Creating a compound view

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

        <ImageView
            android:id="@+id/photo"
            android:layout_width="48dp"
            android:layout_height="48dp"
            android:layout_alignParentRight="true" />

        <TextView
            android:id="@+id/name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_toLeftOf="@id/photo" />

        <TextView
            android:id="@+id/phone_number"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/name"
            android:layout_toLeftOf="@id/photo" />
</merge>

import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.RelativeLayout;
import android.widget.ImageView;
import android.widget.TextView;

import myapp.R;

/**
 * A compound view to show contacts.
 *
 * This class can be put into an XML layout or instantiated programmatically, it
 * will work correctly either way.
 */
public class ContactView extends RelativeLayout {

    // This class extends RelativeLayout because that comes with an automatic
    // (MATCH_PARENT, MATCH_PARENT) layout for its child item. You can extend
    // the raw android.view.ViewGroup class if you want more control. See the
    // note in the layout XML why you wouldn't want to extend a complex view
    // such as RelativeLayout.

    // 1. Implement superclass constructors.
    public ContactView(Context context) {
        super(context);
        init(context, null);
    }

    // two extra constructors left out to keep the example shorter

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public ContactView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(context, attrs);
    }

    // 2. Initialize the view by inflating an XML using `this` as parent
    private TextView mName;
    private TextView mPhoneNumber;
    private ImageView mPhoto;

    private void init(Context context, AttributeSet attrs) {
        LayoutInflater.from(context).inflate(R.layout.contact_view, this, true);
        mName = (TextView) findViewById(R.id.name);
        mPhoneNumber = (TextView) findViewById(R.id.phone_number);
        mPhoto = (ImageView) findViewById(R.id.photo);
    }

    // 3. Define a setter that's expressed in your domain model. This is what the example is
    //    all about. All controller code can just invoke this setter instead of fiddling with
    //    lots of strings, visibility options, colors, animations, etc. If you don't use a
    //    custom view, this code will usually end up in a static helper method (bad) or copies 
    //    of this code will be copy-pasted all over the place (worse).
    public void setContact(Contact contact) {
        mName.setText(contact.getName());
        mPhoneNumber.setText(contact.getPhoneNumber());
        if (contact.hasPhoto()) {
            mPhoto.setVisibility(View.VISIBLE);
            mPhoto.setImageBitmap(contact.getPhoto());
        } else {
            mPhoto.setVisibility(View.GONE);
        }
    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <!-- The compound view becomes like any other view XML element -->
    <myapp.ContactView
        android:id="@+id/contact"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/message_list"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

</LinearLayout>

package myapp;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.ViewGroup;

public class ContactsAdapter extends RecyclerView.Adapter<ContactsViewHolder> {

    private final Context context;

    public ContactsAdapter(final Context context) {
        this.context = context;
    }

    @Override
    public ContactsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        ContactView v = new ContactView(context); // <--- this
        return new ContactsViewHolder(v);
    }

    @Override
    public void onBindViewHolder(ContactsViewHolder holder, int position) {
        Contact contact = this.getItem(position);
        holder.setContact(contact);  // <--- this
    }

    static class ContactsViewHolder extends RecyclerView.ViewHolder {

        public ContactsViewHolder(ContactView itemView) {
            super(itemView);
        }

        public void setContact(Contact contact) {
            ((ContactView) itemView).setContact(contact); // <--- this
        }
    }
}