Android EditText Gmail like to field

This technique -- referred to as "chips" -- is discussed by Roman Nurik in a Google+ post. He, in turn, points to Macarse's answer here on StackOverflow. They, in turn, point to the implementation of this UI that you see in the stock messaging client.

I open-sourced our solution TokenAutoComplete on github. Mine has been tested back to 2.2. I designed my code to allow pretty simple implementations and customizations.

Here's an example implementation using my library:

Subclass TokenCompleteTextView

public class ContactsCompletionView extends TokenCompleteTextView {
    public ContactsCompletionView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected View getViewForObject(Object object) {
        Person p = (Person)object;

        LayoutInflater l = (LayoutInflater)getContext().getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        LinearLayout view = (LinearLayout)l.inflate(R.layout.contact_token, (ViewGroup)ContactsCompletionView.this.getParent(), false);
        ((TextView)view.findViewById(R.id.name)).setText(p.getEmail());

        return view;
    }

    @Override
    protected Object defaultObject(String completionText) {
        //Stupid simple example of guessing if we have an email or not
        int index = completionText.indexOf('@');
        if (index == -1) {
            return new Person(completionText, completionText.replace(" ", "") + "@example.com");
        } else {
            return new Person(completionText.substring(0, index), completionText);
        }
    }
}

Layout code for contact_token (you can use any kind of layout here or could throw an ImageView in if you want images in the token)

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

    <TextView android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/token_background"
        android:padding="5dp"
        android:textColor="@android:color/white"
        android:textSize="18sp" />

</LinearLayout>

Token backgound drawable

<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <solid android:color="#ffafafaf" />
    <corners
        android:topLeftRadius="5dp"
        android:bottomLeftRadius="5dp"
        android:topRightRadius="5dp"
        android:bottomRightRadius="5dp" />
</shape>

Person object code

public class Person implements Serializable {
    private String name;
    private String email;

    public Person(String n, String e) { name = n; email = e; }

    public String getName() { return name; }
    public String getEmail() { return email; }

    @Override
    public String toString() { return name; }
}

Sample activity

public class TokenActivity extends Activity {
    ContactsCompletionView completionView;
    Person[] people;
    ArrayAdapter<Person> adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        people = new Person[]{
                new Person("Marshall Weir", "[email protected]"),
                new Person("Margaret Smith", "[email protected]"),
                new Person("Max Jordan", "[email protected]"),
                new Person("Meg Peterson", "[email protected]"),
                new Person("Amanda Johnson", "[email protected]"),
                new Person("Terry Anderson", "[email protected]")
        };

        adapter = new ArrayAdapter<Person>(this, android.R.layout.simple_list_item_1, people);

        completionView = (ContactsCompletionView)findViewById(R.id.searchView);
        completionView.setAdapter(adapter);
        completionView.setPrefix("To: ");
    }
}

Layout code

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

    <com.tokenautocomplete.ContactsCompletionView
        android:id="@+id/searchView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</RelativeLayout>