myView.findViewById(R.id.motherLayout);
            RelativeLayout itemClicked = myView.findViewById(R.id.itemClicked);
            ImageView arrowImg = myView.findViewById(R.id.arrowImg);
            LinearLayout discLayout = myView.findViewById(R.id.discLayout);

            itemClicked.setOnClickListener(v -> {
                // code here ===
                if (discLayout.getVisibility() == View.GONE){
                    TransitionManager.beginDelayedTransition(motherLayout, new AutoTransition());
                    discLayout.setVisibility(View.VISIBLE);
                    motherLayout.setBackgroundColor(Color.parseColor("#724CAF50"));
                    arrowImg.setImageResource(R.drawable.ic_up_arrow);
                } else {
                    TransitionManager.beginDelayedTransition(motherLayout, new AutoTransition());
                    discLayout.setVisibility(View.GONE);
                    motherLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
                    arrowImg.setImageResource(R.drawable.ic_down_arrow);
                }
            });


            return myView;
        }
    }