Collapsing cardview example

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

item.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 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/card"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginBottom="8dp"
    android:animateLayoutChanges="true">

    <RelativeLayout
        android:id="@+id/contents"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:animateLayoutChanges="true"
        android:padding="16dp">

        <TextView
            android:id="@+id/title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="22sp"
            tools:text="Notification #1" />

        <ImageView
            android:id="@+id/toggle"
            android:layout_width="20dp"
            android:layout_height="20dp"
            android:tint="#000"
            android:layout_alignParentEnd="true"
            app:srcCompat="@android:drawable/arrow_down_float" />

        <TextView
            android:id="@+id/body"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_below="@id/title"
            android:text="lorem ipsum" />

        <View
            android:id="@+id/divider"
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:layout_marginTop="16dp"
            android:layout_below="@id/body"
            android:background="@color/cardview_dark_background" />

        <TextView
            android:id="@+id/footer"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/divider"
            android:layout_marginTop="8dp"
            android:text="Some footer" />

    </RelativeLayout>

</android.support.v7.widget.CardView>

MainActivity.java

package com.samid.collapsingcard;

import android.animation.LayoutTransition;
import android.support.constraint.ConstraintLayout;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.CardView;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        RecyclerView recycler = findViewById(R.id.recycler);
        recycler.setLayoutManager(new LinearLayoutManager(this));
        recycler.setAdapter(new MyAdapter());
    }

    private static class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {

        @Override
        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            View itemView = inflater.inflate(R.layout.item, parent, false);
            return new MyViewHolder(itemView);
        }

        @Override
        public void onBindViewHolder(MyViewHolder holder, int position) {
            holder.title.setText("Notification #" + position);
        }

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

    private static class MyViewHolder extends RecyclerView.ViewHolder {

        private final TextView title;
        private final View toggle;
        private final View body;

        public MyViewHolder(View itemView) {
            super(itemView);

            this.title = itemView.findViewById(R.id.title);
            this.toggle = itemView.findViewById(R.id.toggle);
            this.body = itemView.findViewById(R.id.body);

            toggle.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View view) {
                    body.setVisibility(body.getVisibility() == View.VISIBLE ? View.GONE : View.VISIBLE);
                }
            });

            CardView card = itemView.findViewById(R.id.card);
            card.getLayoutTransition().enableTransitionType(LayoutTransition.CHANGING);

            RelativeLayout contents = itemView.findViewById(R.id.contents);
            contents.getLayoutTransition().enableTransitionType(LayoutTransition.CHANGING);
            contents.getLayoutTransition().setStartDelay(LayoutTransition.CHANGE_DISAPPEARING, 0);
        }
    }
}