TokenAutoComplete


Source link: https://github.com/splitwise/TokenAutoComplete

Planning note

If you're already using the library, I'm looking at redesigning some of the core components to make this library more reliable and deal with some lingering bugs. Please give me feedback on how you're using it here

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:2.0.8@aar" 
}
 

Maven

<dependency>
<groupId>com.splitwise</groupId>
<artifactId>tokenautocomplete</artifactId>
<version>2.0.8</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

  1. Subclass TokenCompleteTextView
  2. 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);

TextView view = (TextView) l.inflate(R.layout.contact_token, (ViewGroup) getParent(), false);

view.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

<TextView xmlns:android="http://schemas.android.com/apk/res/android"
  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" />

Token background drawable

<shape xmlns:android="http://schemas.android.com/apk/res/android" >
  <solid android:color="#ffafafaf" />
  <corners android:radius="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", "[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);

  
}
 
}

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:radius="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:radius="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.TokenTextView):

public class TokenTextView extends TextView {

...

@Override
  public void setSelected(boolean selected) {

super.setSelected(selected);

setCompoundDrawablesWithIntrinsicBounds(0, 0, selected ? R.drawable.close_x : 0, 0);

  
}
 
}

contact_token.xml

<com.tokenautocomplete.TokenTextView
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  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:maxLines="1"
  android:ellipsize="end"
  android:padding="4dp"
  tools:text="Glenda Jönsson" />

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);

TokenTextView token = (TokenTextView) l.inflate(R.layout.contact_token, (ViewGroup) getParent(), false);

token.setText(person.getEmail());

return token;
  
}
 
}

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(' ');

OR

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. 

Resources

Easy to implement a drop-down warning / message.

This is a simple and elegant menu control.

Error handling library for Android and Java.

Confetti is a high-performance, easily-configurable particle system library that can animate any set of objects through space. You can specify your starting conditions and physical conditions (e.g. X and Y acceleration, boundaries, etc.), and let the confetti library take care of the rest.

Library to convert between RxJava 1.x and 2.x reactive types.

An A/B Testing Library for Android that makes writing simple tests simpler by using annotations.

Topics


2D Engines   3D Engines   9-Patch   Action Bars   Activities   ADB   Advertisements   Analytics   Animations   ANR   AOP   API   APK   APT   Architecture   Audio   Autocomplete   Background Processing   Backward Compatibility   Badges   Bar Codes   Benchmarking   Bitmaps   Bluetooth   Blur Effects   Bread Crumbs   BRMS   Browser Extensions   Build Systems   Bundles   Buttons   Caching   Camera   Canvas   Cards   Carousels   Changelog   Checkboxes   Cloud Storages   Color Analysis   Color Pickers   Colors   Comet/Push   Compass Sensors   Conferences   Content Providers   Continuous Integration   Crash Reports   Credit Cards   Credits   CSV   Curl/Flip   Data Binding   Data Generators   Data Structures   Database   Database Browsers   Date &   Debugging   Decompilers   Deep Links   Dependency Injections   Design   Design Patterns   Dex   Dialogs   Distributed Computing   Distribution Platforms   Download Managers   Drawables   Emoji   Emulators   EPUB   Equalizers &   Event Buses   Exception Handling   Face Recognition   Feedback &   File System   File/Directory   Fingerprint   Floating Action   Fonts   Forms   Fragments   FRP   FSM   Functional Programming   Gamepads   Games   Geocaching   Gestures   GIF   Glow Pad   Gradle Plugins   Graphics   Grid Views   Highlighting   HTML   HTTP Mocking   Icons   IDE   IDE Plugins   Image Croppers   Image Loaders   Image Pickers   Image Processing   Image Views   Instrumentation   Intents   Job Schedulers   JSON   Keyboard   Kotlin   Layouts   Library Demos   List View   List Views   Localization   Location   Lock Patterns   Logcat   Logging   Mails   Maps   Markdown   Mathematics   Maven Plugins   MBaaS   Media   Menus   Messaging   MIME   Mobile Web   Native Image   Navigation   NDK   Networking   NFC   NoSQL   Number Pickers   OAuth   Object Mocking   OCR Engines   OpenGL   ORM   Other Pickers   Parallax List   Parcelables   Particle Systems   Password Inputs   PDF   Permissions   Physics Engines   Platforms   Plugin Frameworks   Preferences   Progress Indicators   ProGuard   Properties   Protocol Buffer   Pull To   Purchases   Push/Pull   QR Codes   Quick Return   Radio Buttons   Range Bars   Ratings   Recycler Views   Resources   REST   Ripple Effects   RSS   Screenshots   Scripting   Scroll Views   SDK   Search Inputs   Security   Sensors   Services   Showcase Views   Signatures   Sliding Panels   Snackbars   SOAP   Social Networks   Spannable   Spinners   Splash Screens   SSH   Static Analysis   Status Bars   Styling   SVG   System   Tags   Task Managers   TDD &   Template Engines   Testing   Testing Tools   Text Formatting   Text Views   Text Watchers   Text-to   Toasts   Toolkits For   Tools   Tooltips   Trainings   TV   Twitter   Updaters   USB   User Stories   Utils   Validation   Video   View Adapters   View Pagers   Views   Watch Face   Wearable Data   Wearables   Weather   Web Tools   Web Views   WebRTC   WebSockets   Wheel Widgets   Wi-Fi   Widgets   Windows   Wizards   XML   XMPP   YAML   ZIP Codes