Upgrading from 1.* to 2.0

There is one breaking change from 1.* to 2.0. You need to extend TokenCompleteTextView<Object> instead of TokenCompleteTextView.

TokenAutoComplete

TokenAutoComplete is an Android Gmail style token auto-complete text field and filter. It's designed to have an extremely simple API to make it easy for anyone to implement this functionality while still exposing enough customization to let you make it awesome.

Support for Android 4.0.3 (API 15) and up. If you need support for earlier versions of Android, version 1.2.1 is the most recent version that supports Android 2.2 (API 8) and up.

Setup

Gradle

dependencies {
    compile "com.splitwise:tokenautocomplete:2.0.2@aar"
}

Maven

<dependency>
  <groupId>com.splitwise</groupId>
  <artifactId>tokenautocomplete</artifactId>
  <version>2.0.2</version>
  <type>aar</type>
</dependency>

No build tools

Download the jar file and add it to your project

If you would like to get the most recent code in a jar, clone the project and run ./gradlew jar from the root folder. This will build a tokenautocomplete.jar in library/build/libs/.

You may also add the library as an Android Library to your project. All the library files live in library.

Creating your auto complete view

If you'd rather just start with a working example, clone the project and take a look.

For a basic token auto complete view, you'll need to

Subclass TokenCompleteTextView
Create a layout and activity for your completion view

Subclass TokenCompleteTextView

You'll need to provide your own implementations for getViewForObject and defaultObject. You should return a view that displays the token from getViewForObject. In defaultObject, you need to guess what the user meant with their completion. This is usually from the user typing something and hitting "," - see the way gmail for Android handles this for example. Here's a simple example:

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

    @Override
    protected View getViewForObject(Person person) {

        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(person.getEmail());

        return view;
    }

    @Override
    protected Person 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

<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; }
}

Note that the class implements Serializable. In order to restore the view state properly, the TokenCompleteTextView needs to be able to save and restore your objects from disk. If your objects cannot be made Serializable, please look at restoring the view state.

Create a layout and activity for your completion view

I'm adding some very stupid "contacts" to the app so you can see it work, but you should read data from the contacts data provider in a real app.

Activity code

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", "marshall@example.com"),
                new Person("Margaret Smith", "margaret@example.com"),
                new Person("Max Jordan", "max@example.com"),
                new Person("Meg Peterson", "meg@example.com"),
                new Person("Amanda Johnson", "amanda@example.com"),
                new Person("Terry Anderson", "terry@example.com")
        };

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

        completionView = (ContactsCompletionView)findViewById(R.id.searchView);
        completionView.setAdapter(adapter);
    }
}

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>

That's it! You can grab the objects the user tokenized with getObjects() on the TokenCompleteTextView when you need to get the data out.

Setting a prefix prompt

If you have a short prompt like "To: ", you can probably get away with setting a drawable on the left side of the TokenCompleteTextView. If you have something longer, you will probably not want your prefix to take up the whole height of the view. If you would like to have a prefix that only indents the first line, you should use setPrefix. This code is a little quirky when restoring the activity, so you want to make sure it only gets called on a fresh start in onCreate:

if (savedInstanceState == null) {
    completionView.setPrefix("Your bestest friends: ");
}

Custom filtering

If you've used the gmail auto complete, you know that it doesn't use the default "toString" filtering you get with an ArrayAdapter. If you've dug in to the ArrayAdapter, you find an unfortunate mess with no good place for you to add your own custom filter code without re-writing the whole class. If you need to support older versions of Android, this quickly becomes difficult as you'll need to carefully handle API differences for each version.

(NOTE: ArrayAdapter is actually well written, it just doesn't allow for easy custom filters)

I've added my own FilteredArrayAdapter to the jar file that is a subclass of ArrayAdapter but does have some good hooks for custom filtering. You'll want to be fairly efficient in this as it gets called a lot, but it's a simple process to add a custom filter. If you are using the TokenActivity above, you simply replace the line

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

with

adapter = new FilteredArrayAdapter<Person>(this, android.R.layout.simple_list_item_1, people) {
    @Override
    protected boolean keepObject(Person obj, String mask) {
        mask = mask.toLowerCase();
        return obj.getName().toLowerCase().startsWith(mask) || obj.getEmail().toLowerCase().startsWith(mask);
    }
};

Duplicate objects

In addition to custom filtering, you may want to make sure you don't accidentally miss something and get duplicate tokens. allowDuplicates(false) on the TokenCompleteTextView will prevent any tokens currently in the view from being added a second time. Token objects must implement equals correctly. Any text the user entered for the duplicate token will be cleared.

Responding to user selections

If you're solving a similar problem to Splitwise, you need to handle users adding and removing tokens. I've provided a simple interface to get these events and allow you to respond to them in the TokenCompleteTextView:

public static interface TokenListener {
    public void onTokenAdded(Object token);
    public void onTokenRemoved(Object token);
}

We can modify the TokenActivity to see how these callbacks work:

public class TokenActivity extends Activity implements TokenCompleteTextView.TokenListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        /* code from the initial example */

        completionView.setTokenListener(this);
    }

    @Override
    public void onTokenAdded(Object token) {
        System.out.println("Added: " + token);
    }

    @Override
    public void onTokenRemoved(Object token) {
        System.out.println("Removed: " + token);
    }
}

In Splitwise we use these callbacks to handle users selecting a group when adding an expense. When a user adds a group to an expense, we remove all the users in the group and the other groups from the array adapter. A user should only be able to select one group and it would be redundant to add users in the group to the expense again.

Programatically add and remove objects

You may want to prefill the list with objects. For example when replying to an email, you would want the To: and CC: fields to have the correct emails in them. You can use addObject to put these tokens in. If you are using TokenDeleteStyle.PartialCompletion , you will want to call addObject(obj, "completion text") to get appropriate replacement text, otherwise just call addObject(obj). You can also remove objects programatically with removeObject though this will remove all objects that return true when calling equals on them. If you have copies in the array, you may need to take special care with this. Finally there is a clear function to empty the EditText and remove all the objects.

Letting users click to select and delete tokens

There are three different styles of click handling build into the project. Please open an issue if you need some behavior beyond this with your code! It's relatively easy to add custom click handling, but I'm not convinced anyone would need anything beyond the ones I've provided. Call setTokenClickStyle to change the behavior.

TokenCompleteTextView.TokenClickStyle.None

This is the default, even though it doesn't match the Gmail behavior. When the user clicks on a token, the view will move the cursor in front of or after the token. Users should not be able to get the cursor in the token as this causes confusing behavior.

TokenCompleteTextView.TokenClickStyle.Delete

When the user clicks on a token, the token will be removed from the field. If you need some kind of confirmation, handle it with the onTokenRemoved callback and re-add the token if the user changes their mind.

TokenCompleteTextView.TokenClickStyle.Select

This behavior most closely matches the Gmail token field behavior, but I did not make it the default to simplify the initial tutorial. The first click on a token will unselect any currently selected token views, then it will call setSelected(true) on the selected token. If you want to change the colors of the token, you will need to add appropriate drawables to your project. In the test project, we have the following:

token_background.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/token_default" android:state_selected="false" />
    <item android:drawable="@drawable/token_selected" android:state_selected="true" />
</selector>

token_default.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <stroke
        android:width="1dp"
        android:color="#ffd4d4d4" />
    <solid android:color="#ffafafaf" />

    <corners
        android:topLeftRadius="3dp"
        android:bottomLeftRadius="3dp"
        android:topRightRadius="3dp"
        android:bottomRightRadius="3dp"/>

</shape>

token_selected.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <stroke
        android:width="1dp"
        android:color="#ffa4a4a4" />
    <solid android:color="#ff7a7a7a" />

    <corners
        android:topLeftRadius="3dp"
        android:bottomLeftRadius="3dp"
        android:topRightRadius="3dp"
        android:bottomRightRadius="3dp"/>
</shape>

If you need more detailed view customization like changing a picture in the token or resizing the token, you will need to provide a custom view to use in the layout you inflate in getViewForObject and override setSelected in that view. You can then make appropriate changes to the view.

Example custom view

In a view implementation (see com.tokenautocomplete.TokenLayout):

public class TokenLayout extends LinearLayout {

    ...

    @Override
    public void setSelected(boolean selected) {
        super.setSelected(selected);

        TextView v = (TextView)findViewById(R.id.name);
        if (selected) {
            v.setCompoundDrawablesWithIntrinsicBounds(0,0,R.drawable.close_x, 0);
        } else {
            v.setCompoundDrawablesWithIntrinsicBounds(0,0,0,0);
        }
    }
}

contact_token.xml

<com.tokenautocomplete.TokenLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:orientation="horizontal">

    <TextView android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/token_background"
        android:textColor="@android:color/white"
        android:textSize="14sp"
        android:paddingLeft="3dp"
        android:paddingRight="3dp"
        android:paddingTop="2dp"
        android:paddingBottom="4dp" />
</com.tokenautocomplete.TokenLayout>

Inflate your custom view:

public class ContactsCompletionView extends TokenCompleteTextView<Person> {

    ...

    @Override
    protected View getViewForObject(Person person) {

        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(person.getEmail());

        return view;
    }
}

Custom completion delete behavior

We've defaulted to the gmail style delete handling. That is, the most recently completed token, when deleted, turns into the text that was there before. All other tokens simply disappear when deleted.

While this is the best in our case, we've provided a couple of other options if you want them. Call setDeletionStyle on the TokenCompleteTextView for different behaviors.

TokenCompleteTextView.TokenDeleteStyle.Clear

This is the default. The most recently completed token will turn into the partial completion text it replaces, all other tokens will just disappear when deleted

TokenCompleteTextView.TokenDeleteStyle.PartialCompletion

All tokens will turn into the partial completion text they replaced

TokenCompleteTextView.TokenDeleteStyle.ToString

Tokens will be replaced with the toString value of the objects they represent when they are deleted

Restoring the view state

If your token objects implement Serializable, the TokenCompleteTextView will automatically handle onSaveInstanceState and onRestoreInstanceState. If you cannot make your objects Serializable, you should override getSerializableObjects and convertSerializableArrayToObjectArray. getSerializableObjects should return an array of Serializable objects that can be used to rebuild your original objects when restoring the view state. convertSerializableArrayToObjectArray should take an array of Serializable objects and use them to rebuild your token objects.

We use something similar to this at splitwise to avoid saving complicated object graphs:

@Override
protected ArrayList<Object> convertSerializableArrayToObjectArray(ArrayList<Serializable> sers) {
    ArrayList<Object> objs = new ArrayList<Object>();
    for (Serializable s: sers) {
        if (s instanceof Long) {
            Contact c = Contact.loadFromDatabase((Long)s);
            objs.add(c);
        } else {
            objs.add(s);
        }
    }

    return objs;
}

@Override
protected ArrayList<Serializable> getSerializableObjects() {
    ArrayList<Serializable> s = new ArrayList<Serializable>();
    for (Object obj: getObjects()) {
        if (obj instanceof Serializable) {
            s.add((Serializable)obj);
        } else {
            //obj is a Contact
            s.add(((Contact)obj).getId());
        }
    }
    return s;
}

Other options

Turn off making a best guess when converting text into a token (allows free entry)

performBestGuess(false);

Collapse the TokenCompleteTextView to a single line when it loses focus

allowCollapse(true);

Change the set of characters that complete a token

setSplitChar(' ');

char[] splitChar = {',', ';', ' '};
setSplitChar(splitChar);

Change the number of characters required to start showing suggestions

setThreshold(1);

Limit the total number of tokens in the field

setTokenLimit(10);

Prevent specific tokens from being deleted by overriding isTokenRemovable on your completion view

License

Copyright (c) 2013, 2014 splitwise, Wouter Dullaert

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

bugraoral/TokenAutoComplete